Amoxicillin

What is this medication for?

• UTI, soft tissue infection, susceptible gram-positive infections, Lyme disease (dog)

How is it given?

Give exactly as your veterinarian prescribed — never change the dose or stop on your own unless your veterinarian has told you to.

• Never give to rabbits/rodents/guinea pigs — fatal enterotoxemia risk shared across penicillins/cephalosporins/macrolides.

What if I miss a dose?

• Give it as soon as you remember — unless it is almost time for the next dose (then skip the missed one; never double up).
• Call your clinic if you miss more than one dose in a row.

Side effects — what should I watch for?

Effects listed as common in this handout

• stomach/intestinal (vomiting, diarrhea, loss of appetite) (Most common)
• Gut flora shift toward resistant gram-negatives (Documented in healthy dogs)

Worth a phone call to your veterinarian

• Neurotoxicity (wobbliness/unsteadiness) (High-dose/prolonged use)

⚠️ Contact your veterinarian or an emergency clinic IMMEDIATELY if you notice

• Hypersensitivity (rash, fever, anaphylaxis) (Uncommon, not dose-related)

Before starting (or refilling), tell your veterinarian if your pet:

• has or has had: Known penicillin/beta-lactam hypersensitivity; do not give penicillins/cephalosporins/macrolides to rabbits, guinea pigs, chinchillas, hamsters — risk of fatal enterotoxemia

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • Bacteriostatic antimicrobials (chloramphenicol, macrolides, tetracyclines)
  • Methotrexate
  • Probenecid

Storage and handling

Room temperature, tightly sealed. Optimal stability pH 5.8–6.5. Oral suspension stable 14 days.

Good to know

• Reasonable first-line empiric choice for feline abscesses per Trepanier 2009.
• Do not use in adult horses orally — poor absorption; foals absorb better (36–43%).
• Never give to rabbits/rodents/guinea pigs — fatal enterotoxemia risk shared across penicillins/cephalosporins/macrolides.