As more and more suburbs pop up, more and more homes are finding unwanted critters entering their home in the fall. Mice can carry disease, fleas, and cause destruction within the home. Many people chose to use a mouse poison, or rodenticide. These have evolved over the past few years to become more effective at killing the mice quicker than before. Unfortunately for the unsuspecting pet owner, they may also be putting this poison out for their pet. Although the location chosen for the bait may seem safe, keep in mind that a mouse can relocate the bait to an area that is within reach of the unintended target.
There have been various types of rodenticides on the market. These include anticoagulants, bromethalin, cholecaliciferol, strychnine, and zinc phosphide. The treatment for ingestion of each of these may vary, therefore it is very important that you bring the box with you when you bring your pet to your veterinarian. Do not delay. Call ahead. Depending upon your distance to travel, your veterinarian may give you instructions as to how to induce vomiting in some instances to prevent any further absorption of the poison.
Many of the older products were called anticoagulants. They worked by binding to the vitamin K in the body of the victim. This vitamin is needed in order for the blood to clot and without it, the victim has overwhelming bleeding from even the littlest thing and will bleed internally and die very quickly. There are several generations of anticoagulants on the market, each one getting more and more potent and requiring supplementation of vitamin K for a longer and longer period to prevent bleeding.
Unfortunately, a newer form of rodenticide is now available called Bromethalin. This was developed as more and more rodents were becoming resistant to the anticoagulants. It may be sold under the trade names of Trounce, Assault, and Vengeance. It will cause an uncoupling of oxidative phosphorylation in the central nervous system and liver mitochondria. This results in decreased nerve impulses causing muscle tremors, seizures, hyperexcitability, ataxia, paddling, hyperthermia, loss of vocalization, forelimb extensor rigidity. These signs may be progressive and may take 3-14 days post exposure leading the owner to believe that no harm has been done by ingesting the poison. There is no test for it other than EEG tests (nerve conduction study of the brain). There also is no antidote.
Zinc phosphide is also a very dangerous product. When an animal eats the bait, the acid in the stomach turns the product into a vary toxic gas. Inducing vomiting in these animals has led to human exposure to the toxic fumes in the vomitus and secondary toxicity. This is why one should ask first before inducing vomiting with mouse poison.
Take home message about rodenticides:
• They are becoming more common in our environment
• Toxic levels can be reached with even small amounts
• Treatment depends upon which type and how much product was ingested so be sure to bring in the box if possible
• Any delay in treatment may be fatal for the pet
• Repeated blood work and treatment can be expensive so be sure to protect your pets from rodenticides. It is not always a happy ending.
Use of enclosed traps may be a better alternative to poison.