Aspirin

Anti-inflammatory, analgesic, antipyretic in horses and dogs; antiplatelet/antithrombotic therapy; musculoskeletal pain and fever; equine laminitis. Salicylate NSAID (acetylsalicylic acid). Mechanism: irreversibly inhibits COX-1 and COX-2 via covalent acetylation → reduced prostaglandin and thromboxane synthesis. Irreversible platelet COX-1 inhibition impairs platelet aggregation for platelet lifespan. Analgesic, antipyretic, anti-inflammatory, and antiplatelet effects. Rapidly hydrolyzed to salicylate after absorption. Key information Do NOT use in cats — extremely slow metabolism, toxic accumulation. Dogs: can be used but NSAIDs with COX-2 selectivity preferred. Horses: low-dose aspirin used for antiplatelet effect. GI ulceration risk — administer with food. Interaction: potentiates anticoagulants.

Oral tablets: Administer orally. May be given with food to improve compliance and reduce GI upset. Administer with food to reduce GI adverse effects. to reduce gastric irritation. Buffered or enteric-coated formulations preferred for long-term use. Tablets may be split as needed for dose. Horses: administer orally in feed. If a dose is missed Administer as soon as you remember. If it is almost time for the next scheduled dose, skip the missed dose and resume the normal schedule. Never double up doses to make up for a missed one.

GI: gastric irritation, ulceration, hemorrhage (COX-1 inhibition reduces protective mucus/prostaglandins). Cats: prolonged toxicity due to slow glucuronidation — gastric hemorrhage, hepatotoxicity, methemoglobinemia, respiratory alkalosis; do not use without careful dosing. Platelet dysfunction (irreversible). Salicylism: vomiting, hyperpyrexia, alkalosis/acidosis.

For animals CONTRAINDICATED in cats (highly toxic — prolonged half-life, Heinz body anemia, GI ulceration). Dogs: narrow therapeutic window — GI ulceration risk; combine with misoprostol if prolonged use required. Avoid in animals with GI ulcers, bleeding disorders, renal disease, or those receiving concurrent NSAIDs. Monitor for GI ulceration; use with caution in animals with GI disease. Irreversible platelet inhibition — discontinue 7 days before surgery. For people handling this medication Wash hands thoroughly with soap and water after handling. Avoid contact with eyes; if contact occurs, flush with water for 15 minutes and seek medical attention. Keep out of reach of children. If accidental ingestion occurs, contact Poison Control (1-800-222-1222). Salicylate — keep away from children (associated with Reye's syndrome in children with viral illness). Do not use in pets without veterinary guidance.

Contact your veterinarian immediately. Aspirin overdose causes GI ulceration and bleeding, and can be life-threatening in cats. Signs include vomiting, lethargy, and pale gums. Contact your veterinarian, a veterinary emergency clinic, or the ASPCA Animal Poison Control Center (888-426-4435) immediately. Do not induce vomiting unless specifically directed by a veterinary professional.