You may not use rat poison, or if you do, it may be tucked away so well Frisky can't get to it. However, just because she doesn't eat the poison itself doesn't mean she's safe. Cats can suffer from secondary rat poisoning by ingesting a mouse or rat who's eaten poison.
If Frisky is particularly curious and gets into the mouse bait, she's at risk for primary toxicosis, the poisoning from ingesting the poison itself. Primary poisoning is a serious risk for pet owners combating a rodent problem with rodenticides. According to the Pet Poison Helpline, effects of primary toxicosis can be mild to lethal, depending how much a cat eats and the poison used. Get her to a veterinarian immediately for treatment.
If Frisky eats a mouse who's ingested poison, she can become very sick even though she didn't eat the poison itself. If that happens, she's suffering from secondary toxicosis, or poisoning, because the poison was passed along the food chain. When a mouse eats a single feed rodenticide, such as warfarin or bromadiolone, he doesn't immediately become sick and die. Instead, the mouse goes about its business for a day or two before dying, as the poison slowly does its work. If Frisky comes across the mouse in her travels, and he becomes her prey, she's also ingesting the poison the mouse ate. Single feed rodenticides use large amounts of poison in order to kill the target vermin in one feeding. Because it takes so long for the poison to act, Frisky has no way to know she's eating deadly prey.
Symptoms of Rat Poisoning
Unfortunately, there's no way to know right off the bat if Frisky's eaten a poisoned mouse. Like the mouse, your cat will wait a day or two before the poison has its effect on her system. Eventually, however, you'll see symptoms alerting you to trouble. Depending on the poison ingested, you may notice a loss of appetite, slight muscle tremors, impaired movement or paralysis in the back legs, seizures, pale gums, bleeding from the nose, bloody urine or feces, swollen belly, red splotches on the skin, lethargy or weakness.
Treating Secondary Poisoning
If you see any symptoms in Frisky, she should see a vet immediately, particularly if you've seen her playing with a mouse. Successful treatment for rat poison ingestion depends on the poison ingested, as well as how much she ate and when she ingested it. The vet will run blood tests and urinalysis, as well as other diagnostic tests as necessary. Depending on her condition, Frisky may need to stay at the hospital and require transfusions, fluids and medication.
Preventing Secondary Poisoning
Having rat poison in the house is risky, no matter how secure it is. To minimize the rodent presence in the house, keep your house clean. Store all food properly and don't feed wildlife, as the food attracts all wildlife, including the mice and rats you're trying to avoid. Rodent-proof your house and outbuildings, taking care to seal entryways where mice can sneak in and find warmth. As for Frisky, it's best to keep her inside. Though you may not use harmful rodenticides, it's hard to know what others in the neighborhood use. She may catch and eat a mouse that's eaten dangerous rat poison elsewhere during her outdoor travels.