I noticed that my 3 1/2 month old puppy was leaving a trail of tiny bloody-looking dots around the house. At first I thought it was her first heat, but it seems she is still too young for that. After watching her for a day, I noticed that she was having trouble urinating and although she has been potty trained for two months, she started urinating in the house (seemingly because of urgency). Could this be a bladder infection?