My Mum sold my dog 5 years پہلے when i was 7 and i just found out as a 12 سال old. How can i get the dog back???

If your mother was the official owner, and I suppose she was because آپ were seven and not an adult, and she sold it with all the paper there is nothing آپ can do against it per law. آپ could only ask the owner if he would sell it back but after 5 years I doubt so.
Sorry آپ can't do anything because it was the dog of your mother, so it was her decision and آپ weren't old enough to decide for yourself if آپ were the official owner, but I doubt that too because آپ were and are to young to buy a dog on the paper

Hi aleks, i am going to be honest with you, but after not having the dog for that long آپ can't get it back unless the سیکنڈ owner gives it away. So if ur parent gave all the papers to the سیکنڈ owner, آپ can't unless آپ contact the AKC یا ask someone. But i'm sorry but آپ can't get the dog back unless there's a reason tbh. And i actually do agree آپ might have been to young for the dog and she didn't want آپ to own it yet cause u were 7. My دوستوں in real life actually had something similar to ur problem were his mum کہا hes going to summer camp, 3 years later we have kept him since.So we could give him back but hes a good boy so we always send pics of him. Again i'm really sorry for not being able to get him.