This is Kamino at approximately 5 months old (he's now a little over a year old). I adopted him last August from Cobb County Animal Control in Marietta, GA. It was a Sunday, and my boyfriend was in town. I had been wanting to adopt a cat, so I decided to have him go with me to look. Just to...
From what I've found, the Chia Pet plant is, well, Chia, which is Salvia Hispanica or Salvia Columbariae. It's part of the mint family and is non-toxic. So, yeah, they could eat it.
If it helps, my cat had problems with his poo for months. Part of it was a sensitivity to corn, then a sensitivity to the food I had changed him to. I ended up mixing a spoonful of white rice in with his canned food at every meal for about 2 week, and it helped to calm down his digestive tract...