Efficacy of a combination of imidacloprid 10%/moxidectin 2.5% spot-on (Advocate® for dogs) in the prevention of canine spirocercosis (Spirocerca lupi)

Abstract

The nematode Spirocerca lupi is a major canine parasite in warm regions of the world, classically causing parasitic nodules in the esophagus, aortic aneurysms, and spondylitis. This study evaluated the preventive efficacy of monthly treatment with imidacloprid 10%/moxidectin 2.5% spot-on (Advocate® for dogs) administered over a period of 9 months in young dogs naturally exposed to S. lupi on Réunion island. One hundred and twelve puppies, aged from 2.0 to 4.0 months and with a negative spirocerca fecal examination at inclusion, completed the study. They were randomly allocated to two groups. Group A puppies (n = 58) received nine spot-on treatments with Advocate® at the minimum dose of 2.5 mg moxidectin/kg bw at monthly intervals. Control group B puppies (n = 54) received no treatment for S. lupi. During the study, regular clinical and fecal examinations were performed, as was final upper gastrointestinal endoscopy. Endoscopy showed that 19 dogs from group B had spirocerca nodules, corresponding to a prevalence of 35.2% in dogs aged 12 to 14 months. In contrast, only one dog from group A had a nodule, corresponding to a preventive efficacy of 94.7% (p < 0.0001). None of the 378 fecal examinations were positive for spirocerca. This study confirms a high prevalence of canine spirocercosis on Réunion and shows that infestation occurs in very young puppies. Furthermore, it demonstrates that monthly spot-on administration of a combination of imidacloprid 10%/moxidectin 2.5% (Advocate® for dogs) in puppies starting at the age of 2 to 4 months achieves effective and safe prevention of canine spirocercosis.

Occurrence of Spirocerca lupi Infection in Hungarian Dogs Referred for Gastroscopy

“…Some literature resources claim disophenol to be the only confirmed adulticide drug, but it does not affect juvenile worms and is not available on the market (Lobetti 2013). Other sources claim that macrocyclic lactones are an effective treatment for benign esophageal alterations caused by Spirocerca lupi (Berry 2000, Kelly et al 2008, Lobetti 2012, Austin et al 2013), while effective prevention is possible with avermectins, milbemycin and moxidectin , Kelly et al 2008, Kok et al 2010, 2011, Le Sueur et al 2010, Nolan et al 2012). In our experience, doramectin-treated patients become symptomfree, but use of the drug is greatly hindered by off-label application and the risk of complications.…”

“…The toxicity depends on the mutation of the MDR-1 Δ gene and the expression of protective glycoprotein P (Lobetti 2013). Milbemycin oxime, applied at 0.5 mg/kg for 28 days (Beugnet et al 2016, Kok et al 2010, 2011, or spot-ons containing a combination of imidacloprid and moxidectin are both confirmed as being suitable for spirocercosis prevention (Austin et al 2013, Le Sueur et al 2010. Although the esophageal granulomas caused by Spirocerca lupi can be successfully treated with doramectin, sarcomas require surgical and oncological treatment (Willard 2013).…”

The Efficacy of a Topically Applied Imidacloprid 10 % / Moxidectin 2.5 % Formulation (Advocate®, Advantage® Multi, Bayer) against Immature and Adult Spirocerca lupi Worms in Experimentally Infected Dogs

“…Therefore control of Spirocerca lupi in the final host by medical prevention or therapy seems to be the only viable option. Most studies in which macrocyclic lactones were tested for efficacy against S. lupi focused on therapeutic efficacy (Berry 2000;Lavy et al 2002;Kelly et al 2008), and although some treatment regimens have indicated promising preventative efficacy (Lavy et al 2003;Kok et al 2010;Le Sueur et al 2010), this issue remains largely unresolved. The present study was designed to evaluate both preventative and therapeutic efficacy in experimentally infected animals.…”

“…The adequacy of infection in the control group enabled a valid comparison of treated groups to the control group. The use of oesophagoscopy to detect oesophageal nodules associated with S. lupi infections is a standard diagnostic procedure (Mazaki-Tovi et al 2002) and has been used often in studies to determine the efficacy of therapeutic procedures in the treatment of progressed spirocercosis (Lavy et al 2003;Kelly et al 2008;Le Sueur et al 2010;Lobetti 2000).…”

“…The prevalence of Spirocerca lupi in many parts of the world is ever increasing (Kok et al 2010) and the need exists for a licensed, cost-effective product which will provide adequate preventative and therapeutic efficacy, demonstrating effectiveness against the migrating immature stages as well as the encapsulated adult stages of the parasite. A study conducted on Réunion Island has indicated that a topically applied formulation consisting of imidacloprid 10 % / moxidectin 2.5 % can be safely and successfully used to prevent canine spirocercosis in puppies (Le Sueur et al 2010), but the preventative and therapeutic ability of this formulation needed to be further investigated. A study was therefore designed to investigate the preventive efficacy (efficacy against immature stages), the therapeutic efficacy (efficacy against mature stages) and the safety of an imidacloprid 10 %/ moxidectin 2.5 % spot-on formulation (Advocate ® , Advantage ® Multi, Bayer) against Spirocerca lupi in experimentally infected dogs.…”