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.