Piper 960x640 2 web


Feline Infectious Peritonitis (FIP)

Piper is a one-year-old British Shorthair. For a couple of weeks Piper had not been feeling herself. She had lost her appetite, had become lethargic and had a persistently high temperature.

Her local vet referred her to the internal medicine service at AURA, to investigate her condition after initial medical management wasn’t appearing to make a difference.


Piper had her first consultation with Dr Jonathan Bray, who recommended an abdominal ultrasound and some blood tests. The ultrasound revealed pleural and abdominal effusion, which is abnormal fluid in the chest cavity and abdominal cavity. Samples of the fluid were taken and sent to an external lab for overnight testing, and Piper was kept in the hospital for IV rehydration and supportive care. 

Ultrasound showing Piper's pleural effusion

The following day the preliminary results arrived back from the lab. These results, combined with the imaging findings and her blood work, strongly suggested that Piper was suffering from Feline Infectious Peritonitis, commonly known as FIP.

FIP is basically a mutation of the feline coronavirus. It can lead to a range of clinical symptoms, including loss of appetite, weight loss, fever, and depression.

There are many different coronaviruses and it’s important to note that feline coronavirus is not related to the coronavirus that caused the COVID-19 pandemic. A cat can be infected with coronavirus but it won’t always develop into FIP.


There are two major types of FIP – a wet and a dry form. Wet FIP causes fluid to accumulate within body cavities – if in the abdominal area, cats may develop a pot-bellied appearance, while fluid building up in the chest area can make breathing very difficult.


With dry FIP, there is no fluid build-up but various organs can become severely inflamed. It commonly affects the brain and the eyes.

The disease predominantly affects younger, purebred cats, like Piper and until recently there was no licenced treatment which meant that it was sadly a fatal disease. When Piper’s mum received the news that it was likely that Piper had FIP, she steeled herself for the worst and was prepared to come to the hospital to say goodbye.


Fortunately, the story did not have to end this way, because recently a treatment has become available. It is an antiviral medication that is initially administered via injections, and then transitions to tablet form which can be done at home. The entire course of treatment lasts roughly 90 days.



Piper returns to AURA for her treatment
Piper returns to AURA for her treatment

Even though we only had received preliminary results, it was recommended that Piper begin treatment without delay and so she remained in hospital to begin the IV medication.

Under the care of Dr Gerard McLauchlan and our internal medicine team, Piper began her course of antivirals. On the second night of her stay she developed neurological signs so her treatment protocol was adjusted to address this as well. Following this she began to show signs of improvement, with her temperature stabilising and her appetite returning.

Shortly after we received confirmation from the lab that it was indeed FIP. Piper’s treatment continued in hospital for a week, after which she was discharged. She then returned for a few more days for subcutaneous injections. After this she was able to receive tablets at home.

Over the next three months at home, she continued to improve, eating as normal and playing happily again. Piper returned for periodic rechecks with the internal medicine team, who were very happy with her progress.

She has now completed her three months of treatment but will need to be monitored for any signs of relapse, which is most likely in the first three months after treatment is completed.


Her local vets will oversee this monitoring, liaising with our team if necessary, and we hope Piper continues to stay healthy and happy with her family at home!

Patient overview






British Shorthair


1 Year Old


Feline Infectious Peritonitis (FIP)
Clinician(s) that treated Piper
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