Paraquat Garden Items Poisoning in Dogs

Garden and agricultural herbicides with the ingredient paraquat are commonly used to fight the various pests that can negatively affect plant growth. It can still be found in the United States, though not as common as in other countries. This poisonous compound is an effective herbicide in wet climates, and is used in the production of crops and crop systems because of the low risk of environmental contamination. Although this risk is low, paraquat is highly poisonous to animals when ingested.

This restricted-use herbicide in the United States can be found in a variety of formulations in sprays and also in liquid forms of fertilizer. Although these contain small amounts of paraquat, they are still highly poisonous when dogs consume them or any plants that they are sprayed upon. This substance is usually found in liquid form or in diluted form when included in herbicides. Due to the highly toxic nature of paraquat, this pesticide may only be used by users that are commercially licensed.

Paraquat garden items poisoning in dogs occurs when dogs ingest paraquat, a powerful ingredient that is included in a variety of herbicides and pesticides. This substance is primarily used for agricultural needs, as well as for weed and grass control.

Paraquat is highly poisonous, and when consumed by dogs the symptoms can develop very rapidly. Symptoms of paraquat poisoning in dogs include:

• Vomiting
• Diarrhea
• Mouth ulcers
• Ulcers in the esophagus
• Drooling
• Excessive thirst
• Confusion
• Elevated heart rate
• Organ failure
• Seizures

Types

Paraquat can be found under different types of registered brand names in the United States. Although rare in the United States, substances that contain this compound must be clearly labeled.  The different types of names that signify paraquat are:

• Gramoxone Super (Syngenta)
• Gramoxone Max (Syngenta)
• Marman USA
• Surefire Herbicide

Paraquat ingestion can lead to death of the dog if not immediately treated. Causes of poisoning of paraquat are:

• Ingestion of paraquat results in oxidation-reduction reactions within tissues
• Damage to the cellular macromolecules (membrane lipids)
• Marked tissue damage
• Mostly accumulates in the lungs

If your dog is exhibiting any of the above symptoms, it is important to take him to the veterinarian as soon as possible. If you know that your dog has ingested any herbicide or pesticide, it is important to tell your physician so he will have a clue as to what he ingested.

The veterinarian will perform a complete physical examination, and run specific tests. Tests include a urinalysis, blood testing, and a biochemistry profile. The veterinarian will also perform a histologic test of his affected tissues and check for paraquat within samples of his tissues. The veterinarian will also want to check for concentrations of paraquat in his biologic fluids by chromatography, spectrophotometry, and radioimmunoassay.

It is very important that the dog receive treatment as soon as possible, therefore, the veterinarian may perform initial testing based on a urine test or plasma test based on dithionite reaction. The veterinarian may also choose to collect samples of the dog’s gastric contents, feces, renal tissue and lung samples. These samples are usually more effective in identifying paraquat over blood samples.

Although there is no antidote to immediately treat the poisoning from paraquat, there are a few methods that can be effective only if the dog is seen immediately after ingesting this toxic substance. Treatment methods may include:

Neutralizing the Poison

Early treatment by neutralizing the poison can be accomplished by giving the dog a substance to absorb the paraquat. In addition to the induction of vomiting and performing gastric lavage, which is the flushing of the stomach contents, various forms of absorbent substances may be used. Calcium montmorillonite, bentonite, or attapulgite clay can be beneficial in absorbing the poison.

Activated Charcoal

Activated charcoal may also be used either alone or in addition to the absorbent substance. Activated charcoal, usually administered after emesis, can help absorb any remaining toxins. In order to prevent perforation of the esophagus, extreme caution must be used in the administration of absorbent material through a tube into the stomach.

IV Fluids

Encouraging the production of urine is very important when an animal is being treated for paraquat poisoning. Intravenous fluids can help with the diuresis of removing any paraquat in the system.

Antioxidants

In some cases, antioxidant therapy may be effective. Propofol, epigallocatechin gallate, trimetazidine, and S-carboxymethylcysteine may be used. Studies are still being conducted on the use of antioxidant therapy for dogs affected with paraquat poisoning; however, your veterinarian may decide on this type of therapy if he feels it can be effective.

Unfortunately, the prognosis for paraquat poisoning is poor. Even if treatment occurs immediately after poisoning, the risks are too great for imminent death. It does depend on the amount of paraquat ingested by the dog and how long it takes for treatment to occur. If the paraquat was ingested in a diluted form and treatment was given immediately, the prognosis may be guarded at best.

If the veterinarian was able to treat your dog and he seems to be recovering, he will give you specific instructions on how to continue to care for your companion. If you are able to take him home as he recovers, the veterinarian will want to see him for routine follow-up visits in order to be sure he is recovering properly. If you notice any new symptoms developing in your companion after treatment, it is very important to contact your veterinarian immediately.