Revolution Flea And Tick

Products used to prevent or control ticks include Frontline, Preventic collars, Permoxin Insecticidal Spray and Wash, Advantix and Revolution. Tick prevention should continue throughout the tick season, in conjunction with daily checking of the pet's skin for attached ticks.

There is a wide range of products available for tick control. They work in slightly different ways, have different lengths of protection and cover different ticks.

The active ingredients commonly used to kill or repel ticks include fipronil, permethrin, amitraz and selamectin.

Selamectin is a very broad spectrum parasiticide with good efficacy against a broad range of internal and external parasites. However the only tick Revolution claims to work against is Dermacentor variabilis, the American Dog Tick. The label warns that in heavy tick infestations, complete tick efficacy may not be achieved after the first dose,so an additional dose may be given two weeks later, with monthly dosing continuing after that.

Trials assessing the efficacy of this product did not check for tick deaths until three days after infestation, so it is not known how quickly selamectin starts to kill ticks. However some efficacy was seen at three days and significantly more at five days. In these trials, the product was seen to have 100 per cent efficacy against Brown Dog Ticks 21 days after product application, however the product makes no claims for efficacy against this parasite.

Selamectin is derived from a sugar produced by a soil bacterium called Streptomyces avermitilis.1

"[Selamectin] is effective against heartworm larvae, fleas, ear mites, sarcoptic mites and the American Dog Tick. In cats, it is effective against heartworm larvae, fleas, roundworms, hookworms and ear mites."

Selamectin, like all of the MLs, works at different dose rates and methods of application for different parasites. In the topical preparation used for heartworm prevention in dogs, the dose used is effective against heartworm larvae, fleas, ear mites, sarcoptic mites and the American Dog Tick. In cats, it is effective against heartworm larvae, fleas, roundworms, hookworms and ear mites.2

All ML products have very wide safety margins for mammals, with adverse reactions uncommon. Allergic reactions to the drug bases are more likely than reactions to the toxicity of the drugs themselves when used as recommended. Occasionally, your pet's skin may react to Revolution, including hair loss and itching, at the site of application.

The safety margin for selamectin applied topically has been shown to be at least 10 times the recommended dose in cats and dog breeds (other than collies) and at least five times that of collies.2 Ivermectin, the most-studied ML, has a safety margin in most breeds of dog of well over 100 times the usual dose used for heartworm prevention (orally) - however in collies it is about 16 times.3 However it does not appear that selamectin has been trialled at doses as excessive as this.

Some breeding lines of Collies display increased sensitivity to the drug as they don't have a particular protein carrier in their blood-brain barrier which regulates the entry of MLs, so the drugs can move freely into the brain and cause nervous problems.

In very young animals the blood-brain barrier is not completely closed, so the drug can enter freely and cause nervous symptoms. This is one reason that selamectin-based products are not recommended for newborn pups or kittens. However they can be given safely from six weeks of age in pups and eight weeks in kittens.

Summary: The use of tick prevention products is recommended throughout the tick season. Your veterinarian can recommend an appropriate product for your pet. Daily checking of pets for attached ticks is also recommended. If a tick is found, it should be removed immediately. Do not touch it with your fingers, and ensure it is pulled out gently backwards, grasping the tick as closely as possible to the mouth parts to avoid leaving the head embedded in the pet's skin.

It is a good idea to keep the tick in a sealed jar to assist the veterinarian to make a diagnosis in the event a tick-related disease is suspected. If you do suspect such a disease, take your pet to your veterinarian as soon as possible. The earlier treatment is started, the better the prognosis.

References
Frontline website, Merial. http://frontline.us.merial.com/home/
Frontline Plus, Frontline Top Spot, Frontline Spray Labels. Merial Ltd, Duluth Ga.
Chin A. et al. Persistent Flea Infestations in Dogs and Cats controlled with monthly topical applications of Fipronil and Methoprene. Aust Vet Practit 35(3) pp 89-96, 2005.
Report of Adverse Experiences, 1998-2003, 2004. Australian Pesticides and Veterinary Medicines Authority. http://www.apvma.gov.au/qa/aerp.shtml
Young D.R. Evaluation of Imidacloprid pls Permethrin vs. Fipronil Topical Treatments to repel and Kill American Dog Ticks (Dermacentor variabilis) on Dogs. Suppl Compend Contin Educ Pract Vet. 24:4(B), pp 17-20, 2002.
National Pesticide Telecommunications Network Fact Sheet: Fipronil. National Pesticide Information Center. http://npic.orst.edu/factsheets/fipronil.pdf
National Pesticide Telecommunications Network Fact Sheet: Permethrin. National Pesticide Information Center. Extension Toxicology Network Pesticide Information Profiles: Amitraz. http://extoxnet.orst.edu/pips/amitraz.htm
Product label, Preventic. Virbac Corporation, Fort Worth Tx.
Preventic Website, Vribac. http://www.preventic.com/
K9Advantix website, Bayer Corporation. http://www.k9advantix.com
Product label, K9 Advantix. Bayer Healthcare LLC, Animal Health Division, Shawnee Mission, Ks.
U.S. Prescribing Information: Revolution?. Pfizer Animal Health .
Revolution for dogs website, Pfizer Animal Health. http://www.revolution4dogs.com
Cats of the Revolution website, Pfizer Animal Health. http://www.revolution4cats.com
Permoxin Insecticidal Information. Dermcare-Vet website. http://www.users.bigpond.com/dermcare/
Product label: Demadex Acaricidal Dog Wash, Delvet Pty Ltd, Seven Hills, NSW.

Frontline® is a registered trademark of Merial
Revolution® is a Pfizer registered trademark
Advantix® is a registered trademark of Bayer AG, Leverkusen, Germany.
Preventic® is a registered trademark of Virbac
Permoxin® is a trademark of Dermcare-Vet Pty Ltd.