Why Is My Dog Suddenly Peeing Where He Knows Not To??

My 3 year old cockapoo Bailey is starting to pee on my bed, and I dont mean just a sprinkle, he pees through the blankets, sheets, and even makes it onto my pillows. He has never done this before, he is trained to pee outside, so why the sudden change? His diet is the same, he has allergies so he is on medication, but its the same meds as always, we don’t have any other animals so I don’t see how it could be a dominance issue. This is just really odd behavior. Why is it happening, and how can I stop it?

Where Can I Find A Cockapoo In Central Pa?

I’m looking for a Young, Cockapoo who is good with kids and preferably house trained if possible. I searched on PetFinder and couldn’t find anywhere close. Please send me comments with links for sites or shelters for me to check out.
Thx
~Me