I have a cat named Tiger, I don't remember exactly how old she is but if I had to guess I'd say about 14. She's over weight and not too active. The most activity she will do is roll around and play with a toy for maybe 5 min before she gets bored and just takes a nap. I feed her twice a day and she gobbles it up really fast. This morning I fed her at her normal time. She came over and barely ate anything. Then she came up and layed on my lap and was shivering. It wasn't particularly cold in here so I was a little surprised. It has been a good 10 hours since I fed her and she still hasn't finished her food. I'd say she's eaten probably 4/5 of it but still, it's normally all gone within 30 minutes. I've also noticed she hasn't been meowing as much or playing, just laying on the bed. To top it off I noticed she's not purring. Normally if I put her next to me and start petting her she purrs, and it's really loud. Today she's been silent. I've even turned everything off to ensure I could hear her clearly. Should I be worried or could it just be a bad day?