I have a 5 year old Lancashire Heeler, who is to say the least a madam! She had always been a protective dog but recently she has become more aggressive. She constantly barks at everything and anything. She attacks the post which comes through the letter box, if someone comes to the house she bites their feet.We have always shut her in another room when someone comes to the house then after a few minutes we let her through and she used to be fine with people, but now she is very aggressive towards people.

She is also starting to be aggressive towards us if we don't let her do something or stop her from doing what she wants then she growls at us and has even snarled at us and gone to bite us.

When out on walks she is a very timid dog and constantly looks round to see if someone is coming and if she hears a noise that she doesn't like then she wants to be off and totally ignores you. Some dogs she is ok with others she goes for.

We did take her to puppy training classes but things have deteriorated over time. I am very concerned about this behaviour and hope you can help?
Many thanks for your time,
Katherine