I have two Shihtzu/Maltese mix dogs, both female, mother and daughter 13 and 8 years old. I have them for almost two years. They bark at my sons and my husband and we all live together so its not like they never saw them before but they bark at them like they are strangers, They also bite their ankles. I can not have anyone come into the house if they are male because they will bark, growl and bite them too. Besides this behavior they are good dogs, they are smart and cuddly. I am at my wits end with this behavior. My husband and sons want them out of the house. My sons try to get the dogs used to them by giving them their favorite treats, feeding them, walking them, petting and sitting with them and this behavior towards them has not changed. Does any one have any suggestions?