Lameness is the second leading reason (behind bovine respiratory disease) that feedlot cattle are pulled and given antibiotics. Lame cattle eat less, grow more slowly and less efficiently, may be shipped early and often don’t grade as well. These add up to a significant economic cost. When cattle get lame late in the feeding period, pre-slaughter withdrawal times limit the number of antibiotic treatment options. 

A team of Canadian researchers led by Agriculture and Agri-Food Canada’s Karen Schwartzkopf-Genswein recently published a review of large-scale studies of foot-related lameness in feedlot cattle (A Review of Foot Related Lameness in Feedlot Cattle; https://doi.org/10.1139/cjas-2024-0047). 

What they did: These researchers reviewed studies of infectious foot-related lameness (i.e. not including chronic arthritis related to mycoplasma or histophilus) in feedlot cattle. These included several multi-year studies conducted in Canadian feedlots with treatment records on between 10,000 to over 1,000,000 cattle. Important hard-to-find details can appear when researchers have data sets that large. 

What they learned: Foot rot is the most common cause of infectious foot-related lameness in feedlots. It can occur at any point in the feeding period (as well as in cow-calf operations). Foot rot causes swelling between the claws of the hoof (often on the hind limb) that may extend into the lower leg. If the front of the foot is clean, a foot rot lesion often looks dark and is surrounded by jagged edges with sloughing skin. Early detection and treatment are key to preventing a worse infection. Foot rot typically responds to any long-acting antibiotic, so if the initial treatment doesn’t work, it’s probably not foot rot. Several different bacteria appear to be involved, which may be why available foot rot vaccines aren’t effective. Foot rot is most common in poor pen conditions; good drainage and a good bedding mound help reduce the risk. 

• RELATED: ‘Grimace scale’ could help gauge pain, stress in cattle

Digital dermatitis (also known as DD, strawberry foot rot, hairy heel wart) is generally much less common than foot rot in feedlot cattle. Digital dermatitis is more commonly associated with dairy cattle. Digital dermatitis is rarely diagnosed in cow-calf operations but is becoming increasingly common in feedlot cattle. It doesn’t usually appear until cattle have been on feed for three months or more and can occur in combination with foot rot. Affected cattle may not be lame and the affected foot may not be swollen, so these cattle may be harder to find in the pen (and may help explain why it isn’t often seen or diagnosed on cow-calf operations). 

Digital dermatitis starts as a circular or oval strawberry-red lesion where the skin and the heel bulbs meet at the back of the foot. In more advanced or chronic lesions, the infected skin can become rough, scaly and develop long hair-like projections. Digital dermatitis generally responds to topical antibiotics such as tetracycline. Copper sulphate footbaths are less effective for treatment, particularly once they’re contaminated by dirty hooves. Properly disposing of used copper sulphate is also a problem. Digital dermatitis is caused by multiple bacteria, but different bacteria than foot rot. There is no vaccine. Clean, well-drained, well-bedded pen conditions help reduce the risk. Digital dermatitis bacteria can survive in the soil to infect new cattle, so once a feedlot is contaminated it probably becomes a fact of life. 

Toe tip necrosis nearly always occurs in the first days to weeks after cattle arrive at the feedlot. It always occurs in one or both hind limbs. There is no swelling, which distinguishes it from foot rot and trauma. It’s believed to happen when the sole of a hind foot has been scraped thin on rough concrete floors in the auction barn or handling area. The worn sole may then develop a tiny crack where the sole meets the toe of the hoof. This allows debris and bacteria to enter (sort of like a sliver under your fingernail) and set up an infection. It’s more common in excitable cattle, and in groups that are handled aggressively. Early in the disease, the affected cattle tend to be slightly lame and take very short steps. However, if left untreated these animals may become three-legged lame. 

Diagnosis and treatment involve nipping the tip of the toe to confirm the diagnosis, allowing it to drain like an abscess, and giving a long-acting antibiotic. Avoiding the temptation to buy wild cattle at a bargain price, having appropriately (not aggressively) grooved floors in handling areas and low-stress cattle handling are the best preventions. 

Bottom line: Not all lameness is caused by an infection, so not all lame cattle need antibiotics. Not all lameness is foot rot, so there is no one-size-fits-all treatment. It’s a lot easier to make an appropriate treatment decision if you can get a good look at the foot before treating it so that you can be more confident about why it’s lame and how to treat it appropriately. 

What does this mean to you? Low-stress cattle handling and keeping pens as clean and dry as possible aren’t always easy or cheap, but neither is lameness. 

The Beef Cattle Research Council is a not-for-profit industry organization funded by the Canadian Beef Cattle Check-Off. The BCRC partners with Agriculture and Agri-Food Canada, provincial beef industry groups and governments to advance research and technology transfer supporting the Canadian beef industry’s vision to be recognized as a preferred supplier of healthy, high-quality beef, cattle and genetics. Learn more about the BCRC at beefresearch.ca.

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The disease was first described in New Zealand as “transit-related lameness,” but it was Dr. F.L. Sick and colleagues who first described the disease in the early 1980s as an outbreak of “toe abscesses” in feedlot cattle in the U.S. Midwest. While we can debate the name, what is clear is the clinical signs and epidemiology (who it affected and when) are well known.

Sick’s original description of toe tip necrosis is as relevant now as it was 40 years ago. Toe tip necrosis syndrome develops soon after arrival at the feedlot. Lameness is nearly always in the hind limbs, but there is no obvious swelling. Animals may have a fever. The tip of the claws may appear rounded and worn, and on close inspection, there is always evidence of white line separation (the juncture where the hoof wall meets the sole).

Although the cause of toe tip necrosis is open to speculation, the “abrasion theory” is the most likely explanation. This theory postulates that excessive wear along the white line results in separation. This allows bacteria to travel along small fissures within the white line, and a subsequent infection causes more separation. Once the infection penetrates the pedal bone (coffin or P3 bone), then it causes bone necrosis, making it extremely difficult to treat — amputating the claw or euthanasia may be the only options.

The infection can also migrate up the tendons of the hind leg causing obvious swelling. And, in some cases, it enters the bloodstream and seeds bacteria into other organs such as the liver, kidneys and lungs, which results in death. Thus, events and flooring that lead to excessive wear along the apical white line should be considered risk factors for the disease.

Diagnosis is best confirmed with a pair of hoof nippers. Nipping the tip of the claw of an affected hoof will reveal dry and black necrotic horn (hoof) tissue, or it may appear abscessed with a dark grey to black discharge. Nipping is not only diagnostic but also allows the abscess to drain. If caught early, cattle will respond to nipping and antibiotics.

Recently, I worked with Dr. Grant Royan to create an extensive photograph library of the many different floorings used in 24 feedlots and auctions located in Alberta, Saskatchewan and Manitoba. Although concrete is used extensively, it becomes slippery when worn and wet. Thus, some auctions and feedlots apply sand/gravel onto the concrete flooring. While this helps prevent slipping, it is also very abrasive.

Working with Dr. J.D. Johnston at the University of Saskatchewan’s College of Engineering, we recreated white line separation by dragging cadaver feet across different types of surfaces. Specifically, we tested four floorings: concrete, concrete plus sand-gravel, rubber, and rubber plus sand-gravel.

