This is an especially interesting topic to yours truly. Before probably around 1976 we did not have a very large raccoon population.
It wasn,t until the mid 1970's that vaccination programs and worming programs for dogs and cattle took off. Now because of products like Ivomec Bot flies are not prevalent like they were in farm animals and wild animals. Rabbits, squirrels, deer, and virtually all animals suffered to a great degree from their presence. I remember in the 70's as many as 50 bot fly grubs coming out of the backs of my cows. Ivomec eliminated that.
Almost all states are Brucellosis free now, allowing for deer and elk numbers to flourish.
Vertually all or most farms now vaccinate for lepto, IBR, Black leg, even pink eye. This prevents the spread of disease to the animals they used to give it to. Even TB in animals is now almost non existent.
Now at the same time average crop yields have tripled allowing for more farm production and more in field leftovers before and after harvest.
Not only have crop yields increased but TDN, including protein, fiber, and oil levels have greatly improved.
Not only are the wild animals less bothered with insects, disease, and helped by stronger regulation, but they are just fed better, especially in farm areas.
In the south in 1960 they eliminated the screw worm that was destroying up to 80% of new born animals.
There is your answer Paul.