Disease Descriptions

Descriptions of Diseases for which the University of Missouri Canine Genetics Laboratory Offers DNA Testing (Listed by breed name)
ALL BREEDS (including mixed breeds)
Degenerative Myelopathy

Canine degenerative myelopathy (DM) is a late-onset disease associated with a mutation in the SOD1 gene and has been confirmed in over 40 breeds. The SOD1 mutation has been observed in over 200 breeds, as well as mixed breed dogs. Dogs with 2 mutated copies of this gene are at higher risk for developing DM. The onset of signs usually occurs at 8 years of age or older. Typically the clinical signs begin with loss of coordination (ataxia) and spastic weakness in the hind limbs and progress over time to paralysis in all limbs. There are no effective treatments.  Canine DM is considered a disease model for amyotrophic lateral sclerosis (ALS, Lou Gehrig’s Disease).

Gene: SOD1

Methemoglobinemia

Methemoglobinemia associated with a mutation in the CYB5R3 gene occurs in numerous breeds.  Then most recognized sign is exercise intolerance that is accompanied by tachypnea (rapid shallow breathing) and cyanosis (bluish skin coloration due to low blood oxygen levels).

Gene: CYB5R3

Neuronal Ceroid Lipofuscinosis (NCL)

The NCLs are progressive neurodegenerative disorders that occur in many breeds and in mixed breed dogs.  The diseases are inherited as autosomal recessive traits.  Common signs include changes in personality, cognitive decline, compulsive behaviors, impaired coordination, seizures, and visual impairment.  Not all signs appear in all forms of the disease.  The different forms of NCL differ in age at onset and rate of disease progression.  To date, mutations in the 9 genes listed below have been found to underlie different forms of NCL.  If your dog is exhibiting progressive signs suggestive of NCL, we can test for the most likely causal mutations.  We also conduct research to identify new mutations that underlie NCL-like diseases that do not result from one of the known causal mutations.

Genes: PPT1, TPP1, CLN5, CLN6, MFSD8, CLN8, CTSD, ATP13A2, ARSG

ALAPAHA BULLDOG

Dermatosparaxis Ehlers-Danlos Syndrome

Alapaha Bulldog Ehlers-Danlos Syndrome (EDS) is a connective tissue disorder that results from a mutation in the ADAMTS2 gene. The disease is characterized by joint hypermobility and loose hyper-elastic skin that is fragile and subject to frequent wounds. Different mutations in the ADAMTS2 gene underlie EDS in other breeds. 

Gene: ADAMTS2

AMERICAN BULLDOG

Neuronal Ceroid Lipofuscinosis (CLN10 Disease)

Multiple forms of neuronal ceroid lipofuscinosis (NCL) occur in dogs and humans. The NCLs are all progressive neurological disorders. The onset of signs in the form that occurs in American Bulldogs typically occurs between one and two years of age when affected dogs start to exhibit ataxia, hypermetria, and paraparesis. Affected dogs exhibit slowly progressive psychomotor decline and are typically euthanized before 7 years of age due to the severity of signs.

Gene:  CTSD

AMERICAN ESKIMO DOG

Primary Lens Luxation

Primary lens luxation (PLL) occurs in multiple breeds due to a variety of mutations. PLL is characterized by lens instability in both eyes, although the severity of clinical signs may differ between the 2 eyes. PLL typically goes undetected until the lens becomes severely dislocated in one eye. Dogs typically present with concurrent partial lens displacement of the other eye, which typically progresses into full displacement over a period of weeks to months. The lens often moves anteriorly causing disruption to the pupil and draining mechanism in the eye, which may result in acute glaucoma.

Gene: ADAMTS17

AMERICAN STAFFORDSHIRE TERRIER (pitbull terrier)

Neuronal Ceroid Lipofuscinosis (Lysosomal Storage Disease)

Many American Staffordshire Terriers and Pitbull Terriers suffer from a late-onset progressive neurological disorder characterized initially by subtle signs of impaired balance and ataxia but progressing slowly to eventually include cognitive decline, generalized motor impairment and seizures. Onset is typically between 3 and 6 years of age, with variable rates of progression. Euthanasia due to the severity of signs has been elected for dogs as young as 7 years, whereas other affected dogs live past 10 years of age. The disease results from a mutation in the ARSG gene that encodes the lysosomal enzyme arylsulfatase G. The canine disease has been classified as a form of neuronal ceroid lipofuscinosis (NCL), although human subjects with ARSG mutations do not develop NCL-like neurological signs. Based on our DNA testing, the disease appears to be quite common in American Staffordshire Terriers and Pitbull Terriers as well as in mixed breed dogs with Pitbull ancestry.

Gene:  ARSG

Adult-onset Laryngeal Paralysis & Polyneuropathy (ALPP)
  • Disease description: American Staffordshire Terrier ALPP is a fatal neurodegenerative disease that becomes apparent when affected puppies reach 3 or 4 months of age. 

Typically, the first sign is breathing difficulty which causes choking, aspiration, and possible pneumonia.  The signs progress to generalized muscle weakness necessitating euthanasia. Based on our studies to date, it appears that there are 2 forms of the disease in American Staffordshire Terriers. We offer a test for the more common form. The genetic basis for the other form remains to be determined. Therefore, your dog could still be at risk for ALPP even if it does not have the mutation we test for.

Gene:  To be published.

AUSTRALIAN CATTLE DOG

Neuronal Ceroid Lipofuscinosis (CLN5 Disease)

The neuronal ceroid lipofuscinosies (NCLs) are progressive hereditary neurological disorders that occur in humans, dogs, cats and other mammals. A form that occurs in Australian Cattle Dogs, Border Collies, and mixed breed dogs results from a mutation in the CLN5 gene.  Subtle changes in stance and balance occur as early as 6 months of age, but typically neurological signs do not become obvious until approximately 10 months of age. These signs include anxiety, loss of housetraining, loss of responsiveness to previously learned commands and verbal prompting, compulsive circling, disruption of previously normal sleep patterns, impaired vocalization, impaired ability to prehend and swallow food, loss of coordination and ability to climb up or down stairs, development of tremors and seizures, exhibition of trance-like behavior, and visual impairment in both dim and bright lighting conditions. These severity of these sings progresses over time so that euthanasia is usually elected before affected dogs reach 2 years of age.

