Chocabloc Border Collies

Border Collie Health

The health and happiness of our dogs here at Chocabloc is our utmost priority and that's why we know the DNA status for hereditary disease of each of our family members.

There are 12 main hereditary health issues when it comes to the Border Collie. These are known as Collie Eye Anomoly (CEA), Neuronal Ceroid Lipofuscinosis (CL), Trapped Neutrophil Syndrome (TNS), Primary Lens Luxation, Degenerative Myelopathy, Ivermectin Sensitivity MDR1, Cobalamin Malabsorption, Myotonia Hereditaria, Goniodysgenesis and Glaucoma, Raine Syndrome Dental Hypomineralisation, Cystinuria and Von Willebrands Disease.

COLLIE EYE ANOMOLY (CEA)

CEA is the most common inherited disease for Border Collies. It is interesting to note that this is not the only breed that can be affected, many of the larger breeds can pass it on. CEA is an inherited disease affecting eye development. The major issue is 'choroidal hypoplasia', a pale patch in the back of the eye caused by abnormal development of the choroid layer. In severe cases can cause blindness. CEA refers to an inherited abnormality in the development of the retina, optic nerve and choroid of the eye. These are all structures at the back of the eye involved with the vision. CEA is a multigenetic trait, is present at birth and does not change with age. There are varying degrees of abnormality with CEA. It can affect one eye or both, from a mild case where vision may be reduced to severe CEA with retinal detachment and total loss of vision.

We are very fortunate that there is a DNA test for CEA to help breeders to choose appropriate mating combinations. Please see the chart at the bottom of the page for mating combinations.

CEA test results are either Normal/Clear- which means that the dog is completely free of both the disease and also does not carrying the gene which will produce the disease. This dog can be mated to a clear dog or a carrier dog without passing on the condition.

Carrier- this means that the dog does not have the disease but carries the gene which may produce the disease. A dog that is a carrier of a disease can be mated with another that is clear and all of the progeny from this litter will be free of the disease. Under no circumstances should a carrier of a disease be mated with another carrier or affected of the same disease.

Affected- A dog has the described disease. A dog which is affected with a disease can be bred with another dog that is clear of the same disease and all of the puppies from the mating will be not be affected with the disease but will all be carriers.

Mating combinations are chosen to make sure that no puppy will ever have the disease, be affected by it.

It is never possible to guarantee that puppies will not suffer from eye problems because although their parents may have been tested, some problems only appear when the dog is older. Some eye conditions are inherited recessively which is why we test our dogs to hopefully ensure that no puppy bred at Chocabloc will have those diseases able to be tested for.

NEURONAL CEROID LIPOFUSCINOSIS (CL)

This is an inherited disease, which is not contagious, but it is fatal and cannot be treated. It affects the nervous system including the brain. Ceroid Lipofuscinosis is known as Battens Disease in Humans.

CL has been found in other breeds of dogs i.e. Cocker Spaniels, Dachshunds, English Setters, Miniature Schnauzers, Rough Collies, and Salukis as well as in Devon Cattle, South Hampshire Sheep and in Siamese Cats

The occurrence of CL in Border Collies is not the fault of any one person or group. The defective gene was carried by an imported dog at a time when the disease was unidentified. Since then, CL has occurred sporadically, as most Australian bred Border Collies are descended from that dog. Affected animals appear normal until aged approx 15 months. From that age any or all of the following signs may be noted:

Unreasonable apprehension or fear of familiar objects/surroundings

sight disturbance,

abnormal gait – is unsteady on feet and has difficulty in climbing or jumping, tends to prop or goose step,

demented behaviour,

mania,

hyperactivity,

rage,

disorientation,

fixations,

loss of toilet training,

strange or abnormal behaviour

The progress and effect of the symptoms will steadily continue to deteriorate and medication cannot improve the condition. Affected animals have all been euthanased by the age of 3½ years. CL symptoms can be confused with other brain disorders.

We are very fortunate that there is a DNA test for CL to help breeders to choose appropriate mating combinations.

CL test results are either Normal/Clear- which means that the dog is completely free of both the disease and also does not carrying the gene which will produce the disease. This dog can be mated to a clear dog or a carrier dog without passing on the condition.

