Pathology in practice. Cutaneous habronemiasis.

The research paper presents a clinical case of a six-year-old Quarter Horse stallion suffering from cutaneous habronemiasis, a skin condition caused by a parasitic worm, as evidenced by a preputial mass and rash. The symptoms progressively worsened, resulting in an ulcerated mass and abnormal blood work, leading to a surgical intervention – a penile resection and castration, followed by histological examination.

Background and History

• The study revolves around a six-year-old Quarter Horse, which was evaluated on account of a preputial mass.
• The horse’s condition was reported by its owners, who noticed the development of a preputial rash a year before the study was conducted.
• Since the rash transformed into a gradually growing ulcerated mass despite treatments such as intra-muscular injections of penicillin and topical applications of silver nitrate ointment, the case necessitated further assessment.

Clinical and Gross Findings

• Detailed physical examination of the horse revealed enlarged and firm superficial inguinal lymph nodes.
• The most evident symptom was a large, multilobulated, firm, pink ulcerated mass that expanded the cranial end of the prepuce. Moreover, the swelling extended to the caudal aspect of the prepuce.
• The condition of the horse warranted a Complete Blood Count (CBC), which showed marked neutrophilia of 14,145 cells/L (considering reference range as 2,260 to 8,580 cells/L) and eosinophilia of 4,100 cells/μL (zero to 1,000 cells/μL as reference range).

Treatment and Results

• Given the severe condition, the horse underwent an en bloc penile resection and castration.
• The tissue extracted was sent for histological examination, and the enlarged, firm superficial inguinal lymph nodes were also surgically removed and submitted.
• The surgical recovery of the horse post anesthesia was uneventful, indicating successful treatment.