Strychnine. Strychnine is a toxin derived from the seeds of Strychnos nux vomica and S. ignatii and is used to control rats, moles and other predators. However, when ingested by dogs, it is extremely toxic, and can cause death. Direct exposure to bait is the most common cause in dogs, although intentional poisonings are not uncommon. Toxicity can also occur from the ingestion of poisoned rodents and birds. The primary effect of the toxin is on the neurological system. The toxin interferes with inhibitory transmitters, which produce a state of muscle rigidity and stimulation. Death is often caused by the effect on muscles that stimulate breathing. If you witness your dog ingesting strychnine, contact your veterinarian at once. He or she may direct you to induce vomiting immediately, if it is within minutes of ingestion. Take all poison packages with you to your veterinarian’s office.
Toads. The Colorado River toad and the giant toad (also called the marine toad) are the two most common poisonous toads found in the United States. Though most toads are bitter tasting and usually result in profuse drooling in any pet that tries to take a taste, only a couple of species of toads are truly poisonous. The poisonous secretions from these toads can affect animals who come in contact with them, causing a host of clinical signs. The poison is highly toxic to pets. Dogs have a high probability of dying if untreated.
Topical Poisons. Poisoning associated with topical medications is uncommon in dogs and cats. The topical product usually associated with toxicity is an inappropriately applied topical flea product. The products specifically labeled for use in dogs can result in serious toxicity if administered to cats. The toxic substance in these products is permethrin, which can have devastating effects if given to cats.
Tylenol. Acetaminophen is a medication commonly used to alleviate fever and pain. Common brands include Tylenol®, Percoset®, aspirin free Excedrin® and various sinus, cold and flu medications. Dogs most commonly receive toxic amounts of acetaminophen because owners medicate them without consulting a veterinarian. They also consume tablets that are dropped on the floor or left lying around. Dogs are less sensitive to acetaminophen than cats. For example, a 50-pound dog would need to ingest over seven 500 mg tablets in order to suffer toxic effects. In the cat, one 250 mg acetaminophen tablet could be fatal. There is no home care for acetaminophen toxicity. If you suspect that your dog has ingested a toxic amount of acetaminophen, (one pill or more), contact your family veterinarian or local veterinary emergency facility immediately.
Vitamins. Vitamin toxicity occurs when the intake of a dietary vitamin exceeds the normal requirement causing adverse clinical signs or disease. Normal requirements differ for different vitamins and there are a variety of causes of vitamin toxicity, depending on the type of vitamin.
Zinc. Zinc toxicity is most often seen in young dogs that ingest some form of zinc. The most common sources are pennies minted after 1982, zinc nuts and bolts, which can be found in transport cages, galvanized metals, zinc-containing ointments (e.g. zinc oxide ointment), and zinc game pieces from board games. Zinc is directly irritating to the stomach lining so it may cause gastrointestinal irritation as well as a potentially fatal blood disorder. Signs include: vomiting, diarrhea, lack of appetite, lethargy and pale gums. A toxic dose for a typical dog may be as few as 1 to 3 pennies (50 to 100 mg/kg).