Buccal micronucleus assay as a useful tool to evaluate the stress-associated genomic damage in shelter dogs and cats: new perspectives in animal welfare

Shelters play a key role in saving animals from straying. However, the space restrictions, the lack of resources and the high animal turnover can increase stress levels and the rate of infectious diseases in cats and dogs. The aim of this study is to evaluate, through the buccal micronucleus assay, the level of genomic damage in shelter cats and dogs with respect to that observed in family cats and dogs. The hypothesis is that stressful environmental conditions, such as those potentially present in shelters, can affect the level of genomic damage. Study population included thirty healthy mixed breed cats and dogs with a minimum two-year presence in a shelter. The control group consisted of thirty healthy cats and dogs living in a home environment, using age/sex matching. The micronucleus assay was performed on one thousand exfoliated buccal cells per subject. Significant differences were found between shelter and family cats and dogs in terms of micronuclei frequency, indicating that a condition of stress found in sheltered animals may increase the levels of genomic damage. The ethotest confirms the increased levels of total aberrations in both stressed shelter cats and dogs. Conversely, no significant differences in the level of genomic damage were found between the sexes, as well as no correlation was found between age and the frequencies of micronuclei. In conclusion, we provided evidence of a possible correlation between physiological stress conditions and increased levels of genomic damage in a sample of sheltered cats and dogs. The results of our study also suggest that the buccal micronucleus assay, also considering the relatively low cost of laboratory procedure and its non-invasiveness, could be potential additional tool that, combined with the ethotest, may be able to provide a more comprehensive picture of the health status of animals living in communities.