Study warns emodepside formulations aren't interchangeable in dogs
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A new American Journal of Veterinary Research study is sharpening the message around extra-label emodepside use in dogs: formulation matters. Investigators at Kansas State University found that the FDA-approved feline topical emodepside/praziquantel product, when given orally to dogs at 1 mg/kg, was not bioequivalent to the canine modified-release oral tablet approved in Europe at the same dose. In seven healthy client-owned dogs, oral dosing of the feline topical product produced markedly higher emodepside absorption than the canine oral tablet, while topical administration in dogs produced plasma concentrations 36- to 122-fold lower than oral dosing. The paper concludes that the cat topical product should not be assumed to behave like the dog oral formulation, even when the active ingredient and nominal dose are the same. (pubmed.ncbi.nlm.nih.gov)
Why it matters: For veterinary professionals managing suspected multianthelmintic drug-resistant Ancylostoma caninum, the findings add pharmacokinetic evidence behind a growing clinical caution. Emodepside has emerged as a potential rescue option when standard combination protocols fail, but in the U.S. it is only approved as a topical feline product, not as a canine oral product. Prior clinical guidance has already warned that the feline topical product has no useful efficacy in dogs when applied topically and that oral extra-label use carries safety concerns, including risk in heartworm-positive dogs and potentially greater susceptibility in dogs with MDR1/ABCB1 variants. This new study helps explain why: different formulations are not interchangeable, and oral exposure may be substantially higher than expected. (cliniciansbrief.com)
What to watch: Expect this study to further shape hookworm treatment guidance, especially around case selection, informed consent, heartworm screening, MDR1 risk assessment, and whether any canine-labeled oral emodepside pathway emerges in the U.S. (aaha.org)