Comments on potential efficacy of monthly administrations of spot-on moxidectin 2.5%/imidacloprid 10% in the simultaneous prevention of major canine filarioses.

Information on the efficacy of pharmaceutical protocols for the prevention of the major canine filarioses (i.e., Dirofilaria immitis, Dirofilaria repens, and Acanthocheilonema reconditum) under natural conditions is scant. Chemoprophylaxis for canine filarioses under field conditions deserves to be studied more fully and information about vector biology, ecology, and seasonality has to be well appreciated to correctly set control protocols. It is advisable that researchers planning field trials to assess the efficacy of any product for the prevention of canine vector-borne diseases should consider different eco-epidemiological aspects of diseases, including their dynamics of transmission, which are driven by complex interactions between animals, pathogens, and vectors.

Potential efficacy of monthly administrations of spot-on moxidectin 2.5%/imidacloprid 10% in the simultaneous prevention of major canine filarioses.

Dirofilaria immitis, Dirofilaria repens, and Acanthocheilonema reconditum are the most important canine filariae. These species are expanding their distribution in both endemic regions and in previously free areas, thus enhancing the risk for single and mixed infestations in both dogs and humans. The present study evaluated the potential use of moxidectin in a spot-on formulation in preventing these dog filarioses in a confined area where the three major canine filariae live in sympatry. The trial was performed in a private shelter with a history of mixed infestations. Twenty-nine negative dogs were monthly treated with a spot-on formulation containing moxidectin 2.5%/imidacloprid 10% in spring and summer of 2010. The blood of the dogs was examined monthly with classical and molecular assays until December 2011. Twenty-six dogs completed the study, and they scored constantly negative to all diagnostic assays. Three further dogs completed the study in February 2011 until when they were filariae-negative. These results show that monthly treatment with moxidectin may potentially contribute in reducing the spreading of canine filarial diseases. The permanent negativity of treated dogs for the study period is discussed in relation to the potential use of this spot-on formulation in the prevention of single and mixed infestations of major vector-borne canine filariae.