Brain is a vital organ that always has high oxygen demands and is highly vulnerable to injury caused by reactive oxygen species (ROS). The hippocampus is a complex structure seen deep in the temporal lobe which is constituted by the dentate gyrus, hippocampus proper (Cornu Ammonis- CA1-CA4) and subiculum. The important functions of the hippocampus are learning and memory. Age-influenced pathological lesions in the hippocampus and variation in the number of neurons in the hilus are the main discussion of this study. The major gross lesions observed in the brain of both younger and older dogs were cerebral congestion, thickened meninges and cerebral edema. The major histopathological findings in the hippocampus were thickened blood vessels, accumulation of lipofuscin pigments in the neuronal cytoplasm, satellitosis, gliosis, neurons with the vesicular nucleus, chromatolysis and neuronophagia. A statistically significant reduction in the number of neurons in the hilar region of the hippocampus was observed in aged dogs.

Gastroenteritis in swine herds pose a big constraint in pig farming due to the economic losses accompanying it. The present study utilised 57 pig carcasses to assess the occurrence and distribution of various gastrointestinal lesions in pigs in Northern Kerala. Gross changes in stomach were observed in 84.21 per cent of carcasses in which mucosal congestion (61.40 per cent) was the most frequent lesion. Principal microscopic gastric lesions observed were mucosal necrosis, cellular infiltration in lamina propria, hyperplastic epithelium, hyperkeratinisation and fibrino-necrotic membrane. Gross changes in at least one region of intestine were evident in all the samples. The most common lesions in intestines were engorgement of mesenteric blood vessels (80.70 per cent) followed by catarrhal enteritis (73.68 per cent). Salient gross lesions such as mucosal ulcers were observed only in caecum and colon, diphtheritic membrane formation was observed in ileum, caecum and colon. Major histological lesions observed in intestines were mucosal necrosis (89.47 per cent) followed by cellular infiltration in lamina propria (68.42 per cent). Histologically, the major site-specific lesions observed were Brunner gland hyperplasia in duodenum, necrosis, hyperplasia, and lymphocytic depletion of Peyer’s patches in ileum, granulomatous infiltration in ileum and colon, neutrophilic colitis and goblet cell depletion in colon. The present study observed a higher incidence of gastrointestinal variations in pigs irrespective of age and further research is needed to understand the etiological factors contributing to such heavy burden of gastrointestinal lesions.