My family adopted a 1yr border collie x with no problems but within 6 months he was aggressive to other dogs on lead, though hes great with people. He had no known aggression problems at the shelter, and we socialised him from day 1. At home hes obediant (e.g. sits + waits for food, walks through the door after us etc) and doesn't act like he thinks hes alpha dog.
We hired professional help, who told us to stop all contact with other dogs, give him the cold shoulder, then slowly socialise him well enough to let him offlead again. We followed his instructions, but after another 6 months there was still no significant improvement.
After that long without dog-to-dog contact, we don't trust him offlead anymore. Walks are stressful and brief, and I know he isn't getting enough exercise. Does anyone know how to help solve his aggression, or even ways of giving dog-aggressive dogs good exercise?
Any help much appreciated. Susan.