I'm always trying to ready myself for what your going through. We have 2 horses, 2 goats, 2 greyhounds and a cat here. All I can do is ask myself if I gave them the type of life I'd want someone to give me.
If the answer is yes, then we can rejoice in both the arrivals and the departures of the creatures we share the planet with.
Hope this eases the pain for you and eases the pain for the next critter that finds its way into your fold.