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Cat not eating and diarrhea on thyroid drugs

15 replies

Allthedays1 · 12/07/2026 07:10

So my cat diagnosed two weeks ago with hyperhyroid. He's been on meds two weeks. Last few days he's had diarrhea just outside of the litter tray. Friday night he wouldn't eat. Then Saturday morning he would eat and seems normal but then Had his meds and didn't want to eatv again. He's slept a lot by the back door so not hiding away but but not doing much. I've got up today to another liquid poo outside the tray and he still don't eat. Sniffs it, licks his lips then walks off. What can I do? He has a check up Tuesday anyway but it's Sunday morning now. I'm worried about our holiday ( have a cat sitter in twice a day) and what he will be like

OP posts:
Judystilldreamsofhorses · 12/07/2026 12:53

Sorry to hear your poor cat isn’t doing well. I’d be inclined to have him checked over before Tuesday personally, I’d be worried about him getting dehydrated if he’s not eating and has an upset tummy, especially if it’s hot where you are. I don’t have experience of thyroid problems but the meds maybe just need tweaked a bit.

Do you have access to a helpline via your insurance? We can speak to a vet 24/7 on either voice or video call with ours via their app, and it can be really useful as a sense check if nothing else. There’s also a symptom checker thing which I expect is AI.

jellycat · 12/07/2026 13:04

We had a cat with hyperthyroidism. She was prescribed Thyronorm - is this what your cat has been prescribed?

We found it so difficult to get it into her that we decided to ignore the stipulation in the leaflet that it’s not given in food. We ended up mixing it with lick-e-mix, in a small bowl, which she would usually eat. She wouldn’t eat it in her normal food. We did this for several years and her thyroid levels were OK, and the diarrhoea stopped, so it obviously worked.

The vets also gave us a paste containing Kaolin, to stop the diarrhoea in the early stages. We used to smear it round her mouth and she’d then lick it off, because again we couldn’t get her to just take it.

So it might be worth going back to the vets and asking for Kaolin paste if you don’t have it.

Allthedays1 · 12/07/2026 16:23

jellycat · 12/07/2026 13:04

We had a cat with hyperthyroidism. She was prescribed Thyronorm - is this what your cat has been prescribed?

We found it so difficult to get it into her that we decided to ignore the stipulation in the leaflet that it’s not given in food. We ended up mixing it with lick-e-mix, in a small bowl, which she would usually eat. She wouldn’t eat it in her normal food. We did this for several years and her thyroid levels were OK, and the diarrhoea stopped, so it obviously worked.

The vets also gave us a paste containing Kaolin, to stop the diarrhoea in the early stages. We used to smear it round her mouth and she’d then lick it off, because again we couldn’t get her to just take it.

So it might be worth going back to the vets and asking for Kaolin paste if you don’t have it.

Hello yeah this is the meds. He was eating it fine for two weeks then last few days stopped and sleeping all the time and has liquid diarrhea. I wonder if it's the meds making him nauseous

OP posts:
Needanadultgapyear · 12/07/2026 16:45

Nausea is not common with thyronorm, if this was my patient I would be more worried that controlling the hyperthyroidism, has brought the blood pressure into the normal range which has unmasked underlying kidney disease.

Allthedays1 · 12/07/2026 18:51

Needanadultgapyear · 12/07/2026 16:45

Nausea is not common with thyronorm, if this was my patient I would be more worried that controlling the hyperthyroidism, has brought the blood pressure into the normal range which has unmasked underlying kidney disease.

Oh god don't say that!! He's only 8. I'm hoping it's not kidney disease

OP posts:
Taranta · 12/07/2026 20:14

Needanadultgapyear · 12/07/2026 16:45

Nausea is not common with thyronorm, if this was my patient I would be more worried that controlling the hyperthyroidism, has brought the blood pressure into the normal range which has unmasked underlying kidney disease.

This is exactly the scenario that played out with my elderly cat. Okay on thyronorm for a while then declined rapidly and the kidney problems surfaced with a vengeance.

