Cushings cat who had radiation therapy is not eating much

Hello. I have a 12-year-old kitty who was diagnosed with Cushing's disease a couple of years ago. We have been maintaining her cortisol and glucose levels well with insulin and trilostane. However, the tumor continued to grow and she started to act "dull". So we came to a fork in the road and chose to have the tumor irradiated. Side effects were supposed to be minimal. She did well for a month or so, and then just did not want to eat, and appeared groggy and dull. The vet school here at UGA seems to think that she has some demylination in the nerve cells of the brain - an acute but reversible side effect. So they have put her on fairly large doses of prednisolone, Cerenia, and Entyce appetite stimulant. Her glucose has been up and down and all over the place - from 50 to 300 sometimes in one day (due to the tumor shrinking and the prednisone interfering and who knows what). They told us we just had to get her through this. the last 4 days or so she has seemed to feel better and seems much brighter and more herself - but still not eating well. Now, the last day or two she has started vomiting, and since she eats so little this is really bad. They have her on 0.66 ml of Prednisolone, and we have continued the Cerenia for more than the recommended 6 days. Does anyone have any idea if this could be a side effect from the medicine, or what is going on? I fear if we can't get her feeling better quickly this will be the end of the road for us. I might take her to the vet school for fluids and see if we can figure out the vomiting issue.

 

What type of radiation therapy did kitty (name?) have? My girl had stereotactic radiation therapy twice for her pituitary tumour (acromegaly) and I did not see the symptoms you describe.

Have you tried ondansetron for nausea? It targets different nausea receptors from Cerenia and in some cases works better. Or kitty could need both like my Neko did at one point. Or the Cerenia dose could be low, some vets underdose. What is the pred and Cerenia dose being given in mg? The ml dose doesn’t mean anything without knowing the concentration in liquid. There is no time limit on how long Cerenia can be given, that is old school so I suspect that vet might be out of date on dosing. I have never given Entyce, but have seen one cat not here react not well to it, made it more nauseous.

 

Thanks for the reply. I am feeling rather desperate at this point. I am not sure the exact radiation - I will have to rummage through papers to find it. She stayed at the vet hospital for five days and had a treatment every day. She had/has a large adenoma on the pituitary, which is (or was) actively producing chemicals (I think it pretends to be a pituitary gland). She was on prednisolone for the radiation itself, which was tapered off. She was doing well and then just quit eating, so they thought it was the "acute early" side effects, which are supposed to be transient. I have found one or two papers on this that talk about these - they are rare. The vet school then started prednisolone. The dosage is 0.66 ml and the concentration is 3mg/ml. So she is getting 1.98 or approximately 2 mg of prednisolone every 24 hours. She weighed about 10 pounds but has been losing weight I am sure. We started out with a transdermal mitirzipine but for some reason they stopped that and prescribed this Entyce. She is supposed to get 0.4ml of 3 mg/ml so that is 1.2 mg every 24 hours. I did not give that last night. We have been giving Cerenia tablets, 8 mg every 24 hours for about 2 weeks. They warned us that it is usually only used for 5 days and this could cause side effects. Do you have any idea what is causing her to not eat well and to vomit? Prior she has always had a good appetite. She is just wasting away at this point. I am thinking hospitalization for fluids (she cannot have a "bubble" due to her thin Cushing's skin"). I contacted the vet school but they have to have a meeting between internal medicine and radiation to give advice.

 

Traditional radiation has more brain side effects than SRT, though short term (first week) brain swelling for which pred is given is possible with SRT. Not this long out though. The tumour causing acromegaly sends out growth hormone, instead of cortisol for Cushings. The tumours look different too, but still treated with radiation on the pituitary. The radiation treatment is not common for Cushings, in my time here, I haven’t seen it. which is why I am comparing to acromegaly treatment.

The prednisolone dose is not high. I have a smaller cat getting twice as much, 1 mg per kg. Maybe go back to transdermal mirtazapine?

 

And, the Cerenia dose is fine. M6 girl was on Cerenia for half a year with no side effects. I would also try ondansetron. It’s a human anti nausea med, but the vet has to write a prescription.

