During this time of pandemic scares, did you know horses, donkeys, and mules have been fighting their own pandemic since the middle ages? Strangles is a highly contagious respiratory disease that spreads quickly and can cause all the horses in a stable to be put in quarantine. Do not confuse Strangles with strongyles, which is a worm horses can get. Read on to learn what every horse person needs to know about Strangles.
What is Strangles?
Strangles is a respiratory disease caused by the bacterium streptococcus equi. This bacteria settles in the lymph nodes of the head and neck of the horse. The lymph nodes then develop swollen and painful abscesses. In the advanced stages of strangles, the swollen lymph nodes put pressure on the horse’s respiratory system. This makes breathing hard, hence the name Strangles. The term “bastard strangles” refers to metastatic Strangles, which affects other lymph nodes of the body, particularly the lymph nodes in the abdomen and, less frequently, the thorax.
Eventually, the abscesses will burst and secrete thick, yellow-green pus from under the jaw and out the nostrils. The death rate is low, at 2%. However, strangles is very painful and can require weeks of recovery time.
How Does a Horse Get Strangles?
Strangles is very contagious. The most common transmission is direct contact with a horse that is either currently fighting, just healed up, or is a carrier of the disease. Some (but not all) horses will become carriers of the disease after being inflicted by it. A horse does not have to show symptoms to be contagious.
The bacteria that causes strangles does not have to live on a host to survive. This persistent organism can survive on equipment, people, and in the environment anywhere from 96 hours to 4 weeks.
It takes an average of three weeks for a horse to recover, but they can remain contagious for up to six weeks.
How to Take Care of a Horse with Strangles
If a horse is infected, that horse needs to be isolated and cared for by one person. This person needs to change clothes and shower before having contact with any other horses. You will need to disinfect all equipment like brushes, buckets, even pitchforks (used to clean stalls) before using the equipment for another horse. Consult your veterinarian to develop a treatment and control program.
Equine professionals who travel from farm to farm, such as veterinarians or farriers who visit a farm with an infected horse or under quarantine, need to shower and change clothes before traveling to the next farm. Also, they need to disinfect their equipment.
Vaccines for Strangles
The vaccines available have limited effective rates and adverse reactions. There are two types of vaccines: internasal and intermuscular. The internasal vaccine is slightly more effective. The vaccine builds up the immunity in the respiratory tract, which can be advantageous since this is typically where the bacteria challenge a horse. The intramuscular vaccines are generally less effective.
Horses that travel to events are more likely to be exposed and will benefit from a vaccine. Consult with your veterinarian about the need for vaccinating your horses for Strangles.
What are the Signs of Strangles in Horses?
The first symptoms of Strangles can occur anywhere from 3-14 days after exposure. First, the horse will develop a fever (103 -106 degrees). One to two days later, the horse will develop a nasal discharge (starts clear then turns thick and yellow), depression, possible difficulty swallowing, and difficulty breathing. The horse may or may not begin to cough. If the horse has trouble breathing, they may stand with their head and nose stretched out in an effort to breathe better.
Treatment for Strangles
The diagnosis of Strangles starts with nasal swabs and swabs of any ruptured abscesses. According to Merck Veterinarian Manual, Complicated cases may require endoscopic examination of the upper respiratory tract (including the guttural pouches), an ultrasonographic examination of the retropharyngeal area, or radiographic examination of the skull to identify the location and extent of retropharyngeal abscesses.
If caught early enough, your vet may be able to stop the development of abscesses with antibiotics. However, the use of antibiotics is under debate and still being studied. The concern is that antibiotics will delay the abscesses from forming and, therefore, unable to drain.
The vet will apply warm compresses to the affected lymph nodes, causing the abscess to swell so it can be lanced and drained. The vet will then flush out the abscess with disinfectant. The spot will need to be flushed out a few times a day for several days. The vet will prescribe pain killers. A tracheotomy may be necessary is the swelling is causing the horse not to be able to breathe.
Since the middle ages, there has been documentation of Strangles in horses. It can affect horses of all ages and is found worldwide. If you are concerned, your horse has been exposed to Strangles, start taking their temperature twice a day for up to two weeks. The earlier the horse can be treated and isolated from the rest of the herd, the better. Scientists are working to develop better vaccines because the current vaccines seem to have limited effectiveness.