|Williams, Mary - Mimi|
Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/19/2004
Publication Date: 8/1/2004
Citation: Kaplan, R.M., Burke, J.M., Terrill, T.H., Miller, J.E., Getz, W.R., Mobini, S., Valencia, E., Williams, M.J., Williamson, L.H., Larsen, M., Vatta, A.F. 2004. Validation of the famacha eye color chart for detecting clinical anemia in sheep and goats on farms in the southern united states. Veterinary Parasitology. 123:105-120.
Interpretive Summary: Recent studies on sheep and goat farms in the southern United States indicate that multiple-anthelmintic resistance in Haemonchus contortus is becoming a severe problem. The objective was to validate a system of identifying animals for treatment of H. contortus infection using eye color scores. Results indicate that the FAMACHA© method is an extremely useful tool for identifying anemic sheep and goats in the southern U.S. and U.S. Virgin Islands. This information is important to small ruminant producers throughout the U.S. and Virgin Islands to manage internal parasites, and extension agents and veterinarians that advise their clients in parasite management.
Technical Abstract: Recent studies on sheep and goat farms in the southern United States indicate that multiple-anthelmintic resistance in Haemonchus contortus is becoming a severe problem. Implementation of a strategy to identify and treat only those animals that are anemic from infection with H. contortus, the FAMACHA© system, was tested and validated for the southeastern U.S. and Virgin Islands. A validation study was performed on the use of FAMACHA© by testing the system in sheep (n = 847) and goats (n = 537) of various breeds and ages from 39 farms located in Arkansas, Georgia, Louisiana, Florida, and the U.S. Virgin Islands. All animals were scored on a 1 to 5 scale based on the color of the ocular conjunctiva using FAMACHA©, and blood samples were collected from each animal for determination of packed cell volume (PCV). Data for both FAMACHA© scores and PCV were evaluated using 2 separate criteria for anemia: eye score values of 3, 4 and 5 or 4 and 5, and PCV values of < 19 or < 15 were considered anemic. Specificity was maximized when eye score values of 4 and 5 were considered anemic and PCV cut off for anemia was < 19, but using these criteria sensitivity was low. In contrast, sensitivity was 100% for both sheep and goats when eye score values of 3, 4 and 5 were considered anemic and PCV cut off was < 15, but specificity was low. In both sheep and goats, predictive value of a negative was greater than 92% for all anemia and eye score categories, and was greater than 99% for both eye score categories when an anemia cutoff of < 15 was used. These data indicate that the FAMACHA© method is an extremely useful tool for identifying anemic sheep and goats in the southern U.S. and U.S. Virgin Islands. However, insufficient data and experience exist to know precisely what will be the best means to apply this system. Further studies are required to determine optimal strategies for incorporating FAMACHA© into integrated nematode control programs.