Hi, I will give as much info as poss so as not to drip feed. We got a beautiful, lovely dog three weeks ago from a rescue centre. She is a small crossbreed, not sure what of but something with curly hair. She is approx 2 and we do not know details of her background but know its not good. From the moment she arrived she has been affectionate but anxious, very well behaved and very, very sweet. In the last week or so she has become obviously territorial of our home, not disproportionately so but barking at people coming in - just for about 30 secs and then running away to cower. Then she comes out with a bit of encouragement and is soon happy to be cuddled/fussed over, or just chills out and goes to sleep.
In the last few days she has started to bite. She does the barking very briefly thing, then runs off to cower, then sits there for a bit looking thoughtful and then lunges. So far (2 occasions) it has been one bite and then she has stopped when told off - no damage caused apart from to clothing but obviously cannot have this long term as cannot take the risk of someone being hurt.
She is fine when out the house and is either friendly or nervous with other people/dogs and has shown literally no other signs of aggressive behaviour.
Sorry to go on so long but really keen to know if people have tips or advice about what we can do. We would hate to muzzel her all the time but realise that may be the only sure way to guarantee no bites. She is on heat, could this make a difference?