The results were clear; concrete with sand-gravel damaged the feet, and we were able to recreate white line separation, which is the first stage of toe tip necrosis. As expected, rubber flooring commonly encountered in dairy barns was the best material. While rubber mats caused the least amount of damage, they become slick when wet with urine and manure. Thus, bedding (straw, wood chips or sawdust) that accumulates over the flooring will provide traction. One novel idea was the use of skid steer tires, which are both flexible and have deep grooves that provide traction.

We encountered numerous facilities using rebar welded in a grid pattern and placed in front of the squeeze. While this provides excellent traction, it may also be too aggressive for high-strung cattle. Another common flooring is metal forged in a mesh pattern. Again, it provides excellent traction, but risks abrasion. Rubberized floorings are becoming more popular and are typically strategically located in areas such as before and after the squeeze, and in other high-traffic areas. These vary from rubber mats used in the dairy industry to woven tires and skid steer tires.

As the fall run approaches, we urge producers, feedlot and auction owners to evaluate their handling facilities. Check the flooring for jagged concrete, metal embedded in the flooring or squeeze, and flat/angle iron that is welded in areas where cattle can damage their feet and legs. If the concrete is slick, then avoid gravel and use bedding or finer sand. Cattle should also avoid sharp turns, which places torsion on the hoof, which may contribute to white line separation.

Last, low-stress cattle handling is key. The hooves can tolerate poor flooring, but if an animal is excited and pushing on those ahead of them in the chutes, then their hind feet will slip on the floor, which is akin to rasping the claws with a metal file. Sub-optimal flooring is also an issue for highly fractious animals that bolt from the squeeze.

We thank the Saskatchewan Ministry of Agriculture (Agricultural Development Fund) and the Canadian Agricultural Partnership for financial support for this research.

– Dr. Murray Jelinski is the Alberta chair in beef cattle health and production medicine at the Western College of Veterinary Medicine (University of Saskatchewan). His research interests include toe tip necrosis, bovine respiratory disease, Mycoplasmosis in feedlot cattle, internal parasites in yearling cattle, abomasal (stomach) ulcers of unweaned beef calves and the changing demographics of the beef industry and rural veterinary practices.

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Dr. Murray Jelinski of the Western College of Veterinary Medicine at the University of Saskatchewan started looking at this disease 10 years ago. His brother, Dr. Mike Jelinski, is a feedlot veterinarian in Alberta, and the two got talking about feedlot diseases, including some that hadn’t been studied. Dr. Eugene Janzen at the University of Calgary and Dr. Oliver Schunicht of Feedlot Health Management Services were also interested in toe-tip necrosis. Schunicht had presented on the disease to the Western Canadian Association of Practitioners after investigating an outbreak in feedlot cattle.

“Back then people were not as aware of it, and it also had different names. In southern Alberta and the U.S. people were calling it toe abscesses,” says Jelinski.

The dairy sector sees white line disease, which sometimes leads to abscesses and develops more in the side wall of the claws.

“Toe-tip necrosis starts at the tip of the toe. Although the two diseases have some features in common, location suggests that causes may be different,” says Jelinski.

Jelinski and his brother asked feedlot practitioners in Alberta to submit feet from animals that developed toe-tip necrosis and were overwhelmed with the response; the disease was much more prevalent than they realized.

“Now there seems to be more cases, but this is what often happens — once you start looking for something you start finding more. Prevalence of toe-tip necrosis in the past 10 years may not have increased but our awareness has, leading to increased reporting,” he says.

Typically these cattle come off pasture, go into the feedlot and within a few days to a month develop hind limb lameness, says Jelinski. The disease usually starts in the lateral claw on a hind foot, and is rarely seen in the front foot.

“If you look closely, you see wear at the tip of the toe, and separation along the white line,” says Jelinski. “Depending on when you catch it, you might see the start of an abscess or just some separation.”

In bad cases the infection has already penetrated the hoof wall, going up into P3 (the coffin bone) in that claw. It can then travel through the tendons and into the bloodstream, he explains. Those cattle become septicemic, as pathogens travel to all organs and seed into the lungs.

“What we see is a classic embolic pneumonia, which we usually associate with liver abscesses. People rarely check the feet to see if there’s a foot infection to explain the pneumonia,” he says.

Several risk factors are associated with toe-tip necrosis. “A pathologist in South Dakota described outbreaks in feedlots in the U.S. in the 1980s. He found cases in clusters, in groups of cattle coming in. He wondered if there might be a temperament factor,” says Jelinski.

Dr. Karen Schwartzkopf-Genswein at the Lethbridge Research Centre, Janzen and Jelinski collectively investigated several outbreaks.

“It became clear that high-strung animals are more likely to get this disease,” says Jelinski. Flighty animals are more apt to injure the hind feet as they push forward in the chute or scramble on rough concrete surfaces.

“Cattle have so much muscle and strength in the hind legs that they put tremendous forces on their toes. If they slip and lose their purchase on the concrete, it is like a rasp and scrapes the toe off,” he says.

Toe-tip necrosis isn’t heard of much in cow-calf operations with pastured cattle.

“Even if cattle travel along a gravel road and stone bruise, that would be different,” says Jelinski. Jelinski and his colleagues think the damage occurs when cattle are being loaded or unloaded on trucks, or at the auction yard, as there is lots of concrete in areas where they are sorted.

“Some cases develop within 24 hours of arrival at the feed yard. That tells me the trauma is happening before arrival — perhaps in transit or at the auctions. We rarely see it later in the feeding period, so it is a disease associated with handling, perhaps on arrival. We have created it by management and can probably manage our way out of it.”

“When people have larger herds on bigger pastures or rangeland, cattle may not have been handled much. If they are only checked occasionally by people on quads or horses, cattle raised are more likely to be flighty,” he says.

Animals that die with toe-tip necrosis have a thinner white line than animals that die of all other causes, says Jelinski. The white line is usually about four to five millimetres in depth, he explains, so if they suddenly wear off a couple of millimeters, fissures develop in the foot. Bacteria then enter the soft while line and produce enzymes that break it down even more.

Jelinski has sectioned more than 300 feet over the years with a band saw. Sometimes he finds organic matter such as manure or straw that’s been impacted into the foot, he says. As the animal takes a step and loads the foot, the white line gapes open. When the foot is lifted it closes up again on any material jammed in there. Pathogens that thrive in a low-oxygen environment get impacted inside the foot and start an abscess, and infection may extend to P3 and surrounding tissues.

Researchers are currently studying flooring and footing at feedlots and auction marts, as well as on trucks and trailers.

“Cattle coming into a feedlot after a wet summer seem more prone to this disease; their feet are softer, more vulnerable to wearing away on abrasive surfaces,” says Jelinski.

He and his colleagues also looked at nutrition and micronutrients within the hoof wall and sole. Prairie Diagnostic Services conducted the analytical work for the project.

“We determined that magnesium levels in horn tissue — hoof wall and sole — were lower in cattle with toe-tip necrosis than in the controls,” he says. “Calcium is implicated in the integrity of horn tissue, but magnesium and calcium are interrelated, and if one is low, the other is low. I suspect that low magnesium could be an indicator for low calcium.”

