Why do some ranches have to deal with strangles year after year? Some people would say that it is due to bad luck, bad management or too many horses. The real issue is understanding how strangles is maintained in a group of horses and how it can show up on a ranch for many years. Some people are unaware of how many different ways strangles can be transmitted. Many ranches have successfully cleared up this financially crippling headache.
Strangles is caused by the bacteria Streptococcus equi. Strangles can be spread by both direct and indirect transmission. Direct transmission is a result of nose or mouth contact. Indirect transmission is a result of contaminated drinking buckets, feed, stalls, bits, halters, people and many other objects. This may actually be the most common way it is spread. Due to its ubiquity, strangles can be spread through one’s entire barn or a horse show quickly. The first step to fighting the disease is being able to recognize the symptoms. The first clinical signs may be not eating well, fever or change in attitude. Other signs to watch for include nasal discharge, coughing, swelling/abscesses underneath the jaw or difficulty breathing. Not all horses will show the classic abscesses under the jaw. Upon seeing these signs, it is best to isolate the affected animals and contact your veterinarian for further diagnostics and treatments.
There are a couple of ways a farm can have a problem with strangles year after year. They bring sick horses onto their farm without proper isolation or they have horses that are shedding the bacteria without being sick. The horses that are showing no clinical signs of strangles but shedding strangles are usually the cause of repetitive outbreaks. These horses are harboring the bacteria in their guttural pouch (the horse’s inner ear) due to not clearing the infection completely. At ESMS, we are seeing more and more horses with this problem. These horses look, act and work normal but are the reason for the continued outbreak in young horses.
The way to resolve this problem is by screening all horses on the farm by either upper airway cultures or by scoping the upper airway and guttural pouches looking for purulent material (pus) in the guttural pouches. This will allow you to identify the horses that are shedding the bacteria and begin to resolve the problem. This is only the first step at fixing the problem but it gives you the necessary starting point. Other steps that will need to be taken are as follows: isolating affected animals, disinfecting everything that came in contact with that horse (especially water sources) and paying close attention to horses that were around infected horses.
This article only touches the surface of what to consider when strangles emerges but, hopefully it provides a little information on how you can help prevent the spread of strangles on your farm. by Dr. Skeet Gibson
