The main difference between a pregnant cat and an overweight cat lies in the changes in the abdomen and the overall evenness of the weight gain. When a cat becomes overweight, it generally gains weight evenly throughout its body, meaning the weight gain is relatively uniform. However, when a cat is pregnant, its belly will mainly swell, appearing noticeably disproportionate to the rest of its body.
A pregnant cat's back will appear slightly droopy from the side, and its belly will be round and swollen, especially from the neck to the tail. If the cat is simply overweight, it will gain weight all over, including the neck and legs, rather than just its belly.