There may be a nutritional basis to this problem, but trauma to the foot is the biggest factor. Thus prevention centres on flooring. Some feedlots have rebar welded together in a cross pattern, or rough concrete at their chutes. Cattle need adequate traction so they don’t slip and fall when leaving the chute, but not so abrasive that it damages the feet.

Cattle handling is also important. Fractious cattle must be handled quietly so they aren’t trying to flee or shove in the chute.

“We’ve seen outbreaks where 40 to 50 per cent of the cattle end up with toe-tip necrosis. In other instances it’s just an odd animal here and there,” says Jelinski. “I don’t think they are always fractious. Most diseases are the result of multiple factors that come together at the right time to tip over the animal’s defenses and develop the disease.”

More people are becoming aware of the risks. Animals developing hind limb lameness soon after entering the feedlot should be thoroughly checked.

“If there’s no other obvious cause of lameness, toe-tip necrosis is a possibility. To diagnose it we use hoof nippers to nip the end of the toe. You’ll either see a purulent bloody black-brown discharge, or a black crusty necrosis of horn tissue,” says Jelinski.

Treatment

“In a current study we’re looking at best practices for treatment. Should we be nipping these toes, treating them like an abscess — to allow drainage — and give antibiotic coverage as well? Or is just nipping enough? Or just antibiotics?”

For treatment of toe-tip necrosis, long-acting antibiotics are generally successful if it’s caught early. However, often there’s separation of the white line before anyone realizes there’s a problem. If the infection gets to the corium (the soft inner tissue beneath the horn), it reaches nerves and blood supply.

“At that point it becomes painful and the animal is lame. If you treat it early, there is good blood supply there, so the antimicrobial would be in high concentration and treatment would be successful,” says Jelinski.

But once the infection reaches the coffin bone or P3, it’s more difficult to treat.

“We have sectioned feet from animals that recovered, and see that the bone has remodeled. If you treat aggressively enough, they can recover from a minor P3 infection, but once it gets advanced we are probably looking at amputating that toe.”

But it’s not unusual to find toe-tip necrosis in more than one of the hind claws, says Jelinski.

“If veterinarians are going to amputate a toe, they’d better check the other toes as well. Euthanasia may be the best option on some animals because this is a very painful condition. You don’t want to leave them three-legged lame in a pen with little hope for recovery.”

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Foot rot on range can be especially troublesome because of the difficulty in mustering cattle for treatment and is a particularly serious condition in breeding bulls. It not only physically affects a bull’s ability to breed, but the increase in body temperature, pain and stress associated with foot rot often suppresses sperm production for an extended period of time. Unless treated very early, foot rot often spells the end of a breeding season for a bull.

Several things need to happen for animals to get foot rot:

• First and foremost, the interdigital space (skin between the claws) is compromised by wet, abrasive environmental conditions, such as those around watering spots on pasture, wet corrals and rough, frozen ground in the spring and fall wherever cattle gather. Cattle grazing on harvested crops can also suffer interdigital injuries. Skin damage provides a portal for bacteria to enter the tissue of the foot.
• Bacteria associated with foot rot need to be present. Fusobacterium necrophorum is typically the bacterium causing foot rot. It invades tissue and creates decay. F. necrophorum is a very common organism and can be found anywhere cattle are found. Fusobacterium can be coupled with other bacteria commonly found in the gut and feces, decreasing the number of F. necrophorum necessary to initiate infection and produce toxins. Toxins stimulate bacterial multiplication, cause tissue damage and promote progression of infection deeper into the foot.
• Wet, abrasive conditions.

The incidence of foot rot varies according to the weather, season and grazing conditions. Foot rot represents approximately 20 per cent of all lamenesses diagnosed in cattle.

Symptoms include:

• Pain, sudden lameness with swelling of the interdigital space and the coronary band (hoof/skin junction).
• Fever, loss of condition, reduced milk production (dairy cattle), loss of appetite and resulting loss of gain (beef cattle).
• Bulls are reluctant to move and may be unable to breed, especially if a hind limb is involved.
• Necrosis (tissue death) of the interdigital space accompanied by a foul odour.
• Without treatment, infection extends to surrounding tissues. Bones of the digit and joints become involved. Chronic arthritis of affected joints is common.

Not all causes of lameness at the level of the foot are foot rot. Sole, tendon and muscle injuries can cause lameness. Sole abscesses require trimming and debridement. Fibromas (corns) that form between the digits cause significant lameness. Sand cracks frequently cause lameness in cattle on pasture. Laminitis (founder) also occurs. It is essential that lameness be properly diagnosed. Your veterinarian can help.

Most cases of foot rot require treatment with appropriate antibiotics. Many common antimicrobials are effective in treating foot rot; all now require a veterinary prescription. Treatment should always begin with cleaning and examining the foot to confirm that lameness is actually due to foot rot. While some very mild cases will respond to topical therapy and supportive care only, most cases require the use of systemic antimicrobial therapy. Sustained release antibiotics may be indicated when treating cattle on pasture.

Your veterinarian may also recommend use of an anti-inflammatory drug like meloxicam or Banamine. More aggressive treatment options need to be considered if deeper structures in the foot are involved including claw amputation and fusion of affected joints.

Prevention and control of foot rot involves increased vigilance during wet, humid conditions. Focus attention to areas where cattle congregate. These areas are often crowded and very wet with high bacterial counts.

A commercially available vaccine against foot rot may reduce the incidence of infection. Vaccination is often recommended for breeding bulls where the cost associated with disease is greatest. Talk to your veterinarian for updated information on treatment and prevention. Generally, the best offense is a good defense. Centre preventive measures on limiting mechanical damage to the foot caused by sharp gravel, brush and stubble. Minimize the time cattle must spend standing in wet areas with high bacterial counts. Adequate dietary zinc and iodine should be provided in the form of well-balanced trace mineral programs.

Take-home messages

Foot rot is a costly, frustrating animal health condition all cattle operations potentially face. The extra labour and expense in dealing with foot rot in confinement and on pasture never goes away. Keep in mind that it is necessary to have a break in skin integrity for foot rot to occur. Early detection and treatment is the key to successful management of the disease. Response to treatment is generally good. A proper diagnosis to rule out other causes of lameness is important. Foot rot in bulls during the breeding season can be costly, making early intervention even more important. Vaccination of bulls against foot rot is worth considering. Feeding a well-balanced diet with appropriate trace minerals is key in prevention. Consult with your veterinarian regarding a prevention program for your farm.

Dr. Ron Clarke prepares this column on behalf of the Western Canadian Association of Bovine Practitioners. Suggestions for future articles can be sent to Canadian Cattlemen or the WCABP.

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Horn, face and stable flies all are irritating to cattle, but stable flies have been particularly bothersome.

“They will bite and irritate the animals on the legs and belly, and control of these pests is very difficult,” says Gerald Stokka, NDSU Extension veterinarian and livestock stewardship specialist.

