Intoxicação crônica por cobre em ovinos: conduta para o diagnóstico conclusivo

Atypical chronic copper poisoning in a sheep secondary to copper wire ingestion - case report

ABSTRACT A 14-month-old female Texel sheep that came from a herd made up of 19 animals showed haemoglobinuria, apathy, and anorexia, and died two days after the start of the clinical signals. The sheep remained in a natural grassland, where trailers were repaired, and multiple copper wires were deposited on the pasture. The animal had tachycardia, tachypnoea, pale mucous membranes, groaning pain on abdominal palpation, circling, head pressing, intensely hemolyzed plasma, and intense azotaemia. The necropsy showed focally extensive oedema in the inguinal and medial region of pelvic limbs, kidneys dark brown, and liver diffusely yellow with an evident moderate diffuse lobular pattern. The abomasum had a considerable amount of enameled material of thickness, firm to the cut, with 1-5 mm (copper wires). Histopathological examination showed marked diffuse tubular and glomerular coagulative necrosis in the kidneys, in addition to neutrophils, macrophages, lymphocytes, and plasma cells with moderate multifocal nephritis. The liver showed centrilobular necrosis, moderate hepatocellular edema, multifocal cholestasis, and in the lungs and brain mild to moderate diffuse edema. Copper content in the frozen liver (in natura) reached 1,598 mg/kg. Copper mesh ingestion led to sheep poisoning, which in this case was considered an atypical form of chronic primary copper poisoning.

Diets containing cactus cladodes on serum and liver levels of microminerals in sheep and goats

Two experiments were performed to evaluate the effects of partial replacement of Tifton hay by Miúda cactus cladodes (Nopalea) or Orelha de Elefante Mexicana (O.E.M.) cactus cladodes (Opuntia) on serum and liver concentrations of iron (Fe), copper (Cu), zinc (Zn), and manganese (Mn) in feedlot small ruminants. The experiment 1 (Exp. 1) lasted 86 days, and thirty-six male Santa Inês lambs (22.0 ± 2.9 kg initial body weight-IBW) were used. In experiment 2 (Exp. 2), lasting 100 days, thirty-six male goats of undefined breed (19.0 ± 2.8 kg IBW) were used. In both studies, the animals were distributed in a completely randomized design, with three treatments (diet control-without cactus; and diets with hay partially replaced by Miúda or O.E.M. cactus cladodes) and twelve replicates. Blood samples were collected to quantify serum micromineral levels, and at the end of the feedlot periods, sheep and goats were slaughtered and liver fragments were collected for micromineral dosage. In Exp. 1, lambs fed Nopalea cactus cladodes diet showed greater hepatic Cu accumulation (441.87 mg/kg DM; P = 0.027). The diets containing cactus cladodes tended to increase serum levels of Cu (P = 0.075) and Zn (P = 0.058). In Exp. 2, goats fed diet containing Opuntia cactus cladodes presented higher serum levels of Fe (P = 0.024) and Cu (P = 0.012). In conclusion, the partial replacement of Tifton hay by cactus cladodes increases hepatic concentrations of Cu in lambs and serum levels of Fe and Cu in goats.

Dietary Zinc Supplementation to Prevent Chronic Copper Poisoning in Sheep

Simple Summary

Sheep are susceptible to copper toxicosis, a deadly disease that usually occurs when the animals ingest large amounts of this mineral. Considering that the susceptibility of sheep to copper accumulation varies widely among breeds and from animal to animal., we evaluate whether Zn supplementation could be an option as a preventive measure to protect against hepatic Cu accumulation in sheep. Zn at 300 mg/kg dry matter (DM) is useful for preventing excessive hepatic Cu accumulation. Hepatic Cu accumulation is lower in animals receiving the Zn supplementation.

Abstract

The aim of this study was to evaluate whether zinc (Zn) supplementation protects against hepatic copper (Cu) accumulation in copper-loaded sheep. Forty cross-bred lambs were assigned to five experimental groups. These included the control group (C) and four treatment groups that received Cu and/or Zn supplementation (dry matter (DM) basis) over 14 weeks, as follows: Cu (450 mg Cu/kg); Zn-35 (450 mg Cu + 35 mg Zn/kg); Zn-150 (450 mg Cu + 150 mg Zn/kg); and Zn-300 (450 mg Cu + 300 mg Zn/kg). Blood, liver, and bile samples were obtained for mineral determination by inductively coupled plasma optical emission spectrometry (ICP–OES). The hepatic metallothionein (MT) concentrations were also determined. At the end of the experiment, hepatic Cu concentrations were higher in all Cu-supplemented groups than in C. Hepatic Cu accumulation was lower in the groups receiving the Zn supplementation than in the Cu group, although the difference was only statistically significant (66%) in the Zn-300 group. The MT concentrations tended to be higher (almost two-fold) in the Zn groups (but were not dose related) than in the C and Cu groups, and they were related to hepatic Zn concentrations. Zn supplementation at 300 mg/kg DM is useful for preventing excessive hepatic Cu accumulation in sheep exposed to high dietary concentrations of Cu.

Utilização de sal mineral rico em molibdênio na prevenção da intoxicação cúprica acumulativa em ovinos - microminerais hepáticos

RESUMO Este estudo avaliou a capacidade de um sal mineral rico em molibdênio (Mo) em prevenir a intoxicação cúprica acumulativa (ICA), mediante a análise das variáveis clínicas e dos teores de cobre (Cu) e Mo hepático. Foram utilizados 25 ovinos cruzados da raça Ile-de-France, aleatoriamente distribuídos igualmente em cinco grupos, em que o grupo 1 recebia dieta contendo 80% de volumoso e 20% de concentrado, os grupos 2 e 3 recebiam 50% de volumoso e 50% de concentrado, e os grupos 4 e 5 recebiam a mesma dieta dos grupos 2 e 3, com a adição diária de 150mg de sulfato de Cu. Os grupos 1, 3 e 5 recebiam sal mineral contendo 300ppm de Mo. Foram realizadas três biópsias hepáticas para determinação de Cu, Mo e Zn. Três ovinos do grupo 4 e um do grupo 5 manifestaram ICA. Não houve diferença na frequência de mortalidade entre os grupos (P=0,56). Os teores de Cu hepático nos ovinos com ICA (2450ppm) foram superiores aos que não intoxicaram (1518ppm). Quanto maior a ingestão de Mo na dieta, menor foi o acúmulo de Cu hepático ao término do experimento (r = -0,72).