Fatal Adverse Reactions of Enterotoxaemia Vaccine in a Sheep Flock

The aim of the present report was to describe the clinical signs, haematological findings and post-mortem lesions in sheep developing fatal complication after enterotoxaemia vaccination in an Awassi sheep flock in Hatay Province. The study included 3 Awassi ewes of 4 years old and 3 lambs from a sheep flock recently vaccinated against enterotoxaemia. Following blood samples collection for routine haematology the live animals were euthanized and subjected to necropsy along with dead animals at the department of pathology. In the histopathological examination, the liver contained multiple, small, randomly distributed foci of necrosis that contained neutrophils. The lungs were affected by mild intra-alveolar and interstitial hemorrhages. There was oedema and haemorrhage around arterioles and venules in the cerebrum. To improve the margin of safety and decrease undesired reactions, pharmaceutical companies provide specific guidelines for the administration of vaccines. However, even when vaccines are administered correctly, there is still the potential for an adverse reaction in a small proportion of the flock. Therefore, further research is obviously needed to discover of developing such an adverse effect.