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This information is provided by Provet for educational purposes only.

You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Various types of substance are used to kill mice, rats and other rodents - and great care should be taken to avoid them being eaten - directly or indirectly - by pets.

A wide variety of substances are used to kill rodents and unfortunately these can also cause serious disease or death in pets including cats and dogs.

Some of the most common compounds are :

  • Vitamin D rodenticides - these contain cholecalciferol which causes high blood calcium - side effects can last for several weeks, and can lead to renal failure. OR
  • Vitamin-K antagonists - these may contain warfarin, coumarin, coumafen, coumatetralyl, brodifacoum or bromadiolone, diphacinone, diphenadione, chlorphacinone, pindone or others. These products  block the effect of vitamin K in normal blood clotting so animals that ingest these poisons bleed to death internally. 
  • Some rodenticides contain both forms of poison mixed together.

Signs of poisoning with rodenticides are non-specific and may include :

  • Inappetance
  • Bleeding from various sites eg nose, in urine. If bleeding occurs into the chest the animal will cough, or have difficulty breathing
  • Dullness,. depression
  • Collapse
  • Diarrhoea - may include blood - fresh red to black
  • Vomiting - may include blood which is usually coffee-brown in colour
  • Increased thirst
  • Increased urination (increase in frequency and volume produced)
  • Very pale mucous membranes
  • Fast heart rate
  • Weakness
  • Fits - muscle twitches, seizures
  • Sudden death in some cases

Poisoning occurs in two ways :

  • Direct - if the animal eats or drinks the poison , or if it eats or drinks bait laced with the poison
  • Indirect - if the animal eats a rodent that has eaten the poison. This is a common route of poisoning for cats which can easily catch mice or rats that are weakened by the poison. 

Rodenticides should be kept away from pets - preferably in a locked cupboard, and predatory pets should not be allowed access to areas in which poison has been placed, until such time as all dead and dying rodents have been removed from the environment.

Treatment depends upon the specific type of poison. Vitamin K supplementation can be successful in reversing haemorrhage due to anticoagulant-type rodenticides, whereas treatment of cholecalciferol poisoning is unlikely to be successful once significant calcium has been deposited in soft tissues - and no specific antidote is available


.Updated October 2013