Strangles is highly infectious meaning that it can easily be transmitted from one horse to another. The most common route is a shared water source, although nose to nose contact is another common way.
There are vaccinations for this disease; however, in my opinion, they are not very effective when compared to isolation and quarantine. Keeping a closed herd is essential. Placing every new horse (or visiting/showing horse) into a 2-week quarantine will effectively prevent the spread of this and other respiratory diseases.
There are carriers of Strangles where the bacteria resides inside a horse without showing disease. When a carrier becomes stressed, the bacteria are allowed to rapidly grow and create either disease in the horse, or while remaining asymptomatic, spread the disease to others via nose-to-nose or a common water source. Stressors include shipping, a change in the community, a severe storm, etc.
While there are no images here, the classic image is a nasal discharge from both nostrils and enlarged lymph nodes under the jaw with or without a noise coming from an altered airflow.
Another form of this disease is called “Bastard Strangles” where lymph nodes become enlarged anywhere on the body, for example on the shoulder, without any respiratory signs (nasal discharge). This is often a sequella of under-treating the primary case of strangles. In other words, an antibiotic is started but is stopped before all the bacteria are killed. For this reason, many practitioners do not treat Strangles with antibiotics; rather they let the illness run its’ course allowing the immune system to handle the bacteria.
One of the characteristics of Strep bacteria is their ability to cause abscess formation. An abscess is the body’s way to wall off the bacteria from the body and then, after some time, spit it out through a hole in the wall draining the pus away. While disgusting to most owners, this is a beautiful process that should not be stopped but encouraged with hot water compresses and skin softening salves such as icthamol.
Strangles can kill horses but usually due to impropper care with additional stresses. Good nursing care is essential. Contamination control is also essential with consious awareness of the ability of humans to transmit the bacteria to other horses. Use separate clothing, grooming and stall cleaning tools. Handle the horse minimally and last after all other horse contact is complete. Don’t allow other animals to enter the sick horse (dogs, goats or other pets) because they can spread the bacteria too.
- Keep new or traveling horses away from the home stock.
- Reduce all stress on the farm and the horses.
- Avoid common water sources with strange horses.
- Keep all ill horses and their equipment away from others.
- Contact your veterinarian, but the best approach is to let the disease run its’ course.
- If antibiotics are used, continue them for a long period after the signs of the disease are gone.
- Listen to your veterinarian for more specific advice.
Strangles is a voluntarilly reportable disease with farm quarentine required in most states in the USA.