Loki needs help
I have a 8 month year old German Shepherd/ Mallinois mix and he is starting to get aggressive towards strangers and other dogs. When growing up he was socialized and walked everyday. He use to love running and playing with the other dogs at the park and dog beach.
I had to switch his dog food from blue wilderness puppy to the regular blue puppy formalu (vet reccomended) because Loki had to high of protein in his diet causing growing pains. With this I had to let him heal for about a month and walked him very rarely during this time period.
While walking he knows (not perfect) but will sit on command, stay on command, and walks to the side of me (I do have to correct him often because he is a ball of unattentive energy). He does walk with a choker chain (the chain without the fangs).
Now when Loki and I go on walks he will lunge at other dogs and other people.
While walking I keep a sharp eye on my surroundings and when someone walks by I have him sit and use a "leave it" command, this works 70% of the time but you can tell by his body motion that he wants to lunge and bark at them. I cannot take him to the dog park anymore because he acts like everydog is a threat and will snap at any dog who gets close. I was walking him in public when a guy randomly came from behind and tried petting Loki and loki turned and snipped at him. Although I know that guy approached Loki wrong I still find it unexceptable.
Things I have tried:
Repetitive walking back and forth fences with dogs on the other side
Walking him on the outside of dog parks
Walking him in very public areas
Using the clicker/ treat method when he doesnt lunge
Using a toy to distract him during walks
Any advice will help! I am 21 years old and have plans of having kids in a couple years and want to tackle his aggression immediatly. A trainer might be out of my finacial reach and really would like to try and train him myself.