Today's Veterinary Practice provides comprehensive information to keep every small animal practitioner up to date on companion animal medicine and surgery as well as practice building and management.
Issue link: http://todaysveterinarypractice.epubxp.com/i/591321
Today's VeTerinary PracTice | november/december 2015 | tvpjournal.com Journal club 100 With the exception of Lyme borreliosis, vector control is the primary means of preventing fea- and tick-borne diseases in dogs. However, insecticide– acaricide studies demonstrating prevention of disease transmission are lacking because effcacy is based on repellant ability and kill time. This randomized, blinded, and controlled study aimed to demonstrate the ability of afoxolaner (NexGard, merial.com) to block transmission of Babesia canis by Dermacentor reticulatus ticks to dogs. Study ReSultS • The 8 dogs in the treatment group received afoxolaner on day 0, and the 8 controls were untreated. Every 7 days for 4 weeks, all dogs were infested with ticks infected with B canis . • Blood and serum for B canis serology (indirect fluorescent antibody test [IFAT] and PCR) were saved every 7 days until day 56. • All of the untreated dogs were positive for babesiosis on blood smear and PCR; 7 of the 8 were positive on serology by day 21. • None of the treated dogs were positive on blood smear, PCR, or serology through day 56. One treated dog was possibly IFAT positive at final testing on day 93. ConCluSionS Afoxolaner demonstrated complete efficacy in preventing transmission of B canis by the tick D reticulatus during 30 days of tick infestation. The Ability of an Oral Formulation of Afoxolaner to Block the Transmission of Babesia canis by Dermacentor reticulatus Ticks to Dogs Beugnet B, Halos L, Larsen D, et al. Parasit Vectors 2014; 7:283. Study ReSultS • Records of a commercial laboratory identified 40 cats with positive PCR results for A phagocytophilum between May 2009 and May 2011. This represented 0.92% of all samples submitted. Historical and clinical data were available for 16 cats. • All cats had access to the outdoors and lived in the northeastern U.S. (CT, NJ, NY, MA, and VT). Most cases occurred in the spring or fall. • The most common clinical abnormalities on the day of test submission included lethargy, fever, and anorexia; mean temperature was 104.5°F. • Morulae were identified in neutrophils in 27% of cases, with inclusions in approximately 4% to 20% of neutrophils in those cats. • Clinicopathologic abnormalities were nonspecific. • Nearly all cats were treated with doxycycline (15 of 16). In all 14 cats with a known response to treatment, clinical signs resolved with doxycycline therapy. ConCluSionS This study highlights several important points: • A phagocytophilum infection should be considered in ill cats with possible exposure to Ixodes ticks. • Manual blood smear evaluation is needed. • Cats with outdoor access in endemic areas may benefit from monthly insecticide–acaricide treatment. • Additional studies to elucidate the role of these pathogens in clinical disease in cats are needed, particularly in those with hematologic abnormalities. Acaricides for cats are limited compared to those offered for dogs, and tick prevention is an important aspect of protection against vector-borne diseases. Studies have evaluated products' ability to prevent fea and tick infestation, but few have evaluated the protection of cats against transmission of disease. This randomized, controlled, prospective study evaluated the use of an imidacloprid 10%/fumethrin 4.5% collar to prevent transmission of Cytauxzoon felis to cats by Amblyomma americanum . Study Re SultS • Two groups (10 cats each) of approximately equal tick susceptibility, one of which had an imidacloprid 10%/flumethrin 4.5% collar placed 30 days earlier, were infested with A americanum infected with C felis . Tick attachment and transmission of C felis as determined by PCR were measured. • No ticks were found on the collared cats. All untreated cats had ticks attached. • None of the collared cats were positive for C felis , while 90% of the untreated cats were positive by PCR at 8 to 16 days after infestation. ConCluSionS An imidacloprid 10%/flumethrin 4.5% collar placed 30 days earlier completely prevented transmission of C felis to cats by A americanum . Despite the opportunity to groom, all untreated cats were infested with A americanum , underscoring the importance of acaricide use in all at-risk cats. Effcacy of an Imidacloprid 10%/Flumethrin 4.5% Collar (Seresto, Bayer) for Preventing the Transmission of Cytauxzoon felis to Domestic Cats by Amblyomma americanum Reichard MV, Thomas JE, Arther RG, et al. Parasitol Res 2013; 112(Suppl 1):S11-S20. —Jessica Pritchard, VMD, Diplomate ACVIM (Small Animal Internal Medicine) North Carolina State University