1. Contact your veterinarian immediately.
  2. Your veterinarian may instruct you to induce vomiting, however, do not induce vomiting unless instructed to.Vomiting can be dangerous if your pet is already starting to show clinical signs of changes in mentation or behaviour.


Acepromazine (acepromazine maleate),acetylpromazine, chloropramazine, prochlorperazine.




Clinical signs occur within 8 hours of ingestion. Clinical signs are dose dependent, meaning that they get more severe with increasing dosage of drug ingested.

  • Depression
  • Drowsiness
  • Profound sedation which may progress to stupor
  • Coma
  • Dilated pupils
  • Weakness, collapse, pale gums due to low blood pressure
  • Uncoordinated gait (ataxia)
  • Drowsiness
  • Slow heart rate (bradycardia)
  • Less commonly, some animals become very excited or agitated, and occasionally more aggressive
  • Tremors/muscle twitching
  • Death at high doses possible


The exact mechanism of action of phenothiazines are not fully understood but they act by blocking dopamine receptors in the central nervous system, inhibiting the release of dopamine and depressing portions of the central nervous system that control body temperature, metabolic rate, vomiting, alertness and blood pressure.


Your vet will also be able to induce vomiting in your pet at the clinic with some drugs if it is stable enough. If required, a gastric lavage may be performed and activated charcoal can be given to help bind any remaining drug in circulation.

Intravenous fluids are usually required to maintain blood pressure.

Animals with excitement or tremors may require treatment with a muscle-relaxant/anti-convulsant such as diazepam.


BSAVA (2012) BSAVA/VPIS Guide to Common Canine and Feline Poisons. Gloucester: BSAVA.

MalouinA&Boller M (2009) Sedatives, muscle relaxants and opioids toxicity. In: Small Animal Critical Care Medicine. Silverstein DC & Hopper K (eds.). Missouri, USA: Saunders Elsevier.

Plumb DC (2011) Plumb’s Veterinary Drug Handbook 7thEdn. Iowa, USA:Wiley-Blackwell