In this study, we investigate the status of calcium (Ca) homeostasis at parturition in three dairy farms (Ⅰ, Ⅱ, and Ⅲ), Heilongjiang, China. Twenty multiparous Holstein cows from each farm were randomly assigned to this experiment. The dietary cation-anion difference (DCAD) was 91 mEq/kg of DM for farm Ⅰ, 152 mEq/kg of DM for farm Ⅱ, and 85 mEq/kg of DM for farm Ⅲ. Incidence of hypocalcemia was above 75% and urine pH was above 7.25 at calving in each farm. Compared to other farms, cows in farm Ⅱ that fed the greatest positive DCAD had the lowest concentration of serum Ca, the highest concentration of serum PTH, and the greatest urine pH at calving (p less than 0.05). However, there was not significant difference in serum 1,25-dihydroxy-vitamin D and hydroxyproline concentration of the cows among three farms. This is the first study to confirm that hypocalcemia is very prevalent at calving in Chinese dairy farms, and the high positive DCAD is a major risk factor that results in hypocalcemia at calving, which may reduce ability of the cow to maintain Ca homeostasis.

A miniature schnauzer (8 years old, male castrated), diagnosed as diabetes mellitus 6 months ahead, were referred to the Veterinary Medical Teaching Hospital of our University with hindlimb stiffness, facial rubbing and tetany. Serum chemistry showed severe hypocalcemia, hypomagnesemia, and measured iPTH (intact pharathyroid hormone) concentration was low (less than 3.0 pmol/L). Consistent rate injection of calcium gluconate (282 mg/kg over 30 min) resulted in prompt relief of the tetany. Then typical treatment for hypoparathyroidism (calcium gluconate and dihydrotachysterol per os) with magnesium administration could control the neuromuscular signs. Diabetes mellitus is being controlled by insulin therapy and prescription diet. Hypomagnesemia in diabetic dog may be induced hypoparathyrodism.

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.