Strangles is an infectious disease that is often a threat to horse owners. Many horses are vaccinated for strangles; however, the disease has several strains that have adapted to its environment. This means that, although your horse has been vaccinated, there is still a chance that they could pick up the disease if you travel frequently. Outbreaks will often occur after you have been traveling with the horse, especially during inclement weather. Due to this fact many boarding barns and trainers have worked with veterinarians to develop vaccines that are specific to the strain of strangles that affect their horses. A horse infected with strangles will show specific symptoms that are commonly associated with strangles.
Strangles is caused by an infection with Streptococcus equi. Symptoms begin with an inflamed upper respiratory tract. The associated lymph nodes also become inflamed, especially those near the jaw. The lymph nodes will often abscess as well, making for a painful sight. The nodes may take 3 to 4 days to swell. These lymph nodes require veterinarian attention immediately as they will rupture after about 10 days. The discharge is a thick, creamy colored puss. The disease gets it’s name from the severe inflammation that will occur in the larynx and pharynx, which makes it difficult for the horse to swallow, often making them go off feed.
Other abscesses may also occur on other parts of the body and on internal organs. This condition is often referred to as bastard strangles. These horses will often go off feed and have a high temperature. They may also have a watery nasal discharge that becomes thick and cream colored. In both cases, the horse’s temperature may drop after 2 or 3 days, but rise again as the lymph nodes develop abscesses.
Strangles will usually only affect horses that are 1 to 5 years old. If you travel with your horse frequently, you will still want to have them vaccinated no matter how old they are. If you board your horse at a trainer, boarding barn or university, they may require that you regularly vaccinate your horse with their specific vaccination. This will protect your horse from the strain of strangles that is present in their area. The disease lives in the ground and will often infect horses during specific times of the year. Horses can also pass the disease on to each other easily as the nasal discharge will contaminate the pasture, water trough, feed bins, buckets, brushes, hay, etc. All of these items should be disinfected in the case of an outbreak. Penicillin is often a good remedy if the horses are treated before the abscesses form.
To prevent an outbreak, new horses to the barn or farm should be isolated for 4 weeks. Carriers may exist for 6 weeks after an outbreak. Carriers will often look and feel completely fine but will spread the disease through what looks like normal nasal discharge. Vaccines should be given to horses of 12 weeks of age or older. The vaccine is given two or three times at 8-week intervals. Annual boosters are also recommended. The vaccine does not prevent an outbreak, but will decrease its severity.