Gene: CLN5

Neuronal Ceroid Lipofuscinosis (CLN8 Disease)

In addition to NCL resulting from a mutation in the CLN8 gene, dogs of Australian Shepherd and Australian Cattle Dog ancestry may also suffer from a form of NCL resulting from a mutation in the CLN8 gene. This form of NCL is characterized by progressive vision loss starting at a few months of age. This is accompanied by progressive loss of housetraining, decreased responsiveness to voice commands, increased sensitivity to noises, compulsive circling and pacing behavior, anxiety, and a loss of the ability to navigate stairs. Affected dogs become progressively more ataxic and may exhibit periods of trance-like staring behavior. These signs become prominent by about 20 months of age. By about 21 months of age, the disease is accompanied by severe behavioral changes that include aggression, disorientation and ataxia. Seizures occur at about this age and increase in frequency and severity over time. Due to the severity of signs, euthanasia is usually elected by 22 months of age.

Gene: CLN8

Neuronal Ceroid Lipofuscinosis (CLN12 Disease)
  • Disease description: The CLN12 disease that occurs in Australian Cattle Dog is a late-onset form of NCL with onset of neurological signs at approximately 6 years of age. Among these related signs are anxiety, impaired ability to recognize and respond to previously learned commands, increased sensitivity to loud or unexpected sounds, sleep disturbances, inappropriate or persistent vocalization, impaired ability to navigate stairs and to jump up or down from furniture, trembling, seizures, stiffness or weakness, loss of coordination, and impaired vision in both bright and dim light. In addition to these signs, neurological examination findings include hypersensitivity to tactile stimuli, clumsiness, a broad-based stance in the pelvic limbs, mild ataxia, unsteady gait on slippery surfaces, intermittent pacing gait, hopping gait in pelvic limbs while trotting, reduced palpebral reflex and reduced menace response in both eyes, normal pupillary light reflexes in response to bright stimuli, and decreased nasal sensation. Due to the progression in severity of signs, affected dogs are typically euthanized at 7 to 8 years of age.

Gene: ATP13A2

Primary Lens Luxation

Primary lens luxation (PLL) occurs in multiple breeds due to a variety of mutations. PLL is characterized by lens instability in both eyes, although the severity of clinical signs may differ between the 2 eyes. PLL typically goes undetected until the lens becomes severely dislocated in one eye. Dogs typically present with concurrent partial lens displacement of the other eye, which typically progresses into full displacement over a period of weeks to months. The lens often moves anteriorly causing disruption to the pupil and draining mechanism in the eye, which may result in acute glaucoma.

Gene: ADAMTS17

AUSTRALIAN SHEPHERD

Neuronal Ceroid Lipofuscinosis (CLN6 Disease)

The neuronal ceroid lipofuscinosies (NCLs) are progressive hereditary neurological disorders that occur in humans, dogs, cats and other mammals. A form that occurs in Australian Shepherds results from a mutation in the CLN6 gene. Disease signs first become apparent after 16 months of age and include progressive vision impairment, anxiety, circling, and loss of coordination. Affected dogs may also exhibit increased sensitivity to touch and sound, cognitive decline, and difficulty eating and drinking. Due to increasing severity of disease signs, affected dogs may have to be euthanized at about 24 months of age.

Gene: CLN6

Neuronal Ceroid Lipofuscinosis (CLN8 Disease)

In addition to NCL resulting from a mutation in the CLN8 gene, dogs of Australian Shepherd and Australian Cattle Dog ancestry may also suffer from a form of NCL resulting from a mutation in the CLN8 gene. This form of NCL is characterized by progressive vision loss starting at a few months of age. This is accompanied by progressive loss of housetraining, decreased responsiveness to voice commands, increased sensitivity to noises, compulsive circling and pacing behavior, anxiety, and a loss of the ability to navigate stairs. Affected dogs become progressively more ataxic and may exhibit periods of trance-like staring behavior. These signs become prominent by about 20 months of age. By about 21 months of age, the disease is accompanied by severe behavioral changes that include aggression, disorientation and ataxia. Seizures occur at about this age and increase in frequency and severity over time. Due to the severity of signs, euthanasia is usually elected by 22 months of age.

Gene: CLN8

Lysosomal Storage Disease
  • Disease description:  A progressive neurological disorder that occurs in Australian Shepherds first becomes apparent at approximately 5 months of age when it manifests as visual impairment and difficulty navigating stairs. Over the subsequent 4 months affected dogs exhibit grand mal seizures, myoclonic tremors, impaired coordination, difficulty chewing and swallowing food, muscle atrophy that is most pronounced in the pelvic limbs, roached back and wide-based stance, and worsening visual impairment.  Due to the severity of signs, affected dogs are usually euthanized by 10 months of age. The disorder is characterized by accumulation of lysosomal storage bodies in cells throughout the central nervous system.

Gene: To be published.

BASENJI

Fanconi Syndrome

Fanconi syndrome in dogs is characterized by impaired function of the proximal convoluted tubules of the kidneys resulting in reduced reabsorption of water, nutrients and electrolytes from the tubular fluid and their eventual loss in urine. The clinical consequences of this disease include polyuria and polydipsia, dehydration, weight loss and muscle weakness. Most cases progress to renal failure within a few years of the onset of initial clinical signs.

Gene: FAN1

Progressive Retinal Atrophy

Basenjis may exhibit a late adult onset form of progressive retinal atrophy (PRA). Initially, affected individuals lose their vision in dim light and their peripheral vision, resulting in tunnel vision. Many individuals can maintain forward day vision for years as disease progresses. Retinal thinning can typically be detected at 5 years old, and by 7 years of age there is usually reduced blood flow through retinal blood vessels.

Gene: SAG

BASSET HOUND

Mucopolysaccharidosis

Mucopolysaccharidoses type I (MPS I) in Bassett Hounds is a hereditary diseases characterized by defective metabolism of glycosaminoglycans (mucopolysaccharides), which accumulate in cells of various tissues. Clinical signs include growth retardation, joint problems, progressive lameness and visual impairment, caused by corneal clouding.

Gene: IDUA

BERNESE MOUNTAIN DOGS

Degenerative Myelopathy (SOD1-B)

As in many other breeds, Bernese Mountain Dog degenerative myelopathy (DM) is a late-onset disease associated with a mutation in the SOD1 gene. However, the SOD1 mutation in Bernese Mountain Dogs differs from that in other breeds. Dogs with 2 mutated copies of the SOD1 gene are at higher risk for developing DM. As in other breeds, the onset of signs usually occurs at 8 years of age or older. Typically the clinical signs begin with loss of coordination (ataxia) and spastic weakness in the hind limbs and progress over time to paralysis in all limbs. There are no effective treatments. 

Gene: SOD1

BLACK RUSSIAN TERRIER

Polyneuropathy & Juvenile Laryngeal Paralysis

Black Russian Terriers suffering from Polyneuropathy & Juvenile Laryngeal Paralysis present at about 3 months of age with laryngeal paralysis and respiratory distress. Affected dogs also exhibit microphthalmia, cataracts, and miotic pupils. They are typically euthanized by 6 months of age for due to severe dyspnea (shortness of breath).

