Diba Forouzanpour, Golara Ostovari, Mehrdad Mashhadi, Hossein Dehghani, and Ali Hajimohammadi
Department of Clinical Studies, School of Veterinary Medicine, Shiraz University, Shiraz, Iran Corresponding author: Ali Hajimohammadi, Department of Clinical Studies, School of Veterinary Medicine, Shiraz University, Shiraz, Iran. Email: email@example.com
Introduction: Habronemiasis, an equine summer sore, is caused by habronema larvae, commonly in tropical and subtropical climates. House flies, face flies, and stable flies transmit the pathogenic nematode larvae. Cutaneous habronemiais is the most common form of habronemiasis in horses. Cutaneous habronemiais is associated with the deposition of larvae in areas where they cannot complete their life cycle. Deposition of larvae is related to local hypersensitivity. Habronema larvae could cause preocular infectious resulting in conjunctivitis, blepharitis, or dermatitis. Case report: An eight-year-old male Arabian horse was referred to the Large Animal Medicine Unit, Veterinary Clinical hospital, Shiraz University, Shiraz, Iran, with a history of wounds on the preocular region and hind limbs. The right eye’s ocular examination revealed abundant mucopurulent discharge, blepharospasm, and chemosis. The granulomatous tumor had a diameter of 1.8 cm and was evident on the palpebral conjunctiva of the medial canthus. The skin lesion was identified as habronemiasis based on the history, and clinical symptoms. Treatment inclua des prednisolone tab with reducing dosage for 30 days, an oral dose of Ivermectin, topical oxytetracycline ointment for seven days, chloramphenicol and triamcinolone eye drop for seven days. The diagnosis was confirmed due to the positive reaction of the lesions to treatment protocol. Conclusion: Ocular habronemiasis is the common form of habronemiasis. Deposing of dead larva causes a hypersensitivity reaction. Treatments include corticosteroids to reduce inflammation-association tissue proliferation, antibiotic ointment for prevention of second bacterial infection, an antihistamine for the prevention of histamine-mediated pruritic and allergic conditions, and oral antihelminth for the killing of adult form in the stomach. . The current study authors suggest fly control is essential in preventing habronemiasis.
Habronemiasis, or equine summer sore, is caused by habronema larvae, commonly in tropical and subtropical climates. Habronema larvae could cause preocular infectious resulting in conjunctivitis, blepharitis, or dermatitis1. Habronema microstoma (H. microstoma), Habronema muscae, and Draschia megastoma are three worms known to cause habronemiasis. Habronema’s adult stage is usually asymptomatic and lives in the equine stomach. Adult female nematodes produce eggs in horse stomachs, and eggs are passed with feces. Then the eggs in the horse feces are ingested by the maggots of various flies. Mature flies deposit the infective L3 larvae on the horse mucus membrane2. Flies mostly deposit their eggs on moist skin area which is attractive to them, like the preocular area. If the horse consumes the parasite’s larvae, the adult parasite will complete its life cycle in the stomach of the horse. A local hypersensitivity reaction occurs on the cutaneous or mucus membrane if the larvae remain on the cutaneous3.