Hello,
I have a female border collie that has just turned two years old, and a male wheaten terrier that is 9 years old. For the past few days my border collie has been biting and acting very aggressive to my terrier. It all started few weeks ago when I was playing with my border collie and stopped for a second to pet my wheaten terrier, who had just walked up to my side. She came over to him and nipped his face , at which time I gave her a command to lie down ; tried to physically separate them ( A bad move on my part.) a fur ball ensued, during which I was bitten as I pulled her mouth away from his throat. The good news is they are both in good health and none of the bites broke there skin. I have used every discipline technique that I can think of (short of hitting), and have consulted a local Border collie trainer with no change. The other day I watched the wheaten terrier’s foot collapse on him when he was walking, so he may have had a small seizure, but I am not sure if this would cause my border collie to have a change in attitude towards him.