Characterization of lesions of nutritional congenital goitre in cattle.

There are few studies that classify and characterize the morphometric and immunohistochemical features of goitre in bovine thyroid glands (TGs). We investigated 39 bovine TGs (fetuses [9], stillbirths [18], neonates [12]) born to dams with low T4 hormone levels and no iodine supplementation and 10 (fetuses [3], stillbirths [3], neonates [4]) born to dams with normal T4 levels and supplemented with iodine. Body weight (BW), TG weight (TGW), TGW:BW ratio and histological lesions were determined. The TGs were classified histopathologically as normal gland (G0), mild goitre (G1), moderate goitre (G2) or severe goitre (G3). Various morphological and morphometric parameters were calculated from microscopic images using image analysis software. Immunohistochemistry was performed to detect proliferating cell nuclear antigen (PCNA). There were significant differences in the TGW:BW ratio among groups (P <0.05): 0.3 ± 0.1 in G0, 0.5 ± 0.3 in G1, 0.8 ± 0.3 in G2 and 1.3 ± 0.7 in G3. In G0, large homogeneous follicles with eosinophilic colloid were seen. In the groups with lesions (G1, G2 and G3), heterogeneity in follicle shape and size, height and area of thyroid follicular cells, height of thyroid follicular epithelium and PCNA immunolabelling were directly related to histopathological grade, with significant differences among groups (P <0.001), gradually increasing from G1 to G3 compared with G0. The TGW:BW ratio and histological grade were positively correlated (P = 0.008).

Photosensitization Induced by Heterophyllaea pustulata in Goats: Sequential Development of Skin Lesions.

Five adult Saanen goats received a single oral dose of Heterophyllaea pustulata containing 42.25 µg/kg rubiadin (anthraquinone) and 3 adult goats were untreated controls. All goats were exposed to sunlight and sequential ear skin biopsies were collected before treatment and at 32 hours, 3 days, 8 days, and 15 days after treatment. Changes at 32 hours after dosing included epidermal spongiosis, single cell death and acantholysis, an increased BAX/BCL-2 protein ratio, and dermal edema. Lesions at day 3 included epidermal and adnexal necrosis, crust formation, and acanthosis. Acanthosis, hyperkeratosis, and dermal fibrosis and neovascularization were present at day 15. The pro-apoptotic (BAX)/anti-apoptotic (BCL-2) protein ratio increased at 32 hours, whereas epidermal and dermal PCNA immunolabeling increased between days 8 and 15 after treatment. The cutaneous lesions were consistent with sunlight-induced damage, and the occurrence in treated but not control goats indicates photosensitization.

Suspected poisoning in beef cattle from ingestion of Prosopis nigra pods in north-western Argentina.

The aim of this paper was to present the first report of Prosopis nigra poisoning of cattle in Argentina. Outbreaks occurred in five farms located in Salta and Santiago del Estero provinces. All animals were examined, euthanized and necropsied. Clinical signs included tongue protrusion, twitches and tremors of muscles of mastication, weight loss and lethargy. Severe atrophy of the masseter, buccinator and lingual muscles was observed, along with neuronal vacuolation in the nuclei of the trigeminal, facial, and hypoglossus nerves. These findings and the clinical signs are consistent with results obtained in animals, spontaneously and experimentally intoxicated with Prosopis juliflora in previous studies. Several species of this genus are native to Argentina. Farmers should be warned about the suspected toxicity by Prosopis nigra, since this species has wide geographical distribution in the country.