I believe it has some connection to depression, obsessions at least. You don't sound like you really have a hoarding problem, at least not yet. Hoarders will have animals everywhere, in cages, in poop, dead, in the yard, in their house, you name it. And I'm talking like a kajillion animals. However, if you feel like you have a problem there may be something going on. Did you ever address the question as to why you'd want to keep getting animals when it's clear you have enough? Hoarders often love animals, but yet forget that the more they get, the worse it gets for them. We had a set of hoarders back at my old job who had it so bad there were dried up, dead horses in their house, out in the yard, dying cows, pugs with their nails so long they couldn't walk, and so forth. You have to start thinking about them eventually, the problem is within you, but perhaps if you consider that you might be able to get a grip on it, otherwise you're going to need help.