Micronema granuloma in the gingiva of a horse.

The research involves a case study of a 4-year-old Appaloosa gelding horse with a mandibular mass identified as Micronema granuloma. The horse was euthanized due to the mass’s extensive involvement leading to eating issues.

Case Background

• An Appaloosa gelding horse of 4 years old was presented with a mass protruding from its mandible body. The mass had clear boundaries and was uniformly firm with ulceration on its top surface.
• The horse faced difficulty eating owing to the mass’s extensive impact resulting in the decision to euthanize the horse.

Microscopic Findings

• Upon further microscopic examination, the mass was found to consist of many discreet microgranulomas that were separated by significant amounts of fibrous connective tissue.
• This connective tissue was found to contain different types of cells including lymphocytes, plasma cells and histiocytic macrophages which are all parts of the immune response.

Identification of Micronema Nematodes

• Upon closer microscopic examination, numerous rhabditiform nematodes were found within the microgranulomas and in the surrounding connective tissue.
• These nematodes were identified as belonging to the Micronema species.
• The presence of these nematodes led to the diagnosis of a Micronema granuloma, a type of proliferative mass that has not been commonly reported in horses.

Significance of the Study

• The findings of the study are significant as it highlighted an unusual nematode infection in a horse, leading to the growth of a protruding mandibular granuloma.
• This case report contributes to the limited knowledge on Micronema infections in horses and could be valuable for further research and for veterinarians dealing with similar cases in the future.