i have a bully who is 5 months old and weighs 5.75 kg ..which is odd for me because he is too small for a 5month bully..for wat i know bullies grow really fast.. i have a pitbull w/c is turning 4months having almost the same weight.. my bully had lack of calcium ..when he got here he couldnt stand up .. i think its rickets or something .anyways..ryt now he could run and walk already but sometimes slip on slippery surfaces.. i think his muscles and bones are still underdeveloped..and for what i have observed ..his growth is slowly developing ..ill post some of his pictures as soon as i can . . i need ur opinions on what should i do ..i gave him tablets for calcium and milk with high calcium content ..i think he is improving ..but his growth is slow..