A. could it be her hip bone maybe? if she is quiet slim those bones can be very visible and resemble protrusions. Has she lost weight lately? if so that might be the reason. If you think she has lost weight you should take her to the vet in order to investigate the possible reason for this.
A. SHe is possibly loosing weight and the pelvic bones are more evident as result of the weight loss. That is a common clinical sign in old cats, and, if higher than 10-15% of her total body weight require more investigations to diagnose the underlying cause. Common weight loss causes in old cats are hyperthyroidism, diabetes mellitus, renal failure, gastrointestinal diseases which can cause malabsorption, liver problems.
Your account has been reactivated.