Nothing found. Try the Latin name or the product name.
Search
Nothing found. Try the Latin name or the product name.
Phenazopyridine
Toxic doses for cat from published sources; they are not treatment doses.
Toxic doses
Single acute ingestion, mg of the substance per kg of body weight. These are toxic doses, not treatment doses.
| Species | Signs begin | Severe | Deaths reported | Source |
|---|---|---|---|---|
| Cat | not established | not established | not established |
Harvey & Kornick 1976
Medium confidence
One clinical case and a dosing study in three cats (Harvey & Kornick 1976). Scientific article A study or review published in a scientific journal. Its findings apply to the animals and conditions it studied. Journal of the American Veterinary Medical Association, J Am Vet Med Assoc 1976;169(3):327-331, 1976 fatal case on 100 mg TID; 65 mg/kg/day: ~50% methaemoglobin; 10-20 mg/kg/day: more Heinz bodies |
Cat
Signs: Methaemoglobinaemia (brown or bluish mucous membranes), Heinz-body haemolytic anaemia, jaundice, liver injury; death.
Phenazopyridine causes methaemoglobinaemia and Heinz-body haemolytic anaemia in cats; no safe dose is established. A cat given 100 mg three times a day for 4 days developed haemolysis and died; in normal cats 65 mg/kg a day for 3 days turned nearly half of the haemoglobin into methaemoglobin, and even 10-20 mg/kg a day raised Heinz bodies. It is a human urinary pain medicine, often in cystitis combination products: do not give it to cats.
Safety information
Known Contraindications
-
Critical
(Cat) Do not give phenazopyridine to cats. It causes methaemoglobinaemia and Heinz-body haemolytic anaemia, with liver injury; a cat on 100 mg three times a day died, and no safe dose is established. Check human cystitis products for it.
Professional reference for veterinary professionals. Not advertising and not a substitute for the product label/SPC.
For veterinary professionals only. It does not replace clinical judgement or the product label; check the dose in the official label (SPC). vetman is not liable for harm caused by using this information.
Trademarks belong to their owners; vetman is not affiliated with the manufacturers and receives no payment from them.
The database is protected under Chapter VII of the Law of Georgia on Copyright and Related Rights; automated or bulk copying is prohibited.
This reference is still growing. Missing a product? Let us know. · Report an error or request an addition · Updated: 22 Oct 2026