Mating combinations are chosen to make sure that no puppy will ever have the disease or be affected by it. See table at the bottom of the page for clarification.

TRAPPED NEUTROPHIL SYNDROME (TNS)

TNS stands for Trapped Neutrophil Syndrome. It is an immune deficiency in Border collies. It is an inherited disorder that is very common in all populations of Border collies with more than 10% of both working and show dogs carrying the defective gene and capable of having affected puppies. Please note that occurrences of dogs affected with TNS are quite rare.

TNS is a condition where the bone marrow produces neutrophils but they are not released into the bloodstream. This results in an impaired immune system that cannot fight infections.
Symptoms are variable, many of the reported TNS puppies have been born looking normal but others have been born small.
Some puppies with TNS have been small and fine boned with narrow heads at some point but this may not be evident until approx 16 weeks.
A common first sign is a bad reaction to vaccinations with signs of fever.
Blood tests may show an abnormally low segmented neutrophil level but TNS can only be definitely diagnosed by bone marrow biopsy.
Any puppy that shows any signs of infection or failure to thrive is a possible case of TNS.
There is no cure for TNS and it appears to always be fatal eventually. Antibiotic and steroid treatment can help affected dogs live a relatively active life.
TNS is an autosomal recessive condition.
The symptoms are extremely variable and will depend on the bacteria that the pup encounters. There may also be other genes that effect the disease expression.
Some dogs do not show symptoms until later in life. Older puppies & young adult dogs diagnosed with immune system problems may have TNS so they should also be tested with the DNA test

TNS test results are either Normal/Clear- which means that the dog is completely free of both the disease and also does not carrying the gene which will produce the disease. This dog can be mated to a clear dog or a carrier dog without passing on the condition.

CORBALAMIN MALABSORPTION

Affected dogs are unable to make adequate amounts of a protein that plays a role in absorption of certain nutrients from the intestinal tract and kidneys, including the B vitamin, cobalamin. Affected dogs have increased levels of methylmalonic acid in their urine (a sign of cobalamin deficiency) from as early as 14 weeks of age, but symptoms of disease may not be recognized by owners for months or years. Symptoms of disease include anorexia, lethargy, poor weight gain, poor muscle mass, and in rare circumstances, a severe neurological dysfunction called hepatic encephalopathy that can lead to altered mental state, seizures, coma and death. Affected dogs have an increase in certain proteins in their urine, and have decreased synthesis of blood cells resulting in Anemia and decreased numbers of neutrophils. Affected dogs require cobalamin supplementation for life that results in disease remission for most animals within a few weeks. Though not associated with clinical disease, affected dogs will continue to pass increased amounts of certain proteins in the urine even with cobalamin supplementation.

GONIODYSGENESIS AND GLAUCOMA

Goniodysgenesis is a condition caused by the abnormal development of the eye which can result in excessive pressure buildup, eventually causing permanent damage to the optic nerve, resulting in blindness. Goniodysgenesis, also known as mesodermal dysgenesis, is an abnormality of the anterior chamber of the eye, and it has been associated with glaucoma and blindness. Goniodysgenesis and early-onset glaucoma has been documented for the first time in Australia in the late 1990s and afterwards have been found also in Europe and the USA. It is particularly commonly diagnosed in some Border collie lineages; in conducted study, 10.8% of Border collies were reported to have moderate or severe pectinate ligament dysplasia, alteration in eye structure responsible for proper humour drainage. Most forms of glaucoma can be placed into two categories, primary and secondary. The term primary glaucoma is used to describe those types of glaucoma caused by an inherited physical or physiological trait that an animal has been predisposed to. (Secondary glaucoma is a term referred to when the disease is triggered by something other than genetics.) Many dogs affected by glaucoma will become blind in the affected eye within the first year. Symptoms of glaucoma include: severe pain, sensitivity to light, winking spasms, sunken eyes, raised third eyebrow, dog winces when you touch the head, watery eyes, pain-related behavioral change (hiding, refusal to eat), red eye, and dilated pupils.

PRIMARY LENS LUXATION.

