Username: WajaGirl
Showname: Kaboodle's On a Comet's Tail
Name: Comet
Gender: Buck
Genetics:astast/Ccch/kk/Dd/bb/sisi/Mm/TT/RR/Hh
Tell me the dos and don'ts of merles and merle breedings: Homologous merles (aka 'double merles', and sometimes incorrectly called 'lethal whites') are dogs with two copies of the merle gene from breeding merles with merles. They have a higher risk of being deaf and blind, even sometimes being born without eyes (a condition called Anophthalmia). One other possible defect is Microphthalmia, where one or both eyes are smaller than normal. This can lead to blindness.
A study done by Texas A&M University found that out of 22 double merles, 8 were completely deaf and two were deaf in one ear. Out of 48 single merles, only one was deaf in one ear, none were completely deaf. Unfortunately merle-to-merle breedings are only forbidden in three breeds, so they continue to go on, creating hundreds of puppies with severe defects.
Fun Fact:
Did you know that the majority of health issues in dogs are actually in dogs having both merle and piebald genes?