Farm Animals and Pandemics
Updated: Oct 15, 2021
The following is a chapter from Dr J's forthcoming book, hoping to be released sometime at the end of 2021 or early 2022.
Joanie has an active show horse barn in Richmond, Maine. She called me one day, excited about her new purchase. She had just bought a yearling filly online and sight unseen. That’s two uh-ohs. The seller is in Georgia. I told Joanie to be sure the youngster was vaccinated for the common equine respiratory diseases at least two weeks before trucking. Too late. She had already been loaded with 6 others coming from 3 different farms in the Deep South. The truck was on its way to New England. I said, “Joanie, even if she gets off the truck looking healthy, be sure to isolate her from the herd for 2 weeks.”
Joanie called when the filly arrived 3 days later. She said the horse was the picture of health so thought she’d be OK, and she turned her out with her herd. That was the third and biggest uh-oh. Her excitement was overriding her good sense. Love is a funny thing. 24 hours later the filly stopped eating, ran a fever, and a thick nasal discharge began. All of Joanie’s other horses were exposed. Over the next week most of her horses, also unvaccinated, got sick with what turned out to be Strangles. Strangles is an upper respiratory disease of horses that is extremely contagious and although only rarely fatal, it does make horses very sick. It can take weeks for complete healing, and then the animal can still be infective for months beyond. Sounds a little like Covid, doesn’t it? Strangles is a reportable disease, so I was obligated to tell the state veterinarian. The Maine Department of Agriculture put the barn under quarantine until the last sick horse had totally recovered. The barn was shut down for a total of 12 weeks. No horses in. No horses out. No visitors. Total cost to Joanie: several thousand dollars in vet bills and the loss of the year’s show season.
Influenza is another respiratory disease in horses that will spread through barns with unvaccinated animals. Vaccines are also recommended against the mosquito borne encephalitis diseases.
The Covid pandemic of 2020 has lessons to teach us about disease prevention and transmission. Veterinarians are well trained in both. My veterinary career started with dairy cattle. Traditionally cows are housed close to each other. That is true for sheep as well. This causes problems when a contagious disease hits a farm. Social distancing is impossible so health problems spread rapidly. When a bug hits a barn, visitors should be barred and vets who travel from farm to farm have to be extra vigilant to avoid taking it to the next place.
Typical uniform for farm vets is a set of coveralls over regular clothes and rubber boots that come up at least ½ way to the knees. We typically carry a stainless steel pail, a squirt bottle of disinfectant that is effective against bacteria and viruses, and a long handled scrub brush. You learn the dance of scrubbing your boots without taking them off: toes, sides and heels. The sole surfaces are cleaned by balancing on one foot while cleaning the bottom of the other. Any object that carries disease is called a fomite. That includes our clothing, hands, and even our vehicles. No one wants to be a fomite. A vet with a reputation of being casual in moving from farm to farm would be soon out of business. Farm vets typically carry extra sets of clothing and coveralls in their truck and may change a few times in a day. Whenever possible we try to make the call to an affected farm the last one of the day.
When horses are being trucked long distance, I try to persuade owners to have a vet at the farm of origin check them out before they leave and vaccinate them weeks before they depart. Face masks don’t work on animals, so we depend on social distancing. New arrivals should unload in an isolated paddock at least 25 feet from other horses. For a period of 2 weeks disposable gloves should be worn when those animals are fed and handled. Hand washing and boot disinfecting is critical for personnel before returning to the main barn. No visitors are permitted for two weeks, no matter how much an owner wants to show off the new acquisition. Here are are some principals that veterinarians have learned both in school and on the job:
Vaccines that have been properly tested and found effective are amazingly protective. For example, in the large animal world, rabies, tetanus and encephalitis vaccines are close to 100% effective. In people vaccines have virtually eliminated small pox and polio.
There are disinfectants that are 100% effective in sanitizing surfaces against viruses and bacteria. When applied routinely they also slow disease spread.
Almost everything we learned from the Covid pandemic including vaccines and social distancing can be applied to livestock.