Skip to main content
ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Virus and Prion Research » Research » Publications at this Location » Publication #102746
Title: A RETROSPECTIVE HISTOPATHOLOGICAL SURVEY OF CAPILLARIASIS IN RACCOONS (PROCYON LOTOR) FROM OREGON, USA

Author
item Hamir, Amirali
item SNYDER, DANIEL - VET.MED.,CORVALLIS, OR.

Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/28/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary: Between November, 1995 and October, 1997, 63 adult raccoons were examined at the College of Veterinary Medicine, Oregon State University, Corvallis, Oregon. The raccoons were from the surrounding areas of Corvallis, Oregon, and were obtained to document abnormal findings. The raccoons were either found dead on highways (road kills); were submitted as suspect rabies cases; or were obtained from local wildlife control organizations. Infection by one particular parasite (Capillaria sp.0 was found in various tissues such as the lining of the mouth (2/63), tongue (10/62), esophagus (2/63), urinary bladder (7/63), and anal sacs (29/30). At the latter site, the parasites were found in 16 males, 12 females, and in one raccoon whose gender was not recorded. Clinical lesions related to infection by the parasite in the anal sac was observed in only 1 of the raccoons. The findings of this study indicate that the parasites in the anal sacs is commonly seen in free ranging raccoons in Oregon, and the infection is essentially subclinical since only 1 case of anal sac impaction caused by the parasite has been reported. Measurements of the parasite and their eggs from the anal sacs indicate that it is most likely a new species which to date has not been fully described in raccoons. It is speculated that the high prevalence of anal sac infection by the parasite in Oregon raccoons may also be true for raccoons in other parts of North America and in parts of Europe and Asia where raccoons have been introduced.

Technical Abstract: 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 was 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 an 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 since 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.