ExoticRx · exoticrx.com/drugs/nitrofurantoin
US brand names:Macrodantin
Nitrofurantoin is dosed at 4.4–5 mg/kg PO q8h in dogs, per Weese JS, Blondeau J, Boothe D, et al. International Society for Companion Animal Infectious Diseases (ISCAID) guidelines for the diagnosis and management of bacterial urinary tract infections in dogs and cats. Vet J. 2019;247:8-25. doi:10.1016/j.tvjl.2019.02.008 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.964 (2026-08-01).. Verify against current literature before clinical use.
Reduced by bacterial enzymes to reactive intermediates that damage DNA, ribosomes, and other macromolecules. Concentrated in urine.
Only effective for lower urinary tract infections (requires urinary concentration). GI upset common. Avoid in renal failure (inadequate urinary concentration). Pulmonary toxicity rare.
Species references:All Cat (Domestic) drugsAll Dog (Domestic) drugs
Each ExoticRx dose rule is graded by the strength of its primary evidence — see the editorial process.
A dog/cat sample is shown here. Cited dosing for all 2 species — reptiles, birds, pocket pets, livestock, and equine — is free on the per-species pages above. Pro adds the weight-based calculator for every species.
| Species | Route | Dose | Frequency | Evidence | Source |
|---|---|---|---|---|---|
| Dog (Domestic) | PO | 4.4–5 mg/kg | q8h | Moderate | Weese JS, Blondeau J, Boothe D, et al. International Society for Companion Animal Infectious Diseases (ISCAID) guidelines for the diagnosis and management of bacterial urinary tract infections in dogs and cats. Vet J. 2019;247:8-25. doi:10.1016/j.tvjl.2019.02.008 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.964 (2026-08-01). |
| Cat (Domestic) | PO | 4.4–5 mg/kg | q8h | Weak | Weese JS, Blondeau J, Boothe D, et al. International Society for Companion Animal Infectious Diseases (ISCAID) guidelines for the diagnosis and management of bacterial urinary tract infections in dogs and cats. Vet J. 2019;247:8-25. doi:10.1016/j.tvjl.2019.02.008 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.964 (2026-08-01). |
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View PlansSource citations and evidence levels available on the live page. Reference only — verify against current literature before clinical use.