 

Thank you for the advice. Apparently nothing is commonplace about Cushings and cats. I found a paper where they irradiated 8 cats but 2 had carcinoma and several had acromegaly. So we are working with data points of maybe 10 total of the papers I have seen. I did speak to the vet school and they did not think any of the meds would likely be causing this vomiting. I have made arrangements to get her into the vet school hospital tomorrow for fluids and to see if we can figure out if something else is going on along with the rest of this. Her blood sugar has been like 300 for several days, pretty flat, and then this evening it decided to go down. It is really just crazy how nothing will stabilize. But the main issue right now is getting her to eat. I will keep you posted as I think this could eventually be helpful to others at any rate.

 

Best of luck, keep us posted. There have been a lot more cats radiated for acromegaly. In 2012, the vet school I went to had done about three dozen with SRT. Add in other schools, and countries, and years going by and you have lots. Got one kitty here doing it this week for acro.

 

Hello. Chloe is still hanging in there but I do not think is eating well. I have her loose with my other cats (she has been confined a lot due to her special diet) and she is sitting up on the cat tree and acting like a cat again. But not eating much - not sure if she is nauseated or what. I found the summary of her care which says she had this type of radiation: 5 fractions of SRT - this was given 5 days in a row back in June. At the current time, she is wearing a glucose monitor and her blood sugar has been normal without insulin so that is a blessing. Everything would be grand if she would just eat better. About a month after the radiation they said she was "dull" and not eating due to side effects from the radiation - at that time I was told that this could last "weeks to months" but was reversible with prednisolone. Now that she is acting more normal, they have tapered her prednisolone down to nothing but yet she still isn't eating well - like maybe half what she should. So, I wonder if we are quitting the pred too soon? The other issue is that we restarted her trilostane due to skin issues (Cushings type issues) and we are not sure if she is getting too much of that or not. Test for that will be done in about a week. Meanwhile I am giving her Cerenia (I wrapped it in a tiny piece of pill pocket and she does not throw it up any more), and the transdermal mirtazapine every night, and sometimes I add in the ondansetron if I think she is particularly poorly. The vet school asked me to taper down the Cerenia so that is only 1/4 pill. I'm thinking I might go back up to 1/2 and see if that helps her eat better. I cannot imagine any other reason why she won't eat much except that she might be nauseated, but why would she be nauseated? She has always been a really good eater. Or should I be giving her the Cerenia PLUS to ondansetron? What do you folks think? This is a multi-faceted problem for sure. If I am not clear please ask me questions and I will attempt to answer them.

 

Is Chloe losing weight now? She will be less hungry with the tumour radiation.

At one point, I needed to give both Cerenia and ondansetron. How many mg if each are you giving? I have seen some vets under dose them. I also found ondansetron better for nausea than Cerenia.

 

Hello - I just weighed her on a baby scale. They had her weight at the vet school as 4.2 kg (9.24 lbs) on 7/28. Tonight she weighs 7.98 lbs on the scale, or 3.63 kg. So she has definitely lost some weight. She feels thin but not bony at this point. They prescribed 1/2 Cerenia tablet which is a 16 mg tablet so 8 mg, then they told me to use the 1/2 pill for a week (I did that longer) and then go to 1/4 pill so that is what I have been doing the last week. The ondansetron they gave is a 4 mg tablet and they told me 1/2 tablet every 8 to 12 hours. My vet told me only to use them together if I "had to" so I have not been using both. It seems to me she eats only a little and then stops. I have no idea if this is due to 1. radiation damage to the brain, still demylinating nerve cells or even loss of sense of smell, 2. she is getting too much trilostane, 3. something else. The only reason I think she is probably nauseated is because when I was giving her the Cerenia without a tiny coating of pill pocket she would gag immediately and throw up. The vet from the vet school said they are not too worried as long as she is eating something - maybe they expect to find that the trilostane is too high of a dose and that is causing the issues. No idea. We will do that test as soon as she is off the pred long enough - maybe a week. And yes, Chloe has gone from being diabetic and having Cushings to not being diabetic so her appetite has dropped a lot I am sure!

 

Cerenia is bitter tasting, most cats will gag or foam at the mouth if they taste it. I put mine in a gel cap. Sounds like the anti nausea med dosing is pretty good.

