New Study Shows Treatment With Feline REVOLUTION® (selamectin) Prior to Heartworm Infection Prevented Lung Damage In Cats

Investigators conclude importance of pretreatment with heartworm preventive for cats

FLORHAM PARK, N.J., November 13, 2014 — New research published in the Journal of Veterinary Parasitology shows that administering the monthly heartworm prevention REVOLUTION® (selamectin) prior to heartworm infection (i.e., mosquito season) prevented heartworm-associated lung damage in cats. The lungs of the cats pre-treated with REVOLUTION showed no difference from the uninfected control group. This study was conducted by a team of investigators led by A. Ray Dillon, DVM, MS, MBA; DACVIM (IM) at the Auburn University College of Veterinary Medicine.

The study, “Effect of pre-cardiac and adult stages of Dirofilaria immitis in pulmonary disease of cats: CBC, bronchial lavage cytology, serology, radiographs, CT images, bronchial reactivity, and histopathology,” demonstrated that pre-cardiac stages of D. immitis-induced chronic lung disease was prevented by the administration of REVOLUTION one month prior to infection.

Radiographs and CT-scans of the heartworm infected, selamectin-treated cats were normal, antibody tests were negative and lungs were histologically the same as normal cats throughout the study. The authors concluded that, “The clinical implication of the study is that heartworm prevention should be initiated at least one month before the first risk of infection.”

About the Study
A controlled, masked research study was conducted to define the initial inflammatory response and lung damage associated with the death of precordia stages of D. immitis in cats as compared to adult heartworm infections in normal cats. In the study, eighteen cats (>6 mo.) were divided into three groups: infected, pretreated with selamectin and infected, and uninfected control. The selamectin pretreated and infected cats were administered 100 L3 by subcutaneous injection. The selamectin pretreated and infected cats were treated according to label directions 32 days and 2 days prior to L3 heartworm infection and continued to receive monthly treatments for the duration of the experiment. After infection, all cats were observed for 240 days.

The full study, A. Ray Dillon, et al., “Effect of pre-cardiac and adult stages of Dirofilaria immitis in pulmonary disease of cats: CBC, bronchial lavage cytology, serology, radiographs, CT images, bronchial reactivity, and histopathology.” Vet Parasitol (2014) can be found here.

About Heartworm Disease in Cats
The incidence of heartworm disease in cats closely correlates with the infection rate in dogs, but in cats the disease is often a result of immature worms that never become adults. Serology demonstrates that in the endemic areas of the U.S. about 25 percent of cats develop positive antibody titers to heartworms.

About REVOLUTION for Cats
REVOLUTION is the veterinarian’s #1 choice in feline parasite protection. FDA-approved REVOLUTION is a unique medication proven to be safe and effective against adult fleas and flea eggs, heartworms, roundworms, hookworms and ear mites. REVOLUTION is available in three- and six-dose packs for a broad range of cat sizes.

For more information on REVOLUTION for cats go to:

Do not use REVOLUTION on sick, weak, or underweight cats. Use only on cats 8 weeks and older. Side effects may include digestive upset and temporary hair loss at application site with possible inflammation. In people, REVOLUTION may be irritating to skin and eyes. Wash hands after use. For more safety information, see full Prescribing Information.

About Zoetis
Zoetis (zō-EH-tis) is the leading animal health company, dedicated to supporting its customers and their businesses. Building on more than 60 years of experience in animal health, Zoetis discovers, develops, manufactures and markets veterinary vaccines and medicines, complemented by diagnostic products and genetic tests and supported by a range of services. In 2013, the company generated annual revenues of $4.6 billion. With approximately 9,800 employees worldwide at the beginning of 2014, Zoetis has a local presence in approximately 70 countries, including 27 manufacturing facilities in 10 countries. Its products serve veterinarians, livestock producers and people who raise and care for farm and companion animals in 120 countries.  For more information, visit
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