Parasitic Granulomatous Dermatitis Caused by Pelodera spp. in Buffalo on Marajó Island, Pará.

Simple Summary: Buffalo are country animals, with great adaptability, and thrive in diverse environments. The State of Pará has the largest herd of buffalo in Brazil, which can be found mainly on Marajó Island in the northern region of the state. As a result, buffalo farming has become widespread in Brazil, and it offers several products to the consumer market. However, in the State of Pará, skin diseases stand out among the diseases that affect this species. This study reports the first case of dermatitis caused by Pelodera spp. in buffalo (Bubalus bubalis) on Marajó Island, Pará. This is the first report of parasitic granulomatous dermatitis caused by Pelodera spp. in a buffalo. The affected buffalo was about seven years old, was a female of the Murrah breed and belonged to a property located on Marajó Island in the State of Pará. During the clinical examination, the animal was in a standing position and presented several multifocal nodular and placoid masses throughout the body, mostly on the forelimbs, hindlimbs, abdomen, mammary glands, perineum, vulva and tail. These masses were also observed on the nasal mucosa, head, neck, back and chest. On macroscopic examination, the skin had several multifocal-to-coalescent sessile nodular and placoid lesions. Histopathology of the skin showed a marked reduction in the number of hair follicles. In the superficial dermis, there was significant multifocal-to-coalescent inflammatory infiltration, consisting of macrophages, epithelioid macrophages, lymphocytes, plasma cells and multinucleated giant cells. In the remaining hair follicles, there were numerous cross and longitudinal sections of small rhabditoid nematodes characterized by a thin cuticle, platymyarian musculature, an intestinal tract, a rhabditiform esophagus and lateral alae (morphologically compatible with Pelodera spp.). The diagnosis of parasitic dermatitis was confirmed by histopathological skin lesions associated with the presence of intralesional rhabditiform larvae morphologically compatible with Pelodera spp. [ABSTRACT FROM AUTHOR]