Ask a Dog Vet and Get Answers to Your Dog Health Questions
I'm very sorry your dog is sick. He sounds quite ill and I think the best thing to do is to take him in to an emergency clinic right away. I can help you find one in your area if you do not know where the closest one to you is.
The pale gums and lethargy that you describe are very disturbing. The best recommendation I can make is that he be seen by an emergency veterinarian right away. I am concerned about blood loss and that he needs life saving medication and intervention. One of the things that may be going on with him is that he is unable to make clots and this causes excessive and dangerous bleeding, the blood in his eye, and in the back of his throat may mean that he is unable to clot, and if so he is in danger of bleeding to death. This can happen for lots of reasons and blood testing is necessary to determine the cause and recommended treatment.
Bleeding can be internal and may be hard to pick up without careful veterinary examination and if the blood comes back after you wipe it then I suspect he is bleeding and unable to clot. Where do you live?
Is there any chance he may have eaten any type of poison like rat or mouse bait?