Gene: RAB3GAP1

BORDER COLLIE

Neuronal Ceroid Lipofuscinosis (CLN5 Disease)

The neuronal ceroid lipofuscinoses (NCLs) are progressive neurodegenerative disorders of which there are multiple forms. The CLN5 form has been identified in Border Collies and several other breeds. Onset of disease signs occurs at approximately 12 to 15 months of age and progresses in severity to the point that euthanasia has been elected at 18 to 28 months of age. Signs include seizures, vision loss, impaired coordination, disorientation, hypersensitivity to auditory and tactile stimuli, ataxia, anxiety, compulsive behaviors, and aggression. These signs are accompanied by progressive global brain atrophy. There are no effective treatments for this disorder.

Gene: CLN5

Primary Lens Luxation (PLL)

As in other breeds, primary lens luxation (PLL) in Border Collies is due to a mutation in the ADAMTS17 gene. PLL is characterized by lens instability in both eyes, although the severity of clinical signs may differ between the 2 eyes. PLL typically goes undetected until the lens becomes severely dislocated in one eye. Dogs typically present with concurrent partial lens displacement of the other eye, which typically progresses into full displacement over a period of weeks to months. The lens often moves anteriorly causing disruption to the pupil and draining mechanism in the eye, which may result in acute glaucoma. If detected early, surgical removal of the lenses may prevent the development of glaucoma.

Gene: ADAMTS17

Glaucoma and Lens Luxation
  • Disease description: In addition to lens luxation due to a mutation in the ADAMTS17 gene, Border Collies may exhibit lens luxation combined with glaucoma due to a mutation in LTBP2. The dislocation of the eye lenses may precede the development of glaucoma, so Border Collies that exhibit lens luxation should be tested for both the ADAMTS17 and LTBP2 mutations. In either case, surgical removal of the dislocated lenses may prevent the development or severity of glaucoma.

Gene: LTBP2

BORDER TERRIER

Spongiform-leukoencephalomyelopathy (Shaking Puppy Syndrome)

Gene: OPA1

CANE CORSO

Neuronal Ceroid Lipofuscinosis (CLN1 Disease)

Cane Coroso’s may suffer from a form of hereditary neuronal ceroid lipofuscinosis (NCL). The NCLs are a group of progressive neurodegenerative disorders with similar signs. The CLN1 form has been identified in Cane Corsos and Dachshunds. In Cane Corsos the onset of signs begins at approximately 8 months of age with progressive visual impairment, ataxia, and lethargy. Due to the progression of sigs, euthanasia has been elected at approximately 10 to 11 months of age.

Gene: PPT1

Dental-skeletal-retinal anomaly (DSRA)
  • Disease description: DSRA in Cane Corsos is characterized by abnormalities in the development and growth of the skeleton and teeth, which are markedly brittle, discolored, or translucent.  The disease also entails progressive retinal degeneration resulting in vision loss.

Gene: MAI3

CATAHOULA LEOPARD DOG

Dermatosparaxis Ehlers-Danlos Syndrome

As in a number of other breeds, Catahoula Leopard Dog Ehlers-Danlos Syndrome (EDS) is a connective tissue disorder that results from a mutation in the ADAMTS2 gene. The disease is characterized by joint hypermobility and loose hyper-elastic skin that is fragile and subject to frequent wounds. A variety of different mutations in the ADAMTS2 gene underlie EDS in other breeds. 

Gene: ADAMTS2

CHIHUAHUA

Neuronal Ceroid Lipofuscinosis (CLN7 Disease)

Chihuahuas with a mutation in the MFSD8 gene suffer form the CLN7 form of neuronal ceroid lipofuscinosis (NCL). This is a progressive neurodegenerative disorder. Neurological signs typically have an onset of 16 to 18 months and include  vision loss, anxiety, ataxia, cognitive impairment, and seizures. These signs are accompanied by diffuse brain atrophy. Due to progression in the severity of signs, affected dogs typically do not survive beyond 24 months of age.

Gene: MFSD8

Primary Lens Luxation

As in other breeds, primary lens luxation (PLL) in Chihuahuas is due to a mutation in the ADAMTS17 gene. PLL is characterized by lens instability in both eyes, although the severity of clinical signs may differ between the 2 eyes. PLL typically goes undetected until the lens becomes severely dislocated in one eye. Dogs typically present with concurrent partial lens displacement of the other eye, which typically progresses into full displacement over a period of weeks to months. The lens often moves anteriorly causing disruption to the pupil and draining mechanism in the eye, which may result in acute glaucoma.

Gene: ADAMTS17

CHINESE CRESTED

Neuronal Ceroid Lipofuscinosis (CLN7 Disease)

Chinese Crested dogs with a mutation in the MFSD8 gene suffer form the CLN7 form of neuronal ceroid lipofuscinosis (NCL) also that also occurs in Chihuahuas. CLN7 disease is a progressive neurodegenerative disorder. Neurological signs typically have an onset of 16 to 18 months and include  vision loss, anxiety, ataxia, cognitive impairment, compulsive behaviors, and seizures. These signs are accompanied by diffuse brain atrophy. Due to progression in the severity of signs, affected dogs typically do not survive beyond 24 months of age.

Gene: MFSD8

Multiple System Degeneration

Multiple System Degeneration in Chinese Crested dogs is a progressive neurological disorder with onset of signs occurring between 9 weeks and 6 months of age. Dogs initially exhibit a mild intention tremor and stiffness in thoracic limb gait, which progresses within 3 to 4 months to severe hypermetric ataxia, spasticity, truncal sway, wide-based stance, delayed postural reactions, and decreased menace response. Dogs eventually become unable to stand and are euthanized by 1 to 2 years of age.

Gene: SERAC1

Primary Lens Luxation

As in other breeds, primary lens luxation (PLL) in Chinese Crested dogs is due to a mutation in the ADAMTS17 gene. PLL is characterized by lens instability in both eyes, although the severity of clinical signs may differ between the 2 eyes. PLL typically goes undetected until the lens becomes severely dislocated in one eye. Dogs typically present with concurrent partial lens displacement of the other eye, which typically progresses into full displacement over a period of weeks to months. The lens often moves anteriorly causing disruption to the pupil and draining mechanism in the eye, which may result in acute glaucoma.

