bulldofg trouble

Question
My english bulldog, matilda, receetly atarted to show aggresion towards our year old jack russel, ernie. Ernie usually nips and picks at her playingly but matlida always just took it and ignored him.  She now attacks him unprovoked and with bad intentions.  She has even begun going after our cat.  My sister is pregnant and our theory is matilda has tuned into that and feels she must protect.  My mom is considering getting rid of her in which case, matlida would come live with me, but i would like to keep her with the rest of my family.  Your thoughts and suggesions would be much appreciated.


Answer
Does she hurt Ernie? Sometimes it is difficult to tell if behavior is provoked or not. What exactly does she do? Does she bite him? roar at him? caused him a trip to the vet? If it's just a display may not be too big a deal. It's certainly possible for a dog to sense changes in a human in their life and change behaviors. It's also possible that there is something else going on (a tick borne disease or hypothyroid disease - which frequently make a dog grumpy or aggressive and can cause sudden behavior changes. If she was in pain that might make her grumpy too. So I'd say a complete vet work-up including bloodwork and a tick borne disease panel and a 6 panel thyroid test.
How old is Matilda? Sometimes age can figure in - either advanced age, or coming to social maturity. If she checks out healthy, I'd probably get with a trainer and work on better structure and leadership in the house so she doesn't feel like she has to make rules and enforce them. I'd also keep her separate from the small dog and cat when she is not supervised. And give an immediate "time out" if she gets snarky at one of the other animals over guarding a human. Sandy Case MEd CPDT www.positivelycanine.com