Clinical and Post Mortem Findings in Cows Suffering from a Wasting Disease

In the winter of 1998/1999 a wasting disease was reported from a number of dairy farms in the Netherlands. In the first months of 1999 more than 20 percent losses among the livestock occurred on affected farms due to fatal prognosis. Clinical symptoms occurred in post partum dairy cows that were characterized by loss in body condition without any obvious reason. In addition, a variety of diseases were observed such as lameness, abortus, endometritis, mastitis and respiratory disease.

Between April 1999 and March 2000, 19 dairy cows from 11 farms were submitted to the clinic of the Department of Farm Animal Health for clinical and post-mortem examination.

The results of clinical examinations and necropsies gave a variety of diagnoses such as mastitis, abo-masal dislocation and claw disorders. The claws of the majority of animals were affected by a severe laminitis, which was characterized by complete loosening of the claw horn from the underlying pododerma at the parietal and solar part of the horn shoe. Interestingly, these alterations were only limited to a distinct part of the claw; in the proximal parts the pododerma was tightly fixed to the underlying tissues. Based on an assumed horn growth rate of 5 to 7 mm per month it was concluded that these animals had suffered from a short-lasting disturbance of blood supply of the claw in spring of 2000. Severe laminitis resulted in various claw disorders such as sole ulcers, superficial interdigital necrosis etc. In addition, the animals developed secondary lesions such as endocarditis and metastatic pneumonia and nefritis.

The results of the examination show that the wasting disease occurring on a number of farms in the Netherlands in 1998/1999 does not form an entity, but is characterized by a broad variety of diseases, with severe laminitis being a central aspect of the disease. The etiology of the disease has not been elucidated until now. In the year 2000, however, wasting disease was only reported from a few farms. The "wasting disease" as described here shows remarkably similarity with "concrete disease" described by Rebhun in 1995.