Peer-reviewed veterinary case report
Neurological safety of topical macrocyclic lactones in cats
By Novotny, Mark J et al.·Published in Journal of the American Veterinary Medical Association·2026·1Boehringer Ingelheim Animal Health·View original on PubMed →
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Original publication title: Topically administered macrocyclic lactone products, including eprinomectin, demonstrate comparable neurological safety in cats based on pharmacovigilance data.
- Species:
- cat
Plain-English summary
A cat was reported to have neurological issues after using topical flea and tick treatments containing macrocyclic lactones, like eprinomectin. The study looked at data from various sources to see if these products caused more problems than others. It found that the rates of neurological side effects, such as ataxia (loss of coordination), convulsions, and muscle tremors, were similar across different treatments. This means that eprinomectin and other similar products are generally safe regarding neurological effects in cats.
People also search for: cat neurological issues after flea treatment · eprinomectin side effects in cats · cat ataxia treatment options
Abstract
OBJECTIVE: The purpose of the study was to evaluate the proportional reporting of neurological adverse events (AEs) associated with feline topical parasiticide products containing macrocyclic lactones (MLs; including eprinomectin) and emodepside by use of postapproval pharmacovigilance data. The intent was to provide veterinarians prescribing these products for their feline patients with the overall comparative context of neurological AE reporting for these products, which have been characterized as substrates for P-glycoprotein transporters. METHODS: The openFDA and EudraVigilance Veterinary Data Warehouse databases were queried for neurological AEs cumulatively reported through December 31, 2024, for marketed parasiticide products containing MLs (eprinomectin, selamectin, moxidectin) and emodepside for topical administration to cats. The frequencies of neurological AE reporting were compared between products with proportional report rates and disproportionality statistical measures. RESULTS: The reporting frequencies of neurological AEs associated with these feline topical parasiticide products were similar. For all products, ataxia was the most frequently reported neurological AE, with proportional report rates ranging from 5.3% to 14.0%. Proportional report rates ranged from 1.7% to 10.7% for convulsion and muscle tremor. CONCLUSIONS: An evaluation of pharmacovigilance data from 2 different sources revealed no evidence of greater proportional reporting for neurological AEs specific to the use of eprinomectin-containing products in cats than for other MLs or emodepside. CLINICAL RELEVANCE: These findings supported the conclusion that ML-containing products (including eprinomectin-containing products) and emodepside are comparable in the frequencies and types of neurological AEs associated with feline topical parasiticide products described as substrates for P-glycoprotein transporters.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/41512448/