Poison Baits and dogs

Animal baits containing strychnine, sodium fluoroacetate, phosphorus, zinc phosphide, and metaldehyde are used in rural areas to control gophers, coyotes, and other predators. They are also used in stables and barns to eliminate rodents. These baits are highly palatable and therefore may be accidentally ingested by a dog. Many are extremely toxic and kill in a matter of minutes. Fortunately, they are being used less frequently because of livestock losses, concerns about persistence in the environment, and the potential to poison pets and children.

Strychnine is used as a rat, gopher, mole, and coyote poison. In concentrations greater than 0.5 percent its use is restricted to certified exterminators. It is available to the public in concentrations of 0.3 percent or less. With better regulation and the use of lower concentrations, strychnine is becoming a less common cause of accidental poisoning. Signs of strychnine poisoning appear within two hours of ingestion. They include agitation, excitability, and apprehension, followed rather quickly by intensely painful convulsions with rigid extension of all four limbs. Seizures last about 60 seconds, during which time the dog throws his head back, stops breathing, and turns blue. The slightest stimulation, even touching the dog or clapping the hands, can trigger a seizure. This type of seizure response is typical only of strychnine. Other signs of poisoning include tremors, champing, drooling, uncoordinated muscle spasms, collapse, and paddling of the legs.

Treatment: Induce vomiting immediately after ingestion. But do not induce vomiting if the dog is unresponsive, convulsing, or having difficulty breathing. Cover the dog with a coat or blanket and proceed as quickly as possible to the nearest veterinary clinic. Further treatment involves administering intravenous diazepam (Valium) or barbiturates to control seizures. The dog is placed in a dark, quiet room and disturbed as little as possible.

Sodium fluoroacetate (compound 1080/1081), a very potent rat and gopher poison, is restricted to licensed pest control operators and is used infrequently in the United States. Dogs and cats have been poisoned by eating a dead rodent that has ingested the poison. The onset is sudden and begins with vomiting, followed by agitation, staggering, convulsions, and collapse.

Treatment: Treatment is similar to that described for strychnine poisoning (on this page).

Metaldehyde often combined with arsenic, is found in rat, snail, and slug baits. It is also used as a solid fuel for camp stoves. The dry form looks and tastes like dog food. Signs of toxicity include excitation, drooling and slobbering, uncoordinated gait, muscle tremors, inability to stand, and continuous seizures that eventually lead to death from respiratory paralysis. Signs many appear immediately or up to three hours after ingestion. Dogs who survive the acute poisoning may die from secondary liver failure.

Treatment: Treatment is similar to that described for strychnine poisoning (on this page).

Phosphorus: This extremely toxic chemical is used in rat and roach poisons and is also found in fireworks, matches, and matchboxes. A poisoned dog may have a garlic odor to his breath. The first signs of intoxication are vomiting and diarrhea. This is followed by an interval of normal behavior, then by further vom- iting, cramps, pain in the abdomen, convulsions, and coma.

Treatment: Induce vomiting when you suspect the dog has ingested a product or poison that contains phosphorus. Do not coat the bowel with milk or egg whites, as this can actually promote absorption. Take your dog to the nearest veterinary facility. There is no specific antidote.

Zinc Phosphide: This substance is found in rat poisons and is used by pest control professionals as a grain fumigant. Zinc phosphide in the stomach releases gas that has the odor of garlic or rotten fish. Intoxication causes depression, rapid labored breathing, vomiting (often of blood), weakness, convulsions, and death.

Treatment: Treatment is similar to that described for strychnine poisoning (on this page). The lavage must be done at a veterinary clinic. There is no specific antidote. The stomach should be lavaged with 5 percent sodium bicarbonate, which raises the gastric pH and delays the formation of gas.