Amprolium
Amprolium is an oral anticoccidial used particularly in calves and poultry. Prolonged or excessive exposure can induce host thiamine deficiency.
Group
Thiamine-antagonist anticoccidial
Mechanism of Action
Competition with thiamine uptake interferes with carbohydrate metabolism in susceptible coccidia.
Dose Rates
Cattle
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Coccidiosis prevention | 5 mg/kg | PO | Every 24 h | Up to 21 days; Calves; supply the full daily amount through the intended oral delivery system. |
| Coccidiosis treatment | 10 mg/kg | PO | Every 24 h | Up to 5 days; Calves; confirm coccidiosis and adequate medicated-water or feed intake. |
Indications
- Treatment and prevention of Eimeria bovis and E. zuernii coccidiosis in calves.
- A historical canine/feline drinking-water regimen is 30 mL of the 9.6% solution in 3.8 L water for seven days; variable intake prevents reliable individual weight-based dosing.
- A feed regimen described for dogs and cats is 1.25 g of 20% powder in daily feed for seven days; this supplies 250 mg active amprolium per animal per day.
Contraindications
- Do not administer to debilitated animals without addressing their nutritional and clinical deficits.
- Avoid excessive or prolonged use in animals at risk of thiamine deficiency.
- The cited calf product does not establish a withdrawal interval in preruminating calves and excludes calves intended for veal.
- Avoid extending puppy courses beyond 12 days because of the risk of thiamine depletion.
Interactions
- Concurrent thiamine can antagonize anticoccidial activity; thiamine is nevertheless needed when treating amprolium-associated deficiency.
Adverse effects
- Anorexia and poor performance with excessive exposure.
- Neurologic signs from thiamine deficiency, including ataxia or seizures.
Toxicity
Stop excessive exposure and treat suspected thiamine deficiency promptly. Monitor intake and neurologic status when medicating feed or drinking water. Neurologic deterioration during treatment can represent drug-associated thiamine deficiency rather than worsening coccidiosis.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Corid 9.6% oral solution 96 mg amprolium/mL. Calf label: meat withdrawal 24 hours; do not use in calves processed for veal. | Oral Liquid | 96 mg / mL | PO |
