Drugs and Equipment - My Preferences
Surgery: My nominal glove size is 7 so 6.5 and 7.5 both work. 8 is way too floppy and 6 can only be worn for short procedures. With polydioxanone monofilament available on reels and cassettes, eg, Patterson Private Label Webmax (scroll to bottom), there's no reason to use inflammatory and unpredictable chromic gut. I like to have atraumatic Brown-Adson as well as rat tooth forceps in the surgery packs.

The following is my preferred list of drugs and supplies. If it's not too inconvenient or costly, I'd like to have your practice consider stocking them. On the other hand, if you already use something you consider "Best in Class" for a problem, I'd love to hear about it and the whys/wherefores that you use it. I'm also hesitant - in some cases - to have you purchase anything that won't be used after I'm gone. Dialogue and the give and take between professionals benefits both parties. The bolded names are my first priorities, the remainders are "nice to have"s. Nuflor and Draxxin are only suggested if ferals and/or difficult to medicate animals are more than occasional clients.

With my own experience as a guide, client compliance is King. Thus SID medications are preferred over BID, and TID/QID medications are reserved for the cash-strapped AND motivated clients.

For treatment of refractory rods (likely Pseudomonas) in ear cytology:
TrizUltra +Keto (4 oz) + 1% enrofloxacin (12 cc of Large Animal Baytril (generic available from Putney)), fill ears BID

Other otic treatments:
Yeast, cocci, allergy  Mometomax, 0.2 to 0.5cc q24h (I throw away the treatment tip and send home a 1cc syringe instead)
Swimming dogs - VetSolutions Swimmers Tx
Cleaner - EpiOtic Advanced
Otodectes - Revolution, q2w x3

Bacterial pyoderma:
Cefpodoxime proxetil (generic Simplicef (Putney)), 5-10 mg/Kg q12-24h
Cefovecine sodium (Convenia), 8 mg/Kg SQ q7d (S. intermedius), q10d (S. canis)

I don't use fluoroquinolones such as Baytril/enrofloxacin for pyoderma as they don't achieve ideal tissue concentrations in skin even at maximum dosage protocols. FQs also increase the risk of MRSI, MRSS, and MRSA.

Pneumonia, UTI, URI in feral or difficult to treat animals, ie, animals you don't want back in the clinic and clients advised to risks; suspected mycoplasma infections (feline URIs frequently have this component); combined with tetradur for resistant/chronic infections:
Florfenicol (Nuflor): dogs 35 mg/Kg q4d SQ, cats 100 mg/Kg diluted in 20-100 ml LRS SQ q7d

Canine pneumonia, especially difficult animals, caveats as above:
Tulathromycin (Draxxin): 4.5 mg/Kg SQ q8d (give with meloxicam)

Acral lick granulomas:
8 mL Synotic + 2 mL Banamine or ketoprofen topically q12h (paired with ABs, e-collar, etc)

Flea preventives:
Capstar, q2d, kills maggots as well as fleas, and can be given per rectum perioperatively if the surgery field becomes "active".
Sentinel, q30d, heartworm prevention and reduction in flea adulticides
Bravecto/Nexgard, both excellent for flea prevention and treating demodex
Comfortis/Trifexis, q30d
Frontline, q2-4w
Revolution, q30d, Every cat should be on this

Giardia (because I've seen so many refractory cases):
Fenbendazole (Panacur), 50 mg/Kg/Day x5d + metronidazole 30-40 mg/Kg/Day x10d
(add in EOD bathing & environmental decontamination EOD at Day 3)

Immune disorders in cats (indolent ulcers, asthma, IBD, pemphigus, etc):
Atopica, 5-10 mg/Kg (Verify FeLV/FIV status first)

Silver sulfadiazine ointment, sugar (for wet to dry bandages)

Controlled Drugs:
A full μ (mu) agonist (morphine or hydromorphone) for analgesia
κ (kappa) agonist (nalbuphine or butorphanol, whichever is cheaperto potentiate dexmedetomidine and alfaxalone for sedating non-painful patients
Buprenorphine (Simbadol for felines is a very exciting development)
Diazepam or midazolam (I prefer the latter as it can go IM but it has a short shelf-life)
Tramadol (now that it's controlled, many clinics write scripts instead of dispensing)
Alfaxalone (2 mg/Kg) + butorphanol (0.2 mg/Kg) + midazolam (0.2 mg/Kg) IM for fractious geriatric||CRF cats

Anaesthesia/Analgesia Drugs:
Dexmedetomidine (Putney now offers a generic)
Propofol (a very smooth induction protocol is 5 mg/Kg each of propofol and ketamine given at 0.1 cc/Kg q30s)
Bupivacaine (I use this extensively in dentals, for intra-testicular blocks prior to neuters, and it's dirt-cheap)
Gabapentin, 5-20 mg/Kg BID-TID (combined with firocoxib and tramadol for pain control in advanced osteoarthritis)

Carprofen (Rimadyl): 4.4 mg/Kq q24h, 2.2 mg/Kg q12h (included for its antineoplastic activity against osteosarcoma)
Firocoxib (Previcox): 5 mg/Kg q24h (generally preferred)
One gastric perforation being too many, I avoid Deramaxx.

Other drugs:
Maropitant citrate (Cerenia), 1 mg/Kg q24h (0.5 mg/Kg IV avoids the burn)
Mirtazapine, 1 mg/cat q24h, 2 mg/cat q2d, 3-3.75 mg/cat q3d (appetite stimulant)
Prazosin: 0.5 mg/cat (>4Kg) q12-24h, 0.25 mg/cat (<4Kg) q12-24h (for relaxing the urethral sphincter in blocked cats)

Doppler BP for cats
TonoVet/TonoPen (nice to have)

Eyes: I like to dilate and do indirect fundoscopy on all my surgical patients during recovery:
Procaineamide (for pain relief)