Primary lens luxation (PLL) is thought to be heritable in most breeds in which it is seen, although clinical signs are generally not seen until the dog is an adult. Secondary lens luxation is not heritable, and occurs secondary to another disease process within the eye. In the terrier breeds (such as the Jack Russell terrier) PLL is associated with an inherited degeneration of the zonules, or the thin ligaments that suspend the lens in place behind the iris (the coloured part of the eye) and in front of the vitreous (a clear, gel-like substance). The genetic mutation has been characterised in a number of breeds, and a genetic test is available. Lens luxation refers to the lens being in an abnormal position inside the eye. Clinical signs in the fox terrier are usually not seen until the dog is in middle age, and include a sudden onset of pain (squinting, tearing etc), redness, and cloudiness of the cornea. The lens may partially or fully luxate into the front chamber of the eye, causing acute glaucoma (increased pressure within the eye). Sometimes the lens may fall backwards into the posterior (back) chamber of the eye, which may displace the vitreous forwards. This may then also lead to a blockage of drainage of fluid from the eye and a secondary glaucoma. Glaucoma (increased fluid pressure within the eye) is a common consequence of lens luxation, and can rapidly lead to blindness. Lens luxation is a veterinary emergency, and if you notice the signs of PLL in your dog’s eye you should see your vet immediately. Diagnosis is by examination of the inside of the eye by a veterinarian, and possibly an ultrasound of the eye. Treatment of PLL is aimed at reducing the fluid pressure within the eye and preserving vision in acute cases, then removing the lens surgically. Blind eyes may be removed to treat pain. Genetic testing is available for the screening of breeding animals, so that two carriers (or any affected animals) are not bred. Although the disease is treated as a recessive one, carrier animals will also occasionally develop lens luxation.

DEGENERATIVE MYELOPATHY

Degenerative myelopathy is normally seen around middle age, and in general diagnosis can only be confirmed at post mortem examination. Breed surveys of some predisposed breeds indicate a fairly low occurrence rate, but most experts think this rate is actually much higher, due to the lack of post mortem follow up of the majority of suspected cases. Signs are due to the immune-mediated destruction of a part of the nerves in the spinal cord, leading to loss of these nerve fibres. The first sign is knuckling of the hind feet, and hind limb ataxia. Once the spinal cord damage progresses past this initial stage (termed proprioceptive deficits), the effectiveness (if any) of treatment is much diminished. Hence early diagnosis is vital. Following this initial stage, hind limb reflexes are affected, then weakness in the hind limbs develops, progressing to total paralysis. Once a dog shows these signs it will almost always respond poorly to therapy. Eventually destruction progresses from the middle of the spinal cord to the upper cord and brain stem, leading to forelimb weakness and eventually interference with the muscles of breathing, causing death. Most dogs are euthanased for humane reasons before this happens. Treatment is with specific supplements and drugs aimed at interfering with the immune destruction in the spinal cord, to slow further nerve damage. The effectiveness of this treatment is variable, but is only of benefit if started as early as possible. Once nerves are lost, they will not be replaced. Degenerative myelopathy cannot be cured. A DNA test is available for predisposed pure breeds to carry out screening of breeding animals.

IVERMECTIN SENSITIVITY MDR1

In certain breeds a mutation on the MDR1 gene (which stands for Multi Drug Resistance 1) makes affected animals sensitive to certain drugs. The first drug that this defect was found to be present for was Ivermectin, used to treat mange and prevent heartworm. Affected dogs suffer seizures when given this drug. It has since been found that the mutation on the MDR1 gene means that the brain is not able to efficiently pump some drugs out of its protected environment the way normal brain vessels do – hence these drugs can enter and build up in the brain tissue, and cause toxic effects such as seizures. A range of drugs are usually pumped out of the brain by the protein pump that the MDR1 gene is responsible for, and so dogs carrying the defective (“mutant”) gene are sensitive to a whole range of drugs. Dogs carrying two copies of the mutant gene are more sensitive to these drugs than those with one copy of the gene. For more details on the drugs involved in this disease, information can be found at http://vcpl.vetmed.wsu.edu/problem-drugs Your vet should be aware if your dog is carrying an affected MDR1 gene, or 2 copies of the gene, as the amount of these drugs given needs to be reduced to avoid toxic effects, or alternative drugs used if available. This genetic defect is known to occur quite commonly in a number of breeds, especially Collies, and a DNA test is available to determine if your dog is carrying abnormal MDR1 gene/s or not.

