Successfully vaccinating livestock can be tricky. Not vaccinating cattle can be a costly error, over-vaccinating can be worse than failing to vaccinate and poor technique can be as costly as either.
According to Susan Schoenian, a University of Maryland extension sheep and goat specialist, choosing not to vaccinate livestock inevitably leads vets to ask producers, “What is your tolerance for risk?”
Vaccinations are proven effective to prevent disease in bovines and ovines. Vaccinate to be safe – otherwise hold the slim hope the farm’s biosecurity is sufficient enough to prevent disease from reaching livestock.
On the other hand, too many farmers are “injection-happy.” For proof, visit a local slaughter plant to see how many carcasses are condemned for injection abscesses.
Talk to animal health professionals about vaccinations and the question is not whether injections cause abscesses in the animal’s tissue but where they will occur.
That is why the dairy industry created its quality assurance program – a program so old, no one bothers to capitalize its name anymore. Dairy farmers were injecting cattle too much and in the wrong places, causing U.S. slaughter plants to call for the nation’s dairy co-ops to provide producer education on drug injection.
Based on the gains the dairy program achieved, other livestock organizations followed suit with their own programs.
The two major kinds of injectible drugs farmers can administer to livestock are vaccines and antitoxins. According to Schoenian, vaccines are drugs used to either create or improve disease immunity.
“Antitoxins are used to treat existing infections on farms,” she said.
There are four types of injections: intramuscular, subcutaneous, intravenous and intranasal.
“Intramuscular injections – injections placing the drug directly into muscle tissue – involve the use of longer needles,” noted Schoenian.
Michael Baker, a Cornell University extension beef specialist, said the advantage of intramuscular injections is they provide a faster response to drugs.
“But injection site reactions can be severe or mild, even with saline,” he advised. “There will also be a 3-inch circumference of meat around the injection site that will be tougher than the rest.”
Schoenian and Baker agree farmers should always ask their veterinarians if they can inject whatever drugs they are using subcutaneously to minimize the carcass damage. “I’ve seen small abscesses when the hide comes off, but they can either be cut out or come out with the hide,” Baker said.
Subcutaneous injections are placed directly under the skin. Both specialists agree a tenting technique is best: place loose skin between your fingers and pull it back to form a tent of skin into which the drug can be injected. Then pull the needle back and out.
Experts can do subcutaneous injections parallel to the skin. Those who are less experienced frequently scrape the tissue directly underneath the injection when they administer sideways and not downward.
Shot placement is a key consideration. Baker reminds cattlemen to place all injections in the cattle’s necks, in front of their shoulders.
Sheep and goat farmers have a few more choices.
“I prefer armpits,” Schoenian said. “But sheep can also be given shots in their flanks, and goats under their tails and in their ears.”
Nearly all the drugs administered to sheep and goats are subcutaneous. But cattle have an IV-only (intravenous) drug, fluxinin meglumine, used to control fever in cattle with Bovine Respiratory Disease (BRD), endotoxemia and mastitis. Fluxinin meglumine must be administered to cattle as an IV and not intramuscularly.
“First of all, withdrawal times for the drug are calculated, based on the injection method. Therefore, the labeled withdrawal time would is incorrect if cattle are not given the drug intravenously,” Baker said. “That’s not much of a problem for dairymen, who have a good bit of experience with IV injections. Cattlemen, on the other hand, can find it difficult.”
Secondly, IM injections cause “a wicked muscle reaction that meat inspectors at slaughter houses are trained to pick up,” he says.
Intranasal injections are gaining popularity.
“They put it straight into the mucosal membrane and they deliver quick absorption and a quick immune response, generally within 12 to 24 hours,” Baker noted.
These injections are especially useful for cattle facing transport. This kind of injectible is given to boost their immunity to stress-related illness in the immediate term, until they can be vaccinated in 10-14 days.
Some people get concerned when they squirt the vaccine into the nose and some dribbles out, but Baker says the drug reps he talks to assure him cattle don’t need very much for it to be effective.
“It’s a 2-cubic centimeter dose, with one in each nostril. The first one’s not so bad, but they see you coming with the second one,” Baker said.
Baker recommended that a 1-inch, 18-gauge needle is the best for cattle. “One inch is plenty long enough and an 18-gauge won’t bend. Some use 20-gauge for calves, but if they break off, it’s a big problem. They can be hard to find and they migrate.”
Schoenian prefers a half-inch, 20-gauge needle for older sheep and goats and three-quarter-inch or five-eighths-inch needles for younger stock. (See figure 1 below)
“They may be hard to find because most livestock pharmaceutical tools are geared for cattle. Longer needles are good for going deeper, wider needles are useful when the solutions are thicker,” she explained. “It becomes a question of availability. Use the smallest needle you can get by with.”
