ExoticRx · exoticrx.com/drugs/hydroxyurea
US brand names:Hydrea, Droxia
Hydroxyurea is dosed at 25 mg/kg PO 3 times weekly (q48-72h) in cats, per BSAVA Small Animal Formulary 10th Ed, Part A (Canine and Feline), Hydroxycarbamide (Hydroxyurea), DOSES - Cats, corpus p.215 (printed p.199) — SOURCE EDITION: BSAVA Small Animal Formulary, Part A — Canine and Feline — ISBN 9781910443705, https://openlibrary.org/isbn/9781910443705. Verify against current literature before clinical use.
Inhibits ribonucleotide reductase, blocking conversion of ribonucleotides to deoxyribonucleotides. S-phase specific. Reduces elevated cell counts rapidly.
Myelosuppression is dose-dependent and predictable. Monitor CBC weekly initially. Megaloblastic changes expected. Used for polycythemia vera, CML, and meningioma in dogs and cats.
Species references:All Cat (Domestic) drugsAll Dog (Domestic) drugs
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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 |
|---|---|---|---|---|---|
| Cat (Domestic) | PO | 25 mg/kg | 3 times weekly (q48-72h) | Weak | BSAVA Small Animal Formulary 10th Ed, Part A (Canine and Feline), Hydroxycarbamide (Hydroxyurea), DOSES - Cats, corpus p.215 (printed p.199) — SOURCE EDITION: BSAVA Small Animal Formulary, Part A — Canine and Feline — ISBN 9781910443705, https://openlibrary.org/isbn/9781910443705 |
| Dog (Domestic) | PO | 50–60 mg/kg | q24h initially, then taper to every other day | Weak | Withrow & MacEwen's Small Animal Clinical Oncology, 5th Ed (2013) - held; rule cites 6th Ed - corpus p.186 (printed p.172), Ch.11; corroborated by Plumb's Veterinary Drug Handbook 10th Ed, corpus p.656 (printed p.629), DOGS: 30-60 mg/kg PO once daily — Plumb's 10th ed (held) printed p.628, Hydroxyurea monograph; page located 2026-08-05 from the book's own running heads, verified to name the drug in its body text. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, ; Withrow and MacEwen's Small Animal Clinical Oncology — ISBN 9781437723625, |
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