MYOTONIA HEREDITARIA

Myotonia congenita also known as myotonia hereditaria (Australian cattle dog type) is an inherited muscle disorder affecting dogs. The muscle cells of an affected dog are over-excitable, which causes muscles to remain contracted rather than relaxing after voluntary activity.

RAINE SYNDROME DENTAL HYPOMINERALISATION

Canine dental hypomineralization or Raine Syndrom is a genetic disorder affecting the Border Collies. The disorder causes severe tooth wear resulting in pulpitis and requiring extraction of those teeth. Dental hypomineralization is a canine model for human Raine Syndrome.Dental examination of the affected dogs reveals a significant wear. Lower incisor teeth can be worn close to the gingival margin. The enamel shows a light brown discoloration and appears dull. Some worn teeth can have a pulp exposure and pulpits as a result of the wear.

VON WILLEBRANDS DISEASE TYPE II

Von Willebrand’s disease is the most common inherited bleeding disorder in dogs and occurs when there is a lack of functional von Willebrand factor. Von Willebrand factor is needed for the normal adhesion of platelets and for normal blood clotting to occur. There are 3 types of von Willebrand’s disease, and type II disease occurs when there is structurally abnormal von Willebrand factor in the blood of affected animals. This is a recessive disorder and is a fairly rare and severe form of von Willebrand’s disease. Because the von Willebrand factor is structurally abnormal, it will not function as it is supposed to in the process of blood clotting. This type of von Willebrand’s disease leads to severe bleeding disorders and episodes of bleeding. Diagnosis may be suspected in a dog that has a bleeding problem but a normal PT and APTT, and can be confirmed by DNA testing for the mutation that causes the disease. Treatment may involve supportive care as an inpatient in hospital, as well as blood and/or plasma transfusions to provide functioning clotting factors. Care must be taken that affected dogs do not play roughly, suffer trauma from falls or jumping from heights, and that veterinarians are always aware of their condition. However severe episodes of bleeding that can be life-threatening may occur regardless.

CANINE HIP DYSPLASIA

Hip Dysplasia in dogs is a disease that is characterised by instability of the hip joint (laxity), pain and eventually degenerative joint disease. Like most medium and large sized dogs, Border Collies can be prone to Canine Hip Dysplasia (CHD) which can cause mild to severe lameness. As a dog approaches middle age, symptoms of CHD often show up as mild arthritis- the dog limps or appears somewhat stiff after hard exercise or upon getting up from a nap. Often the dog seems fine after he moves around and stretches himself a bit. These symptoms can become worse as the dog ages. Treatment varies from pain management to several choices of surgery (including total hip replacement). We work with a very knowledgeable vet specialist and have our dogs here PennHip scored. Please note: Some of the major causes of CHD is rough play, a dog being overweight, indulging in over-exercise whilst young or slipping on floors or stairs as puppies. It is imperative that you, as the new puppy owner are extremely cautious about how your puppy is exercised and cared for during the growth stage.

Expected Results of Mating Combinations for Inherited Recessive Diseases
Parent 1	Parent 2
Parent 1	Normal	Carrier	Affected
Normal	All = Normal	1/2 = Normal 1/2 = Carriers	All = Carriers
Carrier	1/2 = Normal 1/2 = Carriers	1/4 = Normal 1/2 = Carriers 1/4 = Affected	1/2 = Carriers 1/2 = Affected
Affected	All = Carriers	1/2 = Carriers 1/2 = Affected	All = Affected

Acceptable Mating Combinations

DNA tested clear dog to clear dog = all offspring clear.
DNA tested clear dog to carrier dog = acceptable as this will not
produce any affected pups. Offspring will be clear or carrier.
DNA tested clear dog to affected dog = acceptable as this will not
produce any affected pups. All offspring will be carriers.

Contact Details

Louise Stonehouse
Wide Bay QLD, Australia
Email : [email protected]