Case series: periocular habronemiasis in five horses in the Netherlands.

The research presents a series of five cases involving horses in the Netherlands affected by habronemiasis, an infection commonly found in tropical and subtropical regions. The infection has been found to contribute to conditions such as conjunctivitis or blepharitis in horses.

Background

• Periocular habronemiasis is a type of infection that affects the tissue around the eyes, usually associated with warm climates.
• This study focuses on a handful of cases in the Netherlands, a region where this condition has rarely been reported.
• The research presents five instances of periocular habronemiasis, most of which are recent, signifying an unusual increase.

Methods

• A diagnosis was made based on the horses’ medical histories, observable symptoms, and histopathologic examination of biopsy specimens.
• All of the cases involved both conjunctivitis and dermatitis, a skin condition that produces sulphur-like granules.
• Microscopic tissue analyses revealed eosinophilic granulomatous inflammation – a specific type of chronic inflammatory response.
• In three cases, nematodes or roundworms were observed upon sectioning the biopsy samples.

Treatment & Results

• A combination of treatments including surgical excision, local corticosteroid, and/or anthelmintic drugs (which are used to treat infections caused by parasitic worms) were applied.
• All the horses received either ivermectin or moxidectin, two common types of anthelmintic medications.
• The treatments led to a healing of the lesions in four horses while one case that was resistant to treatment resolved spontaneously when the weather turned colder.

Conclusion

• The findings propose a potential rising prevalence of periocular habronemiasis in the Netherlands.
• The researchers suggest that habronemiasis should be considered a potential diagnosis when presented with horses showing signs of granulomatous conjunctivitis or dermatitis, especially during summer months in Western Europe.