my rottweiler is 8-9 yrs old. no past health problems. awhile ago she got an eye infection and i kept medicating her as told by vet, went to a new vet who said her eyelid was introverted and that i could get surgery or continue medication the rest of her life. due to age and obesity he recomended the med. since then i have continued the med . any way. since the initial eye infection she has been drinking water like crazy. always thirsty. i asked the vet to test her for diabetes-------negative. her mouth has really seemed dry to me the last few months. but i really noticed it more when i took her to be groomed yesterday. before--when i took her in the car--i was wet, the inside of the car was wet--with slobber. none yesterday except a couple of drops. .i changed her dog food a couple of days ago to light adult food, cause my chihuahua was having cramps and vet recommended changing. chihuahua is 7. any thoughts???