Strangles in a highly contagious infectious disease and can be serious or occasionally
even fatal as a result of late diagnosis. Know what to look out for and you will almost
certainly avoid the unnecessary suffering of your horse and others. An outbreak of Strangles in the UAE was recently reported by 7Days.
What is strangles?
Strangles is a highly contagious infectious disease caused by a bacteria called Streptococcus equi. The bacteria affects the lymph nodes and is spread to other horses by direct contact, contaminated food, water, equipment or people’s hands/clothing. Horses can also catch the disease by inhalation of the bacteria, but this is less common. The organism can survive for long periods in the carrier horse or in the environment in the right conditions.
Younger horses (1-5 years old), sick horses, horses with compromised immune systems, herd horses, stud farms, racing stables, livery yards and riding school horses are more at risk because of the way the disease is spread. Poor condition, parasitic infestation, the introduction of a new horse to a yard, poor general management, stress factors, cold and damp weather can all lead to the contraction of strangles. Outbreaks of strangles are often associated with a non-related viral infection that further weakens horses and makes the development of strangles more likely.
Strangles is not usually fatal, but if left untreated the lymph nodes can abscessate. The abscesses usually burst and drain away, but in severe cases an abscess can become so large it causes the windpipe to become crushed resulting in suffocation of the horse. Occasionally the bacteria will overwhelm the local lymph nodes of the submandibular region and will spread systemically throughout the horse. Abscesses can then form in the lymph nodes of the lungs, intestines and even in the brain itself. Such an overwhelming infection is called “bastard strangles” and rupture of these abnormally placed abscesses can prove fatal.
How do I know if my horse has strangles?
If your horse has strangles, you will notice a change in his demeanor, he will become depressed and lose his appetite and he will find it difficult to swallow due to the inflamed lymph nodes. Some lymph nodes may abscessate and discharge pus in the throat area or under the jaw. Your horse will develop a sudden high temperature (often as high as 104°F) and nasal discharge, you will also notice pain and swelling in the throat area and occasionally coughing. In most cases however, symptoms do not appear until after 2-6 days from infection, although in individual animals this may increase to 14 days. In this picture you can clearly see this foal has swelling in the pharyngeal area, a sure sign of strangles.
What should I do if I think my horse has strangles?
If you think your horse has strangles it should be immediately isolated, away from other horses, only then should you call your veterinarian. Your veterinarian will perform a physical examination. Isolation of the bacteria from a clinical case by sampling any discharging pus or via throat swabs is the only way to definitively diagnose the case. Endoscopy of the guttural pouches is very useful in diagnosing the carrier case, including culturing flushings from the pouches. If the diagnosis is positive your veterinarina will discuss the options for treatment with you. In most cases, treatment of strangles usually starts with an intensive nursing regimen. Your horse will need to be rested and must remain in isolation, in a dry and warm environment. Feeding soft palatable feeds will help the horse eat, and fermenting abscesses with hot packs will encourage abscesses to burst and drain. In severe cases, abscesses may need to be drained surgically, to avoid suffocation, and then be flushed.
The use of antibiotics in the treatment of Strangles in controversial and should be discussed with your veterinarian. The recovery rate is good if detected at an early stage. Once treated, horses will show improved demeanor within 2-5 days and their appetite will return along with a reduced temperature. Most horses are no longer infectious 6-8 weeks after apparent recovery and disappearance of symptoms. Some individuals, however, can remain carriers of the disease organism for months to years. In these cases the bacteria is primarily found in the guttural puch and shedding of the bacteria from this source can cause continued infection of new in-contact, previously unaffected, animals.