Cutaneous Habronemiasis

• Grossly:
  • Single or multiple tomorous masses that proliferate and ulcerate
  • Red to brown, on section have small gritty yellow to white foci
• Microscopically:
  • Nodular dermatitis
  • Eosinophils, epithelioid macrophages, multinucleated giant cells
  • Larvae and necrotic tissue
  • Granulation tissue with neutrophils along ulcerated surface

Description

Cutaneous Habronemiasis is a hypersensitivity reaction to the larvae of the nematode species Habronema and Draschia. The Larvae are deposited by the housefly and stableflyhouse flies or stable flies on the skin when they feed.

Signalment

The condition occurs most commonly in warm wet climates such as the tropics and sub tropics but is also a common skin condition in the UK. It affects moist regions of the body and open wounds and has a seasonal occurance whihc partially or fully resolves over the winter.

Diagnosis

Clinical signs

Single or multiple nodular lesions Excessive granulation tissue Pruritus lesions most commonly occur on the legs, ventral abdomen, around the eyes, urethral process and prepuce and at the site of pre-existing wounds.

Prognosis

Recurrence is common. Fly control, meticulus wound management and regular anthelmintic use is needed to prevent or limit the condition.

References

• Knottenbelt, D.C. A Handbook of Equine Medicine for Final Year Students University of Liverpool
• Rose, R. J. and Hodgson, D. R. (2000) Manual of Equine Practice (Second Edition) Sauders.

Also known as:

Summer sores Granular dermatitis Bursautee