HELP! Agression Issues in a 5yro GSD
I recently took in a 5 yro male gsd as a favor to my nursing instructor. She warned me he was somewhat unsocialized but a sweek dog once he warmed up to you. I went and picked him up and there was some growling in the car but nothing umbearable. When I got him home it was a completely different story I rescue animals and have worked with unsocialized and nervous dogs before and I have 2 gsd's at my house that I use to help train unsocialized dogs. When I brought in the new shepherd my dogs accepted him right away but he was lunging at them and snapping and growling so I put him into the kennel to let them meet through the fence. The new gsd jumps up on the fence growling at them with no provoking. He has a serious issue with feet I'm thinking he was possible kicked. When I told my instructor the issues I was having she let me know his true colors saying they had to get rid of him because her husband was afraid he would attack one of the neighbor kids! She also told me he has been a chain dog since 8 wks old
I have been working with him for about 2 weeks and he is letting me in the kennel with him now but still growls around. I don't want to have to put him down unless there is no other solution. But I will not risk my family or my dogs. Any ideas on things to try?