كتاب Factors Affecting the Success Rate of Treatment of Recumbent Dairy Cows Suffering from Hypocalcaemia

Factors Affecting the Success Rate of Treatment of Recumbent Dairy Cows Suffering from Hypocalcaemia من كتب طب بيطرى CLINICAL MEDICINE Department for Farm Animals and Herd Management, University of Veterinary Medicine Vienna, Vienna, Austria Factors Affecting the Success Rate of Treatment of Recumbent Dairy Cows Suffering from Hypocalcaemia C.-C. Gelfert 1,3 , I. Alpers 2 , M. Dallmeyer 2 , M. Decker 2 , A. Hu ̈ ting 2 , S. Lesch 2 , W. Baumgartner 1 and R. Staufenbiel 2 Addresses of authors: 1 Department for Farm Animals and Herd Management, Clinic for Ruminants, University for Veterinary Medicine Vienna, 1210 Vienna, Austria; 2 Clinic for Ruminants and Swine, Free University Berlin, 14163 Berlin, Germany; 3 Corresponding author: Tel.: +43 1 25077 5215; fax: +43 1 25077 5290; E-mail: Carl-Christian.Gelfert@vu-wien.ac.at With 10 tables Received for publication April 3, 2006 Summary We aimed to investigate the ratio of accompanying diseases in cows suffering from clinical hypocalcaemia and their influence on cure rate. In five veterinary practices in different regions of Germany, all recumbent cows around parturition were included in the study for a period of 1 year. After recording the case history a clinical examination was done and a serum sample was taken to measure the concentrations of calcium and phosphorus magnesium, b -hydroxybutyrate, total bilirubin, cholesterol, urea, and the activities of ASAT, CK, and GLDH. Only cows with hypocalcaemia entered the statistical analysis. Hypocal- caemia was the major cause of recumbency in cows of the sec- ond lactation or elder. Muscle damage was the second frequent diagnose in recumbent cows and the major concomitant disease in hypocalcaemic cows. The overall cure rate was between 89.4% and 94.8%. Calcium and phosphorus concentrations did not have an influence on cure rate. Non-cured cows had higher serum activities of CK (p<0.043) and ASAT (p<0.006). Nevertheless, the activities of CK and ASAT were no good predictors of treatment failure because of their low specificity and the high cure rate of the cows in the five practices. Introduction Hypocalcaemia is still the major cause of dairy cows becoming recumbent in the peripartal period (Shpigel et al., 2003; Gelfert et al., 2004, 2005). The onset of lactation increases the calcium requirement (Goff and Horst, 1997). If the mobilization of calcium from the bones and intestine fails to compensate for the loss of calcium in the milk, the plasma calcium concen- trations will become too low to be able to support nerve and muscle function (Goff and Horst, 1997; Goff, 2004). It is still recommended to treat such animals with an intravenous infusion of organic calcium solutions (Staufenbiel, 1999; Martig, 2002). However, prior to the treatment of a recumbent cow, a detailed clinical examination must be made in order to exclude other possible causes of a recumbent cow. The main differential diagnoses vary from disorders of the musculoskel- etal system (traumatic injuries, bone fracture), neural disorders (e.g. obturator paralysis) to metabolic diseases due to mineral deficiencies (e.g. hypomagnesaemia, hypocalcaemia), energy deficiency, or hepatic failure (Dirksen, 2002). Other possible differential diagnoses are toxic metritis, toxic mastitis, ileus, and shock due to the rupturing of the intestine, abomasal ulcer, or generalized peritonitis (Dirksen, 2002; Hunt and Blackwelder, 2002). Depending on the occurrence of a disturbed sensorium or the disturbed general health of the parturient cows, the possible differential diagnoses vary. In the field, the possibilities of a detailed clinical examination are often limited, in which the symptoms are either not clearly visible or non-specific (Bostedt et al., 1979; Stolla et al., 2000). Metzner and Klee (2005) showed that clinical signs are not specific for a particular mineral deficiency (e.g. calcium or phosphorus). They also found that the classical symptom of hypocalcaemia, the disturbed sensorium, was found less severe than in previous studies (Malz and Meyer, 1992). Therefore, a given uncertainty remains after the clinical examination, in which the examining veterinarian must choose the treatment with the highest probability of success. Recent papers have reported a decreased success rate after the first treatment of the standard therapy (Meschke, 1997; Abele and Wolf, 2000; Roesch, 2000; Stolla et al., 2000). Some of them assume that the increased prevalence of recumbent cows suffering from hypophosphataemia may contribute to the impaired success rate (Abele and Wolf, 2000; Stolla et al., 2000). Stolla et al. (2000) also assumed that the high preval- ence of recumbent cows with increased creatinkinase (CK) activity may contribute to the decreased success of the first therapy, but he did not prove it. Other authors found significant differences in hypocalcaemic cows with different treatment outcomes (Gelfert et al., 2004). Unsuccessfully treated cows had higher activities of CK and aspartate- amino-transferase (ASAT) than the cured ones. It is still unknown whether such factors accompanying the hypocalcaemia have an impact on the curing rate of recumbent dairy cows suffering from hypocalcaemia.
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