Live vs. killed vaccines
Killed vaccines require cattle to receive booster shots within two to six weeks of the first shot.
“If you don’t, you won’t get a successful level of immunity,” Baker said. “I am still seeing farmers sending unvaccinated cattle to sales or using killed vaccines the day before.”
Calves should be vaccinated with killed vaccine before weaning to get them primed for the stress. Good protocol requires vaccinations two to three weeks prior to weaning, followed by a second round six to eight weeks prior to sale and transport.
More frequently, the fed cattle business seems to prefer calves be vaccinated with modified-live vaccines. These vaccines contain partially killed, live viruses designed to give the disease to livestock but not at its full force.
“In ‘cowboy terms,’ that means they will get the sweats,” Baker noted.
Killed vaccines can be stored for up to four weeks in a refrigerator. Modified live virus vaccines need to be used within an hour of being mixed.
Farms that vaccinate cows when they are pregnant must be very careful with the four-way, IBR, BVD, PI3, BRVD shot to prevent risk of abortion.
As far as live vaccines go, Baker said if there are any for cattle, they are not commonly used.
Cornell University animal scientists performed an immunity study using pregnant ewes and Clostridial Type D, published in 1997. In it, they compared the immune response of lambs vaccinated at birth versus lambs whose mothers were vaccinated and they were not.
They concluded there were absolutely no benefits to vaccinating lambs prior to six weeks of age. Instead, ewes should be vaccinated three to four weeks before birth so they can provide passive immunity to diseases via their colostrum.
Baker stated these results are valid for cattle, too. “Research also shows cows with 5 to 6 body condition scores produce far better colostrum than cows with 3 to 4 body condition scores.”
That means paying attention to nutrition for the mothers is at least as important as administering shots. “By and large, we tend to be more deficient in energy than protein in the Northeast,” Baker said.
Mature cows need 8 percent protein before calving and 10 percent after. Most Northeastern farmers have no trouble getting hay with 10 percent protein.
When the temperatures dip from the low 20s to zero, cows need 10 percent more energy, which they get by eating more or being fed supplements.
Veterinarians will recommend calving vaccinations when farms report scouring and early respiratory problems. Schoenian says some veterinarians don’t think vaccines are as effective with goats and recommend does be vaccinated once every six months.
Schoenian recommends using passive immunity with sheep. She suggests vaccinating the mom four weeks before lambing. If she has never been vaccinated before, or you’re unsure if she has, vaccinate four weeks before and give them a booster two weeks ahead of lambing. She also recommends using a head-gate to hold animals steady while they are being injected.
Though there are vaccines available for a number of sheep and goat diseases, the one most pros like to recommend is a clostridia vaccine. One is a three-way CD-T vaccine – for clostridium perfringins Type C and D and tetanus. The other is an eight-way vaccination, offering the same protection and more. The three-way vaccine is fine for most sheep and goat farms.
Prior to breeding ewes, vaccinate for vibriosis, campylobacter, chlamydia and toxoplasmosis. Pregnant ewes should be vaccinated during their last month of pregnancy, but two weeks before lambing. This sets up the passive immunity they will provide their offspring in the first weeks of their lives.
Schoenian suggests vaccinating lambs at six to eight weeks of age and follow with a booster three to four weeks later.
Sharps, the industry term for used needles, must be disposed in a medical disposal site. Baker noted they can be collected in a liquid detergent bottle. Once the bottle is full, your veterinarians may be willing to take care of them. Some might do it for free while others will charge what they are charged for disposal. Local hospitals might also be persuaded to help.
Withdrawal times refer to the number of days between the last time animals were injected with drugs and the day they are shipped to slaughter.
“All vaccines have withdrawal times,” Baker said. “They are at least 21 days and some as long as 60 days. Some antibiotics are longer and some are shorter.”
Farmers must read drug labels to notice differing withdrawal times for different species or dosages.
Some drugs work on one species and not others. For example, Schoenian says pneumonia and clostridial virus vaccines used for cattle are not effective for use with goats or sheep.
Extra-label drug use means using drugs for species, injections or dosages not covered on the label. To be legal, farmers must have a client relationship with a veterinarian who knows what extra label uses they are using.
Some clinics require a certain number of visits to the far each year as a condition for prescribing drugs in this fashion.
“Vets must take responsibility for what you [the farmer] do on the farm,” Baker said.” They must be confident you are doing the right thing because they, too, will be liable for the drugs you administer.”
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