Submitted by rottnbully on August 7, 2003 - 4:00am. low thyroid could cause problems with conception and should be checked prior to breeding. low thyroid dogs will show up with skin problems, lethargy, obesity, and other things im sure i do not know. if you are asking because there is a problem, i would think a simple t4 level will let you know basic thyroid function, and then go from there with mo