Monday, November 25, 2019

Lab Coat Color

There are three coat color outcomes in labrador retrievers: black, brown, and yellow.  A homozygous dominant (BB) offspring becomes a black lab. A heterozygous (Bb) offspring is also a black lab, but carries the chocolate gene.  Brown labs have a bb genotype. Yellow labs have a homozygous recessive epistatic gene (ee).  Among the three, brown labradors are the least common.  This article talks about some of the health concerns more prevalent in brown labs.  The study referenced in the article showed that chocolate labs lived an average of 10.7 years whereas the average lifespan of black and yellow labs was 12.1 years.  Chocolate labs experienced life-threatening conditions including musculoskeletal disorders and cancer as well as non-life-threatening concerns including ear infections, joint conditions, dermatitis, and obesity.  The suspected reason for the increased health concerns in brown labs is the high demand by dog owner's for the chocolate coloring.  Because this is a recessive gene, it is less likely to have offspring with a brown coat and dogs are often inbred to achieve this coat color.


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1 comment:

  1. It's unfortunate to see how excessive inbreeding has led to various health concerns in chocolate labs. The more inbreeding that occurs, the more prevalent these issues will become, as inbreeding is likely to allow common recessive genetic disorders/defects to surface that wouldn't normally. Hopefully this will show dog breeders that inbreeding will only lead to more defects in their animals.