Neonatal calf diarrhoea remains the most common cause of morbidity and mortality in preweaned dairy calves worldwide. This complex disease can be triggered by both infectious and non-infectious causes. The four most important enteropathogens leading to neonatal dairy calf diarrhoea are Escherichia coli, rota- and coronavirus, and Cryptosporidium parvum. Besides treating diarrhoeic neonatal dairy calves, the veterinarian is the most obvious person to advise the dairy farmer on prevention and treatment of this disease. This review deals with prevention and treatment of neonatal dairy calf diarrhoea focusing on the importance of a good colostrum management and a correct fluid therapy.

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Calf diarrhoea causes substantial economic losses in cattle herds worldwide. Neonatal calves are particularly sensitive to infections with enteropathogens. The present study focused on prevention against the main infectious causes of neonatal calf diarrhoea i.e. Escherichia coli, rota- and coronavirus, and Cryptosporidium parvum. Dairy herds (n=24) with a high percentage of neonatal calves scouring (>10%) were included and calves were sampled for the presence of these four enteropathogens. To decrease diarrhoea problems among neonatal calves, a standard protocol was tested on 13 herds (treatment group) where both C. parvum and either E. coli or rota- or coronavirus were identified as being involved, the other 11 herds served as control group. The protocol consisted of 2 points of action: preventive vaccination of dams against E. coli, rota- and coronavirus, and preventive administration of halofuginone lactate to newborn calves. The average percentage of calves suffering from neonatal diarrhoea (39.7% versus 14.3%, P<0.01) and the average percentage of faecal samples positive for C. parvum (34% versus 11%, P<0.05) differed significantly between control herds and treatment herds after implementation of the protocol. No significant differences between control and treatment group were observed in the percentage of calves excreting E. coli, rotavirus and coronavirus, both before and at the end of the trial. Furthermore, risk factors potentially associated with the development of neonatal calf scours were determined. Non-significant results were obtained for the effect of the protocol on duration of diarrhoea and the effect of the colostral IgG quantity on the risk of diarrhoea. Passive immunity transfer status of the calves, measured both before the onset and at the end of the study, were non-significant between groups.

During the last decade, several computer assisted sperm analysis (CASA) systems have been validated for canine sperm quality assessment. Regarding the impressive possibilities of these systems, further research is required to determine which CASA measurements are of clinical importance in canine andrology. In the present study, the sperm quality parameters obtained by the Hamilton-Thorne Semen Analyser (Ceros 12.1; HTR) were correlated with the body weight and the age of the dogs. Moreover, the sperm quality parameters of dogs with a different breeding history were compared. The sperm-rich fraction was collected from 111 dogs of 50 different breeds, which were presented at our department. Immediately after collection, the concentration, the total sperm output (TSO) and 13 different sperm motility and velocity characteristics were measured by the HTR. The percentage of live spermatozoa and the spermatozoal morphology were examined on eosin/nigrosin stained smears. Based on their breeding history, the dogs were divided in three groups: 'fertile' (n = 60), 'subfertile' (n = 17) or 'not used for breeding' (n = 34). Significant (p < 0.05) correlations were established between the body weight of the dogs and the TSO (r = 0.245) and velocity curvilinear (VCL; r = -0.220), respectively. The age was negatively correlated with the percentage of normal spermatozoa (r = -0.203; p < 0.05). The correlations with all the other evaluated sperm parameters were low and not significant. Significant differences between the 'fertile' and the 'subfertile' group were found for all of the evaluated sperm quality parameters (except for BCF, LIN, STR and MEDIUM). In conclusion, dogs tend to produce ejaculates with a lower percentage of normal spermatozoa with increasing age and dogs with higher body weights produce ejaculates with a higher TSO and a lower VCL. Significantly poorer sperm characteristics were found for dogs with lower in vivo fertility results.

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