Bella is the oldest in the litter and I did not notice the knot until today, I play and hold them everyday, so I am very surprised to have just noticed it. The knot is tight, and about the size of a small walnut. I read some of the other questions about lumps(knots). However those questions referred to dogs my little Bella is only barely 4 weeks old. Bella is American red nose pit/coyshepard. Thank you! Billi

I suggest a vet visit if it is still there tomorrow. My concern is that it came so quickly.