{"id":6485,"date":"2019-11-01T11:36:57","date_gmt":"2019-11-01T15:36:57","guid":{"rendered":"https:\/\/qa.vet.purdue.edu\/news\/?p=6485"},"modified":"2026-06-01T08:39:45","modified_gmt":"2026-06-01T12:39:45","slug":"is-your-dog-hiding-its-true-colors-pvm-researchers-provide-answers","status":"publish","type":"post","link":"https:\/\/vet.purdue.edu\/news\/is-your-dog-hiding-its-true-colors-pvm-researchers-provide-answers.php","title":{"rendered":"Is Your Dog Hiding its True Colors? PVM Researchers Provide Answers"},"content":{"rendered":"
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Researchers in the Department of Basic Medical Sciences found that some breeds of dogs have hidden coat colors \u2013 and in some cases, other traits \u2013 that have been lurking all along. For example, the Australian Shepherd (shown in photo) is one of around 18 recognized breeds of dogs that have the genetic potential to be born without a tail. However, up to 48 of the breeds analyzed in the study possess the tailless gene variant, usually at a very low frequency. (Photo provided)<\/figcaption><\/figure>\n<\/div>\n\n\n

A study conducted by researchers in the Purdue University\nCollege of Veterinary Medicine shows that some breeds of dogs have hidden coat\ncolors and other traits.  If you have a\npurebred dog, it\u2019s likely that he or she looks fairly similar to other dogs of\nthe same breed, especially when it comes to the color of their coats.  But if a purebred puppy does not look exactly\nlike its siblings when it\u2019s born, chances are, it might not be a flaw \u2013 but\nrather a hidden gene variant that decided to show itself.<\/p>\n\n\n\n

A research team led by Dr. Kari Ekenstedt, assistant professor of anatomy and genetics in the College\u2019s Department of Basic Medical Sciences, and Dr. Dayna Dreger, the lead scientist in Dr. Ekenstedt\u2019s canine genetics research laboratory, looked at a dozen different genes in 212 dog breeds. The Purdue researchers, together with industry partners at Wisdom Health, analyzed data that had been initially collected by WISDOM PANEL™ for the development of canine DNA tests. The work was published October 28 in PLOS ONE<\/a>.<\/p>\n\n\n\n

\u201cThese are purebred dogs with traits that their breed clubs\nsay they\u2019re not supposed to have,\u201d said Dr. Ekenstedt, whose research program\nfocuses on canine genetics. \u201cThe message of this paper is, \u2018Hey, these gene\nvariants exist in your breed, and if a few dogs are born with these traits,\nit\u2019s not caused by accidental breeding and it\u2019s not a mutt; it\u2019s a purebred\nshowing this known genetic potential.\u2019\u201d<\/p>\n\n\n\n

Along with analyzing the data, researchers used standard\nbreed descriptions from major American and international dog breed registries\nto determine coat colors and tail lengths that were accepted within each breed.<\/p>\n\n\n\n

\u201cThere was a lot of information we didn\u2019t expect,\u201d Dr. Dreger\nsaid. \u201cWhen it comes to different dog breeds, their standards are mostly based\non preference and aesthetics. We make assumptions for certain breeds based on\nwhat we expect their coat colors to be.\u201d<\/p>\n\n\n\n

Dr. Ekenstedt explains that coat color genes have a\nsignificant amount of epistasis between them, meaning that what happens at one\ngene can mask what\u2019s happening at another gene. Because of epistasis, it\u2019s rare\nto see those masked genes actually expressed in a dog\u2019s coat color.<\/p>\n\n\n\n

One example of a \u201cfault\u201d allele \u2013 a gene variant that would\ncause a trait that is not allowed in a breed standard \u2013 is an allele that\ncauses the color brown, which affects both hair pigment and skin pigment. The\ncolor is allowed in breeds like the Labrador Retriever where it causes the\nchocolate color. However, researchers observed that in breeds where brown is\nnot allowed, such as the Rottweiler and the German Shepherd Dog, brown alleles\nexist at low frequencies. <\/p>\n\n\n\n

Another example of a fault allele is in the Weimaraner, which exists in both long-haired and short-haired varieties. At least one dog breed organization does not allow long-haired Weimaraners, while several others do allow them.  Of the Weimaraners sampled in this data, the long-haired allele is present at a 4% frequency.  <\/p>\n\n\n\n

The same goes for other traits, too, Dr. Dreger says. For\nexample, around 18 recognized breeds of dogs have the genetic potential to be\nborn without a tail \u2013 such as the popular Australian Shepherd. But the data\nshows that up to 48 of the breeds analyzed possess the tailless gene variant,\nusually at a very low frequency; one of those breeds is the Dachshund.  \u201cA breeder would certainly be surprised to\nsee a Dachshund born without a tail,\u201d Dr. Dreger said. \u201cThe chances are low,\nbut our research shows that the potential is there.\u201d  <\/p>\n\n\n\n

Both Drs. Dreger and Ekenstedt hope the research prompts\nsome discussions within the dog community. \n\u201cI want this to start science-based conversations,\u201d Dr. Dreger said.\n\u201cWe\u2019re not here to make decisions on what a breed should or shouldn\u2019t look like\nor what a breed club should do. We\u2019re here to say these are the facts, and\nthese are the gene variants that naturally exist in these breeds.\u201d<\/p>\n\n\n\n

They also hope the study changes some perspectives when it\ncomes to what is to be expected with certain breeds of dogs. \u201cThere\u2019s an\nassumption that the standards for these different breeds of dogs are set in\nstone,\u201d Dr. Dreger said. \u201cPeople will often make assumptions that if it doesn\u2019t\nmatch this, it\u2019s not purebred. This data shows that there is a lot of variation\nin some of these breeds, and the standards are not as concrete as we expect\nthem to be.\u201d<\/p>\n\n\n\n

Wisdom Health funded a Veterinary Summer Scholar position related to the study for Blair Hooser, a Purdue veterinary student in the DVM Class of 2021 and co-author on the paper. Partial support for Dr. Ekenstedt was provided by the National Institutes of Health.<\/p>\n\n\n\n

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