“Too many flies feeding on cows can lead to a decrease in weaning weight,” notes Karl Hoppe, Extension livestock systems specialist at NDSU’s Carrington Research Extension Center. “It’s generally accepted that 100 flies per side or 200 flies total per beef cow is the point where decreased weaning weight will cause economic losses.”

The main fly control methods are insecticide-containing ear tags; pour-on, spot-on and spray-on insecticides; insecticide dust bags; ropes filled with oil and insecticide; oiler/rubbers; mister/foggers and sprayers.

Another option is a walk-through mechanical flytrap. As cattle walk through the trap, a series of strips made of canvas or old carpet dislodge most of the flies. Light attracts the flies to the screened sides of the trap and they can’t escape. Visit the University of Missouri Extension website for more information about this system.

Products such as Rabon and IGR can reduce fly population if they are fed to cattle early enough, which is two to three weeks before moving the cattle to pasture. These products need to be continued throughout the summer, Stokka says. They inhibit larval growth of flies that lay eggs in manure patties.

Flies will migrate from herd to herd, so if the neighbour doesn’t control flies, the flies will move to other herds, Hoppe says. Rotating cattle to pastures some distance away can be helpful because new populations of flies take some time to develop.

Water can cause foot rot

To find relief from fly bites when fly pressure is high, cattle will crowd or bunch together, or they may stand in stock ponds or other water. The water reduces the number of bites from stable flies on the legs, and the mud creates a shield for protection later. Also, a wet tail provides an effective fly swatter.

However, standing in water to avoid flies creates an opportunity for the soft tissue between the toes to get soft and prone to foot rot infections, Hoppe says. The infection is painful, so the cow will limp and even leave the herd to rest. Cows also will lose weight because limping keeps them from grazing.

“Appropriate antibiotic therapy is necessary to control the infection and inflammation before the cow develops permanent damage to the foot,” Stokka says.

Cattle also will stand in groups, stomping the ground and creating dust to fight flies. This can lead to eye irritation. Face flies will feed on the eye secretions and can transmit bacteria that may lead to pink eye. Antibiotic therapy is necessary to decrease the infection before the cow develops a permanent eye lesion, which could limit its vision.

“While timely administration of antibiotics can help in the healing process of foot rot and pink eye, it can be rather difficult to sort cattle and restrain them for injecting antibiotics,” Stokka says.

Many ranchers have opted to use dart guns to help deliver antibiotics to cattle while the animals are grazing, but the best option is proper restraint and treatment, according to Stokka. He recommends producers consult with their veterinarian about the appropriate antibiotic choices.

“However, if this method of treatment is used, use only air pump equipment,” he adds. “Spend enough time to get within 15 to 20 feet of the animal, and use the appropriate dose for the size of the animal.”

While fly control is needed, keeping up with fly pressure is difficult, the specialists say.

“Use different insecticides to help control fly populations,” Hoppe advises. “Consider adding larvicides in the mineral mix or periodic applications of fly control products, or consider using rotational grazing techniques and natural fly predators.”

This article was originally published in the Aug. 2, 2018 issue of the Manitoba Co-operator.

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Banamine transdermal, a non-steroidal anti-inflammatory drug (NSAID) produced by Merck Animal Health, was released at the end of January. This pour-on product, with flunixin meglumine as the active ingredient, is used to reduce fever related to bovine respiratory disease (BRD). However, it’s the drug’s proven ability to relieve pain related to foot rot that is stirring up interest now that has been included on its label.

“Initially, it came out that it was an anti-pyretic,” says Roy Lewis, a technical services veterinarian with Merck and frequent Canadian Cattlemen contributor. “The biggest application for that in the cattle world would be a calf in a feedlot with pneumonia, let’s say. It’s going to be given an antibiotic of some sort, and then this drug would help pull the fever down, and so that was on the label initially.”

Lewis explains that most pharmaceutical companies that produce an anti-inflammatory drug are now focusing on specific ailments or procedures that cause pain. “That’s what they want to get on the label so that people see that they can use it for that.” In the case of banamine transdermal, Merck used foot rot as a model for lameness.

Merck chose to focus on lameness because it is an issue that affects all types of operations, and it was simple to measure the drug’s effectiveness, says Lewis. For example, for a product to be approved by the United States Food and Drug Administration (FDA), the drug company has to prove that it works. When it comes to proving that an animal’s pain has been lowered, pain needs to be measured in a simple way. As Merck was able to do this, banamine transdermal was approved by the FDA.

• Read more: Ancient scourge remains a problem in modern rations
• Read more: Not all lameness is foot rot

This was achieved by using pressure plates to measure how much weight an animal puts on a specific foot as they walk. After walking lame cattle over a pressure mat to record this and other metrics, the cows were given the drug and then walked over the same mat six hours later. Based on this research, Merck found that the treatment decreased the pain in these animals by measuring the amount of pressure they put on the affected foot.

“It’s pretty easy to measure,” says Lewis, who explains that pain resulting from other ailments and procedures, such as castration, is often harder for researchers to quantify. “We know it’s painful and we know scientifically these drugs should work. Now we just have to prove it.”

While there are a number of different banamine products currently available for cattle, this specific treatment, a translucent red liquid, is applied along an animal’s back from withers to tailhead. It’s advised to apply this to dry, undamaged skin, not rubbing the product into the animal’s skin or hair. Producers need to ensure the animal doesn’t get wet for around six hours, according to the label, though Lewis suggests this length of time may be unnecessary, as it starts to absorb in about 15 minutes.

The drug was developed as a topical application for ease of administration. “As innocuous as it might be to give them a needle, you have to catch them in a chute or have them restrained, and it does in itself create a little bit of pain,” he says. You can apply it easily in an alley or by walking up to the animal if it is quiet enough.

Banamine transdermal comes in a plastic bottle with a graduated dosing chamber. The recommended dose is one ml per 15 kilograms, which Lewis says is a fairly low dosage. “It’s absorbed pretty quick and reaches maximum levels in the body in about two hours.”

The withdrawal time for slaughter is 13 days after the last treatment. As no milk withdrawal has been established, the drug is not yet approved for lactating dairy females.

The label warns that the drug shouldn’t be used on breeding sires “as the reproductive safety has not been evaluated.” Lewis confirms that this caution is due to the fact that there hasn’t been research into this particular area, so the implications are not yet known. “That’s where veterinarians have to use what we call ‘extra-label use’ and use our own best judgment,” he says. “If they know that this bull is lame and it should have this, in my eyes I don’t see any issue with it.”

The label also warns that NSAIDs may have the potential to delay calving, so it is not recommended for use within 48 hours of an expected calving date. As well, administering the drug immediately after calving may interfere with uterine involution and expulsion of foetal membranes resulting in retained placentae. This particular caution is related to the original injectable form of banamine, and Lewis confirms that it is a legitimate concern to consider when choosing a fever or pain reducer. “There is a little bit of higher incidence of retained placentas if it’s used,” he says.

The adverse reactions listed on the label include “transient swelling, erythema, dandruff, broken (or) brittle hair, hair thinning, alopecia or thickening of the skin… at the application site,” which may be due to an overdose.

The label advises that producers wear protective gloves and safety glasses when applying the drug. Lewis notes that while this may make producers worry that it’s particularly dangerous, earlier pour-on products were introduced before more recent safety regulations, and wearing safety glasses and gloves is always a good precaution when using topical treatments.

