MyDogDNA Breed Data: Pyrenean Sheepdogs part 2., on traits

Coat type

Furnishings – defining the coat type variety

The DNA test for furnishings is the most interesting coat type variant in Pyrenean Sheepdogs. In addition to structural differences, the hair on the dog’s muzzle is what defines the dog’s breed variety. The Furnishings locus controls the muzzle hair. Dogs homozygous for furnishings have typical muzzle hair for longhaired Pyrenean Sheepdogs. Dogs that are homozygous for the non-furnishings allele do not have any long facial hair and are defined as smooth faced Pyrenean Sheepdogs. Dogs that are heterozygous for the furnishings allele can look either like smooth faced dogs with some longer hair on the muzzle or like long-haired dogs with a little shorter muzzle hair than usual. With DNA testing, the looks of puppies can be assessed beforehand. The DNA test for furnishings is a marker test, testing two markers that are associated with the occurrence of the furnishings phenotype.

Homozygous for furnishings

Heterozygous for furnishings

Homozygous non-furnishings

Curly coat 

The variant causing curly coat occurs rarely in Pyrenean Sheepdogs. It is possible that this variant would cause increased waviness of the coat in Pyrenean Sheepdogs. The effect of this variant in the breed still needs some further investigation.

Coat length – all Pyrenean Sheepdogs have genetically a long coat

All Pyrenean Sheepdogs tested to date are genetically long coated. The L allele causing short coat causes the extremely short hair in for example Labrador Retrievers and Border Collies. The furnishings locus accounts for some coat length variation in Pyrenean Sheepdogs but not all of it. Coat length variation in Pyrenean Sheepdogs apart of the furnishings locus is caused by unknown genetic causes.

Body size

Size variation within the breed is big and many genetic size variants are seen in the breed 

The genetic causes for size variation between breeds have been studied greatly. Intrabreed size variation however has been studied less. The size of Pyrenean Sheepdogs varies greatly (even from 35cm to 55cm) and many different genetic size variants are seen in the breed.

The MyDogDNA-database has a new feature where the owner can write the dog’s height and weight in the database. After this, the dog appears on a table showing size variation within the breed.

Size graph

This graph gives interesting information about the size of tested dogs of the breed. For example the breed standard of Pyrenean Sheepdog dogs includes size limits for height but not for weight. The size graph gives interesting information about the normal weights of Pyrenean Sheepdogs. This knowledge might be of interest for example for owners struggling with their pet’s weight management. The size graph of longhaired Pyrenean Sheepdogs also shows, that most of the tested dogs are in the lower range of the breed standard height. On the contrary, tested smooth faced Pyrenean Sheepdog males are quite large (average height 50.4cm).

The size graph also allows you to see the size variation of dogs carrying the same genotype. By moving the mouse over a dot on the graph in the database, also other dogs with the same genotype are highlighted on the graph. This allows you to see how big the size variation is within dogs of the same genotype.

Size graph of longhaired Pyrenean Sheepdog dogs. This graph shows for example, that all tested female dogs that have reported sizes to the database, are in the lower end of the breed standard size. It must be noted, that the graph includes only ten longhaired female dogs until now.

Size table

The size table begins with the average size of all tested dogs. The genotypes of tested dogs are listed in the table so that the genotypes that result in the largest heights are on the top and the smallest ones are on the bottom. Blue boxes represent that the dog is homozygous for an allele reducing size from wolf size. White boxes represent that the dog is homozygous for an allele that is seen in dogs the same size as wolves. If the box is half blue, half white, the dog is heterozygous for an allele that reduces size. The table also tells how many dogs have the same genotype. The average size of the genotype’s dogs becomes more accurate as there are more tested dogs with the same genotype.

HMGA2 is the strongest size marker seen in Pyrenean Sheepdogs. IGF1, GHR1 and STC2 are weaker size markers and their effect usually depends on other size markers. The size table shows that many different genotypes can lead to a similar height. Tested dogs have until now been of similar size so the size effect of different genotypes is not so clearly shown yet. However, we already see that the smallest longhaired Pyrenean Sheepdogs carry the largest amount of size-reducing alleles of the tested dogs.

Size table of longhaired Pyrenean Sheepdogs. The possible size effects of different genotypes will be more evident as there are more tested dogs with the same genotype and when more dogs of different sizes are tested. However, we can already see the two highlighted genotypes on the table that seem to lead to different adult sizes.

Structural characteristics 

Natural bobtail (the T-box mutation) 

The T-box mutation is the most important structural characteristic for Pyrenean Sheepdogs in the MyDogDNA testing panel. Short-tailedness caused by the T-box mutation can cause the tail to be for example ¾ of normal length, which can be difficult to differentiate from a normal-length tail. Mating two dogs carrying the T-box mutation is prohibited in some countries due to possible severe developmental defects caused by homozygosity for this mutation. DNA testing can be used to make sure that two dogs carrying this mutation are not mated.

Bobtailed puppy (heterozygous for the T-box mutation)

Long-tailed adult (does not carry the T-box mutation)

Skull shape

There is no direct DNA test for dog skull shape. This test identifies a marker that has been associated with long or short skulled dogs. The test does not tell the actual skull length of the dog, only if it most probably belongs to a breed that typically has a short or long skull. The most common allele in this locus in Pyrenean Sheepdogs is the allele seen in long skulled dogs.

Ear erectness

Ear erectness is another trait that does not have direct DNA test and which is related to floppy or pricked ear breeds rather than individuals. Other things that affect ear erectness include ear size and rigidness. This test basically only tells if the dog belongs to a breed with pricked or floppy ears. The ears of Pyrenean Sheepdogs are neither pricked or floppy and typical test results of this locus can be either pricked or floppy.