Some species of animals such as primates and some birds also get high cholesterol levels like humans. Treatment mostly centers around dietary modification. There are hundreds of species of fishes in waters off New England. A good reference is a book by Bigelow and Schroeder, Fishes of the Gulf of Maine . Data on fish abundance 100 years ago are quite sparse so it is difficult to predict if species composition has changed, but it is unlikely that any species of fish has become extinct in the ocean waters off New England during the past 100 years.
Some species are less abundant due to overfishing, but the species still exists.
Hopefully, we will ensure that no species becomes extinct during the next 100 years. Most animals have very strong immune systems that protect them from germs they may get from drinking water from puddles and streams. Sometimes animals do get germs that make them sick by drinking from these sources just as we might . Some sounds they make and body postures they take on are often associated with specific situations such as desiring to play, eat food, etc. Most of what dolphins say, especially what they say to each other, is communicated with clicks or whistles which we humans do not understand.