stomach virus?

My cat has been throwing up on and off for 3 days now. At first I thought maybe the food didn't agree with him, we tried a new food about 2-3 weeks ago. So I bought the old recipe yesterday...I also thought maybe he ate something that didn't agree with him...this has happened before, he usually gets a bad case of the runs. But now he is still throwing up-should I take him to a vet? His behavior is normal and he is still eating, especially his daily treats!
Please let me know if anyone has been through this and what to do.
Thanks

Buffygirl,

How old is your cat? If he is a baby, you'll need to get him to the vet, as kittens can become dehydrated in a matter of 24 hours. Does the "throw-up" have whole pieces of food in it? If so, it could be that your cat is eating too much too fast. How is he acting? Does he go outdoors?? If so, he could've eaten some critter or something. Keep an eye on him. As long as he's eating, drinking and using the litterbox, he's probably just got an upset stomach.

Let us know how you make out.

Unfortunately, it could be anything. Its always safe to take them to vet just to make sure.

Give him gentle kisses from me. :)

Is he doing any better today?

Thank you all for your responses and warm wishes...the next day he got better and has been back to normal ever since! I am sticking to the original food just in case. Again, thanks for your support.