What are Fistulous Withers?
A fistula is an atypical area that comes from an infection, and leads from the body of the horse to the outer part of the body. Fistulous withers occurs when the outer part of the withers of the horse is filled with a pus-like substance from infection.
The withers of the horse is the upper part of the back, which is also the highest point. It is located past the shoulders right at the neck area. Withers is also a term used to measure the height of the horse. A bursa is a sac within the horse’s synovial membrane that contains fluid. A bursa provides cushioning to protect the joints, and is located between the tendons and the bones.
In fistulous withers, the supraspinous bursa becomes swollen and inflamed. This can be caused by a variety of conditions, such as infections or trauma. It is known as an inflammatory disease which can become chronic. Although this condition may be quite painful, symptoms do not usually arise for a few years. Horse owners typically notice that their horse may have fistulous withers by marked swelling above the shoulders and also pain in the horse when it is touched.
Fistulous withers in horses occurs when the bursa, known as the supraspinous bursa, becomes inflamed. This bursa is located where the withers of the horse are located in the upper back area.
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Symptoms of Fistulous Withers in Horses
It is very important to pay attention to your horse’s coat and skin to be sure there is not an infected bursa in the shoulder area. Although symptoms do take time for the owner or veterinarian to notice, being aware of how your horse’s shoulder area feels may help you diagnose it early on. Symptoms include:
- Withers that are swollen
- Draining fistulas
- Fistulous that have a bump or cyst
Fistulous withers is known as other names as well. The veterinarian and articles relating to the condition may use the names interchangeably. Other types of names include:
- Saddle sore
- Wither inflammation
- Wither sinus inflammation
- Evil poll
Causes of Fistulous Withers in Horses
There are several different causes of this condition, one of them being a saddle that is quite tight upon the horse. Causes of fistulous withers include:
- Ill-fitting saddle
- Parasite infestation
- Trauma, such as contact with a sharp fence or other horse
- Bacterial infection
- Open wound
Diagnosis of Fistulous Withers in Horses
If you suspect your horse has fistulous withers, or if you notice any swelling on his back, make an appointment with your veterinarian. The veterinarian will assess your horse’s clinical signs and review his medical history. He will also ask questions about your horse’s symptoms and how long you have noticed your horse being in discomfort. You will also be asked about your horse’s environment and the type of saddle in use.
Your veterinarian will take cultures of fluid from your horse’s bursa and have them lab tested. This will determine if any infection or bacteria (Brucella) has infected your horse. Brucella abortus is a bacterium which can spread from horse to human. This bacterium, when spread to humans through open wounds, inhalation, or mucous membranes is referred to as undulant fever. The veterinary caregiver will also check the bursa wall for any inflammation. The bursa wall may be distended, and may rupture.
Once diagnosed, this condition is difficult to treat. This is because it becomes firmly established within the tissues of the horse and symptoms do not usually appear for a long time. Typically, by the time the horse is diagnosed with fistulous withers, it is very advanced. If it is found early, the condition can be treated with antibiotics. If the horse is vaccinated with the Brucella abortus vaccine, this may prevent the condition from occurring from the bacterium.
Treatment of Fistulous Withers in Horses
Once your horse has been diagnosed with fistulous withers, he will begin treatment. Treatment, however, is challenging due to the shoulder area having poor opportunities for effective drainage. Treatment methods will consist of:
Removal of Saddle
The veterinarian will advise you to remove your horse’s saddle immediately until he heals. The way the saddle can rub up against his withers can prevent your horse from healing. Also, the veterinarian will recommend that you take a break from riding him while he is healing.
Your horse will need a lot of time to rest to give his body an opportunity to recover from any infection or inflammation.
The most common method of treatment is surgery to remove the tissue from the infected fistula. The veterinarian will recommend your horse to an equine surgery clinic or equine hospital. The surgery will be followed up by antibiotics to prevent any further infection.
Clofazimine and oxytetracycline are the antibiotics of choice, especially against the bacteria known as Brucella. Your veterinarian may prescribe antibiotics in the early stages or, if surgery is needed, after the surgery to promote better healing.
Recovery of Fistulous Withers in Horses
Prognosis is good if treatment is started early. If your horse had surgery, your veterinarian will explain to you what you need to do in terms of his recovery and management of the surgical area. If your horse is on antibiotics, your veterinarian will give you specific instructions on how much and how often your horse needs to take the medication. Your medical professional will give you advice on what to look for in terms of side effects or any new symptoms. If any new symptoms arise that concern you, contact your veterinarian.
Your veterinarian may suggest to you to remove the horse’s saddle while he is in recovery. For future prevention, be sure his saddle fits properly and is well-balanced on his back and shoulder area. The saddle should never be tilted backward or forward. The saddle needs to completely stay off of the withers. Also, the stall of your horse needs to be safe as a preventative of any opportunities for shoulder injuries.
If your horse has an infection from Brucella abortus, he should be kept away from the cattle-free pasture in which he acquired the bacteria for at least two to three months.