Border Collie - Inherited Traits and Diseases

During the Industrial Revolution, the market’s need for lamb, wool, and mutton drastically increased, making vast land in the Borders of Scotland and Northern England ideal for farming and production of these goods. The land was broad and fenceless, and the farmers needed a hardworking herding dog to help with the shepherding tasks. With this aim the Border Collie was bred, resulting in dog breed today well known for its high intelligence, athletic appearance, quick learning abilities and herding skills.

All Border Collies today can trace their ancestor to a single dog, the Old Hemp, who was a tricolour dog bred by Adam Telfer. He lived at the end of 19th century in Northumberland, the very border of England and Scotland, which is today considered the place of origin of Border Collies.

Although Border Collies had worked with shepherds for hundreds of years prior to Old Hemp, the term ”Border Collie” was used for the first time in 1915 by the Secretary of the International Sheep Dog Society in order to register the breed as a separate one from other collie breeds.

There are several theories about the origin of the breed’s name. According to one theory, the word collie is based on an English word ”coal” or ”colley”, and it refers to the black colour. Another theory is based on Gaelic language, where collie means ”useful”, while another theory says the word originates from the German word ”Kuli”, which means ”worker”.

Border Collies control livestock with specific technique, known as ”the eye”

Physical Appearance and Coat Colour of Border Collies

The Border Collie is a medium-sized dog with a double coat which can vary from smooth to rough. Although black and white is the most common coat colour in Border Collies, they can appear in every coat colour and pattern recognised in dogs.

The most common coat colours are black and tan, saddle pattern, sable (influenced by genes on A locus and controlled also by genes on K locus), black (influenced by genes on K locus), brown (influenced by genes on B locus), blue or lilac (influenced by genes on the D locus), recessive red (influenced by genes on the E locus), merle (influenced by genes on the M locus), Irish spotted, piebald spotted and extremely white (influenced by genes on the S locus).

A variety of coat colours and influence of D locus. Upper row: black ( K locus) and chocolate (B locus) merle. Below: diluted coat colours, blue merle, and lilac and white.

Various coat types are also present within the breed, hence Rough, Smooth, and Curly Coated Border Collies. The breed has various eye colours, and heterochromia appears most often among merles.

Health

In general, the Border Collie is a healthy breed, but it has characteristic health conditions. Common genetic diseases are hip dysplasia, collie eye anomaly, progressive retinal atrophy, lens luxation and epilepsy. Grey collie syndrome is specific for collie breeds, from Rough, Smooth to Border collie. Hereditary disorders restricted to Border Collies are specific genetic forms of intestinal cobalamin malabsorption and neuronal ceroid lipofuscinosis. Deafness appears to be common as well. Dogs homozygous for merle coat gene, also known as double merles, are especially prone to auditory and ocular defects. A dog affected by any of the named disorders should not be mated.

Other less common disorders affecting Border Collies are glaucoma, juvenile cataracts, osteochondritis, hypothyroidism and diabetes mellitus.

The most common genetic disorders are:

Collie Eye Anomaly (CEA)

Collie eye anomaly (CEA) is an inherited eye disorder caused by abnormalities in the choroid, which is tissue that supplies nourishment and oxygen to the retina. Due to changes in the choroid, collie eye anomaly is also known as choroidal hypoplasia. It is known to affect Rough Collies, Smooth Collies, Border Collies, Australian Shepherds and Shetland Sheepdogs. Symptoms of CEA can vary in their severity among affected dogs. A typical indication is a choroid thinning, which develops at around five to eight weeks of age. This change is not detectable by the naked eye, which makes an inspection of puppies’ eyes by an ophthalmologist crucial. The disorder may also cause defects of the sclera, characterized by colobomatous lesions and present as pits within the optic nerve head. Tortuous retinal vessels and multiple retinal folds can be present as well. In severely affected dogs, especially those with colobomas, retinal detachments occur, which leads to blindness. Severely affected dogs also develop occasional intraocular hemorrhage.

Collie eye anomaly is inherited in an autosomal recessive pattern.

Primary Lens Luxation (PLL)

Primary lens luxation (PLL) is a disease characterized by weakened zonular fibers, which are ligaments in the eye that hold the lens in its normal position behind the iris and pupil. In the case of a partial breakdown of the zonular ligaments, the lens becomes partially dislocated, condition known as lens subluxation, while a complete breakdown of the zonular ligaments results in a lens fully dislocated from its normal position, a condition recognized as lens luxation. While lens luxation can also occur as a consequence of trauma or tumor, PLL is a form of this disorder that arises spontaneously and is not caused by a previous disease or injury.

PLL is inherited in an autosomal recessive pattern.

Progressive Retinal Atrophy (PRA)

Progressive retinal atrophy, or PRA, is a common canine eye disorder that affects the retina. He disorder affects both eyes but is not painful for the dog. However, it is of progressive nature and in the final stages of the disease, complete vision loss occurs and the dog remains fully blind. You can read more about PRA symptoms, types, genetics and diagnostics here.

Grey Collie Syndrome (GCS)

Grey collie syndrome is a disorder characterised by an abnormally low concentration of neutrophils in the blood, resulting in a weakened immune system and creating a severely negative impact on the dog’s overall health. Affected puppies can be recognised soon after birth. They appear weaker and their coat is greyer or a lighter colour than normal. The nose of an affected collie will never be black. Due to immunity problems caused by the low neutrophil count, affected dogs suffer from gastrointestinal problems, fever, bleeding, blood poisoning and bacterial infections of the eye, respiratory system or skin. The life expectancy of collies with this disorder is usually less than three years.

Grey collie syndrome is inherited in an autosomal recessive pattern.

Neuronal ceroid lipofuscinosis (NCL)

Neuronal ceroid lipofuscinosis in Border Collie is a disorder which belongs to a wider group of disorders known as NCLs. It primarily affects neuronal cells and its typical clinical signs are behavioural abnormality, sleeping problems, mental retardation, dementia, seizure, motor abnormality such as ataxia, and in most cases visual problems leading to blindness. The condition causes possible outbursts of aggression, hallucinations, hyperactivity and epileptic fits. Most affected dogs lose their ability to coordinate everyday muscular activities. Due to the severity of this neurodegenerative disorder, most affected collies rarely survive beyond 28 months.

Trapped Neutrophil Syndrome (TNS)

Trapped neutrophil syndrome is an inherited disorder of the immune system. Bone marrow of affected dogs produces neutrophils but they are not released into the blood stream, hence the name. This impairs the immune system, rendering it unable to fight infections and inflammations. At first affected puppies cannot be identified, but they may appear smaller and more prone to infections. Currently, there is no cure for TNS has been developed, but the dog’s life can be prolonged through antibiotics and steroids. The condition is inherited in an autosomal recessive pattern and the carrier rate appears to be high—10% of the population of show and working Border Collies. There is no evidence that TNS carriers have increased immune problems.

Border Collie DNA tests

Border collies are intelligent, hardworking dogs that are always eager to learn new tricks. However, hundreds of years of selective breeding have made an impact on this breed. High carrier rates for certain genetic disorders, as well as lower rates for other disorders, require DNA testing in order to prevent the incidence of disease. DNA tests available for Border Collie are CEA, NCL, and TNS. Except for disorders, coat colour loci (A locus, B locus, D locus, E locus, M locus and S locus) can be tested as well, which enables prediction of future coat colour.