Cutaneous and ocular habronemiasis in horses: 63 cases (1988-2002).
OBJECTIVE
To describe clinical manifestations of cutaneous and ocular habronemiasis in horses and evaluate outcome of treatment.


METHODS
Retrospective study.


METHODS
63 horses.


METHODS
The diagnosis was made on the basis of history, clinical signs, and identification of calcified concretions (sulfur granules) in lesions. Histologic examination of biopsy specimens was used to confirm the diagnosis. Case horses were compared with a control population of 12,720 horses examined during the same period.


RESULTS
Arabians, gray horses, and horses with diluted coat colors were overrepresented; Thoroughbreds were underrepresented. Lesions were identified most often during the summer and early fall. The medial canthus of the eye, male genitalia, third eyelid, and distal portions of the extremities were the most commonly affected locations. Twenty-five lesions were biopsied, and results of histologic examination were consistent with a diagnosis of habronemiasis. However, nematode larvae were seen in only 11 (44%) biopsy specimens. Treatment consisted of surgical removal (7 horses) or medical treatment (56) consisting of debulking granulation tissue and topical, intralesional, or systemic treatment with corticosteroids. All horses were treated with ivermectin.


CONCLUSIONS
Results suggest that cutaneous and ocular habronemiasis should be considered when examining a horse during the summer months with a proliferative, moist, granulomatous lesion. Treatment should be aimed at decreasing the size of the lesion, reducing inflammation, and preventing recurrence. In general, the prognosis was good, and healing occurred within a few weeks. Fly control and regular deworming with ivermectin are recommended to reduce the incidence of habronemiasis.
Pusterla
Nicola
N
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
Watson
Johanna L
JL
Wilson
W David
WD
Affolter
Verena K
VK
Spier
Sharon J
SJ
D017677:Age Distribution; D000818:Animals; D000969:Antinematodal Agents / Q000627:therapeutic use; D002140:California / Q000453:epidemiology; D005123:Eye / Q000469:parasitology / Q000473:pathology; D015822:Eye Infections, Parasitic / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D005260:Female; D006200:Hair Color; D006734:Horse Diseases / Q000453:epidemiology* / Q000469:parasitology / Q000473:pathology; D006736:Horses; D007559:Ivermectin / Q000627:therapeutic use; D008297:Male; D011379:Prognosis; D012189:Retrospective Studies; D012621:Seasons; D012876:Skin Diseases, Parasitic / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D017205:Spirurida Infections / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D016896:Treatment Outcome
D000969:Antinematodal Agents; D007559:Ivermectin