Banamine transdermal has a low freezing rate and a high flammability rate. The latter makes it safe to use at brandings, as opposed to pour-on products that contain rubbing alcohol. “In fact, I tried to set it on fire and I couldn’t,” says Lewis.

Lewis anticipates that Merck and other drug companies will be looking into new label applications for pain relievers like banamine transdermal. “Following the Beef Code of Practice and what the public is dictating, more and more pain killers are being used. So this drug and probably the other ones that are out there for pain, the companies will be researching more applications for it, like giving it at a hard calving or post-surgical,” he explains. Regardless, a veterinarian can help you decide what kind of pain reliever is best for your situation.

“I think what’s going to happen is over time, veterinarians will have most of the pain killers at their clinic, and they’ll help the producer decide.”

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Importance of diagnosis

Lameness may be from a nail in the foot, injury (a pulled tendon or broken bone), an abscess or snakebite. Dr. Eugene Janzen from the faculty of veterinary medicine at the University of Calgary says a common cause of lameness in range cattle is a problem in the hoof such as a hoof crack, an overgrown toe that’s broken off, or even a hoof abscess.

Even though an abscess is an infection, it won’t respond to systemic antibiotics. Abscesses must be opened and drained, to relieve pressure and pain. “Swelling in other areas of the body are not as painful because skin will stretch, but with an abscess in the foot there is bone on one side and hoof horn on the other side, so the pressure is excruciating,” says Clark. “It’s like the pain when we smash a finger or toe and swelling underneath the nail makes it worse. If you’ve ever had an abscess under a fingernail or toenail, you can understand how painful it is for the poor cow. You have to relieve the pressure,” he says.

An abscess is a localized infection, sealed away from blood circulation, and can’t be adequately treated with antibiotic injections. Flushing it out and treating topically is the way to deal with it.

“Foot rot is a different kind of infection. The cow may have stepped on a stone or something sharp that cuts through the skin between her toes. Once the skin is pierced, bacteria in the environment can easily enter, and get into the fat pad between the toes. Fusobacterium necrophorum is everywhere — one of the common bacteria that assist with decay and rotting of dead things,” Clark explains.

“The tissues between the toes actually start to rot. The toes are separated because of the infection and swelling. There will also be symmetrical swelling of tissues above the hoof. It will be hot to the touch and the skin (on a white-legged animal) will be red. The lesion smells like rotting flesh. If you look closely you can see gray-green rotting tissue protruding,” he says.

“It’s easy to look at a lame foot and see whether it’s foot rot. Even from horseback you can get close enough to see the swelling between the toes. If it’s foot rot you can treat with antibiotics and it should get better. If there’s no swelling, it’s not foot rot and treating it will not help. In that situation, you need a closer look at the foot and remove the stone or the nail or deal with the abscess or whatever the pain-causing situation might be,” says Clark.

“The swelling from foot rot is below the fetlock, and just above the hoof,” says Janzen. If the swelling extends above the fetlock joint it’s probably not foot rot.

“Infection in the interdigital cleft may be due to a variety of bacteria ubiquitous in the environment. The common one is Fusobacterium and this is the one for which a vaccine has been created. Other pathogens can be involved as well, and complicate the infection. None of them, however, can produce foot rot on their own without a break in the skin. The people who have tried to reproduce foot rot in experimental trials have all had to scarify the interdigital area,” he says.

“Thus you need two things for foot rot to occur — the ugly bacteria and the injury. In dairy cattle we often see foot rot in what dairy practitioners call ‘new barn syndrome’ which means the cows have more interdigital injuries if the concrete hasn’t been worn off and smoothed yet. If cows are walking on an abrasive surface and also have to walk through a slurry of manure, this becomes a perfect combination for foot rot,” Janzen says.

“The literature about foot rot states that incidence in range cattle is something between one and four per cent but livestock people here in Alberta would probably say it’s higher, depending on the year. Also, if a ranch has cowboys training horses, the owner tells me their foot rot rate is high. The cowboys want roping practice so they catch and treat any cattle that they think might have foot rot — and they may be over-treating.”

On the flip side, some ranchers don’t ride among their cattle often enough to see the ones with foot rot and may not treat them soon enough. Long-standing cases may result in serious complications like joint and tendon sheath infections.

Treatment

“Penicillin will work, but you need to dose it daily. Many other drugs have a foot rot claim on the label, but there’s little point in using something like Nuflor or Micotil because they are more expensive. I use long-acting oxytetracycline, since it is less expensive, and generally one treatment will do it. The only drawback with this drug is that there is a fairly long withdrawal period, so you need to be very certain you are treating foot rot,” he says. You wouldn’t want to discover later that the animal has a broken foot (rather than foot rot) and the best choice would be slaughter.

“If the cow is at home in the yard where you can treat daily, you can use the oxytet that’s not long-lasting, or use trimethoprim sulfate,” says Janzen. “If you are not absolutely sure it’s foot rot, and it might be something else like a broken bone in the foot, and one of your alternatives might have to be slaughter, consider using Ceftiofur since it doesn’t have a withdrawal time, in Canada,” he says.

“For treating range cattle, sustained-action antimicrobials provide coverage for more than one day. It doesn’t matter which one you use but long-acting oxytetracycline is probably the most commonly used. It’s probably best to save the more modern drugs for when oxytet no longer works. Some of our pharmaceutical people have cautioned us about using the sustained-action antimicrobials that are more organ-specific, such as the drugs that concentrate in mammary tissue or the lungs, for instance (for treating things like mastitis or pneumonia). Those would not be our first choice for treating foot rot,” Janzen says.

“If the lameness doesn’t get better after antibiotic treatment, there are only two explanations,” says Clark. “One is that it is not foot rot. It’s an abscess or some other problem. Second, if you let foot rot go too long before treating it, infection can spread from the fat pad between the toes and get into the joints. This is much more serious. Once the infection gets into the joints it starts destroying the cartilage. Even if you can eventually clean up the infection (which is much more difficult once it’s in a joint), you are still dealing with an arthritic joint. That animal will still be lame, and you are faced with either slaughter or possibly amputating the toe — depending on the circumstances. Those are your only choices,” he says.

Janzen says that half the cows sold as culls because of lameness are suffering from complicated cases of foot rot. “It’s very serious if the infection has got into the joint, and even worse if it’s into the tendon sheath because antimicrobials won’t get in there,” says Janzen. There’s no economical way to treat that condition in cattle.

This is why it’s important to catch it early. On a longstanding case of foot rot — in situations where cattle are on large range pastures and you don’t see them every day — it might take two doses of antibiotic to clear up, according to Clark. “But the main thing to keep in mind is that if it’s not starting to improve after the first treatment, you need a closer look at the foot to make sure of what you are dealing with,” he says.

In most cases a producer can make a diagnosis of foot rot, and treat appropriately. “But rather than assuming a lameness is foot rot, figure out why the animal is lame. There are many reasons that an animal could go lame. This is why I am nervous about using dart guns in which an antibiotic can be delivered at long distance. Advertisements for these guns often use foot rot as their example, but if you can’t get close enough to get a good look at the foot, that’s not a good idea!” says Clark.

