A retrospective histopathological survey of capillariasis in raccoons (Procyon lotor) from Oregon

A 2-yr retrospective survey (1995-1998) of 63 adult raccoons (Procyon lotor) from Oregon, northwestern United States, was conducted by histopathological examination of various tissues. An overall prevalence of capillariasis was recorded in 52% of the raccoons. Highest prevalence of nematodes (29/30, 97.7%) was present in the anal sacs, where variable numbers of nematodes, their ova, and extensive diffuse inflammatory cellular infiltrate were evident. Lesser numbers of nematodes were also seen in the mucosa of the anterior alimentary tract (mouth 2/63, tongue 10/62, esophagus 2/63) and in the urinary bladder (7/63). However, at these sites, there was a paucity of inflammatory infiltrate. The findings of this study indicate that capillariasis of the anal sacs is commonly seen in free-ranging raccoons in Oregon, and the infection is essentially subclinical because only 1 case of anal sac impaction has been reported. Measurements of the nematode and their ova from the anal sacs indicate that it is most likely a new capillariid species, which to date has not been fully described in raccoons. It is speculated that the high prevalence of anal sac infection by a Capillaria sp. in Oregon raccoons may also be true for raccoons in other parts of North America and in parts of Europe and Asia where this species has been introduced.

Cerebral larva migrans in a raccoon (Procyon lotor)

During 1997, gross and histopathologic examinations were performed on an adult female raccoon (Procyon lotor) that was live-trapped in Corvallis, Oregon. Multifocal eosinophilic granulomas indicative of neural and visceral larva migrans were observed. However, within these granulomas, the presence of parasitic larva was seen only in the cerebrum. Morphologic characteristics indicated that the nematode was an ascarid larva. However, it was smaller than the larva of Baylisascaris sp. This appears to be the first documented case of cerebral larva migrans in a raccoon.

Synthesis and endectocidal activity of novel 1-(arylsulfonyl)-1-[(trifluoromethyl)sulfonyl]methane derivatives

We have recently synthesized a series of novel disulfonylmethane compounds that have shown anthelmintic and insecticidal (endectocidal) activity. Several analogues have shown activity against the internal nematode Haemonchus contortus. In sheep studies, these analogues have shown 100% control of this internal parasite at a 10 mg/kg rate. In vitro activity against the biting flies, Stomoxys calcitrans and Haematobia irritans, has been observed at rates as low as 25 and 2.3 ppm, respectively. Only marginal activity against the liver fluke Fasciola hepatica and Trichostrongylus colubriformis was seen. Respiratory control index values on rat liver mitochondria for this series suggested uncoupling of oxidative phosphorylation as a mechanism of action. Compound 1 is considered to be a promising agent for treatment of parasitized sheep.

Biochemical, biological, and genetic characterization of a sylvatic isolate of Trichinella

Biological, biochemical, and genetic relationships of Trichinella isolates were assessed and compared from 3 species of Illinois fur-bearing mammals. Tongue muscle collected from 1987 through 1989 from 323 raccoons (Procyon lotor), 9 red fox (Vulpes fulva), and 1 coyote (Canis latrans) were digested and Trichinella muscle larval prevalences and mean intensities (larvae/g) determined. The prevalence and mean intensity of tongue muscle-stage larvae were 2.8% and 44.4% and 326 and 2 larvae/g for raccoon and red fox, respectively. The single coyote examined for muscle larvae was negative. Seven of 13 Trichinella isolates (5 raccoon, 2 red fox) were maintained and amplified in mice. Comparative analyses of DNA from larvae of these isolates and from other Trichinella isolates were performed by dot-blot hybridization using specific repetitive DNA probes. DNA from the 7 Illinois sylvatic isolates reacted with the Trichinella T5 isolate DNA probe pUPB-3.7 and did not cross-react with the Trichinella spiralis probe pBP-2. The sylvatic isolates of Trichinella were also analyzed using 27 allozymes. Their allozymic patterns were similar to Trichinella reference strain T5 from Pennsylvania, except for mannose phosphate isomerase. These results suggest that the Illinois wildlife isolates belong to the Trichinella T5 genotype according to the classification system established by the International Trichinella Reference Centre and as defined here by positive hybridization to the pUPB-3.7 probe. Results from Southern blot analyses using rRNA as a probe and allozyme patterns revealed some heterogeneity among geographical isolates of the T5 genotype.

