Canine Organophosphate Poisoning Symptoms

Organophosphate poisoning affects thousands of dogs each year. Organophosphate is the active ingredient found in many insecticides, including those used for flea and tick infestations and garden and lawn care. Organophosphate poisoning warrants immediate veterinarian attention. Symptoms can occur within minutes or take several hours to manifest.

What Is Organophosphate Poisoning?

Organophosphate poisoning occurs whenever organophosphate is absorbed by the body through the skin, gastrointestinal tract or respiratory system. This toxin attacks the enzymes cholinesterase and acetylcholinesterase used by the nerves of the nervous system to communicate, thereby slowing down nerve-muscle communications, resulting in damage to the nervous system throughout the body. This produces a continuous stimulus to organs, nerve tissue and muscles because acetylcholine remains attached to neurons. This is why a dog may exhibit shaking or seizures.


Products containing organophosphate are safe providing they are used correctly; however, insecticides should never be combined. The use of a flea collar or a flea bath should be done separately, not combined. This could be toxic for any pet and even fatal. Organophosphate poisoning occurs whenever a product containing the substance is misused, overused or if multiple products containing organophosphate are used simultaneously. It is best to read all warning labels before using any product containing organophosphate. Following directions on the warning labels will prevent any possibility of organophosphate poisoning.

Before using any product containing organophosphate on any sick dog, consult a veterinarian. Sick dogs have a depressed immunity system and exposure to any insecticide can affect them greatly.

Symptoms of Organophosphate Poisoning

The following is a list of possible symptoms of organophosphate poisoning. Depending upon the amount a dog has absorbed or ingested determines the type and severity of the symptoms.

  • Constricted pupils
  • Vomiting
  • Diarrhea
  • Muscle weakness
  • Urinating
  • Drooling
  • Difficulty breathing
  • Anorexia
  • Depression
  • Seizures
  • Possible death

Types of Organophosphate Insecticides

There are two types of organophosphate insecticides: 1) insecticides used for flea and tick infestations and 2) insecticides used for garden and lawn maintenance. Common organophosphate insecticides are used in flea dips, flea collars and topical flea products.

Brand name garden and lawn insecticides include such chemicals as disulfotin, diazinon, fonofos, chlorpyrifos, acephate, matathion and parathion.

Treatment for Organophosphate Poisoning

Immediate action must be taken in the event that a dog has been poisoned by a product containing organophosphate. It is important to seek medical attention before the toxins are absorbed into the body. Bringing in the organophosphate product will hasten the process of diagnosing the problem and thereby treating the poisoning quickly. Decontaminating and stabilizing the dog is key to combating the poisoning.

Using a gastric lavage, the veterinarian will induce vomiting by flushing out the stomach. A tube is inserted into the stomach via the mouth and activated charcoal, usually in powdered form, is given by way of this tube. The charcoal binds with the toxins and together they are eliminated before they can be absorbed by the body and cause damage.

Treatment is determined by the symptoms being manifested. For example, if the dog is dehydrated, IV fluids would be administered. If the dog is experiencing seizures, anticonvulsant medication would be given. If the dog is experiencing difficulty in breathing, then an oxygen cage would be used. The sooner the treatment begins, the better the prognosis.