Most veterinarians recommend that all calves receive a blackleg vaccine including other clostridials (usually in a 7 or 8-way vaccine) by 90 days of age. There is also data that shows calves can receive this type of vaccine at a younger age.
Dr. Chris Chase, Department of Veterinary and Biomedical Sciences, South Dakota State University, says the literature tells us that if there are maternal antibodies present these might not work, but field experience time and time again shows that those vaccines definitely have some efficacy.
“This is especially true for C. perfringens in young calves, or for blackleg,” he says.
“You can give these vaccines and not have to worry so much about problems with maternal antibody interference, because with Clostridia we are actually vaccinating against an exotoxin. This is a simpler antigen, and easier for the immune system to see and attack, compared with some of the viruses,” explains Chase.
If a producer has problems with enterotoxemia caused by C. perfringens, for instance, calves can be vaccinated at a very young age, even if the cows were vaccinated during pregnancy to stimulate high levels of maternal antibodies in colostrum.
Combo vaccines with Redwater, Tetanus
“In South Texas or the Gulf Coast states (and in much of the Rocky Mountain areas and a few other states), many ranchers need to include ‘redwater’ (C. hemolyticum) in the clostridial vaccine,” says Dr. Tom Hairgrove, Texas A&M University.
This can vary from ranch to ranch, depending on the risks, which include the presence of liver flukes that damage the liver and set up ideal conditions for infection with C. hemolyticum. These flukes are spread by certain snails.
Some people think they don’t have snails or liver flukes because they live in an arid region.
“I practiced awhile in dry West Texas and had a client who had a lot of problems with liver flukes. That ranch had irrigated pasture with all the right conditions for flukes. The problem is more prevalent, however, farther down along the Gulf Coast,” says Hairgrove. It pays to discuss these things with your own veterinarian, who will be familiar with the problems in your specific area.
The combination clostridial vaccines will have your bases covered, but you need to know what’s in those specific combinations. An 8-way vaccine may include tetanus or hemolyticum but not both.
“Use a clostridial vaccine appropriate for your husbandry practices and locality. In some areas, calves become infected with tetanus after routine castration and if you use banding for castration, vaccination for tetanus is essential. Also make sure you booster these vaccines properly,” Hairgrove says.
Most clostridial bacteria are always present in the environment, but certain things can set things up for increased risk and actual disease.
“Blackleg is usually seen in calves, but can occur at any age, in animals that don’t have adequate immunity,” he says.
Make sure you are giving proper dosage. Clostridial vaccines come in a 2 ml dose or a 5 ml dose.
“If you use a 50 ml syringe and adjust it to give 2 ml doses, it won’t be as accurate for that small dose as a smaller size syringe will be. And if you get a little bit of air in that syringe and lose a half ml in that dose, you’ve lost 25 percent of that product. If it’s a 5 ml dose and lose a half ml, you’ve only lost 10 percent of that product. This might make a difference on whether or not it will work,” he says. — Heather Smith Thomas, WLJ correspondent
