Rat Bait – Anticoagulant

Anticoagulant rat baits:

The most common type of rat baits available are anticoagulants (prevent normal clotting of blood).   Common brands that are typically anticoagulants include but are not limited to: D-Con, Talon, Havoc, Weather Block, Super Caid, Ratimus, Contrac, Promar, Ramik, Diphacin, Ciad Drat, Rozol, Pival, and PMP.

The most common ingredients in these brands that prevent clotting include:
Warfarin, Brodifacoum, Pindone, Chlorophacinone, Bromadiolone, Diphacinone, Coumarin, and Valone.

Disease description:
This category of rat bait works as an anticoagulant by leading to a vitamin K deficiency in the body. As a result, the clotting factors that are dependent on vitamin K (II, VII, IX and X) become depleted, leading to a bleeding disorder.  Clinical signs typically develop a 4-7 days after ingestion of the toxin.  Ultimately, a bleeding disorder will occur in some location in the body, either internally (in the abdomen, chest, brain, lungs, bladder etc) or externally (skin, nose, mouth, etc).   Rat or mouse poison pellets are often colored blue or bright green, and the coloring can sometimes be seen in the feces. Bromethalin pellets can also be the same colors but do not cause hemorrhage.

Clinical Signs: 

Clinical signs can vary depending on how much bleeding has occurred and where the bleeding occurs.  The most common clinical signs include weakness, lethargy, collapse, pale gums, increased respiratory (breathing) rate, vomiting, and decreased appetite.

Testing for anticoagulant toxins:

The PIVKA (proteins induced by vitamin K absence or antagonism) test can detect ingestion within 6-8 hours.  Clotting tests like PT can also detect ingestion within 48-72 hours but neither test is specific for rat bait (other things can cause them to be increased)

Treatment:  

Treatment will vary depending on how quickly ingestion is identified.  If the pet is found eating the toxin, then the first step is decontamination with emesis (making them vomit) and giving activated charcoal to bind any toxins already in the intestines.   If enough toxin was already absorbed then a course of Vitamin K1 for 2-4 weeks (depending on which toxin was ingested) will prevent clotting problems in most cases.   Vitamin K1 MUST be given with food to be effective!  If decontamination is done quickly and effectively then most pets will not require any additional treatment (including vitamin K1).  We will typically recommend checking a clotting time 48 hours after the known ingestion to ensure that further treatment is not needed.    If vitamin K1 therapy is neeeded then a clitting time still needs to be checked 48 hours after the course of medication if finished.

If clinical signs are already present then additional treatments like fresh frozen plasma transfusion +/- blood transfusion may be needed to help the blood clot until the vitamin K can start working.

 Prognosis:

Prognosis for anticoagulant toxin ingestion is good with early detection, treatment, and owner compliance.   Once clinical signs are present the prognosis is worse but most pets still make a full recovery but may depend on how aggressive they are treated and how bad their clinical signs are.  Obviously, it is also much more expensive to treat once clinical signs are present.