Big thing you would expect if it’s due to general plastic/pollution prevalence is obesity in pets/wild animals.
From a quick search: https://www.livescience.com/10277-obesity-rise-animals.html
"In aquatic invertebrates, microplastics cause a decline in feeding behavior and fertility, slow down larval growth and development, increase oxygen consumption, and stimulate the production of reactive oxygen species. In fish, the microplastics may cause structural damage to the intestine, liver, gills, and brain, while affecting metabolic balance, behavior, and fertility; the degree of these harmful effects depends on the particle sizes and doses, as well as the exposure parameters"