Hepatitis is a type of liver disease seen in horses. A vital organ, the liver can shut down before the effects of the disease are apparent in horses. This also means that by the time the symptoms of hepatitis are displayed, it can be too late to start treatment. Therefore, it is important to bring your horse to a veterinarian immediately if you suspect it has hepatitis.

Symptoms and Types

As far as horses are concerned, there are two different forms of hepatitis:

• Acute Hepatitis
  • Loss of appetite
  • Dull pain in the abdomen
  • Increase in pulse rate
  • Labored and quickened breathing
  • Nervous behavior
• Chronic Hepatitis
  • Loss of appetite
  • Diarrhea
  • Weight loss
  • Abdominal pain
  • Increase in pulse rate
  • Labored breathing
  • Nervousness (e.g., head pressing, wandering, confusion about surroundings)
  • Complications with vision or complete blindness

Causes

Acute hepatitis is usually caused by some type of viral infection and is due to the ingestion of toxins. These toxins may be biological, chemical, or both. Chronic hepatitis, on the other hand, is caused by ragwort, a poisonous weed that possesses toxins which slowly eat away at the cells in the liver. And while a horse will not eat ragwort purposely, it occasionally makes it way into the hay and can go undetected, as it does not have any particular taste. Another effect of the toxins on the liver is cirrhosis, which can be fatal.

Liver fluke is also known to cause chronic hepatitis in some horses.

Diagnosis

Other than observing the horse's clinical symptoms, your veterinarian will confirm the diagnosis of hepatitis by examining a tissue sample from the horse, in addition to conducting further tests on the animal.