Gene: ADAMTS17

CHINESE FOO DOG

Primary Lens Luxation

As in other breeds, primary lens luxation (PLL) in Chinese Foo dogs is due to a mutation in the ADAMTS17 gene. PLL is characterized by lens instability in both eyes, although the severity of clinical signs may differ between the 2 eyes. PLL typically goes undetected until the lens becomes severely dislocated in one eye. Dogs typically present with concurrent partial lens displacement of the other eye, which typically progresses into full displacement over a period of weeks to months. The lens often moves anteriorly causing disruption to the pupil and draining mechanism in the eye, which may result in acute glaucoma.

Gene: ADAMTS17

CHINESE SHAR-PEI

Lens Luxation & Glaucoma

As in other breeds, primary lens luxation (PLL) in Chinese Shar-Pei dogs is due to a mutation in the ADAMTS17 gene. PLL is characterized by lens instability in both eyes, although the severity of clinical signs may differ between the 2 eyes. PLL typically goes undetected until the lens becomes severely dislocated in one eye. Dogs typically present with concurrent partial lens displacement of the other eye, which typically progresses into full displacement over a period of weeks to months. The lens often moves anteriorly causing disruption to the pupil and draining mechanism in the eye, which may result in acute glaucoma.

Gene: ADAMTS17

CLUMBER SPANIEL

Pyruvate dehydrogenase deficiency

Clumber Spaniels with hereditary deficiency in the enzyme pyruvate dehydrogenase suffer from exercise intolerance and post-exercise collapse accompanied by a build up of lactic acid during exercise. Management includes exercise restriction and a high-fat diet with thiamine and carnitine supplementation. The disease results from a mutation in the PDP1 gene.

Gene: PDP1

COTON DE TULEAR

Neonatal Cerebellar Ataxia (Bandera’s syndrome)

Numerous hereditary disorders in dogs are characterized by ataxia (uncoordinated movements). In Coton De Telear’s a variant in the GRM1 gene is associated with a form of ataxia that manifests shortly after birth. Most affected puppies are unable to stand or walk without assistance and use swimming-like movements to propel themselves toward a goal. They may also exhibit fine vertical tremors at rest.  Due to the severity of signs, affected puppies usually need to be euthanized.

Gene: GRM1

DACHSHUND

Neuronal Ceroid Lipofuscinosis (CLN2 Disease)

The neuronal ceroid lipofuscinoses (NCLs) are lysosomal storage diseases characterized by intracellular accumulation of autofluorescent granules and progressive degeneration of the central nervous system. Multiple forms of NCL occur in dogs, humans, and other species. Among these is CLN2 disease that occurs in Dachshunds. Signs first become apparent at approximately 4 months of age and include visual impairment, head tremors, decreased menace response, myoclonus, ataxia, and cognitive decline. Late in the disease progression, dogs may suffer from grand mal seizures. Due to the progressively increasing severity of signs, most affected dogs are euthanized between 10 and 11 months of age.

Gene: TPP1

Retinal Atrophy – Cone Rod Dystrophy

There are many forms of retinal atrophy in dogs that are characterized by impaired vision. While these diseases may have subtle differences in clinical signs and in the appearance of retinal changes, genetic testing should be performed for confirmation of a diagnosis when possible. A form of hereditary retinal degeneration that occurs in Dachshunds is associated with a variant in the RPGRIP1 gene. This disorder is characterized by changes in the granular appearance of the tapetal fundus followed by generalized tapetal hyperreflectivity and retinal vascular attenuation, starting at approximately 6 months of age. Electroretinogram responses are usually normal until the dogs are at least 10 weeks old, but then decline in amplitude and are usually unrecordable by about 9 months of age.

Gene: RPGRIP1

Glycogen Storage Disease

Dachshunds with a mutation in the PFKM gene usually present with muscle cramps and exercise intolerance. The disorder resulting from this mutation may also entail hemolytic crises with hemoglobinuria and bilirubinuria after excessive excitement, exercise, or hyperthermia. During a such a crisis, the dog can develop severe anemia, icterus, fever, lethargy, and anorexia. These signs usually resolve within several days. Muscle wasting, hepatosplenomegaly, and increased total body iron stores have also been reported in affected dogs. Dachshunds with this disorder can have a normal lifespan.

Gene: PFKM

DALMATIAN

Leukodystrophy/Lysosomal Storage Disease

A rare adult-onset disorder in Dalmatians is characterized by anxiety, pacing and circling, hypersensitivity, cognitive decline, sleep disturbance, loss of coordination, loss of control over urination and defecation, and visual impairment. Signs first become apparent when dogs are approximately 18 months old and progress slowly. The progression of signs eventually becomes severe enough that euthanasia has been elected when the dogs reach 7 to 8 years of age. The disease is accompanied by accumulation of autofluorescent lysosomal storage bodies similar to those seen in some of the neuronal ceroid lipofuscinoses and by pronounced abnormalities in the myelin surrounding nerves.

Gene: CNP

DOBERMAN PINSCHER

Dancing Doberman Syndrome
  • Disease description:

Dancing Doberman disease is a disorder of the Doberman Pinscher with varying age of onset from a few months to middle age.  This disease is characterized by intermittent flexion of one or both pelvic limbs while standing.  Signs usually begin in a single limb.  The contralateral pelvic limb may become affected.  Affected dogs develop weakness and atrophy of the distal pelvic limb musculature and may prefer to sit.  The disease insidiously progresses over several years.  Chronically, affected dogs may develop postural reaction deficits. 

Gene: Unpublished discovery

ENGLISH COCKER SPANIEL

Adult-onset Neuropathy
  • Disease description:

Adult-onset neuropathy of English Cocker Spaniels (AONECS) is a progressive weakness due to a neuropathy is an autosomal recessive, hereditary disorder in English Cocker Spaniels.  Signs typically begin between 7.5 and 9 years of age and consist first of an uncoordinated gait or wobbling in the hind limbs.  The stance in the hind limbs is wide-base and the hocks will drop lower to the ground.  The weakness eventually progresses to also involve the front limbs.  When affected dogs become nonambulatory in all limbs, they may develop difficulty in swallowing.  The neurologic signs progress over 3 to 4 years, more slowly than those of degenerative myelopathy.

Gene: Not yet published.

ENGLISH SPRINGER SPANIEL

Progressive Retinal Atrophy (PRA)

   English Springer Spaniels may suffer from progressive degeneration of the retina with accompanying visual impairment resulting from a mutation in the RPGRIP1 gene. Ophthalmoscopic signs, including changes in the granular appearance of the tapetal fundus followed by generalized tapetal hyperreflectivity and retinal vascular attenuation, can be detected as early as 6 months of age. The electroretinogram amplitudes of affected dogs are initially normal but are greatly diminished or unrecordable extinguished by 9 months of age.

