Hepatogenous photosensitization by Brachiaria spp. in sheep: first report in Mexico

Ruminants are highly susceptible to photosensitization caused by the ingestion of hepatotoxic plants. In two adjacent farms in Colima, Mexico, several sheep exhibited signs of depression and crusting dermatitis involving the ears, periorbital skin, eyelids, nostrils, and axillary regions. Results of serum biochemistry were indicative of liver injury. Post mortem examination revealed jaundice, craniofacial edema as well as an enlarged liver having an orange-brown discoloration; on the cut surface, the hepatic parenchyma had a subtle zonal pattern. Histopathological findings were those of severe necrotizing dermatitis, lymphoplasmacytic cholangiohepatitis, and renal tubular necrosis. Acicular crystals were microscopically and ultrastructurally evident in hepatocytes, Kupffer cells, biliary ducts, renal tubules and interstitium. The clinical, gross and microscopic findings were consistent with hepatogenous photosensitization. A field investigation revealed that affected sheep had been grazing Brachiaria spp., a potentially toxic grass originated from Africa and commonly cultivated in Australia and South America. This grass contains hepatotoxic saponins that cause liver injury and secondary hepatogenous photosensitization. Although frequently reported in South America, to our knowledge, this is the first report of Brachiaria spp. toxicity in Mexico.

Hepatogenous photosensitization by Brachiaria spp. in sheep: first report in Mexico

Ruminants are highly susceptible to photosensitization caused by the ingestion of hepatotoxic plants. In two adjacent farms in Colima, Mexico, several sheep exhibited signs of depression and crusting dermatitis involving the ears, periorbital skin, eyelids, nostrils, and axillary regions. Results of serum biochemistry were indicative of liver injury. Post mortem examination revealed jaundice, craniofacial edema as well as an enlarged liver having an orange-brown discoloration; on the cut surface, the hepatic parenchyma had a subtle zonal pattern. Histopathological findings were those of severe necrotizing dermatitis, lymphoplasmacytic cholangiohepatitis, and renal tubular necrosis. Acicular crystals were microscopically and ultrastructurally evident in hepatocytes, Kupffer cells, biliary ducts, renal tubules and interstitium. The clinical, gross and microscopic findings were consistent with hepatogenous photosensitization. A field investigation revealed that affected sheep had been grazing Brachiaria spp., a potentially toxic grass originated from Africa and commonly cultivated in Australia and South America. This grass contains hepatotoxic saponins that cause liver injury and secondary hepatogenous photosensitization. Although frequently reported in South America, to our knowledge, this is the first report of Brachiaria spp. toxicity in Mexico.(AU)

Chronic eosinophilic leukemia in an African hedgehog (Atelerix albiventris)

A 5-year-old African hedgehog (Atelerix albiventris) was presented to the veterinarian with history of anorexia and progressive weight loss. On clinical examination the mucous membranes were pale, and the skin exhibited extensive alopecia with crusting in all four limbs and tail. A large subcutaneous mass was palpated on the left lateral femur which subsequently was diagnosed histopathologically as a squamous cells carcinoma. The owner declined further tests and the patient returned home where it continued to deteriorate and finally died 90 days after initial presentation. The carcass was submitted for postmortem examination. Necropsy finding included an enlarged spleen with rounded borders and meaty pulp, hyperplastic bone marrow and multiple white foci in both kidneys. Tissues were submitted for cytology, histopathology and electron microscopy. Splenic cytology revealed a monomorphic population of granulocytes with cellular atypia which were most consistent with neoplastic eosinophils. Similar myeloid cells were also seen histologically in kidneys, liver, intestine, heart, skin and brain. The bone marrow was completely effaced with similar cellular infiltrates. Luna stain for eosinophils was positive in all tissues. Electron microscopy showed that neoplastic cells had granules and electron-lucent crystalloid characteristic of eosinophils. Based on these finding chronic eosinophilic leukemia wasdiagnosed, and to our knowledge, eosinophilic leukemia in hedgehogs is rarely reported in the literature.

Chronic eosinophilic leukemia in an African hedgehog (Atelerix albiventris)

A 5-year-old African hedgehog (Atelerix albiventris) was presented to the veterinarian with history of anorexia and progressive weight loss. On clinical examination the mucous membranes were pale, and the skin exhibited extensive alopecia with crusting in all four limbs and tail. A large subcutaneous mass was palpated on the left lateral femur which subsequently was diagnosed histopathologically as a squamous cells carcinoma. The owner declined further tests and the patient returned home where it continued to deteriorate and finally died 90 days after initial presentation. The carcass was submitted for postmortem examination. Necropsy finding included an enlarged spleen with rounded borders and meaty pulp, hyperplastic bone marrow and multiple white foci in both kidneys. Tissues were submitted for cytology, histopathology and electron microscopy. Splenic cytology revealed a monomorphic population of granulocytes with cellular atypia which were most consistent with neoplastic eosinophils. Similar myeloid cells were also seen histologically in kidneys, liver, intestine, heart, skin and brain. The bone marrow was completely effaced with similar cellular infiltrates. Luna stain for eosinophils was positive in all tissues. Electron microscopy showed that neoplastic cells had granules and electron-lucent crystalloid characteristic of eosinophils. Based on these finding chronic eosinophilic leukemia wasdiagnosed, and to our knowledge, eosinophilic leukemia in hedgehogs is rarely reported in the literature.(AU)