Flea and Tick Products and Their Risks

As a responsible pet owner, protecting your dog from fleas and ticks is crucial, but with so many options available, it’s important to understand exactly what you are giving or applying to your dog. Products like permethrin and fluralaner are commonly used to kill fleas and ticks, but recent studies and reports suggest they can also pose risks to your dog’s health. In this article, we’ll break down how these treatments work, their potential side effects, and what to consider before using them on your pet.

How Flea and Tick Products Work

Permethrin

Permethrin, discovered in 1973, is a popular ingredient in flea treatments, available in spot-on formulas and flea collars. It kills fleas and ticks by disrupting their nervous systems. Permethrin is absorbed by fleas either through their outer layer or when they feed on your dog. Once absorbed, it affects their nerve cells, causing continuous nerve stimulation, which leads to their death. Essentially, permethrin over-stimulates the fleas’ nervous systems until they can no longer function.

Fluralaner

Fluralaner, found in products like Bravecto, is another commonly used flea and tick treatment, but it works differently. It belongs to a class of drugs called isoxazolines, which block key receptors in the nervous system of fleas and ticks, leading to paralysis and death. Fluralaner is administered orally or topically and is distributed throughout the dog's body. When fleas or ticks bite your dog, they ingest this ingredient and die shortly after.

Side Effects of Flea and Tick Treatments

While permethrin and fluralaner are effective at killing fleas and ticks once they have bitten your dog, they are not without risks. Understanding the potential side effects is important to ensure your dog’s safety.

Permethrin Side Effects

Some dogs may experience mild to severe side effects. Skin irritation at the application site, such as redness and itching, is common. In some cases, dogs may develop neurological symptoms like tremors or seizures, especially if they accidentally ingest the product or if the dose is too high. Dogs with a history of neurological disorders may be at a higher risk for these side effects.

It’s especially important to note that cats are extremely sensitive to permethrin. If a cat comes into contact with a dog treated with permethrin, they can suffer serious poisoning, leading to symptoms like drooling, tremors, and even death.

Fluralaner Side Effects

Fluralaner, like other isoxazolines, can also cause side effects, particularly in dogs with pre-existing neurological conditions. The most common side effects include vomiting, diarrhoea, lethargy, and a reduced appetite. However, in some cases, fluralaner has been associated with more serious neurological symptoms such as tremors, seizures, and muscle twitching. The FDA has issued warnings about the potential for these products to cause neurological side effects in dogs​.  

Long-Term Risks and Environmental Concerns

According to a study published in the International Journal of Environmental & Agriculture Research (IJOEAR), there are concerns that these chemicals could pose long-term health risks to dogs. Repeated exposure to permethrin and fluralaner may lead to the accumulation of these substances in the body, potentially causing immune system suppression, liver damage, or even cancer. While the treatments are generally considered safe by those who manufacture them when used correctly, the long-term effects of regular use are still being studied.

There’s also an environmental impact to consider. Permethrin, for example, is highly toxic to aquatic life. When a treated dog is bathed or swims, the chemicals can wash off and enter local waterways, affecting fish and other aquatic species.  

What Pet Owners Should Do

Before using flea and tick treatments, it’s important to have a conversation with your vet, especially if your dog has a history of health issues or is already on medication.  If your dog shows signs of side effects, such as vomiting, tremors, or changes in behaviour, contact your vet immediately.

At The Dog Nutritionist, we recommend seeking out more natural options to repel the fleas and ticks in the first place.  They may include repelling plants around the garden, apple cider vinegar coat rinses and repellent sprays before heading out on walks.  

Understanding how these products work and the potential side effects will help you make informed decisions about your pet’s health especially if your dog has pre-existing conditions.