Protein Losing Enteropathy in Cats

Protein losing enteropathy in cats (PLE) is a condition in which the normal protein synthesis that occurs in the intestinal tract becomes disrupted. In a healthy cat, food is broken down in the stomach and intestine into important nutrients that the body can use, including protein. Normally, protein is absorbed into the bloodstream and carried throughout the body to be used to build muscle and provide fuel. In a cat suffering from PLE, protein is not properly absorbed into the bloodstream through the intestinal barriers, causing the protein to be eliminated instead of utilized by the body. If not treated properly, PLE is a dangerous condition for your cat as it prevents it receiving adequate nutrition and can eventually lead to death. If you suspect your cat is suffering from this disease you should seek immediate veterinary care.

Symptoms of PLE in your cat will all relate to the malabsorption of protein. These may include:

• Watery diarrhea
• Mucus in stool
• Weight loss
• Vomiting
• Lethargy
• Exercise intolerance from lack of energy
• Unnaturally extended stomach
• Pooling of liquid under the skin or the appearance of swelling typically seen around neck and legs

Enteropathy is a general term that refers to any dysfunction of the intestine. In cats suffering from PLE, either damage or defect has occurred to the lining of the intestine. This lining typically allows protein and other particles to pass through to be absorbed by the bloodstream. There are a variety of underlying diseases and conditions that may cause PLE. Some of these include:

• Infection
• Cancer
• Parasites
• Heart failure 
• Lymphangiectasia (problems of the lymphatic system) either inherited (rare) or acquired, typically through lesions or other damage
• Inflammatory bowel disease
• Chronic allergies

Diagnosis of the underlying cause of PLE in your cat will begin with a thorough physical examination in your vet’s office. Your veterinarian will look for telltale signs of any heart issues. These include listening to your cat’s breathing sounds and their heartbeat to identify any potential abnormalities. During the physical exam, your vet will also look for swelling in your cat, referred to as edema, which would indicate the body is failing to properly dispose of excess fluid, another telltale sign of heart disease.

If a parasitic infection is suspected as the cause of your cat’s PLE, your vet will order one of several tests to look for hook or roundworms, the most common culprits. These tests will involve collecting a small portion of your cat’s stool. You may be able to aid in this test by bringing along a sample from home, preferably one that has been uncontaminated by litter. This can be accomplished by removing most of the litter from your cat’s normal box and placing a layer of newspaper over the top.

Next your vet will want to run a full blood panel and urinalysis. These tests will allow your veterinarian to screen for certain infections, determine if there is evidence of cancer or other inflammatory processes causing an immune response, and will also determine levels of vitamins and nutrients within the blood. This will confirm whether your cat is suffering from a malabsorption condition. In order to collect a blood sample, your vet will need to insert a small needle into a vein in your cat. This procedure is relatively painless and can be quickly done in a matter of minutes. The results may need to be sent to an external lab and can take some time to return.

As a final diagnostic test, your vet may wish to look at the intestinal tract of your cat using a procedure called an endoscopy. In this test, your cat will be sedated so that your vet can insert a small tube and camera through their anus into their intestinal track. This will allow your veterinarian to see any changes, lesions or other visual clues regarding the cause of your cat’s PLE. This procedure also allows your veterinarian to remove a small sample of tissue to biopsy. A biopsy of the intestinal wall is the definitive diagnostic tool of PLE when other causes have not been identified. 

Treatment of your cat’s PLE will depend on the underlying cause of the condition. In cats with worms, a course of antiparasitic drugs will be prescribed. Your vet will also recommend a preventative treatment of dewormer.

Heart issues are often complicated and will be addressed on a case by case basis. In some cases, a heart condition can be managed and your cat’s life prolonged with restricted activity and treatment with certain drugs. If your cat suffers from inflammatory bowel disease, your veterinarian may prescribe drugs to suppress your cat’s immune system to eliminate the irritated reaction of the digestive tract. 

Prognosis for your cat suffering from PLE will depend on the treatment and the underlying cause. In cases where the disease can be successfully managed, it will be important that you follow your veterinarian’s advice regarding prescription timing and dosage. In some cats, long term supplementation of calories via food additives may be needed in order to ensure adequate nutrition throughout their life.