Epidemiology of Ostertagia ostertagi in cow-calf herds in the southeastern USA

Ostertagia ostertagi is commonly found in the brood cow and nursing calf in the southeastern USA, this information being derived from fecal egg counts, coproculture and necropsy results; however, clinical disease and large burdens of this parasite are rarely reported. Fecal egg counts in brood cows are routinely low and are generally reported to be 10 eggs per gram of feces (EPG) or less. Nematode egg counts in spring-born calves are also generally low prior to weaning; they increase steadily during the spring and summer and peak from late summer to fall weaning. That egg counts in spring-born calves are low for several months after birth is probably a reflection of minimal grazing activity. It appears that Ostertagia ostertagi may be of equal or less importance than other nematode genera for spring-born calves in the southeastern USA. The role that Ostertagia ostertagi plays in fall-born calves or in year-round calving herds has not been adequately investigated. Also, the role that the adult cow plays, with low egg counts and small Ostertagia ostertagi burdens, in contamination of pasture is not understood during either lactation or dry periods. Treatment of beef calves prior to, or at weaning can reduce contamination and transmission of gastrointestinal parasites on pastures which may be subsequently grazed by these or other weaned calves. Data on parasite population dynamics from tracer calf studies in cow-calf herds in the southeastern USA have identified peak periods of transmission and incidence of specific genera or stages. This information, in conjunction with routinely used cattle production and management practices such as time of calving, should provide means to more accurately define optimal timing for strategic parasite treatment programs and their overall effect on beef production in the southeastern USA.

First report of a Demodex sp. in raccoons (Procyon lotor)

Demodex spp. mites were seen in skin sections of 5 of 53 raccoons (Procyon lotor) necropsied on Parramore Island, Virginia (USA). In all infections, mites were present in the skin over the lower legs; in one raccoon they also were located in a follicle of a vibrissa. None of the raccoons had Demodex-related gross lesions. Histopathologically, minimal lesions were seen in the affected follicles. This is the first documentation of Demodex spp. in raccoons.

Helminth parasites of the raccoon (Procyon lotor) from north-central Arkansas

Twenty-three species of helminths (4 trematodes, 2 cestodes, 14 nematodes, and 3 acanthocephalans) were found in the gastrointestinal tract, lungs, pancreas, tongue, urinary bladder, and subcutaneous tissues of 30 live-trapped or hunter-shot raccoons from north-central Arkansas between November 1989 and April 1990. Helminths were not detected in the brain, diaphragm, gallbladder, heart, liver, reproductive system, or trachea. Each raccoon examined was infected with 3 or more of the following helminths: Brachylaima virginiana, Eurytrema procyonis, Fibricola cratera, Pharyngostomoides procyonis, Atriotaenia procyonis, Mesocestoides spp., Arthrocephalus lotoris, Capillaria aerophila, Capillaria plica, Capillaria procyonis, Capillaria putorii, Crenosoma goblei, Cruzia americana, Dirofilaria tenuis, Dracunculus insignis, Enterobius sp., Gnathostoma procyonis, Molineus barbatus, Physaloptera rara, Trichinella spiralis, Centrorhynchus wardae, Macracanthorhynchus ingens, and Oligacanthorhynchus tortuosa. All helminths collected with the exception of D. insignis constitute new geographic distribution records. Occurrences of C. aerophila, C. wardae, and O. tortuosa are new host records. One nymphal pentastome, Porocephalus crotali, was found in the liver of 1 raccoon, constituting a new host record.

Prerequisites for oral immunization of free-ranging raccoons (Procyon lotor) with a recombinant rabies virus vaccine: study site ecology and bait system development

A model baiting system suitable for the delivery of an oral rabies vaccine to free-ranging raccoons (Procyon lotor) was developed and tested on barrier islands in South Carolina (USA). Features of barrier island physiography and ecology were studied relative to selective bait deployment and site biosecurity. Capture-mark-recapture data were obtained from 228 raccoons. Raccoon density estimates, using a modified census assessment technique, were one raccoon per 1.8 to 2.7 ha. Mean (+/- SE) and range home area estimates of radio-collared raccoons were 84 (+/- 15.6) ha (27 to 176 ha) by a minimum convex polygon method and 138 (+/- 22.8) ha (43 to 241 ha), by a harmonic mean transformation method. Habitat utilization determinations of radio-collared raccoons were conducted to identify study areas to potentially maximize selectivity of bait towards raccoons and to reduce the absolute number of baits deployed. Island raccoons showed a habitat preference for maritime forest, maritime shrub and marsh areas. Additionally, there was no evidence of inter-island or mainland exchange of ear-tagged or radio-collared raccoons. A disease and mortality survey was conducted to identify baseline pathology and incidental lesions in the target raccoon population, prior to actual vaccination initiation. Thirty-eight percent of 30 clinically suspect raccoons sampled had intracytoplasmic eosinophilic inclusions diagnostic of canine distemper; no other lesions suggestive of viral etiologies were found. Serological surveys for raccoon poxvirus and rabies virus antibodies were negative. Antibody titers to canine adenovirus 1 and 2 indicated a moderate level of exposure (approximately 10 to 16%) in the raccoon population. Overall, 93 to 100% of placebo baits were consistently disturbed by 7 days post-bait deployment, and bait acceptance rates by raccoons ranged from 49 to 85%, by using a modular systems approach to select the optimum combination of bait attractant, biomarker, matrix, density, and distribution. These results suggest that a large proportion (up to 85%) of a free-ranging island raccoon population can be selectively and safely targeted, marked and monitored utilizing a proposed oral bait delivery system for recombinant or other rabies vaccines.

