Enzootic calcinosis in sheep in Uruguay: a brief review and report of two outbreaks

Abstract

This study aimed to do a brief review of enzootic calcinosis in sheep and to report two outbreaks of Nierembergia rivularis poisoning in sheep in Uruguay. The outbreaks occurred in farms located on an island (Outbreak A) and on the border (Outbreak B) of the Rincón del Bonete lake. Sheep of all ages were affected, with the exception of suckling lambs. The first clinical signs occurred in early October, and deaths occurred from December to February. Outbreaks A and B had morbidity of 10%, and the mortality was 7.2% and 2.8% in Outbreaks A and B, respectively. The clinical signs included weight loss, retracted abdomen, stiff gait, and kyphosis. An autopsy was performed on one sheep from each outbreak. Pulmonary and arterial calcification, nephrocalcinosis, and osteopetrosis were observed in gross and microscopic examination in both sheep. Thyroid C-cell hyperplasia and carcinoma was observed in sheep A. Sheep B showed thyroid C-cell hyperplasia and parathyroid chief cell atrophy. The parathyroid was not examined in the sheep from Outbreak A. The differential diagnosis of enzootic calcinosis in southern South America should consider four toxic plants in the Solanaceae family: Solanum glaucophyllum, Solanum stuckertii, Nierembergia veitchii, and Nierembergia rivularis.

Plants causing poisoning outbreaks of livestock in South America: A review

“…7 C) occur in the State of Rio Grande do Sul in Brazil, in hilly areas, and Nierembergia rivularis ( Fig. 7 D) in Uruguay in humid areas mainly in the borders of the lakes and streams ( Machado et al, 2020a ; Schild et al, 2021 ). In the case of Nierembergia veitchii , an action similar to 1,25(OH) 2 D 3 was demonstrated in chickens ( Riet-Correa et al, 1987 ).…”

“…Two species of Nierembergia cause enzootic calcinosis in sheep and less frequent in cattle ( Riet-Correa et al, 1987 ; Machado et al, 2020a ; Schild et al, 2021 ). Nierembergia veitchii ( Fig.…”