Gene: RPGRIP1

Progressive Retinal Atrophy (PRA)
  • Disease description:

English Springer Spaniels may also suffer from a later-onset form of PRA that causes progressive loss of vision. If your English Springer Spaniel is exhibiting apparent visual impairment, it is advisable to test for both genetic variants associated with PRA in this breed.

Gene: Not yet published.

Dyserythropoietic Anemia & Myopathy Syndrome (DAMS)
  • Disease description:

Dyserythropoietic Anemia and Myopathy Syndrome (DAMS) in English Springer Spaniels is an early onset disorder characterized by impaired opening of the mouth, difficulty swallowing, muscle atrophy, progressive weakness, cardiomyopathy, and anemia. Affected dogs have low activity levels and ability to exercise relative to unaffected dogs of the same breed. Other clinical signs that may appear include difficulty in lapping water, aspiration pneumonia, seizures, and chronic diarrhea. Due to the progression of signs and poor quality of life affected dogs are usually euthanized.

Gene: Not yet published.

Glycogen Storage Disease/Phosphofructokinase Deficiency

English Springer Spaniels with a mutation in the PFKM gene exhibit muscle cramps and exercise intolerance accompanied by a mild increase in blood creatine kinase levels. Affected dogs can also suffer from hemolytic crisis with hemoglobinuria and bilirubinuria after excessive excitement, exercise, or hyperthermia. This can result in severe anemia, icterus, fever, lethargy, and anorexia. This anemia usually resolves within several days. Affected animals have a normal life span, usually but persistent bilirubinuria and reticulocytosis. In some cases dogs may also exhibit muscle wasting, hepatosplenomegaly, and increased total body iron stores.

Gene: PFKM

ENGLISH SETTER

Neuronal Ceroid Lipofuscinosis (CLN8 Disease)

English Setters with a progressive neurodegenerative disorder characterized as a form of neuronal ceroid lipofuscinosis (NCL) were discovered by Dr. Nils Koppang in Norway in the late 1950s.  The dogs were bred for NCL research for many years and in 2014 the causative variant was identified in the CLN8 gene. Testing since 2014 has not identified any dogs with the risk variant outside of the research colony, which no longer exists. However, this test in still offered for English Setters that present with signs consistent with CLN8 disease.  These signs have an onset of 12 to 14 months and include progressive visual impairment, cognitive decline, compulsive circling, ataxia, and limb paralysis. Affected dogs suffer from seizures starting at 17 to 24 months of age that become progressively more severe and frequent. Death or euthanasia due to the severity of signs occurs by 27 months of age.

Gene: CLN8

FIELD SPANIEL

Adult-onset Neuropathy
  • Disease description:

Adult-onset neuropathy in Field Spaniels is similar to the English Cocker Spaniel disorder. The disease is characterized by progressive weakness due to neuropathy.  Signs typically begin between 7.5 and 9 years of age and consist first of an uncoordinated gait or wobbling in the hind limbs.  The stance in the hind limbs is wide-base and the hocks will drop lower to the ground.  The weakness eventually progresses to also involve the front limbs.  When affected dogs become nonambulatory in all limbs, they may develop difficulty in swallowing.  The neurologic signs progress over 3 to 4 years, more slowly than those of degenerative myelopathy.

Gene: Not yet published.

GERMAN SHORTHAIRED POINTER

Neuronal Ceroid Lipofuscinosis (CLN8 Disease)

The CLN8 form of neuronal ceroid lipofuscinosis (NCL) has been identified in German Shorthiared Points. Onset of signs occurs at approximately 11 months of age with loss of coordination that grows progressively worse over time. Affected dogs become clumsy, ataxic, and bump into stationary objects, walls, and people in a familiar environment. By 15 months of age signs include compulsive circling and tongue movements, jaw chattering, and confusion caused by familiar sounds. From that time forward there is a progressive decline in the ability to understand and respond to previously learned commands and other behavioral cues and regression in previously learned housetraining. At 17 months of age visual impairment in both bright and dim light becomes apparent, and by 18 months there is hesitancy to climb up or down stairs. Progressive anxiety develops between 18 and 21 months of age. Due to the increasing severity of signs, affected dogs are euthanized before 24 months of age.

Gene: CLN8

GOLDEN RETRIEVER

Neuronal Ceroid Lipofuscinosis (CLN5 Disease)

The neuronal ceroid lipofuscinoses (NCLs) are progressive neurodegenerative disorders that occur in many dog breeds. There are multiple forms of NCL associated with sequence variants in different genes. A form that occurs in Golden Retrievers results from a mutation in the CLN5 gene. The neurological disease signs first become apparent at approximately 13 months of age, followed by gradual increases in severity. The first sign is loss of coordination causing the dogs to bump into objects and have difficulty climbing stairs. The impairments in coordination are particularly evident when the dogs are excited. The loss of coordination progresses with age and eventually becomes apparent even when the dogs are calm. Also among the early neurological signs are anxiety and agitation, accompanied by long periods of constant pacing and circling starting at approximately 15 months of age. At about the same age the affected dogs lose the ability to recognize or respond to previously learned commands and behaviors and begin to exhibit compulsive behavior such as fixation on a toy. Mild seizure-like activity such as snapping at the air (fly biting) and gum smacking begin as early as 15 months of age. Seizure activity becomes progressively more severe and begins to involve the whole body after about 18 months of age with some episodes lasting for up to an hour. In addition, trance-like behavior starts at approximately 18 months of age. Visual impairment in both bright and dim light become apparent by 18 months of age and worsens over time. In the later stages of the disease the affected dogs may become aggressive toward people. Due to the progression of signs, affected dogs are usually euthanized by 2 years of age.

Gene: CLN5

HAVANESE

Neonatal Cerebellar Ataxia (Bandera’s Syndrome)

The signs of Bandera’s Syndrome become evident in puppies as early as 2 weeks of age and include head titubation, intention tremors, and severe gait, stance, and ocular ataxia. Most affected puppies are unable to stand and use propulsive movements (‘‘swimming’’) for goal-oriented activities. They frequently fall to lateral recumbency with subsequent decerebellate posturing and paddling. Ocular motor abnormalities include fine vertical tremors at rest and saccadic dysmetria. The condition is nonprogressive at least until 4 months of age.

