Hi Lisa,
I've used a similar supplement, Hepatosyl, and our vet said it's OK to give regularly but I suggest you check first with Smoky's vets because they will have his full history and will be able to assess whether it's OK for him to take to help resolve the flare and perhaps continue on with regularly thereafter.
Could possibly be due to pancreatitis. If the malodourous stools are yellow/pale/clay-like in colour and have a sort of 'fluffy'/marshmallowy texture (steatorrhea - see if the stools will float in the toilet bowl) that may be suggestive of exocrine pancreatic insufficiency which could be a temporary issue that resolves after a flare or could be chronic if it persists after a flare subsides, in which case pancreatic enzyme supplementation would be indicated.
I have recently learned that one possible cause of chronic diarrhoea (and perhaps vomiting) can be due to hyperthyroidism. (Lúnasa's just been diagnosed with this after months diagnostics and treatment for possible colitis/IBS.) I know from Saoirse that pancreatic issues may produce a knock-on effect in the function of other parts of the endocrine system. Saoirse was biochemically mildly hypothyroid for a time (ESS - euthyroid sick syndrome). Apparently an overactive thyroid can impact gut motility, speeding it up so that food doesn't stay in the gut long enough to be digested properly. Note: Lúnasa was severely polyphagic on one particular food; she was eating nearly double what she should have needed and she was pooping about 4-5 times a day (foul-smelling, paler, fattier stools). Also, she could not go any longer than about 3½-4 hours between feeds without throwing up.
It might be worth asking your vet whether it would be worth running some blood tests to check Smoky's status. I'd suggest checking liver and kidney function, Spec fPL to check status of pancreas, B12/folate (in case food malabsorption might have caused levels to fall), and perhaps a thyroid test.
Mogs
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