Notoedric acariasis in the porcupine (Erethizon dorsatum)

Six of 16 porcupines (Erethizon dorsatum) live-trapped in Sullivan County, Pennsylvania were infested with the mite Notoedres douglasi. Alopecia was evident in the ventral inguinal area and the infested skin was thickened, wrinkled and had multifocal areas of extensive hyperkeratosis. Microscopically the skin lesions consisted of extensive acanthosis and hyperkeratosis with variable cellular infiltrate in the dermis. Mites were seen in tunnels in the hyperkeratotic skin sections. This is the first report of notoedric acariasis in the porcupine.

Pancreatic duct hyperplasia in a raccoon (Procyon lotor) caused by Atriotaenia procyonis

A raccoon (Procyon lotor) live-trapped in Philadelphia, Pennsylvania was heavily infected with the tapeworm Atriotaenia procyonis. Histopathologic examination of the duodenum revealed this tapeworm attached to the mucosa; the mucosa was mildly hyperplastic without a significant inflammatory infiltrate. This tapeworm was seen also within the proximal pancreatic duct and histopathologic lesions associated with its presence consisted of marked hyperplasia of mucosal cells, causing the formation of an extensive papillary projection into the duct lumen. Inflammatory cellular reaction was minimal, consisting primarily of lymphocytes, and was seen in the mucosa and submucosa of the duct. The presence of A. procyonis in the pancreas of this raccoon is considered to be an aberrant location for this parasite and has not been reported previously.

Lesions associated with pulmonary parasites in bobcats (Felis rufus) from Arkansas

Two of five bobcats (Felis rufus) from southwestern Arkansas had natural pulmonary infections of Paragonimus kellicotti and Filaroides rostratus. Pairs of P. kellicotti were found in spherical cyst-like structures approximately 1 cm in diameter. Filaroides rostratus were seen as serpentine pale white areas on the pleural surface and also firmly embedded in fibrous capsules in the pulmonary parenchyma. Histologic lesions associated with the presence of these parasites consisted primarily of a verminous bronchitis. Clinical signs or compromised pulmonary function were not associated with these infections.

Lung lesions in an opossum (Didelphis virginiana) associated with Capillaria didelphis

An opossum (Didelphis virginiana) live-trapped on Parramore Island, Virginia was infected with the lung parasite Capillaria didelphis. Lung lesions associated with this parasite were extensive and consisted of numerous areas with central necrosis deep within the parenchyma. Necrotic foci were present around airways and consisted of a mixture of inflammatory cells and cellular debris, adult nematodes and many bipolar eggs. This parasite causes severe verminous pneumonia in the opossum.

Sarcocystis kirkpatricki n. sp. (Apicomplexa: Sarcocystidae) in muscles of raccoons (Procyon lotor) from Illinois

Sarcocysts of Sarcocystis kirkpatricki n. sp. (Apicomplexa: Sarcocystidae) are described from the skeletal and heart musculature of 66 (66%) of 100 raccoons (Procyon lotor) from Illinois. Histologic examination of muscle tissues from tongue, diaphragm, esophagus, and heart revealed that 61%, 47%, 32%, and 2%, respectively, contained sarcocysts of this species. Juvenile raccoons (less than 1 yr old) were more likely (P less than 0.01) to have sarcocysts in the tissues examined (52/60 or 87%) than were adults (14/40 or 35%). Histologically, sarcocysts in the 4 tissues were similar: the cyst wall was 2-3 microns thick, PAS negative, and had fine hairlike surface projections; interior septa were indistinct. Ultrastructurally, sarcocyst walls had short (mean = 2.8 microns), straight to sloping, villuslike projections. Longitudinal tubular filaments inside these projections extended from the tips to the base, where they terminated in a granular electron-dense layer of the primary cyst wall. Thin septa were within the sarcocysts. Feeding experiments utilizing dogs and cats as potential definitive hosts were negative.

