The chronic and relapsing pancreatitis is an interesting addition to his history. I had been under the impression that he had had a full recovery, but it sounds that isn't the case. Now it is a condition reported to be excruciating in people and is known to cause poor appetites, belly discomfort, sometimes vomiting in cats. So, I am glad he responds to the steroids, but if pancreatitis is still though to be grumbling along, then we’d really want him on stronger pain relief (ie Gabapentin or even Buprenorphine). Furthermore and especially if he relapses when off the steroids, we do usually need these cats on an easily digestible/low fat diet; so that may need to be considered if he isn’t on one already. As well, while I don’t like mentioning more testing, if he has a persistent pancreatitis, we’d want to be having his vet scan the pancreas (potentially a job for a senior vet since it is tricky to do) with teir ultrasound since we can see pancreatic abscesses and tumors cause pancreatitis like signs that wont’ settle.
And as I noted its interesting to have a chronic relapsing pancreatitis added to Tam’s situation. The reason is because as I noted it tends to be an uncomfortable condition. And it is quite possible that if he is sore with that, his skin/itching behavior could be related to a displacement behavior. This is a behavior where cats target another site because they cannot address or remove pain elsewhere (its an odd pattern of irritation here but I'd still be a wee bit suspicious). Its akin to cats with cat bite abscesses on their back ends or anal gland issues hissing at their bums. So, it is possible that his general discomfort/agitation is related to underlying pain or the pancreas issues may just be lowering his general pain tolerance threshold. So, since we have this and he cannot tell us it is causing no bother, I’d be leaning to our pain relief trial even more.
In regards ***** ***** Metacam, I do think it was a red herring. If we are going to see sensitivities to that drug, it tends to be GI upset (vomiting, diarrhea, stomach ulcers in overdose cases) and not skin issues. And if there was already irritation and the shaving left razor burn, then that is more of a fit for the signs.
As for summary of what we’d like to do, a basic blood test (CBC/chemistry) would let us check the anemia, liver, and kidney functions. FIV/FeLV tend to be tested together and usually can be done at the same time. We could also check for herpes/calicivirus (ideally with virus isolation for calicivirus and PCR testing for herpes) but I would delay testing for those if his mouth is better just now (just since herpes is intermittently shed and testing is best done when they are in the early stages of an acute flare up). That way we avoid false negatives and needing to retest in the future.
Though further to all of that or if you wish to take a slower approach, we’d want to discuss hyperaesthesia and a potential trial on the Gabapentin (which he can have with the steroids and is well tolerated if needed for the long term, only potentially causing a bit of sedation initially) with his vet. And I do think that is a worthwhile avenue for him since the biting you sounds to be him telling you that you were causing him discomfort (which could be related to his joints, pancreatitis –which is very sore for them, or the hyperaesthesia we are concerned about). As well, if they have just seen him recently, they may even be willing to dispense the drug and let you trial it first before bringing him back in.
Finally, the travel situation is a difficult one and truly our best option will be what you think will cause him the least stress. If he can be kept in (ie cat flap shut) while the friend is watching that may be best. Though if he isn’t too put out by travelling and you can restrict him to a room, en suite bathroom, or even a big dog kennel where you are staying; then he may be best with you.But it is very much a decision that needs to based on what you think he’d tolerate best.