My cat has bloody,formed stools when eating grain-free dry food,Why?

Do you know why my 1 1/2 year old,rescued cat can only eat canned food or his stools will have blood in them? I have had him to the Vet. The Vet said he tested positve 3+ coccidiosis but he never had any diarrhea at all. I gave him the medicine for the coccidiosis but he continued to have blood in his stools. So I switched him to Friskies Pate and he does not have any blood anymore. However I tried to give him a small amount of grain-free dry food after 2 weeks of a 100% canned food diet and he immediately began to bleed again. Why? Anybody else have this issue with their cats?

Some kitties cannot tolerate an all grain-free diet.  One of mine can't and he has to eat a little bit of prescription dry food to keep everything working well.  It could also be that something in the formulation of the grain free dry food doesn't agree with his system.

Thank you for your comment stephanietx! You lead me to do a review search on the food I was feeding him. Look what I found >>> http://www.viewpoints.com/The-Goodlife-Recipe-Dry-Cat-Food-reviews  >>> However  the several other rescued /fostered cats seem to do fine on The Good Life Indoor Chicken Formula??? Anybody else feed their cats The Goodlife?

My guess would also be that there is something in the Goodlife formula that is bothering his system: bloody stools can be a sign of sensitivities. It sounds like he does well on Friskies pates, though, so that's a good option!

LisaHE thank you for caring and your comment! The only issue I have with feeding him all canned food is he has become more aggressive. He was the very sweetest cat while he was eating dry food. However within 48-72 hours of all canned food I noticed his personality changing. He is defiant at times now where he never was before. He  bit my boyfriend when he was playing with him...he has never bitten before!!! He would just run away if he did not like something or somebody. I wonder if you or anybody else have experienced a cat 's personality and behavior changing for the worst when he/she was fed canned food???

You're welcome, Rosa Bood! It's interesting what you say about the aggression: we noticed that our cats (particularly one) got more, hmm, assertive (I recall minor skirmishes after meal time) when we started feeding them Rad Cat, a frozen raw food that's pure meat, they particularly love. That behavior diminished fairly quickly, though, when they were more used to the food; we never had to find a way to handle a serious problem. It was almost as if they started feeling like real meat-eating carnivores because they were eating food that was more like natural prey for them. And then the food became the new norm and they calmed down. (I seem to recall reading/hearing that other cats had similar reactions but don't remember particulars...)

You might want to try posting a question in the behavior forum to see if anybody has ideas on handling his aggression!

Thank you LisaHE. It has only been 3 weeks since he has been eating 100% canned food. Therefore I will wait one more week before I post a question in the behavior forum. I'm glad to hear your cat reverted back to his old self fairly soon, and this gives me hope my cat will also.

You're very welcome. Yes, our cats did revert to their allegedly normal selves. They were roughly the same age as your cat and they were also very, very active then: that was the age when my husband exercised them very hard a couple times a day to wear them out. I suspect that helped a lot! They particularly loved running up and down hallways, chasing sponge balls or catnip toys.

Good luck!

I just noticed a little blood in my cat's stools again. I had started him on a little Purina Sensitve Stomach (non grain-free) dry food 5 days ago. I wonder why this cat can not tolerate any dry food. I give him 1 1/2 cans of canned food plus I add water to the dry kibble and mix in some of the canned food...and 5 drops of fish oil every other day. Any ideas what is causing the bleeding? His stools never look moist enough. They are like a thick,dry putty consistency. He has been passing a lot of hair in his stools. Can a bulid up of hair in the intestinal tract cause small pebble like,dry stools? Can a build up of hair cause blood in stools? His stools have had traces of blood on and off for 4 months...every time I give him any kind of dry food along with his canned food. However he never has any blood in his stoools when he eats 100% canned food. The Vet has not found anything wrong with his last fecal test except coccidiosis 3+  which was totally shocking since he has never had any loose stools! He finished the Sulfa drug over 10 days ago. I took him him on Monday,3 days ago and the Vet said he no longer has a coccidiosis problem. Has anybody else had a cat that bled whenever it was fed any dry food?