When money is borrowed, interest is typically calculated as a percentage of the principal, the amount owed to the lender. The percentage of the principal that is paid over a certain period of time (typically a year) is called the interest rate. Interest rates are market prices which are determined by supply and demand.
Swollen nipples in dogs is a common symptom seen in mastitis. Mastitis occurs when there is an infection of the mammary glands. Mastitis is common in female dogs who are in the process of nursing. In mastitis, the dog's mammary glands become swollen and painful. The milk is toxic in affected nipples.
Your dog may also have heart disease or heartworm disease which can cause the abdomen to fill with fluid. Other causes for a swollen abdomen in dogs is overeating, bloat and intestinal parasites. Abdominal swelling in cats can be attributed to many of the same things. Cats can ingest foreign objects, they may be suffering from cancer or have a mass on an organ, or they can be in heart failure.