Horse owners cringe to hear of confirmed cases of equine strangles at boarding barns or show facilities within their own areas. Although often not life-threatening, strangles is one of the most contagious diseases affecting horses. And because equine strangles is not considered an infection meriting mandatory reporting (like EHV-1, equine herpes virus) in certain states, actual cases may be difficult to track.
What is strangles?
Caused by a bacterial infection known as streptococcus equi, strangles attacks the equine lymph nodes, particularly in the upper respiratory tract. The disease was named for its strangling effect on an affected horse, when the enlarged lymph nodes obstruct the animal’s airway, restricting his ability to breathe normally.
Common symptoms of strangles include abscesses (often bursting and oozing pus), appetite suppression or loss, depression, difficulty swallowing, enlarged lymph nodes (especially along the jawbone and throat), fever, laryngitis, lethargy, listlessness, nasal discharge (usually yellow or green and lasting for several weeks), and overall discomfort. A horse with strangles may extend his neck and hold his head lower than usual, perhaps easing the discomfort of his swollen lymph nodes.
Equine strangles is generally diagnosed by a veterinarian after doing a nose, throat, or abscess swab culture. Some vets will then prescribe poultices and frequent disinfecting of any erupting abscesses as treatments. Experts debate the value of antibiotics for strangles.
If the infection spreads to the horse’s brain, lungs, abdominal organs, or other vital parts beyond the upper respiratory system, it is called bastard strangles. In the worst cases, equine strangles may lead to serious illnesses, prolonged immunodeficiency issues, or even death.
Equine strangles seems to affect young horses the most, such as those under five years of age. Nursing foals seem to contact it less frequently. Veterinary experts believe older horses may have gained immunity through vaccinations or prior infections. Horses that have recovered from strangles frequently demonstrate immunity for five years or more.
Infected horses may contaminate others who come into contact with shed bacteria, often through respiratory secretions or abscess drainage. Nose-to-nose contact may be the most common culprit, although other means of transmission are frequently to blame. Horses may remain contagious six weeks or more (in some cases, years) after recovering from strangles.
The incubation period for equine strangles is approximately three to 14 days after exposure.
How can the risk of strangles infections be minimized?
- Quarantine the barn, if a horse has strangles. Within the barn, keep affected horses isolated from healthy ones.
- Avoid contact with outside horses (and minimize barn visitors) during a strangles outbreak in the area. Plenty of stables cancel clinics and special events at such times as a safeguard.
- Routinely separate incoming horses or those returning from show facilities, particularly during an outbreak of strangles. The barn management may require veterinary health certificates on all new or visiting horses.
- Make sure horses have their own tack, grooming supplies, and other equipment, as shared gear may transmit the infection. Do not share feed or water buckets, troughs, or waterers when any horse in the barn has (or has recently had) strangles. Instruct barn staff to fill water buckets without dipping hoses into each one, as this may spread the germs as well.
- Avoid stabling or pasturing infected horses near healthy ones. Horses may chew or lick or sneeze on windows, stall bars, field fencing, or other shared surfaces — or on one another.
- Wash hands often when handling affected horses, supplies, or barn equipment. Dispose of all contaminated first aid supplies promptly in covered trash containers.
- Restrict handling of affected horses. The fewer people handling the horses during a strangles outbreak, the better.
- Clean and disinfect stalls of sick horses often. This includes wiping down walls, bars, and other surfaces and replacing bedding frequently to remove any nasal or abscess discharge completely.
- Apply fly protection liberally and often. Flies can spread equine strangles by carrying secretions from one horse to another.
- Vaccinate horses against equine strangles. Horse veterinarians routinely recommend this. Although the strangles vaccine does not guarantee immunity, horses receiving it tend to enjoy some protection from infection and perhaps lesser cases, if they do contract strangles. To protect a barn’s equine population optimally from the infection, all horses receive the same prevention.
Can humans contract strangles?
Health experts disagree on this, but some contend that people can actually be affected. This does not occur often, but it seems possible. The best protections include covering faces and hands when caring for affected horses and practicing proper hygiene (such as thorough hand washing and wardrobe changes) afterwards to minimize the spread of equine strangles.