Degree Final Project defended by Esther Vázquez Fernández

July 21^st, 2022

Animal abuse is of mayor concern in today`s society, with an increasing number of reported cases. Violence towards animals is considered an additional factor of interpersonal violence, making essential to advance in the field of forensic veterinary pathology. Starvation, the involuntary loss of body mass, is one of the main causes of death in cases of animal abuse. Starvation is due to a catabolic state that induce atrophy in most organs. However, the mechanism beyond atrophy is not fully understood. The aim of this research is to retrospectively study a series of dog forensic cases diagnosed as starvation referred to the VISAVET Health Surveillance Centre (UCM) (2014-2021). This study included the analysis of macroscopic and histopathological lesions. In addition, to understand the mechanisms underlying atrophy, a morphometric histological analysis of the liver, stomach and duodenum; and an immunohistochemical study (Ki-67 and caspase-3) of the spleen, liver, testis and duodenum have been performed. Thirteen dogs with a body condition score of 1 (38.4%) or 2 (61.6%) over 9 were studied. The most significant gross lesions were muscle and adipose tissue atrophy (100%), dehydration (100%), testicular atrophy (100%), exsanguinated spleen (100%), gastritis (77.78%) and chronic enteritis (66.67%), and traumatic lesions (38.5%). Histopathological study revealed atrophy in skin (42.9%), skeletal muscle (57.1%), spleen (100%), liver (28.6%), pancreas (42.9%), testis (100%) and thyroid gland (28.6%). Histological morphometric study confirmed atrophy in liver and duodenum in starved dogs, compared to healthy dogs (body condition score of 5/9). In the stomach, increased mucosal thickness was observed in starved dogs. The results of caspase-3 immunohistochemistry, a marker apoptosis, showed a higher percentage of apoptotic cells in the white pulp of the spleen (16.3%) and testis (100%) of starved dogs compared to the spleen (9.4%) and testis (0.0%) of healthy dogs. There was no difference in caspase-3 immunoexpression in liver (0.3% vs. 0.0%) and duodenum (92.5% vs. 95.4%). Immunoexpression of Ki-67, a marker of cell proliferation, revealed a lower percentage of dividing cells in spleen (9.3%), testis (0.0%) and duodenum (21.2%) of starved dogs compared to spleen (10.9%), testis (100%) and duodenum (95.4%) of healthy dogs. There was no difference in Ki-67 immunoexpression in liver between starved and healthy dogs (0.6% vs. 1.6%). This study contributes to a better understanding of the mechanisms of atrophy caused by starvation in forensic cases of dog abuse. This methodology could be useful in the diagnosis and confirmation of atrophy in these cases