Is there any possibility that someone in the neighborhood has been intentionally poisoning them? Some people do things like that!
Or has someone maybe had an exterminator come to spray their house recently? They were here last weekend to spray my house and I had to be very careful with my dogs because they said the spray could easily kill animals. Not so much the fumes, but they should not come in contact with the sprayed areas until they were thoroughly dry. I had to put them in their crates and leave them in a well ventilated unsprayed room for about three hours until I was sure it had all dried. They did the outside too, with big hose-like sprayers, and any little critters coming along after they did it would have walked through the wet spray and got it on their feet. Just a thought...