 

Chloe is staying at the vet school this weekend. She was eating almost nothing at home. She seems very interested in the food and licks at it or maybe takes one bite but then stops. She is supposedly eating a little at the vet school on fluids. They are telling me that there may be some brain damage from the radiation (to the hypothalamus) and she might not ever start eating again. So they are recommending I put her down - of course she cannot survive if she doesn't eat. But I am puzzled as to what is causing this - no one really knows - she seems to feel good, is bright and active - the diabetes is in remission - but she just can't seem to eat. It is SO very frustrating. I asked them to put her back on the prednisolone - what could it hurt at this point? But I don't think it is making any difference. One of the vet school doctors says we could put in a feeding tube but we don't know what underlying condition we are trying to treat - and with Cushing's it probably would never heal correctly. So this is all very discouraging. They are giving Chloe the Cerenia (1/2 tablet) plus Entyce (.25 ml) plus ondansetron ( 1 pill) plus the prednisolone. Any ideas/suggestions would be welcomed.

 

Leo had a feeding tube just prior to small cell lymphoma diagnosis. My vet indicated the feeding tube was temporary. And I think that is good advice. A permanent feeding tube would be very challenging. Leo kept trying to pull it out.

Cerenia and Ondansetron worked kind of okay for Leo. But his SCL got worse. And at some point a disease can just overcome the treatment. In the end, he had eating issues and was on a downslope of losing weight.

Leo's issue of not eating was a combo of SCL issues and throat growth from Acromegaly. Externally the same effect that Chloe has - one or two bites, then wouldn't eat. Nausea and physical eating issues. For Chloe the nausea could be causing the issue, and Ondansetron could help resolve it. I would ensure that she is getting a sufficient dose. And it can be re-dosed every 8 - 12 hours.

• In cats, the usual dose is 0.11 mg per pound (0.22 mg/kg) every 8 to 12 hours.

 

What food is she getting at home? Just wondering if she needs something completely different. I sometimes used to have to assist feed a bit before Neko would eat. Like food in her tummy helped her feel better and got her started.

I am surprised at the possible brain damage theory. Usually they do a CT scan to map the brain for radiation planning, then have the cat with a bite guard to keep their head in place, then another CT scan before radiation to make sure the beams are going in the right place.

Neko didn’t have a feeding tube, but we have had many cats here, like Leo, have a temporary one that was a life saver until the underlying condition was treated.

 

I'd consider syringe feeding before a feeding tube primarily because of the risk of skin tears and poor healing, but that's just my instinct and not based on experience. I've done both -- i.e., syringe fed multiple cats and dogs through illnesses, plus have dealt with feeding tubes (PEG- and E- tubes) in cats multiple times.

I've not heard of a Cushing's cat having SRT, so this is interesting. My acrocat had SRT but didn't have the post-treatment symptoms you describe.

One thing you might do is consider asking for cyproheptadine as an appetite stimulant rather than Entyce or mirtazapine. Cyproheptadine isn't prescribed as often these days but I still favor it over the others (fewer side effects in my experience and sometimes more effective). As long as it isn't contraindicated with the other meds, it might be worth a try.

I also don't know whether you've tried other foods, but I've seen cats "sour" on a food that they happened to be eating when they were ill (sort of like how one might never eat chocolate ice cream again after getting sick on it). Even perhaps try a different bowl. Odd as it sounds, they can "connect the dots" in unusual ways. As someone once said here, feed beer and hotdogs if that's what they'll eat (not really, of course, but do what you have to do short term). I do think it's possible that your cat might need to relearn (or be "reminded") how to eat normally again and syringe feeding can prime the pump, so to speak. My dog has just been through a difficult time and I have to "prime" him by lacing the food with a/d and canned chicken and hand feeding the first few bites (or more). I once syringe fed a cat for months until she decided to eat in her own. Others here have done the same. Sometimes it just takes awhile.

Has the vet done recent bloodwork to rule out other problems?

Did they check the back of the cat's throat for issues?

Finally, was the SRT supposed to be curative for the Cushing's? I'd think that as the tumor subsided, the trilostane dose would certainly need to be adjusted (else you could inadvertently throw the cat into an Addisonian scenario, no??). Just mulling out loud here...

Good luck and let us know what happens!