“In the old days, before we had all these new drugs, we treated foot rot locally with an antiseptic or antimicrobial wrap around the foot,” says Janzen. “I’ve also read about research where people cleaned the interdigital cleft with soap and water. If you did that religiously for four or five days in a row, the foot would heal just as well as it would with antimicrobial treatment. But no one wants to lift up a cow’s leg five days in a row to wash out the foot! Maybe 20 years from now if society says we can’t use antibiotics anymore, we may have to resort to these sorts of treatments again!”

Prevention

Janzen says some ranchers are fencing off water holes and lifting the water with solar pumps to a trough on higher, dry ground. “Then cattle don’t have to go into the water holes to drink. The PFRA in Saskatchewan was instrumental in demonstrating to producers that cattle preferred to drink from the troughs rather than have to wade in the filth and mud.”

There is a foot rot vaccine available. “It’s been in use a long time, but there isn’t a clinical trial that actually demonstrates whether it works or not,” says Clark. “The problem with this vaccine is that in many producers’ minds it is a lameness vaccine. But it is only a foot rot vaccine, and foot rot is not as common as they think, so it’s hard to gauge whether the vaccine has any benefit. In the absence of evidence, I am a little cautious,” says Clark.

Janzen adds, “If foot rot is caused by Fusobacterium necrophorum (the) vaccine will probably be protective, unless the infection is complicated by or caused by Bacterioides spp. In Canada, some producers give their bulls this vaccine when they do their breeding soundness evaluation in the spring,” he says.

“When I was growing up, everyone believed that foot rot could be prevented by feeding organic iodine with the salt. Many ranchers still feed iodized salt, or salt blocks containing iodine, in an effort to prevent foot rot. Whether it prevents foot rot or not, is equivocal. The level at which you’d have to add iodine, or organic iodide, in salt would likely be prohibited by the federal government regulations in Canada. Organic iodine has been withdrawn in Canada for that application,” says Janzen. “You can still put iodine in salt, but at such a low level that it’s hard to tell if it helps.”

The post Not all lameness is foot rot appeared first on Canadian Cattlemen.

There are many different types and causes of lameness, ranging from genetics (e.g. conformation), nutrition (e.g. founder), the environment (e.g. frostbite), injuries and infection (e.g. foot rot, hairy heel wart). Some may have several causes, like toe tip necrosis syndrome (TTNS).

This syndrome always affects the hind claws and usually develops within three weeks of arriving at the feedlot. The disease begins when the white line of the hoof separates. The white line between the sole and hoof wall is thin, and represents an inherent weakness in the hoof. If the white line separates, bacteria can penetrate into the hoof and affect the underlying P3 (coffin) bone at the tip of the toe. Animals that are treated early will probably recover, but successful treatment is unlikely once the P3 bone itself is infected. The extreme lameness that results from untreated (or unsuccessfully treated) TTNS causes a rapid loss in body condition and poor performance. The disease is sporadic, but clusters by truckload and feedlot pen.

Opinions differ on how TTNS gets started. Some think the infection starts on the outside and works its way in. Excitable cattle may damage the soles of their feet while struggling in the chute, allowing bacteria to enter and infect the hoof. Alternatively, perhaps the cattle struggle because their feet are already sore from abrasions on concrete flooring in auction marts or processing facilities, or from standing in the truck for long periods. Others think that TTNS may work its way from the inside out through the hoof, perhaps related to a pre-existing infection in the bloodstream, grain in the feedlot receiving diet, or BVD.

Dr. Murray Jelinski of the University of Saskatchewan and co-workers recently published a study to better understand how TTNS develops (“The lesions of toe tip necrosis in southern Alberta feedlot cattle provide insight into the pathogenesis of the disease;” Canadian Veterinary Journal 56:1134).

What they did: In October and November 2012, three commercial veterinary practices collected hind feet from 67 feeder heifers and steers (averaging 385 to 700 lbs.) that died or were euthanized in commercial feedlots (on average within three weeks of feedlot arrival) and submitted them to the research team. For each TTNS-affected animal, hooves from an unaffected control animal were also collected. At the university, each hoof was sliced lengthwise into thin sections. The location, nature and severity of the lesions were described and compared between TTNS-affected and control hooves.

What they learned: The white line between the hoof and sole had separated in all of the TTNS-affected hooves, but in only three per cent of control hooves. The white line was also significantly thinner in TTNS-affected hooves than in control hooves. In TTNS-affected hooves, tissue in the toe tip was always visibly inflamed, the centre of the toe was inflamed about two-thirds of the time, and the upper section of the toe was only inflamed a quarter of the time. Microscopic examination only found dead (necrotic) tissue in areas that were also inflamed. There were no signs of smaller, isolated infections apart from the toe tip infections. Unlike foundered cattle, the P3 bone was not rotated in TTNS cases.

What it means: TTNS most likely moves from the outside in, not the inside out. This is significant because the prevailing belief is that the disease begins with cattle damaging the soles of the hooves. This leads to thinning and weakening of the white line, and separation of the sole from the hoof wall. As previously noted, once the bacteria breach the white line, they travel into the foot to infect the P3 bone and other soft tissues. The infection doesn’t always end at the foot. Sometimes it spreads up the leg along the tendons and between the muscles, or it may even enter the bloodstream where it spreads to the lungs, liver, and kidneys.

The finding that the disease appears to move into the foot rather than starting at P3 and moving outwards may help us prevent it. Specifically, flooring should provide traction, but must not result in excessive wear. This typically occurs when animals are overcrowded and agitated in the chutes, resulting in hind feet being abraded by concrete flooring as they push against the animals ahead of them. Considering both the flooring and how the animals are being moved and handled may help prevent costly losses.

The Beef Research Cluster is funded by the National Checkoff and Agriculture and Agri-Food Canada with additional contributions from provincial beef industry groups and governments to advance research and technology transfer supporting the Canadian beef industry’s vision to be recognized as a preferred supplier of healthy, high-quality beef, cattle and genetics.

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The finding, which was part of a larger study in progress led by researchers from the Lethbridge Research Centre and University of Calgary Veterinary Medicine (UCVM), didn’t come as a surprise to veterinarians who work with feedlots because improved medicines for pneumonia in combination with treatment on arrival have substantially reduced the number of respiratory disease cases in fall-placed calves.

It’s easy to see that an animal is lame, but not always as easy to determine what’s causing the problem. Dr. Michael Jelinski of Veterinary Agri-Health Services, Airdrie, Alta., demonstrated this concept in a video quiz to lead off a lameness workshop held at the UCVM annual beef cattle conference this summer.

Narrowing it down to lameness most often seen in fall-placed calves in Western Canada, he says foot rot, mycoplasma arthritis, toe-tip necrosis and, in some feedlots, digital dermatitis are leading causes. Laminitis, injuries and potential ergot poisoning may also be problematic.

• More from the Canadian Cattlemen: The importance of field diagnosis

Foot rot and digital dermatitis

Classic signs are rapid swelling and redness in the soft tissue between the claws usually causing the claws to spread apart. The area feels warm and has a rotten odour if the infection is oozing out. Left unchecked, the swelling will spread up around the hairline at the top of the hoof and back into the dewclaw area up the fetlock.

