Introduction
When pets like cats hunt and eat wild animals, there is a potential risk of secondary poisoning if those prey animals have ingested bait or poison. Mice and rats are common targets for various rodenticides used to control pest populations. If a mouse or rat eats this bait, there can still be poison present in their system when caught and eaten by a cat or other predator.
This secondary poisoning occurs when the toxins pass from the primary poisoned animal (mouse/rat) to the secondary animal (cat) who eats it. The severity depends on the type and amount of bait or poison consumed. Some rodenticides meant for mice and rats can be lethal even in small doses for cats and dogs. Being aware of the risks and signs of secondary poisoning is important for all pet owners.
Types of Bait
The most common and effective rodent baits are anticoagulant rodenticides. Anticoagulants work by preventing blood clotting and causing internal bleeding, leading to organ damage and eventual death in rodents.
According to Rodent Baits and Bait Stations – DIY Pest Control, common anticoagulant ingredients in rodenticides include bromadiolone, brodifacoum, and difethialone. When ingested by rodents, these active ingredients disrupt the blood clotting process. The rodents bleed internally until they eventually die from blood loss and organ failure.
Anticoagulant baits come in various forms like pellets, blocks and gels. They are designed to be attractive to rodents – flavored with food like peanut butter or bacon. The effects of anticoagulants are cumulative so rodents need to consume the bait over several days, ensuring a lethal dose is built up in their system before death occurs.
Signs of Poisoning in Mice
Mice that have ingested rodenticides may show signs of poisoning within 1-2 days. The most common signs include:
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Lethargy and weakness – poisoned mice may appear sluggish, uncoordinated, and reluctant to move.
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Bleeding – anticoagulant rodenticides prevent blood clotting, leading to uncontrolled internal or external bleeding. This can manifest as bloody urine, nosebleeds, bleeding gums, bruising, or blood in the stool.
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Breathing issues – rodenticides can cause fluid buildup or bleeding in the lungs, resulting in labored breathing, wheezing, or gasping.
Other possible signs are dilated pupils, muscle tremors or twitching, seizures, and paralysis. The specific symptoms depend on the type of rodenticide. Without treatment, poisoned mice will die within several days (Source 1).
Secondary Poisoning in Cats
Cats eating poisoned mice can also be poisoned. This is known as secondary or relay poisoning. Rodenticides like bromethalin and warfarin do not necessarily kill rodents right away. The toxins bioaccumulate in the rodent’s tissues over several days before causing death. When a cat eats the rodent, the cat essentially eats the poison that’s accumulated in the rodent’s body.
According to the Pet Poison Helpline, the amount of poison transferred to a cat depends on how much poison the rodent ingested before dying. The more poison the rodent ate over several days, the more poison can transfer to the cat. A cat would need to eat many rodents that died from the poison before toxic effects kick in. But in high enough amounts, secondary poisoning can sicken or even kill cats.
One source states: “Secondary poisoning can occur when small carnivores, such as feral cats, ingest poisoned rodents. However, the dose of anticoagulant bait found in the tissues of poisoned rodents is much lower than that in the original bait. To cause toxic effects, a cat would need to consume many poisoned rodents.” (Source)
Signs of Poisoning in Cats
Cats exhibit several symptoms if they ingest poisoned mice or rats. The most common signs include lethargy, vomiting, and bleeding.
Lethargy is one of the first symptoms of rodenticide poisoning in cats. The cat may seem tired, weak, and unwilling to move around normally. This happens because the poison disrupts the cat’s normal blood clotting ability, leading to internal bleeding and anemia. According to VCA Hospitals, lethargy from blood loss prevents sufficient oxygen from reaching the cat’s tissues and organs.
Vomiting is another common symptom, which may contain blood if there is gastrointestinal bleeding. Cats may vomit repeatedly over the first 24 hours after ingesting the poison. Vomiting can lead to dehydration and electrolyte imbalances if left untreated.
Bleeding is a hallmark of anticoagulant rodenticide poisoning. Cats may bleed from the nose, mouth, or in their stool. Bleeding under the skin can also occur, leading to bruises. Prolonged bleeding from minor cuts or injuries is also indicative of clotting problems. According to PetMD, death usually occurs from severe internal hemorrhage involving the lungs and brain in poisoned cats.
