My dog (who is a street dog). Is a very active canine and frequently plays (read shouts and jumps) at a lot of people frequently. Also he is used to night outs across the neighborhood (so the security guard and other dogs kind of hate him). But as of late my dog has become solitary and does rarely (read: not at all) venture out. I am worried about this because the dog was hale and healthy just two days ago but now whines at practically every touch and scarce interacts with anyone. Please help
Whining at practically every touch indicates that he is in pain. The best would be to go for a vet. If there is no vet, you should watch your dog closely. Does he has any wounds? Does he walk in evenly rythm or does he limp? Are there any parts of his body swollen? Try to localize the source of the pain. Touch him at every part of his body. Start softly, increase slowly the pressure. If he is whining go to another part of his body. There should be some parts you can touch without producing pain. Localize the borders where he has pain and where not. If you recognize some health issues and there is absolutely no vet you can ask for help, try to keep your dog calm and every wound clean and hope that everything heals on its own. Ensure that he eats and drinks enough. Try to hinder him from wandering around until he is healthy. But if you can go to a vet, you really should do it.
But it is also possible that he is physically healthy but had some hard experience and got a trauma. Be calm and friendly with him and have patience. You will regain his trust after a while.
I know that there are countries where it is normal that dogs are roaming, but that is always a problem (e.g. health issues like hydrophobia). Not neutered and spayed dogs are reproducing and more roaming dogs without health care are produced. If you can afford it (and if it is not already done), you should let your dog be neutered, so that he can't produce puppies. If there are just three female dogs in his near and all of them get three surviving puppies each year, your dog produces 27 new roaming dogs in the next three years.