German/Indian Spitz can be finicky with food and may require change of diet. However, that is not the case here. Due to deteriorating teeth roties maybe hard to chew and so could be the bones in the chicken. Try canned food that has no bones and has glucosomine and chondroitin for osteoarthritis. Check the ingredients of the canned food as phosphorus content should be low as your Spitz is already 12-year-old. Canned food will be soft. Milk should be minimum and should be at room temperature. You can also give her Venky's Gutwell for pre and probiotic to keep digestive enzymes appropriate. Gutwell is in powder form and can be mixed in diluted curd. How is the quality of its fur? Many a times a dog will eat after it has been given good brushing. Our pet have always been German Spitz, the last two being abandoned adults requiring medical attention when adopted. Appy is the fourth that came to us in Oct 2013 with a maggot infested wound around the base of its tail and one ear chewed and starving. Appy is great now at around 12kg (5 yrs of age) on Farmina LG N&D Pomegranate & Chicken kibble that we order from dogspot. It is only given once a day. As I earlier said they can be finicky with food. So as a second feed we give it Drool Puppy Large breed as the size of kibble is suitable for its small jaws and is a lot more crunchy than Farmina. Before Appy there was Bozo (adult German Spitz) that passed away in Jan 2014 due to kidney calculi after having been with us for just 3 years. No cure here for kidney impairment due to stones (homeopathic or allopathic) that also caused pain in the hind legs while on a walk. I just hope that your Spitz lives well and long.