Diagnosis
Diagnosing rodenticide poisoning in cats often involves blood tests to check the cat’s clotting ability. The veterinarian will look for increased clotting times due to a deficiency in vitamin K and the inhibition of certain clotting factors. Specific blood tests like prothrombin time (PT) and activated partial thromboplastin time (APTT) can help confirm impaired blood clotting. Prolonged PT and APTT times indicate that the blood is not clotting as quickly as it should. The veterinarian may also check blood cell counts and look for signs of internal bleeding.
In cases of secondary poisoning, where a cat has ingested an animal that consumed poison, the diagnosis can be more difficult. There may not be clear evidence that the cat directly consumed poison. However, blood tests showing impaired clotting ability along with a history of the cat eating rodents, birds, or other animals known to have ingested poison can help veterinarians make an accurate diagnosis.
Treatment
Treatment for rodenticide poisoning in cats focuses on flushing the toxin out of the body and administering an antidote. Some common treatments include:
Vitamin K1 injections or oral supplements. Vitamin K1 helps the body produce blood clotting factors and can counteract the effects of anticoagulant rodenticides. High doses are often needed over several weeks or months (source).
Blood transfusions. If a cat is actively bleeding, a blood transfusion can provide clotting factors and replace lost blood volume.
Inducing vomiting. If ingestion was recent, the vet may induce vomiting to remove any bait still present in the stomach. Vomiting should only be induced under veterinary supervision.
Other supportive care like intravenous fluids, oxygen therapy, and monitoring blood work may also be provided. With prompt aggressive treatment, many cats can recover fully from rodenticide poisoning.
Recovery and Prognosis
With prompt treatment, the prognosis for cats who have ingested rat poison is good. However, relapses are possible if treatment is discontinued too soon. Vitamin K supplementation needs to be continued for several weeks after initial treatment to ensure the rat poison is fully cleared from the body.
Cats being treated for rat poison toxicity need to be closely monitored, even after they are discharged from the veterinary hospital. Blood clotting times and vitamin K levels should be regularly checked to watch for any recurrence of symptoms. Typically, vitamin K treatment will need to continue for 3-4 weeks.
Most cats will make a full recovery within 4-6 weeks with appropriate treatment. However, any delays in seeking veterinary care or stopping medication too soon increases the risk of complications. Provided treatment is consistent and adequate, cats can recover fully from rodenticide toxicity. But owners do need to be vigilant in watching for any return of symptoms after treatment ends.
Overall, the prognosis is good if the poisoning is caught early and treated aggressively. But owners should be prepared for an extended recovery with the need for ongoing medication and follow-up testing. With prompt and proper treatment, most cats survive rat bait ingestion.
Prevention
The best way to prevent secondary poisoning in cats is to avoid using rat and mouse poisons entirely. There are several steps pet owners can take to limit rodent access and use safer trapping methods:
Use bait traps or live traps instead of poisons. Products like the Victor Electronic Rat Trap provide a humane way to trap mice without poisons. You can also use non-toxic baits like peanut butter in standard snap traps. This eliminates the risk of poisoning pets while still removing mice from your home.
Seal any potential entry points for mice like cracks and holes. This limits access to your home and removes food sources. Caulk or fill gaps in walls, floors, doors and windows. Also ensure lids are tight on garbage cans.
Clean up any spilled pet food or crumbs. Don’t leave pet food out overnight. This removes an attractive food source for mice.
Store human and pet food in sealed metal or thick plastic containers to limit access. Keep pet food bags in lidded bins.
Cut overgrown vegetation and woodpiles near the home. Mice are attracted to areas with cover.
Use natural rodent repellents like peppermint oil, cloves, chili powder or ammonia-soaked cotton balls. Strong smells deter mice.
Adopt cats – cats are excellent natural mousers. Just be sure to limit their outdoor access to avoid hunting poisoned mice.
With some simple prevention steps, you can avoid the use of harmful poisons while still keeping mice out of your home.
Conclusion
When mice consume poison baits, toxins can accumulate in their bodies. If a cat eats a poisoned mouse, the toxins can then be passed on to the cat in a process called secondary poisoning.
The main signs of poisoning in cats include lethargy, loss of appetite, vomiting, drooling, tremors, seizures, and potentially death. Secondary rodenticide poisoning in cats is a dangerous medical emergency requiring immediate veterinary treatment.
The best way to prevent secondary poisoning is to avoid using rodenticides and bait stations if you have cats or other pets in the home. Keeping pet food and garbage securely sealed can help deter mice without the need for poisons. With proper prevention, cats can avoid tragic poisoning incidents involving baits or mice.