blood in stool

Question
My cocker is 5 yrs old. He has been the BEST dog I have ever had. He is so well behaved in and out. Only wants to please me and follow me every where. People can not get over how well behaved and sweet he is. I got him as a puppy, he was house broken very easy, and has never ran off or barked allot or even came close to biting anyone. The biggest problem is not being able to board him or leave him at a groomers for long period, he gets very stressed easily. I recently got back from Fl. we stayed at a condo on beach while max stayed with a friend. We got back on the 13th and today the 16th I noticed he had blood in his stool. and also acted like he had a hard time going and a thick like blood came out. He had his yearly about a month ago, is current on his heart worms and also is on front line. His food is dry dog food. I was never told to give him canned dog food. He has never been real crazy about the dry dog food, but will eat it. I did notice he looked like he has lost some weight since we have been back, but I figured it was from the stress of the trip. He also has just finished some antibiotics from having his teeth cleaned 2 weeks ago. I will be taking him to vets to have a few stitches taken out in the next day or so. He had a mole removed when they had him under to clean his teeth. Knowing the information I have given you, can you tell me what you think the blood could be from, and should I stop feeding him dry dog food. He was on lamb and rice nutra dry food, but recently switched to pedigree, because of the cost. He had eaten the pedigree a few years ago, so thought he would be ok with the switch. If I need to put him on can food, then I will. I love my Max and am very concerned with the blood in his stool. My vet I am contemplating finding another vet. I feel like when I take my pets in, they charge me for things not real necessary. it has happened several times with my visits. I feel like she is "over kill" so to speak on the treatments, just to make an extra "buck" So I wanted to get your opinion first before taking Max to her again.

Answer
Hi Terri, I apologise for the delay in answering your question, my internet has been playing up sorry.
Firstly I would recommend you find another Vet their bills are high enough without paying over the odds for things he keeps adding on. Secondly I would say the reason for this is change of Diet I personally dont like Pedigree foods, they contain a lot of colours and additives which can upset your dogs tummy, I feed my Cocker on James wellbeloved which is a natural food (Dry) with not additives flavouring or e numbers or colours, so I would slowly switch him back to a good food (dry) or wet James Wellbeloved do both or Burn Or Arden Grange which are all obtainable over the internet or a local stockist and whilst yes its more expensive than pedigree yhou dont need to feed so much so it balances itself out.
I hope your little man is feeling better soon if the blood continues, then I would take him to another vet.
Best wishes
Kathy