Proposed field evaluation of a rabies recombinant vaccine for raccoons (Procyon lotor): site selection, target species characteristics, and placebo baiting trials

Prior to a limited field application of an orally-administered vaccinia-rabies glycoprotein (V-RG) recombinant virus vaccine for wildlife, background data were obtained for the proposed site on Parramore Island, Virginia (USA). Mammalian target and nontarget species, potentially at risk for exposure to vaccine were inventoried. Placebo baiting trials with a fishmeal polymer bait resulted in high bait disturbance (88 to 100%), primarily by raccoons (Procyon lotor), with infrequent visitation and no evidence of bait consumption by deer (Odocoileus virginianus), small mammals or avian species. Definitive bait acceptance rates by raccoons (indicative of bait ingestion) were difficult to accurately determine based exclusively on premolar and vibrissae samples collected antemortem from live-trapped raccoons for tetracycline and rhodamine B biomarker analyses, respectively. Bait acceptance rate was more accurately determined during a pilot baiting trial conducted on North Island, South Carolina, when mandibles (postmortem samples) were examined for tetracycline incorporation. Parasitologic findings in raccoons on Parramore Island included Hepatozoan procyonis, Phagicola angrense and Physaloptera rara and a variety of incidental microscopic lesions, and provided baseline pathological data for comparison subsequent to V-RG vaccine application. A population density estimate of one raccoon/2.7 ha was calculated using mark-recapture data for comparison after vaccine deployment. Limited reproductive data, including estimates of pregnancy rates by palpation, the number of live kits/litter live-trapped with previously pregnant raccoons or observed in the dens of radio-collared raccoons, was gathered to assess the effect of proposed oral vaccination with V-RG vaccine. Home ranges were assessed by radio-telemetry of 15 raccoons; all radio-collared raccoons currently reside on Parramore Island.(ABSTRACT TRUNCATED AT 250 WORDS)

Dirofilaria immitis in a river otter (Lutra canadensis) from Louisiana

A single adult male river otter (Lutra canadensis) from Louisiana was found naturally infected with Dirofilaria immitis. One adult male nematode was found in the heart; lesions attributable to the presence of the parasite were not found. This is the first report of D. immitis in the river otter in North America.

Scanning electron microscopic observations of adult Baylisascaris procyonis (Nematoda)

The scanning electron microscope was used to illustrate the microtopographic features of the caudal end of adult male Baylisascaris procyonis. The male tail was relatively long, smoothly attenuated and often had a small button-like or mucronate termination. The preanal papillae were situated ventrally in two slightly divergent and somewhat irregularly spaced rows. Anterior and posterior to the anus were two slightly raised roughened patches consisting of several rows of small spines. Just anterior to the anus along the outer margin of the preanal roughened patch was a large double medioventral papilla. There were five pairs of postanal papillae with the first pair just posterior to the anus being double while the remaining four pairs were more closely associated in a group near the tail end. The second pair were also double papillae; however, in a few specimens they were not fused and appeared as two single closely associated papillae. The last three pairs of papillae were single. The fourth pair of caudal papillae were the phasmids and in the center of each was a ringed pore-like opening. The spicules of the male had a highly sculptured surface with a pincher-like terminal end.

An American Board of Orthodontics case report

A case report is presented of an Angle Class I dental malocclusion, significant bimaxillary dentoalveolar protrusion, anterior open bite, and spacing of the maxillary and mandibular incisors. [This case was presented to the American Board of Orthodontics in partial fulfillment of the requirements for the certification process conducted by the Board.]

Phagicola angrense (Digenea: Heterophyidae) as a cause of enteritis in a raccoon (Procyon lotor)

Numerous Phagicola angrense were associated with enteritis in a single male juvenile raccoon (Procyon lotor) live-trapped on Parramore Island, Virginia (USA). The raccoon was weak, ataxic and had melenic soft feces. The carcass was emaciated, pale and had ascites. Mesenteric vessels appeared prominent and the stomach and the intestines contained fetid bloody material. The small intestinal mucosa contained three locally extensive sites of necrosis. Histopathologically, there were numerous small digeneans both attached to the mucosa and free within the lumen. Digeneans were usually found deep within the crypts where the epithelium was markedly attenuated and devoid of epithelial cells at the point of parasite attachment. In the lamina propria there were areas of acute hemorrhage and infiltration with plasma cells and eosinophils. This appears to be the first record of severe enteritis in the raccoon caused by this digenean.

New information on the location of Capillaria procyonis (Nematoda: Trichuroidea) in the tongue of a raccoon (Procyon lotor)

Histologic examination of the tongue of one juvenile male raccoon demonstrated the presence of adults and unembryonated eggs of the nematode Capillaria procyonis within parasite-induced tunnels in the stratified squamous epithelium. There was no inflammatory infiltrate within the epithelium or the subjacent lamina propria. The shape of tunnels approximated that of the resident nematodes and were lined by flattened and attenuated epithelial cells. Therefore, the site of infection of C. procyonis in the raccoon includes the oral, lingual and pharyngeal epithelium in addition to the esophagus.