Typically, the animal will be very lame and avoid putting weight on the affected hoof if at all possible.

“If foot rot is suspected and it doesn’t respond to an antibiotic appropriate for foot rot, then it’s probably not foot rot,” Jelinski says. Unfortunately there are plenty of alternatives causes for lameness.

Digital dermatitis (hairy heel warts) is a highly contagious skin infection that doesn’t respond to injectable antibiotics.The cause is still not clearly understood, but spirochete bacteria along with other bacteria and possibly a virus have been implicated.

Raised lesions appear between the claws and often on the bulbs of the hooves and around the dewclaws. Swelling isn’t common, however, the lesions may occur along with foot rot.

Historically, digital dermatitis has been an issue in dairy barns, but its prevalence has been increasing in Alberta feedlots in recent years.

The standard dairy treatment is to clean the foot and apply a topical antibiotic with a short-term wrap, Jelinski explains. This can be difficult to do in a feedlot. In outbreak situations, feedlots have used footbaths of copper sulphate or formalin with some success.

“Given the increasing prevalence of this disease and the difficulty managing it, it’s important for feedlots to be vigilant with lame cattle that are not responding to treatment for what may appear to be foot rot,” he advises.

Mycoplasma arthritis

Mycoplasma arthritis generally starts as a pneumonia. When animals are under stress with weakened immune systems, mycoplasma bacteria can invade the lungs and from there enter the bloodstream and settle into joints.

Any joint can be affected, but ankle, stifle, hock, and elbow infections are common.

Stifle joint infections caused by mycoplasma arthritis may be mistaken as foot rot, however, animals with a stifle problem will typically stand with the toe on the affected side just touching the ground and the foot won’t be swollen.

Mycoplasma pneumonia can respond to an appropriate antimicrobial given early, but joint infections are difficult to treat. You have to get enough antibiotic into the joint to be effective, especially when there is tissue damage from the infection. Some of these animals will come around with time, but it could be weeks or even months. About one to two per cent of animals in a feed yard will be affected with a joint infection due to mycoplasma and some will require euthanasia, but the numbers vary greatly by feedlot.

Toe-tip necrosis syndrome

One theory is that it sets into the hoof through a weakness at the tip of a claw thought to be caused by wear and tear on the hooves that happens along the way from the farm to the feedlot. Typically, it starts in one or more hind claws, but can affect front claws as well.

Jelinski says some feedlots see it more than others. The big risk factors seem to be transport time, animal temperament and floor conditions.

Although most feedlots are aware of the condition, it is often misdiagnosed as an injury due to trauma or handling because lameness may start to appear within a few days after arrival.

This is why treatment is often delayed. In the meantime, the infection may spread deeper into the claw tissues and bone where it becomes untreatable and ends up with the animal being euthanized. It’s often a surprise to see what’s going on in the hoof when the animal is necropsied, Jelinski adds. For more detail see our related story in this issue.

Sloughing hooves

Ergot toxicity has been more common in recent years with wet growing conditions more conducive to ergot bodies forming in cereal heads, says Jelinski. The severity of associated lameness problems tends to cluster by feedlot depending on where they source grain. Grain screenings in pelleted supplements are another source of ergot toxins.

Ergot toxicity may first show up as lameness in the feet. Over time a line of demarcation (splitting of the skin) may become evident between the dead and healthy tissue. Some hooves may be affected worse than others and in severe cases the entire foot or claw sloughs off.

“The degree of damage caused by ergot toxins depends on the amount of toxin consumed and animals may recover from low-level poisoning when contaminated grain is removed,” he says.

Prairie Diagnostic Services at the Western College of Veterinary Medicine in Saskatoon now has equipment in place to test feed for ergot toxins.

• From the Manitoba Co-operator: Frozen ears and feet – but not from the cold

Laminitis

In a healthy hoof, a layer of laminae cushioned between the hoof wall and the third bone (the bone coming down to the tip of the hoof) holds the bone parallel to the hoof wall. When laminae weaken or tear from the hoof wall, the third bone begins to rotate downward putting pressure on the sole.

Laminitis in feedlot cattle is associated with a rapid increase in highly digestible carbohydrates (grain) in the diet, which changes the acidity in the rumen and in turn kills off some types of digestive organisms that release toxins into the bloodstream as they die. The toxins cause swelling in blood vessels of the hooves leading to impaired circulation.

A hardship groove associated with an abrupt change in diet will become noticeable across the hooves as they grow out. Sole overgrowth, skinny claws (flipper feet) and other claw abnormalities may become apparent in time.

Once laminitis sets in there is no practical treatment, however, animals with mild cases may get along just fine on soft ground in well-bedded pens. Marketing affected animals in a timely manner is advisable.

Others

Bruises, sprains, torn ligaments, ruptured tendons and, the very odd time, fractures can happen during routine handling and in pens when animals jostle at the feed bunk.

Nerve and brain damage also cause peculiar behaviour and strange gaits which can be mistaken as lameness.

Spastic paresis is an example of a hereditable condition where sensors in the muscle bundles keep the leg muscle tight causing the hock to hyperextend with each step. A severe joint infection can trigger an acquired form.

Abscesses from needle injection sites too close to the spine have been known to create a “wobbler” when the infection pushes up into the spinal cord just behind the head.

“Lameness is, of course, an economic concern for feedlots because of the cost of medications and labour to care for the animals, but it’s equally an animal welfare concern because many lameness conditions are very painful and may become chronic,” Jelinski says. “Unfortunately, we can’t do much to manage the pain. Unless we know the condition has a chance of improving with appropriate treatment, it’s best to deal with it by early marketing or euthanasia.”

The post Lameness in feedlot cattle appeared first on Canadian Cattlemen.

“We often complain about disease not responding to treatment. But the drugs we have are fairly effective. If the animal is not getting better, it’s probably because you are treating it for the wrong thing. For instance, there are a lot of diseases that don’t respond to antibiotics. They are amazing drugs but they don’t affect viruses, parasites or nutritional problems. “They only treat a bacterial infection — and only certain types of bacterial infection,” he explains. You have to select an antibiotic the bacteria are susceptible to.

“Also keep in mind that with some bacterial infections, the tissue is so rapidly destroyed that treating the bacteria is not the issue; pathology is the problem. An example would be an infection in the joint of the foot. Even if you can eliminate the infection, there is still residual damage, making the animal lame,” he says.

“Diagnosis can be difficult. It takes four years of vet school for us to even come close. It’s not something that can be taught instantly. A person needs experience as well as classroom study, and cattle producers must recognize the difference between a presenting sign and a diagnosis,” he says.

“Cattlemen generally have a set of skills that are very hard to teach. I would love to have the skills they have — being able to tell when an animal is a bit ‘off’ and not acting quite like it usually does.” It helps to observe the herd from afar, before the animals notice you, because an alert animal may mask the signs of sickness. Astute observation is a skill most stockmen have.

