Blood in stool

Hi, We purchased one of those feeders that is supposed to stimulate our dogs brain by opening slots and things to get at the food. This meant we changed his food (big mistake apparently). We then noticed that he had blood mixed with mucus in his stool shortly after. Not much just a spot or two that looked like raspberry jam. He was acting completely normal. We took him to the vet and they suggested we put him on sensitive diet food and add a probiotic. We did a gradual transition to the new food. Weeks went by and still no improvement. Still acting fine (drinking, eating, and pooping/peeing all normal). We were concerned so we took him again. They did blood work, x-ray, fecal, prostate exam...all normal. They suggested we put him on a different food (salmon) that they had good luck with in the past. He also had a round of antibiotics. Blood is still in stool but he isn't eating like he normally did. I don't think he likes the new food. He will eat about 1/2 then stop. Still pooping and drinking normally. Will eat treats. We are concerned that he doesn't like his new food but are hesitant to change once again. Any suggestions that anyone may have would be greatly appreciated.

Hello - I don't currently understand how using one of those special dishes would cause blood in the stool, so with my current knowledge I would expect that to be a coincidence and wonder whether - because this bowl and the new food offered a reasonable explanation for slowing down of a setter's eating - an accompanying reduced food intake might have been slightly masked?  It's always worth checking with your vet who knows the specific circumstances of this case.   Mucous and fresh-looking (red) blood often originate at the other end of the digestive tract, towards the rectum.  In general, worms and potentially other parasites, tumours, polyps, parvovirus or other haemorrhagic gastroenteritis, irritable-bowel type problems might be on the list (your vet will advise).  Another possibility might be pancreatitis which causes abdominal pain (reduced food intake) - I have heard of this causing blood in stools, although it is not one of the most common signs.  Clotting problems can cause blood in a range of unusual presentations.   None of the things I have listed are routinely  treated by antibiotics or picked up by standard blood profiles.  Therefore it may be that your vet has more tests to carry out if they are to pinpoint the cause of this problem.

Thank you for the reply. To use the special dish required us to switch his food which correlated with the appearance of blood in his stool. We have reverted back to his original dish and tried going back to his old food but that didn't solve the problem. Sorry for the confusion...I don't think it was the change in dishes but the change in food that may have kicked this episode off. Currently, we are feeding him salmon flavored food for sensitive stomachs. He smells the food then walks away. He will eat about half of it but then stops. But if we put it on a paper plate or hand feed him, he will eat it then...although he still doesn't look too excited about it. He still eats treats and such fine.