Description

Named for the district in northeastern Western Australia where the disease most often occurs, Kimberley disease leads to congestion and hemorrhage of the liver and spleen, with accompanying emaciation, weakness, and stupor brought on by eating a plant that contains toxic alkaloids.

The disease occurs when pyrrolizidine alkaloids are absorbed in the intestine and transported to the liver, where they are metabolized to pyrroles, which are toxic and damage the liver. The process causes healthy cells to be replaced with fibrous tissue, resulting in liver failure. This same process can also lead to lung damage which in turn may affect the heart and lead to heart failure. 

Symptoms

• Weakness
• Stupor
• Emaciation
• Loss of coordination
• Damage to the nervous system
• Erratic behavior, such as walking in circles
• Loss of control of hindquarters

Causes

Kimberley disease is caused by eating plants of the genus Crolataria that contain poisonous pyrrolizidine alkaloids that are extremely toxic to horses.

Prevention

Knowledgeable land management is the best prevention of Kimberley disease or any disease caused by the ingestion of toxic plants. Plants containing poisonous alkaloids are often unpalatable and horses usually do not eat them if proper forage is available. By identifying weeds and plants in pastures and sowing a mixture of pasture plants to keep one type of plant from dominating, horses will have a safe environment in which to forage.

Horse owners should ensure that machinery, seed, fodder, and livestock are free of contaminants before they enter the property. New livestock brought onto the property should be kept in a separate area for at least four days to allow seeds to pass through the animal in an area where they won't contaminate pasture land.

Treatment

At the first signs of Kimberley disease, or any similar disease, a veterinarian should be contacted. Keep affected animals as quiet as possible. Remove animals showing symptoms of toxicity to a clean holding paddock or yard. In some cases, it may be possible to save the horse by using gastric lavage to remove any residual poisonous material from the stomach.

Giving a laxative to prevent further absorption and eliminate poisonous material from the digestive tract may also help. A veterinarian may recommend large volumes of intravenous fluids to support circulation and protect the kidneys and other organs. Unfortunately, with Kimberley disease, the horse often dies shortly after clinical signs become apparent.