Gene: GRM1

JACK RUSSELL TERRIER

Neonatal Ataxia
  • Disease description: Early-onset cerebellar ataxia (neonatal ataxia) becomes apparent at <2 weeks of age when Russell Group Terrier (Includes Jack Russell and Parson Russell Terriers) puppies begin to walk.  Posture evaluation reveals prominent axial musculature, intention tremors, wide-based stance and increased extensor tone in all limbs.  Gait evaluation shows severe cerebellar ataxia and dysmetria (hyper- and hypometria).  Decreased postural reactions were observed in all limbs.  Limb spasticity progressed to a tiptoed stance of the digits.  A dancing gait, hypometria  in all limbs, decrease in forward ambulation and greater tendency to fall are observed as the disorder progressed.  Spinal reflexes remain intact; however,  joint flexion of distal limbs decreased as limb spasticity increased in severity.  Ocular examination reveals intact vision with absent menace response and persistent, fine, oscillating eye movements with positional slow vertical and rotatory nystagmus.  Signs of spasticity in the facial muscles are evident by muscle contracture upon excitement.  The genetic inheritance pattern is autosomal recessive.  Histopathology shows a cerebellar granuloprival degeneration.       

Gene: Publication in preparation.

Spinocerebellar Ataxia

A number of genetically distinct forms of hereditary ataxia occur in Russell group terriers. The CAPN1 form manifests as a slowly progressing pelvic limb incoordination, with an onset usually between 2 and 9 months of age. As the disease progresses affected dogs exhibit a characteristic “dancing” or “prancing” gait, especially affecting the pelvic limbs.

Gene: CAPN1

Spinocerebellar Ataxia

In addition to hereditary spinocerebellar ataxia resulting from a variant in CAPN1, terriers in the Russel group have been found to exhibit ataxia with myokymia (muscle twitches), seizures, or both myokymia and seizures with an onset of between 2 and 6 months of age.

Gene: KCNJ10

JAPANESE CHIN
Gangliosidosis, GM2
  • Disease description:

Japanese Chin dogs with GM2 gangliosidosis presented at 15 and 18 months of age with progressive cerebellar ataxia, spastic, hypermetric postural reactions, obtunded mental status, and visual impairment. Affected dogs are typically humanely euthanized at the owners’ request by about 2 years of age due to progression of the signs.

Gene: HEXB

KERRY BLUE TERRIER
Multiple system degeneration

Puppies with a variant in SERAC1 that results in multiple system degeneration first exhibit signs between 4 and 6 months of age. Puppies initially present a mild intention tremor and stiffness in thoracic limb gait, which progresses within 3 to 4 months to severe hypermetric ataxia, spasticity, truncal sway, wide-based stance, delayed postural reactions, and decreased menace response. Signs ultimately progress to akinesia and inability to stand resulting in euthanasia being elected by 1 to 2 years of age.

Gene: SERAC1

LANCASHIRE HEELER
Primary Lens Luxation

As in a number of other breeds, Lancashire Heelers can suffer from lens luxation due to a variant in the ADAMTS17 gene. Primary lens luxation (PLL) is characterized by dislocation of the eye lens in both eyes, although the severity of the dislocation may differ between the 2 eyes. PLL is typically first detected when the lens displaces at least partially in one eye. The initial partial displacement of the lenses usually progresses to full displacement over a period of weeks to months. The displaced lens often moves forward causing disruption to the pupil and draining mechanism in the eye, leading to acute glaucoma.

Gene: ADAMTS17

MIXED BREEDS
Methaemoglobinaemia

Methemoglobinemia associated with a mutation in the CYB5R3 gene occurs in numerous breeds.  Then most recognized sign is exercise intolerance that is accompanied by tachypnea (rapid shallow breathing) and cyanosis (bluish skin coloration due to low blood oxygen levels).

Gene: CYB5R3

Primary Lens Luxation

Primary lens luxation (PLL) due to variants in the ADAMTS17 gene occurs in a number of purebred dogs as well as in mixed breed dogs. The disorder is characterized by dislocation of the eye lens in both eyes, although the severity of the dislocation may differ between the 2 eyes. PLL is typically first detected when the lens displaces at least partially in one eye. The initial partial displacement of the lenses usually progresses to full displacement over a period of weeks to months. The displaced lens often moves forward causing disruption to the pupil and draining mechanism in the eye, leading to acute glaucoma.

Gene: ADAMTS17

NOVA SCOTIA DUCK TOLLING RETRIEVER
Degenerative encephalopathy
  • Disease description:

Nova Scotia Duck Tolling Retrievers suffering from degenerative encephalopathy exhibit progressive neurological dysfunction starting at four months to five years of age. The most consistent clinical sign is profound sleep derangement characterized by frequent episodes of marked involuntary movements during sleep. The duration of episodes typically ranged from a few seconds to 15-30 minutes, although some owners report occasional episodes lasting longer than one hour. The episodes were reported to occur up to 10 times in a sleep period. The dogs make running movements, sometimes lifting their heads and frequently vocalize. Some owners also report that the dog would be difficult to awaken from sleep. The dogs learned basic obedience but had difficulty with advanced training. Affected dogs showed increased anxiety and heightened awareness, which sometimes manifested as noise phobia or obsessive-compulsive activity. With progression of the disease, some dogs began having aggressive interactions, or lacked self-control, with other dogs and sometimes their owners. Some owners reported abnormal swimming motion (the dog adopting a vertical position in water), while others felt this was part of normal learning to swim. The owners also reported reduced tail movement and gait abnormalities. One dog was reported to have been urinary and fecally incontinent. Affected dogs are frequently euthanized due to progressive debilitating behavior anomalies.

Gene: Publication in preparation.

PARSON RUSSELL TERRIER
Neonatal Ataxia
  • Disease description: Early-onset cerebellar ataxia (neonatal ataxia) becomes apparent at <2 weeks of age when Russell Group Terrier (Includes Jack Russell and Parson Russell Terriers) puppies begin to walk.  Posture evaluation reveals prominent axial musculature, intention tremors, wide-based stance and increased extensor tone in all limbs.  Gait evaluation shows severe cerebellar ataxia and dysmetria (hyper- and hypometria).  Decreased postural reactions were observed in all limbs.  Limb spasticity progressed to a tiptoed stance of the digits.  A dancing gait, hypometria  in all limbs, decrease in forward ambulation and greater tendency to fall are observed as the disorder progressed.  Spinal reflexes remain intact; however,  joint flexion of distal limbs decreased as limb spasticity increased in severity.  Ocular examination reveals intact vision with absent menace response and persistent, fine, oscillating eye movements with positional slow vertical and rotatory nystagmus.  Signs of spasticity in the facial muscles are evident by muscle contracture upon excitement.  The genetic inheritance pattern is autosomal recessive.  Histopathology shows a cerebellar granuloprival degeneration.

Gene: Publication in preparation.

Spinocerebellar Ataxia

A number of genetically distinct forms of hereditary ataxia occur in Russell group terriers. The CAPN1 form manifests as a slowly progressing pelvic limb incoordination, with an onset usually between 2 and 9 months of age. As the disease progresses affected dogs exhibit a characteristic “dancing” or “prancing” gait, especially affecting the pelvic limbs.

