Abstract
The most relevant diseases in calf rearing are diarrhoea followed by respiratory tract disease. Further problems arise with disease of the umbilicus and joints. Other problems occuring regularly in the time from birth to weaning can be ruminal drinking and abomasal ulceration. There are many causes of calf diarrhoea and the disease varies considerably in its severity. Infectious as well as non infectious factors contribute to the disease. The most commonly encountered microorganisms are viruses, bacteria, protozoa as well as fungal infections. In the majority of cases more than one enteropathogen is responsible in the development of diarrhoea. Non infectious causes of diarrhoea include management factors like hygiene, feeding and immune status of the animal. The main clinical symptoms shown by the calves are results of the diarrhoea. These signs are dehydration, metabolic acidosis and energy deficiency. However diagnosis of the causative agents should be performed if a herd problem is evident. Therefore it is important to sample more predisposed animals at the farm including clinical healthy neighbour calves, as many pathogens are just detectable in the faeces at the beginning of disease. Therapy and general management strategies do not differ widely between diarrhoea caused by different enteropathogens. Therefore therapy is based on rehydration and the supply of buffers and energy. Calves with mild diarrhoea still drinking should additionally be fed with electrolyte fluids including buffers between milk feeding times. To improve the passive immunisation of calves against rota- and coronavirus as well as against different strains of E. coli vaccination of the pregnant dam can be proposed. This management strategy can only be successful if colostrum management as well as hygiene is improved.
