I'm sorry to hear of this with Sparky. For the purposes of our discussion, I'm going to assume that "problems with anal glands" has been suggested by Sparky's scooting and/or licking his anus excessively. It's important to recognize that unless his anal glands are obviously impacted/infected, those symptoms are most often due to an allergic dermatitis rather than primary anal gland disorders. His licking his feet is supportive evidence of an allergic dermatitis; it's a symptom commonly attirbuted to both food intolerance and atopy (allergies to environmental allergens).
It sounds as if Sparky's vet understands this because both a steroid and hypoallergenic food trial have been tried. If neither have been helpful, food intolerance is more likely than atopy and a different hypoallergenic diet should be considered; in particular, a hydrolyzed rather than novel protein diet. If Sparky remained symptomatic inspite of being fed a hydrolyed protein diet, atopy becomes the more important differential diagnosis and either a larger dose of steroid or the new cytokine antagonist oclacitinib (Apoquel) should be considered. Oclacitinib works as well as a steroid but without a steroid's adverse effects. His glands shouldn't be expressed monthly unless they truly are impacted/infected.
For now, the antipruritic (anti-itch) tranquilizer acepromazine should be on board. Sparky needs a break and this drug will allow him to sleep until either an injectable steroid is administered or oclacitinib is initiated. Please respond with further questions or concerns if you wish.
I wouldn't expect blood work to be informative but I have no objection to it being performed. You're welcome to share out conversation with Sparky's vet. if you prefer, you can say that you've done your due diligence and would like to discuss a few things as I've alluded to above.
(I'm going to try to mark your new post as duplicate so you won't be charged twice. Please stay in this conversation if you wish.)
Thank you for your kind accept. I appreciate it. I can't set a follow-up in this venue so please return to our conversation - even after rating - with an update at your convenience. You can bookmark this page for ease of return.