Well, the decision was taken out of my hands as he had diarrhoea last night and then this morning was straining with more diarrhoea. When I looked under this tail, there was a fleshy bulge. I phoned another vet clinic, the only one that's open in my small town on the weekend, and got him in. He had an anal gland abscess, so that's all cleaned out. Lot of puss and other gland was close to impacted. So, regular anal gland expressions are in his future as part of routine. Don't want this happening again. However, it's not directly clear whether the anal gland issue was the cause of Fraser's illness or something that's come along in addition. He didn't have a clear fever in previous vet visits, there was no mention of anal gland emerging problem in the 2 visits last week, the most recent on Friday. The vet this morning is going to ask for the tests that were done last Sunday from my usual clinic to see what they might tell a new set of eyes. Today's vet said a new set of blood tests may not provide further information, so probably not indicated right now. But, he did take a fecal sample, so at least that is an additional source of information. At this point, I'm glad to have a second opinion. The first vet (locum as my vet is away) may not have made any errors in diagnosis as apparently anal abscesses can blow up overnight. But I'm not sure he was as proactive as he might have been. Having said that, I know even with human doctors, the diagnostic method is to eliminate things in an orderly manner, so maybe he did right by Fraser.
In the meantime, the boy is very unhappy in his cone of shame for the next 10 days and he's on two sets of antibiotics to knock out the infection. Fingers crossed that anal glands were the source of his illness all this week. If not, a clear diagnosis of whether there's some underlying thing that still needs to be addressed. Also in the meantime, I usually try to eat a low carb diet, but there was a bakery right across from the vets, so home I came with a filled croissant and chicken roll. I may even have ice cream later.