Carbamates Poisoning in Dogs

Carbamates are known as acetylcholinesterase inhibitors and are used in agriculture as fungicides, herbicides, and insecticides. In simple terms, this pesticide affects the central nervous system of garden and agricultural pests such as mollusks, fungi, and bugs. This product is also has pharmaceutical benefits and is being used in medications for neurological disorders like Parkinson’s disease dementia. Documentation on poisonings in dogs by carbamate is found as exposure to the pesticide. Symptoms can include tremors and convulsions. Death is common with the ingestion of large amounts, though in many cases prompt treatment can enable a recovery. Some of the names of carbamate products are Aldicarb, Methiocarb, Methomyl, Carbaryl, Oxamyl, and Fenoxycarb.

Carbamate is a pesticide derived from carbamic acid and primarily affects nerve impulse transmission. Extremely toxic to dogs, carbamate exposure must be treated by a veterinarian as soon as possible because ingestion or inhalation can be fatal. Dermal exposure can also be very toxic.

With carbamate poisoning in dogs, symptoms can appear within 30 minutes. They can also be delayed up to 3 hours. Immediate care is necessary because the absorption of this poison is rapid; do not wait for symptoms to appear before taking your dog to the veterinarian clinic or emergency room. The most common symptoms seen as the poison begins to take effect are:

• Vomiting
• Convulsions
• Tremors and twitching

Other signs of carbamate poisoning which are commonly documented in canines are all indicative of the ingestion of a very dangerous product.

• Hypersalivation
• Diarrhea
• Urinary incontinence
• Constricted pupils
• Loss of control of bodily movements
• Abdominal cramping
• Fluid buildup in the lungs
• Muscle contractions
• Shaking
• Sensitivity to stimuli

With a severe toxicity, symptoms can include a slowdown of heart beat, blue mucus membranes, collapse, and coma.

Types

Carbamate poisoning in dogs affects the body in many ways.

Muscarinic effects 

• Felt in the smooth muscle of the intestine and glands, the cardiac muscle, CNS, and iris
• For example constriction of the pupil of the eye
• Slowness of the heart
• Production of watery fluid in the lungs

Nicotinic effects

• Felt at the neuromuscular junctions of striated muscle and synapses of autonomic ganglia
• For example muscle contractions
• Weakness
• Paralysis

Central nervous system effects

• For example depression
• Apprehension
• Seizure
• Coma

Cholinesterase enzymes which affect nerve impulse transmission are the target of carbamate

• Carbamate is quickly absorbed
• The gastrointestinal tract, skin, and lungs are the path for absorption
• The carbamate is then broken down by the liver and excreted by the liver, kidneys, and lungs
• Most cases of toxicity are due to the ingestion of the pesticide (such as in fly bait which is palatable to dogs)
• There are also cases of malicious poisoning of pets by the mixing of carbamate products in meat
• In some countries, carbamate has been used illegally as a rodenticide, increasing the chances of exposure and toxicity to dogs

There are no diagnostic tests that can immediately diagnose a carbamate poisoning in dogs. The veterinarian will form his conclusion on the history and specifics that you are able to provide, if any, and the clinical signs. The signs of carbamate poisoning are severe as are the rapid effects. Immediate action will be taken if poisoning is suspected in order to give your dog the best chances of survival. Blood tests may be able to point to toxicity by carbamate, but this diagnostic tool will not be utilized until treatment is already underway.

Immediate and aggressive treatment can allow for a good recovery prognosis. Intravenous fluids will be started for rehydration if needed, and for the administration of medication.

Atropine

This is an antimuscarinic drug that slows down or stops overstimulation and excess of nerve impulses. It will help regulate the heartbeat of your pet, slow down the buildup of fluid, and inhibit symptoms like spasming of the bronchi. 

Diphenhydramine

This medication can reduce tremors and muscle contractions.

Diazepam

A sedative, diazepam can relax muscles and give your dog the opportunity to rest as the veterinarian continues treatment.

Emetics

Depending on the condition of your pet and the timing of the poison, vomiting may be induced and gastric lavage performed.

Active charcoal

This compound is commonly used when the situation warrants as it can bind the poison and inhibit further absorption and may aid in a more rapid elimination from the body.

Other therapies

The veterinary team will monitor your dog’s vital signs, maintaining his body temperature, assuring he is rehydrated and his electrolytes are balanced and returned to normal. Seizure control is also an important part of the recovery process.

With a carbamate poisoning, the good news is that though the symptoms can be intense, they may resolve in a fairly quick fashion with adequate treatment. The key to recovery is timely supportive treatment to reverse the intense symptoms that your pet may be experiencing.