Weight loss, blood in sick and stools change in behaviour

Good morning My dog has been putting on weight and losing weight just as fast over the last 2 years, recently he has been sick blood and has blood in his stools but after he had been he was still trying to go but all that was coming out was blood, he sleeps all the time only gets a little bit excited when people come in or it's time for a walk, we had 2 dog from puppies and they usely have the odd fight but over the last couple of day he had got very aggressive with his brother to the point where he only has to walk past when he's with me and he will go for him. We been to vets and had bloods and x-rays to be told there is something abnormal in his gut/ intestine, but they not sure what it is so change his food and gave him medication, but when I asked questions the vet said she didn't understand what I was asking any advice will be greatly receive thank you My sister did put a post up for me too 

Hello!  It is not unusual to see something in the intestine and be unsure what it is.  It is not right for me to comment on your dog in any case, especially not with such limited information, so I will tell you about some general conditions for pets in this condition. Being soft tissue, guts are difficult places to radiograph and sometimes more advanced forms of imaging or an exploratory laparotomy are necessary.  Good questions include, what possible things COULD it be?  (Vets call this the differentials list).  Which are looking more likely?  Which of the possibilities could cause a dramatic change in a short time if it's them?  On this basis, do any possibilities need to be ruled out immediately, or what do the owners need to look out for?  Which tests would help to distinguish between them? Would a referral help? Furthermore, have all infectious diseases been ruled out and do the owners need to keep your pet away from other dogs?  Are any treatments (bloods / fluids / clotting tests) needed now?  Is any treatment needed to protect the patient in the meantime?    This conversation should take place very soon

I'm not sure why the vet didn't understand your question but if this is literal, an interpreter may be important.

Thank you in your opinion what do you think about his size he is husk x staff x spaniel.

This is another good question for your vet;. We grade body condition on an objective scale according to strict perimeters your vet may do this also.

This is another good question for your vet. We grade body condition on an objective scale according to strict guidelines.  Your vet may do this also.