Cat with ascites (sudden onset) - need help with diagnosis

Hello, I have already taken my cat to the vet, who has done extensive testing, but we do not have any answers. I'm really hoping someone will be able to make a suggestion, because I am scared my cat is dying. Basically, I started giving my 7yo cat Foxy transdermal Prozac (for behavioral issues - aggression toward her littermate) a couple of weeks ago. The next day she was lethargic and sleepy, but I figured that was a common side effect. She got somewhat more and more lethargic over the next few days and then I noticed her stomach seemed to be swelling on the sides. I brought her into the vet. (A month prior, she had just had a checkup with completely normal bloodwork and physical exam - no findings whatsoever.) The vet did an ultrasound and took X-rays. Found a large build-up of fluid in the abdomen. All organs looked normal but the intestinal walls appeared to be slightly thickened and inflamed, and the fatty tissue between her organs was inflamed. The lab analyzed the fluid and ruled out any sort of pathogen, pancreatitis, etc. The technician cannot say with certainty that it is cancer, but did find abnormal epithelial cells that could be consistent with a sarcoma or carcinoma. The vet says the only other option she hasn't ruled out is steatitis, but Foxy has been on a balanced commercial diet her entire life. The vet says it's just a coincidence that this started exactly after I began administering the prozac, but I still believe (and hope, since maybe that's a better chance for recovery) it could be what has triggered this illness. Since bringing her home, she has continued to be lethargic. She is not showing any of her behavioral issues. She was a very feisty, active cat two weeks ago. Now she sleeps all day and occasionally sits and stares into space, seeming confused and out of it, and sometimes licking her chops. She loved to play but won't do it now. She seems skinnier, and the vet found that, after removing the fluid, she had lost several ounces since her checkup about a month prior to this exam. She is still eating, but maybe not as much. She is drinking a lot of water - seems quite thirsty. She is peeing normally, I think (can be hard to tell with two cats), and pooping regularly but smaller amounts than before. So my questions are: If it is steatitis, could it be ideopathic and therefore possibly a strong reaction to the medication? Is there anything else it could be? And is there anything else I should be doing for her to address the ongoing symptoms? Vet just says wait and see and monitor her but if I should be giving her an anti-inflammatory/steroid or appetite stimulator or something, I want to insist on that. Thank you in advance.

Hello - it sounds as though your vet has done a very thorough work-up on this case and, although you have given me a fair description, your vet has more information and is therefore in a better position to advise you than I am. The key symptoms from your description appear to be lethargy and ascites, with weight-loss.  Lethargy can indeed be a side effect of Prozac.  However, given that your vet has considered this and decided that it is unlikely to be significant, it may be that they are right; I do not know how much you gave or exactly how (did you shave the skin before applying the patch for example), so your vet has more information than I do.  I have heard anecdotally that transdermal uptake can be less reliable in some cats so it might depend on you cat and how much you gave,  and how, and what the blood supply to the patch was like.  More vitally, it is illegal for owners to give any kind of prescription medication to their cat without a prescription.  If your vet wants to find any more information out about the effectsc of Prozac on cats, they are likely to have access to the VPIS (veterinary poisons information service) who can give them researched expert advice as to what to do in this situation.  More to follow.

'Idiopathic' is not a causative factor.  As my pathogy lecturer used to say, 'it means we idiots do not know what the pathology is, but crucially it does NOT mean that there is no pathology / nothing wrong.'  After all, the clinical signs sound quite severe - drooling can often be a sign of feeling sick.   You tell me that your vet hasn't found any answers, but on reading through they actually seem to have established an awful lot:  that she has ascites, that she has lost weight even when the fluid is accounted for (if I understood that correctly?); that the abdominal organs appear normal as far as they can see on ultrasound; that there is no obvious sign of a pathogen in the fluid they took (Im not sure they can 'rule out any kind of pathogen' based on this - finickity I know, but thats an important difference) and also that there are epithelial cells consistent with a carcinoma / sarcoma.  Cancer can be diffuse. There isnt always a 'lump.'  They might also be able to tell you how well concentrated the urine is - ie how well the kidneys are holding up, and more about the type / cellularity of the abdominal fluid, which often sounds like mumbo-jumbo to owners, but can be interesting to vets in trying to pinpoint the cause.

They may also have found steatitis, which can be associated with the diet.  I suppose how likely they think this is, will depend on their knowledge of your particular cat.  I also wonder about panceatitis (bloods and ultrasound can provide detailsabout this).

Overall, it sounds as though your vets have taken a good opportunity to gather a lot of information.  Sometimes this can be overwhelming, especially when the answer remains unclear.  Good questions for them can be:  what are you suspicious of that you havent you ruled out so far?  (Steatitis?  Cancer?  Pancreatitis?????- Anything else?) How can we tell the difference between them?  Is it important to tell the difference between them at this stage?  How can we help our cat at this stage in term of treating the symptoms?  What would you do next if this was your cat?  - these will usually be helpful in working out how to move the case on.

Ps heart disease can sometimes cause ascites - again, your vet may already have ruled this possibility out.

Thank you for these replies. To clarify, it's not that I don't trust my vet so much as I'm really really hoping it's still possible that this was a reaction to the medication, which was prescribed, but which I've since stopped administering. (It wasn't a patch; it was a cream applied to the ear flap.) And it was just so strange that she was a completely normal, seemingly perfectly healthy cat, who had just had an annual physical with blood work to confirm that, until the day after I started administering the medication. And she declined so rapidly from there - within a few days her stomach was filled with fluid. So I figured maybe someone might be able to think of something we haven't considered or tried. The vet says she has ruled out heart disease and pancreatitis based on the imaging and analysis of the fluid. And Foxy was on a normal commercial diet, so she thinks steatitis is unlikely. I know that ideopathic means unknown, but was hoping that in this case unknown maybe could encompass something like a fluke reaction to a medication (i.e. the prozac). I appreciate the suggested questions, and I wonder - since you're saying that pathogens couldn't be entirely ruled out based on fluid analysis - if antibiotics might be something I could ask about as well, or if bacteria would have shown up in the analysis if it were present enough to cause this level of symptomology.