TheChaffinch · 12/07/2026 20:19

Mine is on thyronorm. He had been ravenously hungry before, eating 4 X as much as normal. His appetite went right down when he started, plus some diarrhoea. Vet suggested a probiotic supplement which helped.
However the vet also warned me of what @Needanadultgapyear says. I'd ring the vet Monday.

Allthedays1 · 13/07/2026 11:44

TheChaffinch · 12/07/2026 20:19

Mine is on thyronorm. He had been ravenously hungry before, eating 4 X as much as normal. His appetite went right down when he started, plus some diarrhoea. Vet suggested a probiotic supplement which helped.
However the vet also warned me of what @Needanadultgapyear says. I'd ring the vet Monday.

Was he his normal self except for the eating. My cat is so lethargic. He's not hiding away but just seems to want to sleep

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Allthedays1 · 13/07/2026 11:46

Taranta · 12/07/2026 20:14

This is exactly the scenario that played out with my elderly cat. Okay on thyronorm for a while then declined rapidly and the kidney problems surfaced with a vengeance.

I'm sorry about your cat. What was his symptoms? My cat is still not interested in eating but his diarrhea has lessened and hes not drinking or weeing loads. He just went over the neighbours fence to mark their garden and came back but would only eat a few dreamies

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TheChaffinch · 13/07/2026 15:48

Allthedays1 · 13/07/2026 11:44

Was he his normal self except for the eating. My cat is so lethargic. He's not hiding away but just seems to want to sleep

He's 16 so not that active anyway. In winter he seems to sleep 23 hours a day. Right now he probably does the same but outside under a bush rather than in his bed.
It doesn't sound like your cat is very well. Maybe the dose is too high?
Either way I think vet.

Taranta · 13/07/2026 19:31

Allthedays1 · 13/07/2026 11:46

I'm sorry about your cat. What was his symptoms? My cat is still not interested in eating but his diarrhea has lessened and hes not drinking or weeing loads. He just went over the neighbours fence to mark their garden and came back but would only eat a few dreamies

well it’s slightly complicated because he was 19, arthritic and I didn’t know his back story having only had him for a year. He was ravenous all the time and drinking /weeing loads so vet put him on Thyronorm. He was okay on it for a bit but then seemed to have off days when he would sniff his food but not eat it, and only drink, then he’d be okay the next day for a few days/weeks. The poor spells got more frequent and vet thought it was kidney disease unmasking. He began to vomit this clear pink tinged liquid and I had him PTS the next day.

Judystilldreamsofhorses · 14/07/2026 17:45

How is your cat, OP? Did you go to the vet?

Allthedays1 · 14/07/2026 17:59

Judystilldreamsofhorses · 14/07/2026 17:45

How is your cat, OP? Did you go to the vet?

Yes thanks went today. He was eating a bit more today but not his whiskas. She said it could be the meds but also could be a bug. Gave us probiotics to give him and said if he still has the runs to go back in 48 hours and get tablets. He's booked in for a blood test but she said there's no point yet as he hasn't been on the meds long enough ( plus I didn't give him any over the weekend)

OP posts:
Allthedays1 · 14/07/2026 18:00

Taranta · 13/07/2026 19:31

well it’s slightly complicated because he was 19, arthritic and I didn’t know his back story having only had him for a year. He was ravenous all the time and drinking /weeing loads so vet put him on Thyronorm. He was okay on it for a bit but then seemed to have off days when he would sniff his food but not eat it, and only drink, then he’d be okay the next day for a few days/weeks. The poor spells got more frequent and vet thought it was kidney disease unmasking. He began to vomit this clear pink tinged liquid and I had him PTS the next day.

Aww I'm sorry x

OP posts:
Judystilldreamsofhorses · 14/07/2026 18:06

Allthedays1 · 14/07/2026 17:59

Yes thanks went today. He was eating a bit more today but not his whiskas. She said it could be the meds but also could be a bug. Gave us probiotics to give him and said if he still has the runs to go back in 48 hours and get tablets. He's booked in for a blood test but she said there's no point yet as he hasn't been on the meds long enough ( plus I didn't give him any over the weekend)

He’s maybe not eating as much as usual because it’s warm? Hopefully the probiotics will do the trick 😊

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