For some, calving season has already started. Others find themselves on final approach to one of the busiest times of year: calving, preparation for breeding season and spring processing of calves and cows before going to pasture. This is an important time to plan herd health programs for the year, make final adjustments to nutrition programs prior to calving and take stock of what’s in the medicine fridge and instrument cabinet.
Keeping livestock healthy and ensuring proper care to individual sick animals is a commitment the industry takes very seriously. It requires the warranted use of vaccines to prevent infections and the judicious use of drugs to treat animals that are sick.
Consideration needs to be given to drugs and vaccines at each stage of production. When are they needed? How are they to be used and stored? How will new products fit in with existing vaccine and treatment protocols? Then there are expiry dates to think about, as well as how these products will be transported and protected in the field. Proper disposal of unused product is another issue of growing concern.
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Frugality often gets in the way of good antimicrobial stewardship (right drug for the right reason) and managing the vaccines kept on farms and ranches. There is the quandary about what should be done with partial bottles of high-priced antimicrobials and vaccines, or bottles with rubber tops that look like dart boards. Handling and managing modern vaccines is particularly important because the efficacy of these products is easily jeopardized.
Vaccines typically used in veterinary medicine include modified-live virus (MLV) vaccines, killed vaccines containing adjuvants to stimulate immunity and recombinant products. The stability and susceptibility of individual vaccines to fluctuations in storage conditions varies considerably.
Killed vaccines, for instance, are generally more robust, while MLV vaccines can be very fragile. MLV vaccines need to be maintained at a fairly uniform cold temperature during transport, storage, and administration. Adjuvanted vaccines are sensitive to freezing temperatures because the adjuvant may separate from other components to form an irritating precipitate. Exposure to direct sunlight can also render vaccines ineffective.
Based on studies, three-quarters of the fridges used to store biologics on farms and ranches do not maintain temperatures at the minimum range of 35 F (2C) and 45 F (7 C). It’s not unusual for the refrigerator entrusted with the storage of thousands of dollars of animal health products to be an old model relegated to the job when a new kitchen fridge is purchased. As a result few veterinary vaccines are held at a stable and ideal temperature of 35 F (2 C).
Freezing can be an even bigger concern. Vaccines consistently stored at an incorrect temperature are often ineffective and should be discarded whether they are outdated or not.
Inexpensive digital thermometers that record high and low temperatures are readily available. Placing a thermometer in the vaccine refrigerator is cheap insurance and a way to monitor storage temperatures. In the view of many veterinarians, finding the right refrigerator for vaccine storage removes one potentially disastrous complication to a farm’s herd health program. Taking a critical look at your vaccine storage should be an annual chore.
A few other important pointers:
- Discard containers if rubber seals appear to be compromised, or labels can’t be read or are outdated.
- Avoid soaps and disinfectants when cleaning syringes. Boiling water and sunlight are the most effective options.
- Virtually all vaccines used in large-animal veterinary medicine should be stored out of sunlight and maintained at between 35 F (2 C) and 45 F (7 C).
- Vaccines should be stored in a designated refrigerator. Storing jugs of water in the refrigerator can help prevent temperature fluctuations.
- Vaccines should be kept in original packaging, and the boxes rotated so newer product with the latest expiration date are used last.
- Food and beverages should not be stored in the vaccine refrigerator.
- Maintain the cold chain during transport. Vaccines should be kept in an insulated cooler. Frozen ice packs or refrigerated packs should be used as needed to maintain the correct temperature range. Monitor the temperature in the cooler and note it immediately before and after transport. A layer of insulation should be tucked between the vaccine boxes and ice packs to prevent freezing. And the cooler should be kept in the passenger cab of the vehicle.
- For lyophilized vaccines (vaccines with a freeze-dried puck), only use the diluent provided with the vaccine. Generally, diluents do not need to be refrigerated, but it is usually more convenient to keep them in the refrigerator with their corresponding vaccine.
- Use a new, sterile syringe and needle or transfer needle to mix vaccines. Do not reconstitute vaccines until they are needed.
- Mark vaccine syringes to prevent “mistaken identity” because many vaccines look similar in the syringe. It’s critical that you avoid using the same syringe to administer MLV and killed vaccines, as the adjuvant in killed vaccines can reduce or eliminate the efficacy of many MLV vaccines.
- Beef Quality Assurance (BQA) recommends using disposable equipment such as single-use needles where possible. Reusable syringes should be heat-sterilized by boiling prior to use.
- Consult your veterinarian about proper sanitation techniques before sterilizing equipment. Improper sterilization can reduce the effectiveness of future injections and result in infection at the injection site. Dr. Dee Griffin, Great Plains Veterinary Center, Clay Center, Nebraska, has a great instructional video on how to clean and sterilize reusable syringes. (Goggle: BQA Tip: How to Clean Syringes | WI Beef Information Center).
- Research has proven microwaves are an effective way to sterilize needles and plastic syringes. Metal vaccine transfer needles can be heat sterilized in the microwave if they are fully submerged in water or well wrapped in wet paper towels.
- Veterinarians deal with the issues of syringe maintenance, equipment and product choices every day. Seek their advice.
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 [email protected] or WCABP [email protected].