Nicotiana Poisoning in Dogs

Nicotiana poisoning is a rarely reported toxicosis that presents in a similar fashion to other poisonings such as disulfoton and yew. The clinical signs and symptoms are complex and are mostly of central nervous system derangement. As the prognosis is drastically improved with early intervention and treatment, it is vital that if you suspect your pet has consumed the nicotiana plant you contact your veterinarian immediately.

Nicotiana is also known as tobacco flower. The toxic components of the nicotiana plant are nornicotine and nicotine (pyridine and piperidine alkaloids). These toxins cause complex clinical signs and symptoms which mostly affect the central nervous system.

The clinical signs of nicotiana poisoning in dogs are mostly of central nervous system derangement. The severity and rate of progression are dependent on the dose consumed. In cases where the dog has consumed large amounts of the toxin they may present with total collapse, slow and shallow respiration, dilated pupils and a weak, rapid pulse. Symptoms include:

• Seizures
• Tremors
• Ataxia/stumbling 
• Dyspnea
• Wheezing
• Bronchoconstriction 
• Increased bronchial secretions 
• Increased salivation
• Lacrimation
• Urination 
• Possibility of seizures or collapse 
• Weak, rapid pulse
• Tachycardia and tachypnea (rapid heart beat and rapid breathing)
• Hypothermia
• Irregular pulse

Types

Studies have revealed that the toxic level of nicotine ingestion due to tobacco consumption in dogs is 5 milligrams of nicotine per pound of your dog’s weight. The lethal dose can be 10 mg/kg in dogs. Ingestion of the nicotiana plant can also result in severe symptoms if eaten in large doses. Other sources of nicotine include:

• Cigarettes
• Cigars
• Nicorette gum 
• Snuff
• Nasal sprays 
• Transdermal patches

Nicotine found in the nicotiana plant and other sources is not absorbed effectively in the stomach but absorbed well in the small intestine, respiratory tract and through the skin. Nicotine causes an overload of acetylcholine (ACh) at sympathetic and parasympathetic ganglia, at neuromuscular junctions of skeletal muscle, and at some synapses in the central nervous system. This results in the overstimulation of nicotinic and muscarinic ACh receptors, triggering nicotinic and muscarinic symptoms. Higher doses cause blockage at autonomic ganglia and myoneural junctions of skeletal muscle.

If you think your pet has had access to the nicotiana plant, inform your veterinarian of this upon arrival. If possible, bring along a sample of the plant to the veterinary clinic. As nicotiana plant poisoning can present similarly to various other poisonings, knowledge of a pet’s access can be very helpful for diagnosis. Conditions that may present in the same way are:

• Organophosphate poisoning 
• Lead poisoning
• Prescription drug ingestion
• Pyrethrin and pyrethroid insecticide toxicoses 

The diagnosis of nicotiana toxicity is usually made by your veterinarian by looking at your pet’s history and symptoms. Your veterinarian will perform a full, clinical examination of your pet. If your pet is vomiting the stomach contents will be examined for evidence of plant matter. 

Although there are tests that can be carried out to test for the toxin in your pet’s blood, urine, and gastric contents, these are not commonly carried out due to the cost and delay in results. It is vital that treatment is commenced as soon as possible.

As there is no cure for nicotine toxicity or nicotiana plant poisoning, your veterinarian will instead aim to reduce the toxin that is absorbed  by your pet’s body and reduce the symptoms experienced. 

If your pet is able to receive treatment before symptoms begin, your veterinarian may induce vomiting or perform a gastric lavage to prevent the absorption of the toxins. However, if your pet is unconscious, this is contraindicated due to the risk of aspiration. There is some research that shows activated charcoal may also be beneficial for your pet as it can bind the toxins present in the stomach. 

If your dog is suffering from vomiting and diarrhea, intravenous fluid therapy may be given to prevent dehydration and help the elimination of nicotine. Other supportive medications your veterinarian may offer are atropine to treat parasympathetic effects, and diazepam if your dog is suffering from muscle tremors, shaking, and seizures. As hypothermia may be an effect of nicotine poisoning, fluid therapy will also benefit due to it’s ability to help regulate temperature.  To further support temperature regulation, it is essential that warm bedding is provided and changed regularly to prevent coldness from dampness and urine scalding.

If your dog has consumed only a small amount of the plant, has been in otherwise good health, and receives care quickly, a good prognosis is expected. It is expected that the nicotine would have left the body within 16-20 hours. It is vital to prevent further poisoning that all nicotine products are removed from your pet’s environment and you are vigilant when off property with your pet, especially if he likes to graze on potentially harmful flowers and foliage. The incidence of poisoning from the nicotiana plant is rare; the chances of ingestion of a product containing tobacco is more likely.