Strychnine Poisoning in Dogs
Strychnine is a very dangerous and strong poison that is often used in baits used for killing rats, moles, gophers, and other rodents or unwanted predators. Having a very short duration of action, the clinical symptoms of strychnine poisoning typically appear within ten minutes to two hours after ingestion, resulting in sudden death.
Patients often will die of strangulation due to spasming of the muscles involved in respiration. Dogs of all ages are equally susceptible to the adverse effects of strychnine.
Symptoms and Types
The following are some of the symptoms of strychnine poisoning:
- Limb rigidity
- Stiff muscles
- Severe spasms leading to arching of the head, neck and back in extreme hyperextension (opisthotonus)
- Uncontrolled violent seizures (sometimes in response to bright lights or noise)
- Breathing difficulties, inability to breathe
- Elevated heart rate
- High body temperature
- Malicious poisoning by lacing foods with strychnine
- Accidental exposure to baits (common in dogs)
- Ingestion of poisoned rodents and birds
Treatment for strychnine poisoning needs to be given immediately. If you know or suspect that your dog was exposed to poison and you can gather a sample of vomit or feces to take to your veterinarian for immediate laboratory analysis, your doctor will be better able to treat your dog quickly and effectively. As much as possible, you will need to give your veterinarian a thorough history of your dog's health, onset of symptoms, and possible incidents that might have led to this condition.
Blood samples will be taken for testing, as poison can cause a number of system failures and imbalances, and treatment will be based on the specific conditions, with the most serious being being given primary attention. Routine laboratory tests will include a complete blood count, biochemistry profile, and urinalysis. The biochemistry profile may indicate an abnormal rise in the levels of enzymes called creatine kinase and lactate dehydrogenase, and the urinalysis may show high levels of the protein myglobin (myglobinuria). A blood sample will also be submitted for determination of blood gases, which are often at abnormal levels due to respiratory muscle spasms. Your veterinarian may also take samples of the stomach contents for analysis and/or to determine if any damage has taken place in the stomach lining.
This is an emergency requiring immediate treatment. It cannot be treated at home. If you suspect that your dog is unwell because of exposure to bait or any other material containing strychnine - which may be suspected based on the presence of baits in your neighborhood, or following a visual confirmation that your dog has recently bitten into and possibly digested a caught rodent or small animal (which may have itself eaten from a poison bait) -- you will need to seek medical attention before the condition becomes dire.
The primary goal of emergency treatment is to prevent strangulation due to spasms of the respiratory muscles, a side effect that is characteristic of this condition. Artificial respiration will be required if your dog is not able to breathe normally. Your veterinarian will also give medications for reducing muscle activity in the hope of avoiding the muscle spasms that make breathing difficult.
Once your dog has been admitted for treatment of strychnine toxicity, it will be placed in a quiet and dimly lit room, as any external stimulus such as noise or bright light can initiate seizures. Your veterinarian will decontaminate your dog's digestive system by performing a lavage of the stomach, giving plenty of intravenous fluids, and administering drugs that will encourage urination so that the poison is removed from the body as quickly and effectively as possible.
In some patients, vomiting may also be induced to remove the poison from the stomach, especially if the ingestion of the poison is witnessed firsthand and the dog can be taken to the animal clinic immediately. Drugs can be given by mouth to bind and neutralize the toxic substances, making them inactive. Drugs to control seizures are also employed, as seizures are the most common problem in patients with strychnine poisoning.
Living and Management
The overall prognosis will depend on the time factor. If treatment is started soon after the ingestion, a favorable outcome can be expected. Controlling the seizures is the most important factor in estimating the prognosis, so if seizures have been controlled, there is a good chance your dog will recover.
After the initial treatment, you may need to revisit your veterinarian a few more times to evaluate your dog's overall health and to make sure that there has not been any permanent damage to the kidneys, nervous system, or any other organs or systems.