Dr. Cathryn Mellersh

Head of Canine Genetics

Cathryn’s research aims to understand the genetic basis of inherited conditions that affect specific breeds of dogs. Her team identify the mutation(s) that are associated with inherited diseases and develop DNA tests.


BSC (Genetics) University of Newcastle-upon-Tyne, PhD (Genetics) University of Leicester

Expertise and Interests

Canine genetics, dog breeding and dog health. Cathryn is a member of the Advisory Council on the Welfare Issues of Dog Breeding, the Kennel Club Dog Health Group and the Kennel Club Health Screening & Genetics Sub-Group. She regularly presents to Dog Breed Clubs on basic genetics and genetic improvement of dogs.

Research Areas

Understanding the genetic basis of inherited conditions that affect specific breeds of dogs. By identifying the mutation(s) that are associated the Animal Health Trust Canine Genetics Research Group develops robust genetic tests that can be used to determine the genotype of individual dogs, usually from a simple cheek swab, to help breeders make sensible breeding decisions that will minimise their risk of producing affected puppies.

Although we will investigate any inherited condition in any breed we have a particular interest in inherited ocular and neurological disorders.  As well as developing DNA tests that help improve the genetic health of dogs we also aim to use our findings to shed light on similar inherited conditions that affect humans, through collaboration with scientists who have complementary fields of expertise to our own.  A key component to our success is the DNA archive that we have built up over the last 12 years; we now have DNA from over 32,000 dogs representing at least 175 different breeds in storage and these samples are fundamental to the research we undertake.  Since 2005 we have developed DNA tests for 25 different mutations that benefit 50 different breeds of dog.  Close to 100,000 dogs have now been tested for these mutations, with the results helping breeders all over the world to make informed breeding decisions.


Cathryn was awarded her PhD in 1991 and has worked in the field of canine genetics ever since. Cathryn spent four years at the University of Leicester, developing some of the first genetic markers for the dog, followed by five years at the Fred Hutchinson Cancer Research Center, in Seattle, USA, where she played an integral role in developing the first maps of the canine genome.

Since taking up her position at the Animal Health Trust in 2001, Cathryn has developed and expanded the Canine Genetics Research Group by initiating and securing funding for many successful studies aimed at identifying the mutations responsible for inherited canine disorders. This has been achieved by collaborating with fellow UK-based and international canine geneticists as well as working very hard to build and maintain good relationships with the Kennel Club, dog Breed Clubs and the dog-owning and breeding community in general. In 2010 Cathryn was invited to become a member of the UK’s Advisory Council on the Welfare Issues of Dog Breeding.

In 2015 Cathryn was co-winner of the International Canine Health Awards (International Prize), run by the Kennel Club Charitable Trust.