Ivermectin performance in horses diagnosed with equine endocrine disorders.
Abstract: Anthelmintic performance against equine cyathostomins can be evaluated by two different non-terminal measures; the Fecal Egg Count Reduction Test (FECRT) and the Egg Reappearance Period (ERP). Most available FECRT and ERP data have been determined in populations of young horses, and very little information is available from mature and senior horses. Furthermore, it is unknown how commonly occurring equine endocrine disorders such as Insulin dysregulation (ID) and Pituitary pars intermedia dysfunction (PPID) may interfere with these measurements, but it has been suggested that horses with these conditions could be more susceptible to parasitic infections. A research population of senior horses and horses with or without PPID, ID, or both were enrolled in this study. All strongylid egg count positive horses were included in an ivermectin (200 μg/kg) efficacy study. These were distributed among the following groups: ID: six, PPID: three, PPID and ID: seven, and healthy controls: three. Strongylid fecal egg counts were determined on the day of ivermectin administration, at two weeks post deworming, and on weekly intervals until eight weeks post treatment. Determination of FECRT and ERP were carried out following World Association for the Advancement of Veterinary Parasitology guidelines. Results revealed high ivermectin efficacy with mean egg count reduction at 99.7% or above in all groups at two weeks post treatment. Egg reappearance was documented at six and seven weeks in the ID and PPID/ID groups, respectively, whereas the PPID and healthy control groups both had ERP at 8 weeks. Statistical analysis found no significant differences in egg count levels between groups during the study. The expected ERP for ivermectin is 8-10 weeks, meaning that two of the groups displayed shortened ERPs. However, due to the small group sizes, these data should be interpreted with caution. Nonetheless, results do indicate a need for further investigation of the possible influence of endocrine disorders on anthelmintic performance in horses.
Copyright © 2024 Elsevier B.V. All rights reserved.
Publication Date: 2024-04-05 PubMed ID: 38603925DOI: 10.1016/j.vetpar.2024.110182Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The study examines the effectiveness of an equine dewormer ivermectin in mature and senior horses with endocrine disorders like insulin mismanagement and pituitary gland dysfunction. It was observed that ivermectin was largely effective, though egg reoccurrence was noticed earlier in certain cases prompting further investigation.
Objective of Research
- The crucial aim of this research was to determine how common equine endocrine disorders like Insulin Dysregulation (ID) and Pituitary pars intermedia dysfunction (PPID) might affect the performance of anthelmintic (worm-removing treatments) in adult and older horses. This study was specifically focused on assessing the impact of these disorders on measures like Fecal Egg Count Reduction Test (FECRT) and Egg Reappearance Period (ERP).
Methodology
- Senior horses and horses with/without PPID, ID, or both, were considered for the research. These horses who tested positive for strongylid (a kind of parasite) egg count were chosen for the efficacy study using the dewormer ivermectin.
- Horses were then sectioned into four groups based on their health conditions: ID, PPID, PPID and ID, and healthy controls.
- Fecal egg counts were performed on the day of ivermectin administration, two weeks after deworming, and then weekly until eight weeks post treatment to observe the drug’s effectiveness and egg reoccurrence pattern.
Results
- The results showed a significant positive response to ivermectin in all the groups, with an average egg count reduction at 99.7% or above two weeks post treatment.
- The reappearance of eggs was noticed in six and seven weeks in the ID and PPID/ID groups, respectively. The PPID and healthy control groups both presented egg reappearance at 8 weeks.
- No significant differences were found in egg count levels among the different groups during the study.
Interpretation and Conclusion
- The study showed two of the groups had shortened Egg Reappearance Periods than the expected 8-10 weeks for ivermectin. Due to the restricted group sizes, these outcomes should be cautiously interpreted.
- The research underlines the need for additional investigations to understand the potential influence of endocrine disorders on anthelmintic performance in horses.
Cite This Article
APA
Nielsen MK, Finnerty CA, Ripley NE, Page AE, McClendon ME, Adams AA.
(2024).
Ivermectin performance in horses diagnosed with equine endocrine disorders.
Vet Parasitol, 328, 110182.
https://doi.org/10.1016/j.vetpar.2024.110182 Publication
Researcher Affiliations
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, 1400 Nicholasville Rd, Lexington, KY 40503, USA. Electronic address: martin.nielsen@uky.edu.
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, 1400 Nicholasville Rd, Lexington, KY 40503, USA.
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, 1400 Nicholasville Rd, Lexington, KY 40503, USA.
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, 1400 Nicholasville Rd, Lexington, KY 40503, USA.
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, 1400 Nicholasville Rd, Lexington, KY 40503, USA.
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, 1400 Nicholasville Rd, Lexington, KY 40503, USA.
Conflict of Interest Statement
Declaration of Competing Interest The authors declare no conflicts of interest.
Citations
This article has been cited 0 times.Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
