Avaliação do quadro clínico e perfil bioquímico de bovinos durante indução e tratamento de hipocalcemia / Assessment of clinical and biochemical profile of cattle during induction and treatment of hypocalcemia

O presente trabalho objetivou estudar o quadro sintomatológico, algumas variáveis bioquímicas e a resposta ao tratamento com cálcio de bovinos com hipocalcemia induzida experimentalmente. Foram utilizadas 12 novilhas distribuídas nos grupos controle (n = 5) e tratado (n = 7). Foi infundida solução de EDTA a 5% até o animal apresentar sinais clínicos de hipocalcemia, quando então era iniciado o tratamento com solução contendo cálcio, fósforo, magnésio e glicose, na dose de 1 mL/kg/PV, em 30 minutos, enquanto que o grupo controle recebia apenas solução fisiológica na mesma dose. Exame clínico e coleta de amostras sanguíneas foram realizados nos tempos T0 (basal), T1 (Fase I, caracterizada por tremores musculares), T2 (ao final da infusão com EDTA), T3 (ao final do tratamento) e T4 (24 horas após o término do experimento). Todas as novilhas mostraram diminuição temporária da concentração de cálcio total e livre, fósforo, e apresentaram quadro clássico de hipocalcemia. A taquicardia, a hipofonese e a atonia ruminal desapareceram no decorrer do tratamento, sendo observado aumento no cálcio livre e total e fósforo. O medicamento usado no tratamento dos animais foi eficaz na recuperação do quadro clínico de hipocalcemia dentro de 30 minutos, promovendo retorno das principais variáveis do perfil bioquímico aos valores basais

The present work aims to study the clinical picture, biochemical profile and treatment response in cattle with induced hypocalcaemia. Were utilized 12 heifers randomly distributed in treated (n = 7) and control (n = 5) groups. The induction model was carried on by continuous EDTA infusion into jugular vein until the animals present clinical signs of hypocalcaemia. After that, the treated group received a calcium (Ca) solution enriched with phosphorus, magnesium and glucose with a dose of 1 mL/kg/BW in 30 minutes, meanwhile, the control group was treated with the same dose of physiologic solution. Clinical examination were performed and blood samples were obtained in times T0 (basal time), T1 (beginning of hypocalcaemia); T2 (end of EDTA infusion); T3 (end of treatment) and T4 (24 hours after the induction). All the heifers present temporary blood calcium and phosphorus reduction and demonstrated classical clinical picture of hypocalcaemia. The treated group present full clinical recovery and blood calcium and phosphorus increase. Most evident clinical signs were increasing heart beat, hypophonesis and rumenal atony. Those symptoms were reversed after calcium treatment. The solution used for treatment was efficient on clinical recovery within thirty minutes, promoting the return to basal levels of the most of biochemical's variables

Hepatogenous photosensitization associated with liver copper accumulation in buffalos.

Four 1.5-year-old, male, Murrah buffalos were maintained during eight months without direct solar exposure during a study of copper toxicosis. Four days after solar exposure, all buffalos presented clinical manifestations consistent with acute photosensitization, including anorexia, apathy, loss of body weight, and generalized cutaneous lesions. Gross lesions were characterized by severe erythema, localized edema, fissures, tissue necrosis, gangrene and crust formation with serous exudation. Liver copper concentration was evaluated, and cutaneous biopsies were taken when clinical signs were evident. The liver copper concentration before solar exposure was increased in all animals. Histopathologic examination of the skin revealed hepatogenous photosensitization characterized by parakeratotic hyperkeratosis, acantholysis, degeneration of squamous epithelial cells, epidermal necrosis with atrophy of sweat glands, and multifocal superficial and deep dermal edema. These findings suggest that asymptomatic accumulation of copper within the liver might have induced hepatic insufficiency thereby resulting in secondary photosensitization when these buffalos were exposed to sunlight.

Clinical observations of cattle and buffalos with experimentally induced chronic copper poisoning.

The susceptibility of cattle and buffalos to chronic copper poisoning (CCP) was compared by using cattle (n=10) and buffalo (n=10) steers distributed into two copper supplemented (n=6) and two control (n=4) groups. Supplemented animals received 2 mg copper (Cu)/kg body weight daily for one week, with an additional 2 mg weekly until the end of the experiment (day 105). Three liver biopsies (day 0, 45, and 105) were obtained for mineral analyses; clinical examinations and blood samples were obtained every 15days. Three supplemented cattle and two buffalos with typical manifestations of CCP died. There were no differences in the frequency of mortality between cattle and buffalos; hepatic copper concentration was higher in cattle than buffalos. These findings suggest that buffalos and cattle might be equally susceptible to CCP. However, buffalos accumulate less liver copper than cattle and have a lower threshold of hepatic Cu accumulation, which leads to clinical manifestation of CCP.