We have 5 dogs, 2 yorkies , an aging terrier of mixed parentage, a Maltese cross and Wally our latest , a shih-tzu/poodle cross . His arrival has upset the balance in the house. he has grown bigger than we expected and although now over 2 yrs old is still really boisterous. The first three dogs live indoors and spend most of their time with us. They are not a problem. Wally and Ben the Maltese live in the utility room and poor Ben is jumped on. Occasionally he retaliates and we have a free-for-all.We would have Benny in the house more often but do not want to leave Wally on his own. Suggestions please.