Feline Infectious Peritonitis (FIP)
Ted presented with a history of weight loss, lethargy and dark coloured urine over the past few days. On physical examination his temperature was found to be elevated and his gums were pale. Abdominal distension was also noted and when firmly tapped a fluid wave could be observed. This suggested the presence of fluid in the abdomen (ascites).
Diagnostics proceeded with a dipstick performed on the dark coloured urine. The dark colour was determined to be bilirubin, a derivative of red blood cell breakdown that is commonly found in association with liver disease or excess destruction of red blood cells. As Ted’s gums were pale, excess destruction of red blood cells was most likely, and it was likely that Ted had anaemia.
X-rays were also taken of the chest and abdomen. The abdominal x-rays confirmed that the enlarged abdomen was due to ascites and not another reason, such as a distended stomach or an abdominal tumour. The chest x-rays were also important to rule out the possibility that Ted had heart failure, which is a fairly common cause of ascites. As was expected based on the normal heart and lung sounds heard during the physical examination, the chest was normal with no signs of heart failure. At this stage, alternative possibilities that we suspected were causing Ted’s ascites and anaemia were bleeding into the abdomen, FIP or liver disease.
After providing Ted with some pain relief and mild sedation, a catheter was inserted into abdomen and a sample of the fluid obtained (abdominocentesis). The fluid obtained was a thick, straw-coloured effusion with a mild amount of blood. This strongly supported the possibility of FIP, however the possibility of a ruptured bladder could not be ruled out.
Unfortunately, as previously mentioned confirming a diagnosis of FIP is very frustrating and complex due to its wide variety of clinical manifestations and the absence of reliable diagnostic tests. At present, histopathology coupled with immunohistochemistry is the only definitive method of diagnosing FIP. These tests are not only costly but also take a few days before results are received. In addition, once a diagnosis is confirmed, treatment of FIP is usually fruitless. Many FIP positive cats die or require euthanasia within days to months of diagnosis.
In light of these facts, our best option was to perform an exploratory laparotomy (open up the abdomen) on Ted to gather further support for our suspected diagnosis. Once the abdomen was opened, the bladder was confirmed to be intact. Additionally, white granular nodules, characteristic of FIP, were identified on the surface of the liver, spleen and abdominal connective tissue. A presumptive diagnosis of FIP was made at this point. After discussing the poor efficacy of treatments with the owner, euthanasia was performed.
Feline Infectious Peritonitis