Maybe it's the name that amplifies the dread horsepeople tend to feel when the grapevine rumors a neighborhood infection.
Certainly, no one who's had to nurse a horse through to recovery wants a repeat experience, and anyone who's read John Steinbeck's The Red Pony about a young boy's first exposure to death and loss can't help but expect the worst of the disease. Yes, strangles has a terrible name and a worse reputation. Horses who come down with a Streptococcus equi infection get an ugly kind of sick, and they seem to be knocked out of training forever.
"People have definitely gotten more panicked about strangles over the years," says George Sengstack, manager of Callithea Farm, a 60-horse boarding stable in Potomac, Maryland. "Fourteen years ago, before we had horses trailering in and out, I had a horse who got strangles. We kept him away from the other horses in a round pen and were really careful [about using separate equipment]. He got better, and it wasn't a big ordeal."
Sengstack's experience with strangles is more the norm than Steinbeck's fatal scenario, but the highly contagious disease can be a real blight on a stable of susceptible horses. Also called equine distemper, the infection typically begins 10 to 12 days after exposure to S. equi.
First the horse experiences a high fever, depression, appetite loss and enlargement of the lymph nodes between the jawbones. Copious amounts of thick, yellow pus begin draining from the nostrils, and before three weeks are up, the abscessed nodes at the throat may burst open to drain. The disease's descriptive name comes from the "strangling" noise produced as severely affected horses struggle to draw breaths into their obstructed airways. Aside from observing the obvious physical signs in diagnosis, veterinarians can run cultures of the nasal drainage to see if it contains the streptococcal organism.
Exposure often occurs when a new horse, who's shedding the S. equi bacterium without visible signs of sickness, is introduced into a herd. The organisms spread from horse to horse through direct contact, such as touching muzzles, environmental contamination and shared equipment, such as feed buckets and bridles. Strangles spreads rapidly, producing large outbreaks in herds not previously exposed or vaccinated. The infection is especially aggressive in populations of foals and young horses. Most horses recover, but fatalities do occur, primarily from secondary pneumonia that takes hold in debilitated or immune-compromised animals. And every now and again, S. equi infect lymph nodes deeper within the body, producing a more dangerous condition called bastard strangles.
Isolation is the single most effective means of controlling the spread of the disease. Infected horses usually show signs within two weeks of exposure, so preventing contact between potential carriers and a healthy herd for at least that long should reduce contagion. Three- to four-week quarantine periods for newcomers or exposed horses are usually enough to slow or stop the spread of the disease.
In textbook terms, then, strangles isn't really a big deal. It hardly ever kills or causes lasting damage to horses, and it's easily controlled by physical separation, the most basic of medical precautions. Yet the fact that strangles isn't effectively prevented or treated by the same means applied to other common equine diseases gives it a rather sinister cast. It must be some sort of super infection, right, if treatment is iffy and vaccines aren't reliable? Well, not exactly. The myths and misconceptions surrounding strangles tend to overplay the current gaps in scientific knowledge about the disease. Given recent genetic advances in characterizing the strangles organism, truly effective prevention is no longer a pipe dream.
Myth #1: S. equi is Invincible
Not true, says longtime strangles researcher John Timoney, PhD, FRCVS, University of Kentucky Keeneland Professor of Infectious Diseases. "That the organism survives and that pastures and farms that have strangles are at risk of recurrences are myths," he says. "It survives for days or for weeks if frozen. It's a very poor survivor in the environment. It competes poorly with other bacteria and lives for hours or days, not weeks or months." Thus, a farm that has gone through a strangles outbreak is not forever sullied. Months later, when all infected horses have recovered and nasal swabs are negative for S. equi, the soil and surroundings are no longer contaminated from that original outbreak.
If strangles does visit your farm, you still want to exercise vigilance about decontamination practices and isolating sick animals because the bacterium is readily carried from horse to horse. Tom Kranz, owner of Longacres Farm in East Aurora, N.Y., took extreme care to contain the disease when a 21-year-old camp pony named Brownie returned from his winter hiatus in Ohio carrying a brewing infection. Brownie was stabled in the isolation barn and cared for by a single staff member, who removed her shoes and donned designated rubber boots before entering the stable. Avoiding all direct contact with Brownie, she fed him, then removed the boots as she exited the stable and put on her shoes. The precaution reduced the likelihood of her tracking the bacteria to other areas of the farm. Finally, Brownie's caretaker disinfected herself, showered and changed clothes before going back to work at the main barn.