Hello, my name is Juan I have a question? I have a 8yr old male dobe, and two chihuahua's male and female. I had the chihuahua's for about 10 years now. My dobe has always treated them well until last Friday. My dobe attacked my male chihuahua and almost killed the chihuahua. I was wondering if anyone had any idea why my dobe has become very aggressive towards the little dog now. A few days later he saw the male chihuahua again and was not happy to see it around. He also was very agressive towards my brothers 1yr old Boxer. even though they have played with eachother before. For some reason my dobe has become very aggressive over the last week, but just with other dogs. Nothing has changed in the household, and he has no problem with our cat.

Thanks, Please respond if you can help with this problem

Is there a female dog in the area in season or close to it?