Pyrethrin Shampoo for Dogs

Pyrethrin shampoo kills fleas but can cause side effects.

Pyrethrin is an insecticide that is added to dog shampoos to kill fleas. Killing fleas without pesticides can be a long, arduous and often unsuccessful process. Fortunately, pyrethrin-based dog shampoos are effective if used as directed. Pyrethrin can make some animals sick so it is important to follow the directions carefully to protect you and your pet. Pregnant or nursing women should avoid exposure to dog shampoos that contain pyrethrin, as there may be a link between pyrethrin exposure and autism, according to "The Sunday Times (UK)."

Mechanism

Pyrethrin, derived from the chrysanthemum plant, is a natural insecticide that attacks the nervous system of insects. Pyrethrins alone may not kill insects completely, and the pyrethrin-like chemicals (called pyrethroids) in most dog shampoos are synthetic , concentrated derivatives of the natural chemical, according to Cornell University's Toxicology Network.

Effectiveness

Pyrethrins are effective at killing adult fleas but they will not kill larvae or eggs. Adult fleas produce 20 to 30 eggs per day, according to the UC Davis Integrated Pest Management Program. These eggs will continue to hatch and re-infest your dog unless they are eradicated from its environment. The most effective flea management program includes treating the dog, its bedding, its carrier and your home. In cases of severe infestation, you may also need to treat your car, yard and anywhere else your dog spends time, according to Manchester Pest Control.

Side Effects

While many dogs will experience no side effects from exposure to pyrethrin in shampoo, some will exhibit serious side effects and will require immediate veterinary care, according to Pet Place. Side effects to watch out for include: lethargy, drooling, muscle tremors, seizures and vomiting. Smaller dogs may be more susceptible to adverse effects from pyrethrins.

In Case of Overdose

If you notice your dog exhibiting symptoms of overdose, wash your dog with warm water and dish soap through three full lathers and rinses. Pyrethrin shampoos are oil based and regular bath soaps won't remove the chemical. Dish soap, particularly with a grease-fighting ingredient, is the best way to remove pyrethrins from your animal. If your dog's behavior returns to normal after bathing, it is probably all right. If symptoms are still presenting, make an emergency trip to the veterinarian, according to Pet Place. If your dog has a sensitivity to pyrethrins, a veterinarian will be able to prescribe an alternative pesticide for eradicating the fleas from your dog.

Warning

According to the Environmental Protection Agency, more than 1,600 pet deaths were caused by pyrethrin between 2003 and 2008. Pet shampoos containing pyrethrins or pyrethroids should never be used on dogs younger than 12 weeks of age. While flea infestation can cause your animal significant distress and can lead to anemia and even death in extreme cases, you should be aware of the risk associated with pyrethrin-based dog shampoos and monitor your pet closely for side effects, according to Vet Info.

References

• Vet Info: Flea and Tick Product Ingredients
• Pet Place: Pyrethrin and Pyrethrin Toxicity in Dogs
• UC Davis Integrated Pest Management Program: How to Manage Pests
• Cornell University Extension: Pyrethrins
• Manchester Pest Control: Fleas