Which species have cited Pyrimethamine dosing data?

Pyrimethamine dosing in the ExoticRx formulary covers 4 species: African Grey Parrot, Amazon Parrot, Cat (Domestic), Dog (Domestic).

Is Pyrimethamine a controlled substance?

Pyrimethamine is not federally scheduled in the US. Controlled-drug status differs by country — verify your local rules.

What are the side effects of Pyrimethamine?

Reported side effects, adverse reactions, and contraindications for Pyrimethamine: Bone marrow suppression possible — monitor CBC. Supplement with folinic acid (leucovorin). Teratogenic. Do not use in pregnant animals.

Pyrimethamine

US brand names:Daraprim

Calculate dosage

Sourced from published veterinary references. Awaiting credentialed clinical reviewer — our editorial process.

Pyrimethamine is dosed at 0.5 mg/kg PO q12h in african grey parrots, per 159. Formulary. In: Chitty J, Lierz M, Chitty J, Lierz M, eds. BSAVA Manual of Raptors, Pigeons and Passerine Birds; British Small Animal Veterinary Association, Gloucester, UK; 2008:384-390. — Source: Carpenter's Exotic Animal Formulary, 6th Ed, p.441 — Carpenter's Exotic Animal Formulary 6th ed, Table 5.4 (Antiparasitic Agents Used in Birds). Verify against current literature before clinical use.

Drug Class

Antiparasitic

Routes

Indications

AtoxoplasmaLeucocytozoonSarcocystisSarcocystosisToxoplasmaToxoplasmosis

Mechanism of Action

Inhibits dihydrofolate reductase in protozoa, blocking folic acid synthesis required for DNA replication. Synergistic with sulfonamides.

Side effects & warnings

Bone marrow suppression possible — monitor CBC. Supplement with folinic acid (leucovorin). Teratogenic. Do not use in pregnant animals.

Evidence levels across 4 dose rules

Moderate×2Weak×2

Each ExoticRx dose rule is graded by the strength of its primary evidence — see the editorial process.

Sample dosing (2 of 4 cited rules)

A dog/cat sample is shown here. Cited dosing for all 4 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	0.25–0.5 mg/kg	q12h	Moderate	Foster SF, Martin P. Lower respiratory tract infections in cats: Reaching beyond empirical therapy. J Feline Med Surg. 2011;13:313-332. doi:10.1016/j.jfms.2011.06.001 — Plumb's 10th ed printed p.1100, Pyrimethamine monograph spanning p.1099-1100.
Dog (Domestic)	PO	0.25–1 mg/kg	q24h; 0.25-0.5 mg/kg may be given q12h	Weak	Plumb's Veterinary Drug Handbook, 10th ed., printed p.1100, Dosages > DOGS; corroborated by BSAVA Small Animal Formulary 10th ed., Pyrimethamine, printed p.354 - 'Dogs, Cats: Toxoplasmosis/neosporosis: 1 mg/kg p.o. q24h or divided q12h for 4 weeks, alongside sulphonamides'Compilation only — we have not located an independent source that prints this figure.

Backed by 4 published sourcesShow

· 159. Formulary. In: Chitty J, Lierz M, Chitty J, Lierz M, eds. BSAVA Manual of Raptors, Pigeons and Passerine Birds; British Small Animal Veterinary Association, Gloucester, UK; 2008:384-390. — Source: Carpenter's Exotic Animal Formulary, 6th Ed, p.441 — Carpenter's Exotic Animal Formulary 6th ed, Table 5.4 (Antiparasitic Agents Used in Birds).
· 673. Page DC, Schmidt RE, English JH, et al. Antemortem diagnosis and treatment of sarcocystosis in two species of psittacines. J Zoo Wildl Med. 1992;23:77-85. — Source: Carpenter's Exotic Animal Formulary, 6th Ed, p.441 — Carpenter's Exotic Animal Formulary 6th ed, Table 5.4 (Antiparasitic Agents Used in Birds).
· Foster SF, Martin P. Lower respiratory tract infections in cats: Reaching beyond empirical therapy. J Feline Med Surg. 2011;13:313-332. doi:10.1016/j.jfms.2011.06.001 — Plumb's 10th ed printed p.1100, Pyrimethamine monograph spanning p.1099-1100.
· Plumb's Veterinary Drug Handbook, 10th ed., printed p.1100, Dosages > DOGS; corroborated by BSAVA Small Animal Formulary 10th ed., Pyrimethamine, printed p.354 - 'Dogs, Cats: Toxoplasmosis/neosporosis: 1 mg/kg p.o. q24h or divided q12h for 4 weeks, alongside sulphonamides'

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