Michelle, I am really worried about your vet’s approach to this whole situation. I have no idea as to why she would consider cancer to be the most likely cause of Buddy’s inappetance. I think you need to start reading about Vetoryl treatment yourself, because it does not seem as though your vet is familiar with the potential side effects and the need for cortisol testing if a dog who’s been taking Vetoryl becomes unwell. There ought to be a printed product insert in Buddy’s box of Vetoryl, but if you no longer have that to look over, here’s a key excerpt:
Here’s a link that will take you to a brochure published by Dechra, the maker of Vetoryl. It contains the info I’ve given above, with a lot more in addition. Your vet has prescribed quite a high dose of prednisone for Buddy — much higher than is necessary if the cause of his inappetance is low cortisol, and can actually cause gastric upset in its own right. At that high dose, unfortunately you’re likely to see a rebound of unwanted Cushing’s symptoms such as excessive thirst and urination. If Buddy’s problem is low cortisol due to the effects of the Vetoryl, much lower doses of prednisone would be adequate to replace the cortisol that he’s lacking.WARNINGS: Hypoadrenocorticism [Addison’s] can develop at any dose of VETORYL Capsules. In some cases, it may take months for adrenal function to return and some dogs never regain adequate adrenal function...Owners should be advised to discontinue therapy immediately and contact their veterinarian if signs of potential drug toxicity are observed (see INFORMATION FOR DOG OWNERS, DOSAGE AND ADMINISTRATION, PRECAUTIONS, ADVERSE REACTIONS, ANIMAL SAFETY and POST-APPROVAL EXPERIENCE). In case of over dosage, symptomatic treatment of hypoadrenocorticism with corticosteroids [such as prednisone], mineralocorticoids and intravenous fluids may be required...
... The most common adverse reactions reported are poor/reduced appetite, vomiting, lethargy/dullness, diarrhea, and weakness...
...If the ACTH stimulation test is < 1.45 μg/dL (< 40 nmol/L) and/or if electrolyte imbalances characteristic of hypoadrenocorticism (hyperkalemia and hyponatremia) are found, VETORYL Capsules should be temporarily discontinued until recurrence of clinical signs consistent with hyperadrenocorticism and ACTH stimulation test results return to normal (1.45-9.1 μg/dL or 40-250 nmol/L). VETORYL Capsules may then be re-introduced at a lower dose...
http://www.animalhealthinternational..._20HighRes.pdf
Once again, it’s indeed possible that there is some other issue that’s causing Buddy’s inappetance. But as I think you’ll see from the published info above, if a dog taking Vetoryl loses its appetite, low cortisol and/or imbalances in blood chemistries due to overdosing always have to be suspected. You want to check out that possibility first. If that turns out not to be the problem, then you know to look elsewhere. But that’s really the first place to start.
Marianne