• More cattle ‘Health’ with Canadian Cattlemen: Hunting for Johne’s disease in Saskatchewan

“The rancher has this ability to pick up on subtle signs that the animal is sick. They can identify the one animal in the herd that is not behaving like it normally does, or behaving differently from the other animals. Stockmen can often identify which organ system is involved — whether it is lame, or showing signs of respiratory disease. They know if the animal is coughing or has a weepy eye, or diarrhea,” says Clark.

“But as a veterinarian my job is to determine why it has a weepy eye, why it has diarrhea, why it is lame, or coughing. Diagnosis is all about the why. This determines the treatment. There is no treatment for lameness, per se. If the animal has a nail in its foot, the nail has to come out. If it has foot rot it needs antibiotics. If it has a broken leg it needs to be euthanized (unless it’s a small calf and the leg could be splinted). We don’t treat all lameness conditions the same way,” he says.

“There are also symptomatic treatments. If an animal is lame you can give it Metacam, to provide pain relief. But this won’t solve the underlying problem. You are merely treating the symptom and not the disease. There are treatments for diarrhea that make good sense — such as giving fluids/electrolytes — but knowing the cause of the diarrhea allows you to more specifically tailor your treatment.” You would treat it differently if it is caused by a bacteria than if it’s caused by coccidiosis or a virus, or worms.

“This is why diagnosis matters. Most people look at a lame cow and assume it’s foot rot. However, foot rot is a very specific disorder. If it’s foot rot, it will get better with antibiotic treatment. If a producer calls and says, ‘Doc, I’ve got a cow with a bad case of foot rot that I’ve been treating for a week,’ then I know it’s not foot rot. It’s either something else, or it’s been neglected too long before treatment was begun and it has gone into the joint. Recognizing foot rot is highly important, so I teach people some of the clues,” he says.

• From the Manitoba Co-operator: Frozen ears and feet – but not from the cold

“When an animal gets foot rot, the key thing is swelling above the hoof. The swelling is symmetrical and affects both digits, forcing the claws apart. If you look closely at the foot, you will see a grey-green slimy mass sticking out from the skin between the claws. If you give that animal antibiotics the foot will get better. Anything else that’s causing lameness needs to be looked at by a veterinarian.”

Abscesses are probably the most common cause of lameness that’s not foot rot. “But you can’t treat an abscess with antibiotics successfully, even though it’s a bacterial infection. The infection is walled off from the blood supply and the antibiotic can’t get to it. Until you drain the abscess, the animal will get no relief,” he explains.

With eye problems, producers need to know the difference between pink eye and cancer eye. “Pink eye is treatable (and often transmissible to other cattle in the summer). Cancer eye in early stages can be treated, or you can put that animal on the cull list. If you see an animal with a weepy eye, take a close look. If it’s not cancer eye or pink eye, lift the eyelid to make sure there’s not a seed head, barley awn or some other foreign object stuck there and scratching the eyeball every time the animal blinks. If there’s something there, just lift it out.”

Calves tend to go downhill quicker than adults if they get sick, because they don’t have the body reserves. “If an animal is ill, your best diagnostic tool is a thermometer — just a simple one you can get at the drugstore. Mark it with a Sharpie pen so you don’t get it confused with one in the house. The new ones are nicer than the old rectal thermometers that you had to tie a string on; the new digital ones widen out and you won’t lose them in the cow’s rectum,” says Clark.

“Taking temperature is easy and can tell you a great deal. Body temperature for cattle should be between 38 and 39.5 C. If a young calf is cold, with subnormal temperature, that’s life threatening. If the temperature is above 39.5 C it’s running a fever. The most common reason for fever is infection. It could be viral or bacterial, but if the calf is running a fever, treating with antibiotics is a good idea. If the calf does not have a fever, there is a question whether antibiotics will help. So the first step is to take that calf’s temperature,” he says.

If you call your veterinarian for advice, report the animal’s temperature. “This gives the veterinarian a lot of information. When we know the temperature along with your description of symptoms, this helps us narrow it down,” says Clark.

“With young calves that aren’t doing right, check the navel. This is a common site of infection. Learn to tell the difference between a navel infection and a hernia. When you squeeze them, hernias generally disappear; the protrusion moves up into the belly. It’s normally soft, rather than hard and hot. The amount of skin at the navel is variable with the breed. What you are interested in, rather than how large the area, is the stalk that you can feel under the skin. It should be thinner than your pinkie finger, and should not be hot or painful. If it’s thick, hot, or painful when pressed, or has a discharge from, it’s probably infected,” he says.

“If it’s a small hernia, the only thing in it is a bit of fatty tissue (omentum). If it’s a large opening, a loop of intestine may come through and become twisted — and that’s life threatening.” A large hernia needs surgical repair.

Pneumonia in calves occurs most often in winter/spring rather than summer. “If the calf is sick in summer it’s usually something else. The thing about pneumonia is that it always gives the calf a fever,” he explains. A thermometer will be a big help.

Scours in calves is caused by multiple things, so knowing the age of the calf and the management can help a veterinarian determine the most likely cause. “If the calf is more than three weeks old, you may be dealing with coccidiosis, whereas under three weeks it is more likely caused by a virus or bacteria. The thing to realize about scours in young calves is that it’s not the scours that kills them. It’s the dehydration. When you look at a calf that’s got scours, it doesn’t matter how shitty its tail is, or what the scours looks like. What we need to check for is dehydration,” says Clark.

“Look at the eyes. When a calf suffers from dehydration it looks like the eye sinks back into the socket. If there is a gap between the eyelid and the eye (a sunken appearance), that’s a bad sign. The second way you can check is take a pinch of skin on the side of the neck, and let it go. It should spring back into place instantly. If it takes a few seconds to spring back, you are dealing with dehydration,” he explains.

“Those calves need fluid/electrolytes, given by stomach tube; don’t try to feed the calf a bottle. That would take you an hour and you’ll end up wearing most of it because the calf won’t want to suck it — and you’ll complain about the effort and never do it again. With a stomach tube you can give a calf two litres of electrolytes in less than a minute. If something is easy, you’ll do it again,” says Clark.

“Another thing I tell people regarding field diagnosis, if they wonder when to stop treating a calf — it’s when you can no longer catch him. If you can’t catch him, don’t treat him. If he’s easy to catch, he needs treatment. I also recommend talking to a veterinarian if you have repeated episodes of the same problem,” he says.

“When you ask your vet for advice, describe what you are seeing. Don’t say, ‘I’ve got calves with pneumonia.’ Tell the vet that you have calves that are depressed and not sucking, and are doing this, this and this (and what the temperature is). Work with your veterinarian to get the diagnosis. If you say your cow has foot rot, this is a diagnosis rather than a description of the lameness, and won’t enable your vet to help figure it out,” he says.

“We want producers to recognize the value of a diagnosis, and get involved in helping their veterinarian make the diagnosis.” The producer and the veterinarian can work together as a team. Producers need to describe, to their best ability, what they are seeing, so the veterinarian can have good clues to work toward the proper diagnosis.

“A phrase one of my colleagues used a lot regarding diagnosis: more mistakes are made from not looking, than not knowing. You make more mistakes if you don’t look close enough at what the animal is actually doing or how it appears. The clues are often there, if you look for them,” says Clark. c

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