Hepatogenous photosensitization of sheep in California associated with ingestion of Tribulus terrestris (puncture vine)

Acute fatal poisoning by spontaneous ingestion of Enterolobium contortisiliquum (Mimosidae) pods in horses

An outbreak of acute poisoning of horses by Enterolobium contortisiliquum pods is reported in the state of Goiás, Brazil. Three horses presented apathy, hyporexia, prostration, jaundice, recumbency and died in 24-48 hours. The main pathological findings were a yellowish liver with an enhanced lobular pattern, multifocal hepatic necrosis mostly in the midzones of lobules and sometimes with a random distribution across the hepatic lobes and swelling of hepatocytes. E. contortisiliquum trees has a wide distribution in South America and cases of poisoning have not been reported in horses.

Photosensitisation of livestock grazing Narthecium ossifragum: Current knowledge and future directions

Photosensitisation diseases can cause production and animal welfare losses world-wide. In North-West Europe a photosensitisation disease complex known as 'plochteach', 'yellowses', 'saut' and 'alveld' occurs in lambs on extensive pastures containing bog asphodel (Narthecium ossifragum). Affected lambs develop lesions on the ears, face and sometimes the back, with erythema, oedema, ulceration and necrosis that can be followed by secondary infection and death. Adult sheep appear unaffected, the incidence in lambs varies from year to year and there are variations in susceptibility between- and within-breeds. The definitive cause remains uncertain although ingestion of N. ossifragum, which contains hepatotoxic saponins, has been implicated in the aetiology. However, problems replicating the disease complex by feeding N. ossifragum in a controlled environment have led to alternative hypotheses, including possible intake of toxins from fungal spores and cyanobacteria. Further research is required to assess the putative role of N. ossifragum, the scale of economic and animal welfare losses associated with the disease, how best to identify affected animals before external clinical signs appear and the treatment and management of clinical cases. Given the challenges involved in isolating the causative agent(s) of plochteach, an animal breeding route may be effective if heritability of resistance/susceptibility can be demonstrated.

Experimental Tribulus terrestris poisoning in sheep: clinical, laboratory and pathological findings

Eleven native sheep, 1-2 years old, of both sexes were randomly divided into two groups, 6 sheep being allocated to the experimental group and 5 serving as controls. The sheep in the experimental group were fed 80% Tribulus terrestris and 20% alfalfa hay and wheat straw, while the control sheep were given a mixture of 40% alfalfa hay and 60% wheat straw. Clinical signs of hepatogenous photosensitivity were observed from day 11, including reddening and crust formation on the muzzle, nose, ears and eyelids, depression, weight loss, icterus, conjunctivitis, and yellow discoloration of the urine. Laboratory findings on weekly samples indicated significant differences (p < 0.05) in white blood cell count, total plasma protein and fibrinogen, total and direct bilirubin, blood urea nitrogen and creatinine concentrations, and aspartate aminotransferase and alkaline phosphatase activities. There were no significant differences in the packed cell volume, in the neutrophil, lymphocyte or eosinophil counts, or in the serum calcium, phosphorus, potassium, sodium or chloride concentrations. At necropsy of the experimental animals, there were various degrees of generalized icterus and the livers were swollen and discolored by bile pigment. Histopathological examination revealed varying amounts of crystalloid material in the bile ducts and renal tubules, hepatocellular degeneration, biliary fibrosis and proliferation, renal tubular necrosis and focal necrosis of cardiac muscle.