Top 5 Prescription Systemic Antibiotics for Dogs in the USA (2025), Vet-Reviewed Guide to Clavamox Drops, Baytril Taste Tabs, Zeniquin Tablets, Convenia Injectable, Doxycycline Hyclate

Clavamox Drops (amoxicillin with clavulanate) is a prescription systemic antibiotic favored for its broad-spectrum beta-lactam activity and a liquid formulation that makes dosing small dogs and puppies easier. It holds a best-in-class position for routine skin, wound and soft-tissue infections because it pairs reliable efficacy with generally lower acquisition cost and flexible dosing compared with long-acting injectables like Convenia. Compared with fluoroquinolones (Baytril, Zeniquin) and tetracyclines (doxycycline), Clavamox is often chosen first-line for mixed aerobic infections and when oral liquid dosing is preferred.

Baytril Taste Tabs (enrofloxacin) are a palatable, prescription fluoroquinolone tablet that provide strong gram-negative coverage and convenience for owners who prefer flavored oral tablets. They are positioned as a market leader for difficult gram-negative or refractory infections where potency and tissue penetration are priorities, though they are generally more costly and used more selectively than first-line options like Clavamox or generic doxycycline. Compared to Zeniquin, Baytril offers a similar fluoroquinolone profile but the tablet taste formulation and established brand recognition can improve owner compliance.

Zeniquin Tablets (marbofloxacin) are a prescription fluoroquinolone recognized for once-daily dosing and favorable tissue distribution, making them a go-to for complicated skin and urinary infections in dogs. Zeniquin earns a market-leading technical reputation for owner convenience and robust activity against many problematic pathogens, although it is typically reserved for cases where narrower-spectrum or cheaper agents (like Clavamox or doxycycline) are inappropriate. Financially, Zeniquin sits in the premium segment alongside Baytril, but its dosing profile can reduce administration errors and clinic rechecks compared with shorter-acting oral agents.

Convenia Injectable (cefovecin) is a prescription, long-acting injectable cephalosporin that reliably provides up to 14 days of systemic coverage from a single clinic-administered dose, making it best-in-class for compliance-challenged patients. Its principal advantage over oral options like Clavamox, Baytril and doxycycline is elimination of at-home dosing, which can translate to fewer missed doses and improved clinical outcomes despite a higher per-dose price and the need for veterinary administration. Convenia is often chosen for outpatient cases where guaranteed short-term coverage and convenience justify the premium cost.