Recipient Organization
University of Maryland Eastern Shore
11868 College Backborne Road
Princess Anne,MD 21853
Performing Department
(N/A)
Non Technical Summary
Internal parasites are a significant threat to the health of horses, with the effects being more evident in young and undernourished individuals. Infestation with internal parasites can result in symptoms ranging from retarded growth, weight loss, poor appetite, rough hair coat, general weakness, anemia, recurrent colic and even death. Because infections with internal parasites are a significant threat to the health of horses in Maryland, typical parasite loads, diversity, and resistance need to be evaluated in order to better understand current and future threats of this disease.
Animal Health Component
75%
Research Effort Categories
Basic
25%
Applied
75%
Developmental
(N/A)
Goals / Objectives
Due to the possible health impacts that parasite infestation and increasing anthelmintic resistance can have on the large horse industry in the state of Maryland and nationally, the objectives of the proposed study are 1) to evaluate the BCS, parasitic load and diversity in 3 herds of horses and 2) to determine the parasite anthelmintic resistance in these herds using the DrenchRite LDA test. In addition, because previous studies have indicated that there was a greater diversity of parasites in Assateagues's feral herd compared to a domestic herd and that horses on the north-end have increased parasite loads compared to those living on the south-end, possibly due to the exposure to parasites from recreational horses on the island, the project will also 3) evaluate the parasitic load and diversity in Assateague's feral horses over time and 4) evaluate the parasitic loads and diversity in recreational horses brought to the island. These experiments will focus on gaining
more information on current trends in parasite diversity and resistance in horses in this area, as well as how recreational horses brought to Assateague influences the parasite diversity on the island.
Project Methods
Four experiments will be conducted to meet the objectives of the proposed study. Experiment 1 will compare the body condition scores, parasite load and diversity of Assateagues feral horses to that of 2 domestic herds. Fecal samples will be obtained from Assateague horses as well as from 2 domestic herds located in Maryland. In addition, height and body weight will be measured and recorded in the domestic herds. The height of the horses will be determined using a tape measure and the weight will be determined using a weight tape estimate as outlined by Carroll and Huntington (1988). Also, BCS will be determined for all horses sampled using the BCS system previously developed on Assateague Island (on a score of 0 to 5 with 0 being emaciated/very thin and 5 being very fat; Rudman and Keiper, 1991). Larval identification and fecal egg counts will be conducted as described by Anon, 1986. In Experiment 2, anthelmintic resistance will be determined in the three herds used in
experiment 1. Fecal samples collected in experiment 1 will be used in this experiment. To determine anthelmintic resistance, in vitro testing using the DrenchRite larval development assay (Horizon Technology, 1996) will be conducted due to its sensitivity. Experiment 3 will determine the loads, diversity, and variability of internal parasites in a subset of horses located on Assateague Island (n = 30-40), and ranging in age from 2 to 26 years. Following individual identification by digital pictures, fresh fecal samples will be collected off the ground immediately after defecation. Samples will be collected from 3/4 different bands located within a close proximity to each other. This will allow for continuous sampling of the same bands over time. Samples will be collected every 30 days for approximately 12 months to determine variability in parasite loads and diversity. Larval identification and fecal egg counts will be conducted as previously described by Anon, 1986. Experiment 4 will
compare diversity of internal parasites in recreational horses in an effort to evaluate impact on feral horse internal parasite infestations. Visitors to Assateague campsites accompanied by their personal horses will be provided with a brief questionnaire, and asked to provide a fresh fecal sample from their horses. The questionnaire seeks to determine the last time and frequency of dewormer/anthelmintic administration. Larval identification as well as fecal egg counts and parasite anthelmintic resistance will be determined as previously described.