Helminth Parasites of the Raccoon (Procyon lotor) from Tennessee and Kentucky

Abstract

From December 1980 through November 1981, 145 raccoons (Procyon lotor) from Land Between The Lakes in Stewart County, Tennessee, and Lyon and Trigg counties, Kentucky, were examined for helminth parasites. Diaphragms were examined for Trichinella spiralis and gastrointestinal tracts for other helminth parasites. Ten species were found including 7 nematodes (T. spiralis, Physaloptera rara, Arthrocephalus lotoris, Molineus barbatus, Baylisascaris procyonis, Gnathostoma procyonis, Dracunculus insignis), 2 cestodes (Mesocestoides variabilis, Atriotaenia procyonis), and 1 acanthocephalan (Macracanthorhynchus ingens). Dracunculus insignis is reported from Tennessee and Kentucky raccoons for the first time. Of the parasites detected, only T. spiralis showed a statistically significant preference for one sex (male) over the other. It was also the only parasite found in greater prevalence in relation to age classes (highest in age classes III and IV). Arthrocephalus lotoris, M. barbatus, B. procyonis, M. ingens, and D. insignis all had seasonal trends in prevalence, and winter intensity of parasites was found to be most similar to that of spring, spring to summer, and summer to fall. The raccoon, Procyon lotor, is a medium-sized mammal that is widely distributed in North America (Hall, 1981). Due to its economic importance, it has been the subject of numerous biologic investigations (see Lotze and Anderson, 1979). Of the previous studies, many have been directed toward questions relating to raccoon parasites (e.g., Chandler, 1942; McNeil and Krogsdale, 1953; Babero and Shepperson, 1958; Jordan and Hayes, 1959; Harkema and Miller, 1964; Bafundo et al., 1980). However, with the exception of Bafundo et al. (1980), little attention has been given to raccoon parasites in Tennessee. Bafundo et al. (1980) investigated prevalence and intensity of helminth parasites in the digestive tract and examined interlocality variation in P. lotor using helminth parasites as characters. This work provided information relating to broad trends in variation of a selected group of endoparasites that were collected during a restricted time period (as is the case in most previous studies). They grouped raccoons occurring in large physiographic regions as single samples and primarily utilized P. lotor specimens taken during October through February (the hunting season). To date, few investigators (see Lotze and Anderson, 1979) have examined raccoon parasitism in a small geographic area over extended periods. Studies of this type appear critical in order to provide a complete understanding of the natural Received 12 December 1983; revised 26 February 1985; accepted 26 February 1985. history of P. lotor and raccoon (host)-parasite relationships. The purpose of the present investigation was to study the helminth parasites of P. lotor (in a small geographic area) as follows: (1) determine the prevalence; (2) compare prevalence between male and female raccoons; (3) examine prevalence in relation to age of the host; (4) observe seasonal trends in prevalence and intensity of parasite species; (5) examine interspecific associations of prevalence. MATERIALS AND METHODS The study area (Land Between The Lakes = LBL) was a 69,000 ha peninsula located between Kentucky Lake and Lake Barkley in Stewart County, Tennessee, and Lyon and Trigg counties, Kentucky. With cooperation of the Tennessee Valley Authority (TVA), 145 P. lotor were collected from December 1980 through November 1981. Counties from which raccoons were collected and sample sizes for male (given first) and female P. lotor are as follows: Tennessee, Stewart-23, 15; Kentucky, Lyon-11, 16; Trigg-35, 38. Specific locality information was not available for 3 additional males and 4 females. Specimens were taken during different seasons (those of the calendar year) in the following numbers (male sample size is given first): winter-8, 13; spring-20, 15; summer-27, 25; fall17, 18. Seasonal data were incomplete for 2 females. Most animals were collected by gun with the use of dogs or spotlight from a boat or truck. Animals were frozen and housed in TVA facilities and later transported to the Department of Biology, Memphis State University, where they were examined. Sixty-one specimens (those with available skeletal material) were aged as juvenile (class I, n = 12), subadult (class II, n = 8), adult (class III, n = 15), or old adult (class IV, n = 26) following Junge and Hoffmeister (1980). Sex of all specimens was recorded. In-