Gene: CAPN1

Spinocerebellar Ataxia

In addition to hereditary spinocerebellar ataxia resulting from a variant in CAPN1, terriers in the Russel group have been found to exhibit ataxia with myokymia (muscle twitches), seizures, or both myokymia and seizures with an onset of between 2 and 6 months of age.

Gene: KCNJ10

PIT BULL TERRIER (OR AMERICAN PIT BULL TERRIER)
Methaemoglobinaemia

Methemoglobinemia associated with a mutation in the CYB5R3 gene occurs in numerous breeds.  Then most recognized sign is exercise intolerance that is accompanied by tachypnea (rapid shallow breathing) and cyanosis (bluish skin coloration due to low blood oxygen levels).

Gene: CYB5R3v

Lysosomal Storage Disease/Neuronal Ceroid Lipofuscinosis

Many Pitbull Terriers suffer from a late-onset progressive neurological disorder characterized initially by subtle signs of impaired balance and ataxia but progressing slowly to eventually include cognitive decline, generalized motor impairment and seizures. Onset is typically between 3 and 6 years of age, with variable rates of progression. Euthanasia due to the severity of signs has been elected for dogs as young as 7 years, whereas other affected dogs live past 10 years of age. The disease results from a mutation in the ARSG gene that encodes the lysosomal enzyme arylsulfatase G. The canine disease has been classified as a form of neuronal ceroid lipofuscinosis (NCL), although human subjects with ARSG mutations do not develop NCL-like neurological signs. Based on our DNA testing, the disease appears to be quite common in American Staffordshire Terriers and Pitbull Terriers as well as in mixed breed dogs with Pitbull ancestry.

Gene: ARSG

POODLE (STANDARD)
Neonatal encephalopathy with seizures

Standard Poodle puppies with neonatal encephalopathy and seizures are small at birth and do not develop normally. They initially nurse poorly, but nursing improves over several days after birth. At approximately 3 weeks of age affected puppies exhibit weakness, ataxia, whole-body tremors, wide-based stance with increased extensor tone, and axial muscle weakness with neck ventroflexion. Affected pups do not interact with the dam or littermates and have slow responses to external stimuli. At approximately 3 to 6 weeks of age, affected puppies develop generalized clonic-tonic seizures that quickly become refractory to treatment. They become laterally recumbent with extensor rigidity and opisthotonus, and usually die or are euthanized before 7 weeks of age.

Gene: ATF2

PUG
Primary Lens Luxation

Primary lens luxation (PLL) due to variants in the ADAMTS17 gene occurs in a number of dog breeds, including Pugs. The disorder is characterized by dislocation of the eye lens in both eyes, although the severity of the dislocation may differ between the 2 eyes. PLL is typically first detected when the lens displaces at least partially in one eye. The initial partial displacement of the lenses usually progresses to full displacement over a period of weeks to months. The displaced lens often moves forward causing disruption to the pupil and draining mechanism in the eye, leading to acute glaucoma.

Gene: ADAMTS17

PUMI
Primary Lens Luxation

Primary lens luxation (PLL) due to variants in the ADAMTS17 gene occurs in a number of dog breeds, including Pmis. The disorder is characterized by dislocation of the eye lens in both eyes, although the severity of the dislocation may differ between the 2 eyes. PLL is typically first detected when the lens displaces at least partially in one eye. The initial partial displacement of the lenses usually progresses to full displacement over a period of weeks to months. The displaced lens often moves forward causing disruption to the pupil and draining mechanism in the eye, leading to acute glaucoma.

Gene: ADAMTS17

RHODESIAN RIDGEBACK
Sialidosis
  • Disease description:

Gene: NEU1

ROTTWEILER
Polyneuropathy & Juvenile Laryngeal Paralysis

Starting at about 5 to 6 months of age Rottweilers with polyneuropathy & juvenile laryngeal paralysis exhibit an altered voice due to laryngeal paralysis, regurgitation, and gait abnormalities progressing to a severe ataxia. Affected dogs have bilateral microphthalmia, small pupils, and lenses with cataract. Some affected dogs additionally exhibit strabismus and/or persistent pupillary membranes. Dogs are typically euthanized between 6 and 16 months of age due to severe dyspnea.

Gene: RAB3GAP1

RUSSELL TERRIER
Neonatal Ataxia
  • Disease description: Early-onset cerebellar ataxia (neonatal ataxia) becomes apparent at <2 weeks of age when Russell Group Terrier (Includes Jack Russell and Parson Russell Terriers) puppies begin to walk.  Posture evaluation reveals prominent axial musculature, intention tremors, wide-based stance and increased extensor tone in all limbs.  Gait evaluation shows severe cerebellar ataxia and dysmetria (hyper- and hypometria).  Decreased postural reactions were observed in all limbs.  Limb spasticity progressed to a tiptoed stance of the digits.  A dancing gait, hypometria  in all limbs, decrease in forward ambulation and greater tendency to fall are observed as the disorder progressed.  Spinal reflexes remain intact; however,  joint flexion of distal limbs decreased as limb spasticity increased in severity.  Ocular examination reveals intact vision with absent menace response and persistent, fine, oscillating eye movements with positional slow vertical and rotatory nystagmus.  Signs of spasticity in the facial muscles are evident by muscle contracture upon excitement.  The genetic inheritance pattern is autosomal recessive.  Histopathology shows a cerebellar granuloprival degeneration.

Gene: Publication in preparation.

Spinocerebellar Ataxia

A number of genetically distinct forms of hereditary ataxia occur in Russell group terriers. The CAPN1 form manifests as a slowly progressing pelvic limb incoordination, with an onset usually between 2 and 9 months of age. As the disease progresses affected dogs exhibit a characteristic “dancing” or “prancing” gait, especially affecting the pelvic limbs.

Gene: CAPN1

Spinocerebellar Ataxia

In addition to hereditary spinocerebellar ataxia resulting from a variant in CAPN1, terriers in the Russel group have been found to exhibit ataxia with myokymia (muscle twitches), seizures, or both myokymia and seizures with an onset of between 2 and 6 months of age.

Gene: KCNJ10

SCHNAUZER, STANDARD AND GIANT
Dilated Cardiomyopathy

Standard and Giant Schnauzers with a variant in the RBM20 gene suffer from left-sided congestive heart failure with a median age of onset of 1.5 years in males and 2.4 years in females. The median survival time after diagnosis of congestive heart failure was 13 days in males and 62 days in females.

