My dog is peeing everywhere

Question
Hello, i have a 3 year old pekingnese & poodle mix named Midnight. We got him as a puppy and we taught him at a young age to go outside. My parents both commute to and from work & are not home pretty much all day and midnight usually gets left in the house until about 3pm when my brother gets home. This was working until a couple months ago Midnight started peeing in our guest room maybe about twice a week. We thought it was because my brother was forgetting to let him out. So we made sure that midnight was getting out more often and my father took a couple days off to make sure. Everything was going fine until this week when my father took another week off and found that midnight had jumped on mty parents bad and peed there, and then last night he peeded on the shoes that were are the fronnt door. He has never done these thinge ever before. He isnt nuedured, but my dad took his urine to the vet to make sure he doesnt have an infection. But my mom has said if it isnt an infection she is going to put him in a shelter. i am away at college and i really dont want to go back home & find that my dog isnt there. Please help!

Answer
If he isn't neutered, then he may very well be urine-marking.  Is there some reason you cannot neuter the dog?  Also, if you purchased your dog from a reputable breeder, he could go back to the breeder, instead of to a shelter.  Even if you neuter him, he may still need to be house trained again - and before doing that, you would need to clean all the areas of the home where any possible odor occurs, using an enzymatic cleaner, such as Petastic.  If you aren't sure where the urine stains are, you can use a black light to find them.  If anything changed during the last several months, such as a new person in the home, scary noises happening (as with construction, or other similar occurrences), or he's being left more and suffering stress (animals often comfort themselves by making things smell "familiar" and that means putting their own scent on those items).  Perhaps prevail upon your mom to try crating the dog when no one is home, and waiting for a break in the school year so that you can resume his house training.