The symptoms of a poisoned pet depend on the type of poison he or she is exposed to. Signs of illness may include the following:

• Vomiting
• Diarrhea
• Seizures
• Blood in the stool
• Lethargy
• Loss of appetite
• Bruising
• Nosebleeds
• Irregular heartbeat
• Inability to urinate

Types of poisoning symptoms in dogs and cats

Gastrointestinal poisoning symptoms
Gastrointestinal symptoms, including loss of appetite and vomiting, result from eating poisons like garbage or lead paint and from toxic plants, such as English ivy and English holly. Diarrhea is caused by eating garbage, medications, some snake bites, chocolate, and many toxic plants, including Chinaberry, iris, poinsettia, pokeweed and daphne.

Seizures and neurologic poisoning symptoms
Seizures and neurologic symptoms are caused by several poisons including strychnine, tobacco, aspirin, antidepressants, alcohol, marijuana, flea repellents, insecticides, gasoline, drain cleaners, dishwasher detergent, and furniture polish. Some frogs, toads, spiders, and snakes also cause seizures in pets, including Coral snakes, the Florida marine toad, the Colorado River toad and the brown recluse spider. Some plants also cause neurologic symptoms, including horse chestnuts and buckeyes.

Bleeding and anemia from poisoning
Bruising, nosebleeds, blood in the stool, and anemia are caused by rat and mouse poisons. Excessive amounts of onions and garlic, sweet clover, and bracken fern also cause anemia and possible death.

Heart symptoms from poisoning
Irregular heart rhythm and cardiac symptoms are caused by many medications and plants including oleander, milkweed, jimson weed, kalanchoe, and mountain laurel.

Kidney symptoms from poisoning
Kidney failure and the inability to produce urine is caused by antifreeze poisoning. Many plants cause kidney damage, including caladium, pigweed, dieffenbachia, Easter lily, and philodendron.

Liver symptoms from poisoning
Liver damage is caused by many medications including acetaminophen (Tylenol) and by many plants including tansy ragwort and rattlebox.

How quickly will my pet become ill?

How quickly your pet becomes ill depends upon how much your pet consumed and which poison is involved. Strychnine causes immediate symptoms, but lead paint and many anti-coagulant rat and mouse poisons cause delayed symptoms.

Cats can be poisoned by flea medication for dogs

Cats are not small dogs and can be poisoned by dog flea medications, such as K9 Advantix. Cats cannot metabolize the ingredients used in this product and must be separated from dogs during treatment. Do not allow your cat to come in contact with a treated dog for 24 hours. Never give your cat flea medications for dogs.
A fluffy, flea-infested Persian cat was dipped with a flea product intended for use on dogs. Within two hours, she was salivating and had muscle tremors. The family called the veterinary clinic and the technician helped them through the emergency. First, the family read the technician the information on the label from the dip. The package said, "for use in dogs" and identified permethrin as one of the ingredients. Now, the technician had something to go on. She described symptoms caused by permethrin: drooling (ptylism), staggering, vomiting , and depression. The family thought their cat had these symptoms.
Next, the technician told the family that the dip had to be removed immediately because permethrin can cause seizures and death in cats. The family quickly washed out the dipping basin, filled it with cat shampoo, and gently washed their cat for ten minutes. Then they rinsed their cat three times. This might have been difficult, but their little cat was too sick to protest.
The next step was to gave their cat activated charcoal (1/2 gram/lb) through a syringe between the back teeth. The charcoal protected their cat from the permethrin swallowed while licking herself when first dipped.

The family paid close attention to their cat for the next three days. Their cat had black diarrhea from the charcoal, but like most cats, recovered fully. The mother asked the oldest girl, who wanted to grow up to be a veterinarian to read the labels of all medications, dips, and flea treatments in the future.

Diagnosis of poisoned dogs and cats

How a poisoning is diagnosed depends, in part, upon how long your pet has been ill. If your pet suddenly becomes ill and your veterinarian induces vomiting, the poison might be identified almost immediately. For example, if your pet is induced to vomit and the vomit is blue, that's a good indication your pet ate rat poison, which is frequently dyed blue. For a definitive diagnosis, the vomited contents are sent to a pathology lab. It is also possible to immediately identify some plants and bulbs in fresh vomit.
On the other hand, if your pet has been ill for a long time, your veterinarian may send blood or tissue samples to the pathology lab. For example, if you have a Bedlington Terrier or a Westie and he or she got into the copper tox used to treat sheep hooves, your veterinarian will send blood and a liver biopsy sample to the laboratory.
If your pet dies, your veterinarian may perform a necropsy and examine the brain and internal organs to identify the cause of death. Information gained from the necropsy helps prevent another pet from dying of the same poison.