Gene: RBM20

SHIBA INU
GM2 Gangliosidosis

Shiba Inus with GM2 Gangliosidosis exhibit progressive neurologic signs starting with generalized tremors and altered tail carriage (tail down) when approximately12 months of age. The tremors become progressively more severe and marked cerebellar ataxia, spastic tetraparesis, anxiety, decreased appetite, decreased responsiveness to verbal commands, trance-like behavior, loss of ability to climb up and down stairs, and impaired vision develop. Because of the progression of neurologic signs, affected dogs are usually euthanized before 2 years of age.

Gene: HEXB

SOFT COATED WHEATEN TERRIER
Paroxysmal dyskinesia

Paroxysmal dyskinesia in Soft Coated Wheaton Terriers is characterized by episodes of involuntary movements. The median reported at onset of these episodes was 2.5 years. Episode frequency ranged from one episode every few days, to greater than 10 per day. Episode duration ranged from several minutes up to greater than 4 hours. No involuntary movements were observed when the dogs were sleeping. In some cases stress, excitement, or loud noises precipitated some episodes, but a clear trigger was not apparent in most instances. The dogs remained alert and responsive during the episodes, but they could not be distracted out of the episode. Typical episodes consist of rapid flexion and extension of one or both pelvic limbs. Most frequently, the flexion alternated irregularly between limbs but sometimes both pelvic limbs were off the ground simultaneously. Episodes often began with one limb or one side was more severely affected. During a mild dyskinesia episode, some dogs repeatedly held one pelvic limb in flexion while walking which resembled a lameness. During more severe episodes, the thoracic limbs also were asymmetrically involved and the dogs appeared anxious and panted. The dogs often developed a kyphotic or less commonly a scoliotic posture, and some episodes consisted of increased extension of the pelvic limbs. Except during the most severe episodes, the dogs are able to stand and walk. Sometimes, however, they have difficulty moving forward and would walk backwards or sideways.

Gene: PIGN

STAFFORDSHIRE BULL TERRIER
L-2-hydroxyglutaricacidemia

The onset of the disease occurs predominantly in dogs at approximately a year of age, although it may not be recognized until affected dogs are older.  Typically the first signs recognized by owners are gait/postural abnormalities.  These abnormalities may include a wide-based posture, paresis, hypermetria, kyphosis, ataxia, and most commonly stiffness and muscle cramping of all four limbs. Affected dogs may also suffer from seizures and muscle tremors.

Gene: L2HGDH

SUSSEX SPANIEL
Pyruvate dehydrogenase deficiency

Dogs with pyruvate dehydrogenase deficiency exhibit exercise intolerance, lactic acidosis, and post-exercise collapse. Management includes exercise restriction and a high-fat diet with thiamine and carnitine supplementation.

Gene: PDP1

TERRIERS (ALL)
Primary Lens Luxation

Many Terrier breeds can suffer from lens luxation due to a variant in the ADAMTS17 gene. Primary lens luxation (PLL) is characterized by dislocation of the eye lens in both eyes, although the severity of the dislocation may differ between the 2 eyes. PLL is typically first detected when the lens displaces at least partially in one eye. The initial partial displacement of the lenses usually progresses to full displacement over a period of weeks to months. The displaced lens often moves forward causing disruption to the pupil and draining mechanism in the eye, leading to acute glaucoma.

Gene: ADAMTS17

TIBETAN TERRIER
Neuronal Ceroid Lipofuscinosis (CLN12 Disease)

Tibetan Terriers can suffer from a late-onset form of neuronal ceroid lipofuscinosis (CLN12 disease) due to a variant in the ATP13A2 gene. Behavioral signs usually appear around 4 to 6 years of age and include cognitive decline, cerebellar ataxia, dementia, seizures, nervousness, aggressiveness, loss of training, hypersensitivity to stimuli, loss of coordination, tremors, and retinal degeneration associated with moderate visual impairment in low light but good visual acuity in bright light.

Gene: ATP13A2

Primary Lens Luxation

As in a number of other breeds, Tibetan Terriers can suffer from lens luxation due to a variant in the ADAMTS17 gene. Primary lens luxation (PLL) is characterized by dislocation of the eye lens in both eyes, although the severity of the dislocation may differ between the 2 eyes. PLL is typically first detected when the lens displaces at least partially in one eye. The initial partial displacement of the lenses usually progresses to full displacement over a period of weeks to months. The displaced lens often moves forward causing disruption to the pupil and draining mechanism in the eye, leading

Gene: ADAMTS17

TOY FOX TERRIER
Primary Lens Luxation

As in a number of other breeds, Toy Fox Terriers can suffer from lens luxation due to a variant in the ADAMTS17 gene. Primary lens luxation (PLL) is characterized by dislocation of the eye lens in both eyes, although the severity of the dislocation may differ between the 2 eyes. PLL is typically first detected when the lens displaces at least partially in one eye. The initial partial displacement of the lenses usually progresses to full displacement over a period of weeks to months. The displaced lens often moves forward causing disruption to the pupil and draining mechanism in the eye, leading to acute glaucoma.

Gene: ADAMTS17

VOLPINO ITALIANO
Primary Lens Luxation

As in a number of other breeds, Volpino Italianos can suffer from lens luxation due to a variant in the ADAMTS17 gene. Primary lens luxation (PLL) is characterized by dislocation of the eye lens in both eyes, although the severity of the dislocation may differ between the 2 eyes. PLL is typically first detected when the lens displaces at least partially in one eye. The initial partial displacement of the lenses usually progresses to full displacement over a period of weeks to months. The displaced lens often moves forward causing disruption to the pupil and draining mechanism in the eye, leading to acute glaucoma.

Gene: ADAMTS17

WEIMARANER
Leukodystrophy/Lysosomal Storage Disease

A progressive neurological disorder in a Weimaraner was associated with a missense variant in the CNP gene. The disease is characterized by fecal incontinence, lethargy, moderate paraparesis, proprioceptive pelvic limb ataxia, falling, cognitive decline, incoordination, decreased interest in food, changes in posture, and episodes of trance-like behavior.  Signs first became apparent at the age of 4 years, 10 months and progressed in severity until euthanasia was elected at 6 years, 7 months of age. Magnetic resonance imaging showed generalized brain atrophy with areas of white matter pathology. The disease was accompanied by pronounced structural abnormalities in myelin throughout the central nervous system and by the intracellular accumulation of autofluorescent lysosomal storage bodies.

Gene: CNP

YORKSHIRE TERRIER
L-2-hydroxyglutaricacidemia

Yorkshire Terriers with L-2-hydroxyglutaricacidemia present with episodes of hyperactivity and aggressive behavior at 6 to 8 months of age. The episodes may last for about 40 minutes with behavior being normal between episodes. The frequency of the episodes decreased when dogs were placed on a commercial protein restricted diet and phenobarbital was administered.

Gene: L2HGDH