Occasionally cattle get sick on pasture and we have to treat them. They may have pinkeye, foot rot, pneumonia or some other ailment that requires individual treatment. Since the cattle are out on grass, and handling facilities are usually not close by, there are only a few options for treatment. If the disease is a herd problem, sometimes we can medicate the water or mineral supplement.
However, the conditions that are usually being treated on summer pasture are problems in individual sick animals that must be treated by injection in the muscle or under the skin. This requires either moving the sick animal to a handling facility and treating in the chute or roping the animal and treating it.
One other option exists, and that is the use of treatment prods or dart guns, including crossbows. Various products are on the market, and they include syringes and needles on the end of a long stick that is thrown javelin style, usually with the treater sitting on a horse, in a tripod or on foot. There are guns or crossbows that also can be used to project a syringe and needle with medication to the sick animal. All of these projectile apparatuses use force and pressure in order to administer the medication to the sick animal from a distance so that the animal does not have to be caught and handled by hand. But how safe are these products, both in terms of food safety and meat quality?
When using these devices, the drug must be administered in a large enough volume so that the animal receives the entire dose of the drug with one shot. Usually there is only one chance to treat these animals, and once they have been hit with a syringe using a dart gun or stick, they are usually hard to find again in the bush. Depending on the animal health product that is used and the type of syringe with the projectile apparatuses, the volume can very from a few cc up to 50 cc per injection site. If we read the label directions of most animal health products, they recommend no more than 10 cc per injection site. When using a product that requires more than 10 cc total for the therapeutic dose, and a dart gun is used to administer the drug, the producer will have used the product off-label, which requires a veterinarian’s written prescription and a valid veterinary-client-patient relationship. The impact of using more than 10 cc per site with an animal health product includes problems in absorption with the drug at the site, which may reduce its effectiveness in treating the condition. As well, research has shown that using 35 cc in a single injection site will cause massive injection site lesions. And if the animal is sent to slaughter based on the label’s withdrawal period, in many cases that time is insufficient to prevent drug residues at the injection site. Thus, it becomes a food safety hazard.
These problems have been shown to occur with long-acting oxytetracycline and tilmicosin (Micotil) administered by dart gun. Some projectile apparatuses supposedly can administer products under the skin (SC), using a needle that has holes on the side, rather than on the end. However, tissue damage and drug residues were a problem when Micotil was used SC with a dart gun and animals were sent to slaughter at the label-recommended date of 28 days after the last treatment. The pharmaceutical company that produces Micotil does not support the use of their antimicrobial with dart guns, sticks or crossbows. Therefore, while dart guns, crossbows and sticks may be an easy and safe way for the handler to treat cattle on range, they are not safe for the consumer who purchases the meat because of the potential of drug residues at the injection site. As well, the scarring produced when using these projectile apparatus creates a serious meat quality problem, which will not resolve with time. If an animal is injected in the back thigh, top butt or even neck with such a projectile apparatus, the meat will be damaged and will not be suitable for consumption as a tender roast or steak.
These factors should be born in mind when deciding how to treat cattle on pasture this summer. Please take the time and have sufficient manpower and handling facilities to do the job right.