My husband and I just bought a female brindle, she is absolutely gorgeous with beautiful white markings. She was the runt of a litter of 9. At 12 weeks old she was the size of her littermates when they were 6wks (5lbs). She is now 14 weeks and weighs only 7.6lbs. She has been to the vet several times and they say she is very healthy but very tiny. Her ribs are visible which is a concern for me. She eats regularly, exercises, eliminates frequently but doesn't seem to be gaining any weight. She has gotten longer and taller since we got her. I just wanted to know if anyone has any advice about weight gain or if we should just be patient.