Pythiosis in Equidae in Northeastern Brazil: 1985-2020.

The epidemiologic, clinical, pathologic, microbiological and immunohistochemical findings of pythiosis in equidae in northeastern Brazil are described. From January 1985 to December 2020 the Laboratory of Animal Pathology of the Federal University of Campina Grande received 1,331 tissue samples of equidae, 202 (15.17%) of which were diagnosed as pythiosis. Equidae of both sexes with ages varying from 4 months to 25 years were affected. Most animals were mixed breed (79.7%) and reared in an extensive system (73.26%). The disease occurred throughout the year but the highest incidence (70.29%) was noted after the rainy season. The clinical course was always chronic. The lesions were preferentially located on the limbs and ventral thoracoabdominal wall and characterized by nodules or tumor-like masses with ulcerations and serosanguineous discharge. The cut surface showed fistulous tracts containing kunkers. The direct examination of the kunkers and microbiological culture revealed sparsely septate and branched hyaline hyphae. Histopathology revealed a marked inflammatory infiltrate of eosinophils with multifocal well-defined areas of eosinophil necrosis and collagenolysis and intralesional negatively-stained hyphal profiles; in the donkey, a pyogranulomatous inflammatory infiltrate was noted surrounding these areas. Immunohistochemistry for Pythium insidiosum revealed strong immunolabelling of the hyphae. Pythiosis occurs endemically in equidae in northeastern Brazil, with seasonal variation in the incidence. The intralesional kunkers establishes an accurate presumptive diagnosis, but confirmation should preferably be performed through histopathology associated with immunohistochemistry, culture-based or molecular methods.

Cutaneous pythiosis in a donkey (Equus asinus) in Brazil.

Our study describes the clinical, epidemiologic, pathologic, immunohistochemical, and molecular aspects PCR of a case of cutaneous pythiosis in a donkey (Equus asinus) from Brazil. During a dry period, the animal grazed for 4 months around a pond where the vegetation remained green. Skin lesions were nodular, multifocal, and disseminated, mainly involving the legs, ventral chest, and mammary gland. On cut surface, there were multifocal to coalescent discrete yellow foci, and occasional small cavitations with a few kunkers. Ulcerative nodular pyogranulomatous and eosinophilic dermatitis with folliculitis and furunculosis were observed histologically. Hyphae were observed in sections stained with Gomori methenamine silver. Immunohistochemistry with Pythium insidiosum antibodies yielded strong immunostaining of hyphae. P. insidiosum DNA was extracted from tissues in paraffin blocks by amplification of a fragment of 105 bp, which targets the 5.8S ribosomal gene. After the diagnosis of pythiosis, the larger skin lesions were excised and treated as second intention healing wounds, which were completely healed 30 days after resection. Small skin lesions regressed spontaneously in ~60 days. The granulomatous inflammation and outcome of the disease in this donkey were similar to cases of pythiosis in cattle.

Poisoning by Talisia esculenta (A. St.-Hil.) Radlk in sheep and cattle.

Talisia esculenta is a tree that produces pitomba, a fruit consumed by human beings in several regions of Brazil. The current study reports 3 outbreaks of poisoning by leaves and fruits of T. esculenta affecting sheep and cattle and the experimental reproduction of the disease in sheep. In the first investigated outbreak, sheep ingested the leaves of the plant; another outbreak affected cattle and sheep that ingested leaves and fruits; and in a third outbreak, sheep ingested only the fruits. The animals developed severe nervous signs, but most recovered. Poisoning was reproduced experimentally in 5 sheep by the administration of 30-60 g of leaves/kg body weight and in 2 sheep with doses of 5 and 10 g of seeds/kg body weight, respectively. No significant necropsy or histologic lesions were found.