ExoticRx · exoticrx.com/drugs/finasteride
US brand names:Proscar, Propecia
Finasteride is dosed at 0.1–0.5 mg/kg PO q24h in dogs, per Sirinarumitr K, Johnston SD, Kustritz MVR, Johnston GR, Sarkar DK, Memon MA. Effects of finasteride on size of the prostate gland and semen quality in dogs with benign prostatic hypertrophy. J Am Vet Med Assoc. 2001;218(8):1275-1280. doi:10.2460/javma.2001.218.1275; Lima CB, Angrimani DSR, Flores RB, Vannucchi CI. Endocrine, prostatic vascular, and proapoptotic changes in dogs with benign prostatic hyperplasia treated medically or surgically. Domest Anim Endocrin. 2021;75:106601. doi:10.1016/j.domaniend.2020.106601 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.552 (2026-08-01).. Verify against current literature before clinical use.
Inhibits 5-alpha reductase type II, blocking conversion of testosterone to dihydrotestosterone (DHT). Reduces prostate size.
Used for benign prostatic hyperplasia in dogs. Teratogenic — do not handle crushed tablets during pregnancy. Effects take weeks. Does not affect libido.
Species references:All 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 1 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 | 0.1–0.5 mg/kg | q24h | Moderate | Sirinarumitr K, Johnston SD, Kustritz MVR, Johnston GR, Sarkar DK, Memon MA. Effects of finasteride on size of the prostate gland and semen quality in dogs with benign prostatic hypertrophy. J Am Vet Med Assoc. 2001;218(8):1275-1280. doi:10.2460/javma.2001.218.1275; Lima CB, Angrimani DSR, Flores RB, Vannucchi CI. Endocrine, prostatic vascular, and proapoptotic changes in dogs with benign prostatic hyperplasia treated medically or surgically. Domest Anim Endocrin. 2021;75:106601. doi:10.1016/j.domaniend.2020.106601 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.552 (2026-08-01). |
Upgrade to Pro or Student to unlock the full dose ranges and frequency for every species. The drug's mechanism, warnings, indications, and cited sources are free to read.
View PlansSource citations and evidence levels available on the live page. Reference only — verify against current literature before clinical use.