Is there a ball on the market that can withstand a dog for longer than a few days?
Lucy and Emily managed to shred and mince a new bought baseball yesterday in less than an hour … 
I tried several other plastic and rubber balls but non really cut it … it’s as the dogs actually like the smell and taste of the rubber/plastic …
I have two tennis balls in the running now and it seems that they manage the chewing and mincing better …
Any other good advice on ball types …
Dog-proof balls? Nothing much is going to withstand a diligent chewer for long, but you could try rubbing them with sandpaper and soaking them in vinegar until the skin gets hard and tough. Or you could just wear some trousers when you play with the dogs.
You also could try those big hard yellow rubber balls (I think they use them for softball or something). They’re a good bit bigger than baseballs – about the size of a large pamplemousse – so it’s difficult for the dog to get his back teeth properly into it. We have one for our big lab, and its looking worse for wear now, but it’s lasted longer than any other one we’ve tried – he can reduce a heavy-duty frisbee to shreds of plastic in about 3 minutes.
They sell them upstairs in a sports shoe shop in Shida Rd very near Grandma Nittis.
Well, well, would ya lookit that? Tigerman’s posting pics of his lopsided balls. Shouldn’t that have a NSFW tag?