You could get them some of those baby teething rings that have water in them that you put in the refrigerator or freezer to make them cold. I brought Kacee home at 6 weeks and I gave her those. She still chews on them some because she's still teething. I also gave her Nylabones. I found some small "soccer balls" at Petsmart that squeak and enjoyed those, too. They were probably an inch and a half in diameter. Just something fun. I don't know if they'd do much with a ball at 4 weeks. I'd give them a rope to tug on, too. I've seen Kacee just chew on hers many times, even when I first brought her home.
