Can the hair from my husband's make my chihuahua sick?

My dog is only like 4 lbs but she loves gnawing and slobbering on my husband's old . She can actually take quite a bit of them in her tiny mouth and I'm just afraid the tiny lil hairs can cause her issues with her digestive tract. Will the hairs from my husband's old tennis cause issues with a chihuahua or is it safe for her to gnaw on his ?