Signs can include bleeding from any part of the body, panting and weakness with pale gums, or sudden collapse.

Laboratory tests used to confirm poisoning include increases in OSPT (One-stage prothrombin time), and APTT (Activated partial thromboplastin time).

The original rat poisons (first generation) use Hydroxycoumarins (warfarin, coumafuryl) or Inadandiones ( pindone, diphacinone, valone). These generally require multiple exposure and don't pass down the food chain. (i.e.. poisoning won't occur through eating a poisoned rat or mouse). Signs take between two and five days to appear and the poisoning only lasts for around one week.

Newer rat poisons use second generation anticoagulants including Brodifacoum, Bromadiolone, and Coumatetralyl. These can produce signs within one to two days and may act for up to one month. They are also able to pass down the food chain.

Treatment depends on the stage of poisoning. Where signs are advanced blood transfusions may be necessary. Vitamin K1 is given for 1 to 4 weeks at a rate of between 1 and 3 mg/kg of body weight.