Flea and Tick Product Ingredients

Before using a flea and tick product, understand the common ingredients and possible side effects. These products effectively prevent parasitic insect infestations, but some animals will suffer from side effects.

Flea and tick products include topical medications, shampoos and collars. Products may require a prescription, but others can be purchased over the counter. Be cautious of over the counter products, as there is a higher incidence of side effects and overdoses with these products.

Ingredients in Topical Flea and Tick Medications

  • Fibronel, found in products like Frontline, paralyzes the insect's nervous system. They can't move, so they can't eat and soon die. The medication enters the bloodstream through pores in the skin and takes effect within 48 hours.
  • Frontline Plus topical ointment includes S-methoprene, to prevent fleas and ticks in the larval stage from hatching. Program uses lufenuron to prevent flea eggs and larva from hatching.
  • Advantix uses a combination of imidacloprid and permethrin. Imidacloprid paralyzes the insect, leading to its death. Permethrin performs in the same manner, but lasts longer on the skin.
  • Revolution includes selamectin, another ingredient that paralyzes the nervous system of a parasite.

Side effects are rare in topical prevention options. However, you should watch for loss of coordination, excessive drooling and tremors. Never give the medications orally. They are meant for topical use only. If your pet does ingest them, warning signs include excessive drooling and vomiting. Contact your veterinarian immediately if you notice these.

Medicated Collars

Propoxur is often used on medicated collars, and provides protection from parasitic insects for up to five or six months. The powder on the collar is harmful if swallowed. If it gets into the eyes, it can cause the pupils to contract for a short while. The medication works by poisoning and killing fleas and ticks. Do not use flea and tick collars on young puppies or kittens.

In 2009, the Natural Resources Defense Countil petitioned the EPA to ban the use of propoxur in flea and tick collars. A number of pet owners found their pets becoming lethargic after treating them with products containing propoxur or tetrachlorvinphos.

Amitraz is another common ingredient. The medication spreads through the animal's body oils and kills infestations within a day.

Medicated collars usually come with warnings that you not use them on elderly dogs, debilitated dogs or dogs that are pregnant or nursing. Most collars require a puppy or kitten to be at least twelve weeks of age. If you use a collar, you can overdose your dog if you also use a topical medication.

Flea and Tick Shampoos

Most flea and tick shampoos include pyrethrin. They're used on dogs and cats older than twelve weeks. Common side effects include skin rashes due to a sensitivity to the pyrethrin oil. If this happens, wash the animal to remove the pyrethrin from its coat.

Of more concern is a report released by the Center for Public Integrity, which includes statistics from the Environmental Protection Agency. Between 2003 and 2008, more than 1,600 pyrethrin-related pet deaths were reported. Deaths were caused by brain damage, heart attacks and seizures. While the odds are low that a pet will die, many pet owners are completely unaware of that slight risk.