Genetic Disorders

CANINE GENETIC DISORDERS

–KNOWN TO AFFECT–

BERNESE MOUNTAINS DOGS

(Based primarily on information from Control of Canine Genetic Diseases by Dr. George A. Padgett)

The following list describes a number of inherited disorders, which are documented as affecting Bernese Mountain Dogs. Some of these conditions are rare in occurrence, others are relatively common. These diseases range in severity from what may be considered cosmetic in nature, to those which are crippling or life-threatening. They are presented in alphabetical order by disease category and not prioritized in any way. Research has indicated that these disorders are genetically transmitted; however, in some instances, the same condition may also have environmental causes, such as trauma, nutrition or other external factors. Unless proven to be otherwise, the causative factor should be considered to be genetics.

“If people tell you their dogs have never produced a defect, their dogs have probably produced only one litter, they don’t follow up on their puppies or what is most likely the case, they are being less than truthful.”
— Dr. George A. Padgett, DVM —

Digestive System

Gastric Dilatation-Vovulus (Bloat & Gastric Torsion)

Distension and twisting of the stomach. Without immediate treatment, death is common.

Mode of Inheritance – Undetermined / Age at Onset < 7 years - Megaesophagus Condition in which the oesophagus is enlarged or dilated. Usually dogs with this condition regurgitate food and water. Mode of Inheritance - Undetermined / Age at Onset < 6 months Behavioural Disorders Excessive Aggressiveness Extremely assertive or forceful with other dogs and people. May attack or bite without reasonable provocation. Mode of Inheritance - Undetermined / Age at Onset < 3 years - Rage Syndrome Sudden unprovoked and explosive aggression directed at people or objects. More common in males. Mode of Inheritance - Undetermined / Age at Onset <3 years Cancer Histiocytosis (Malignant Histiocytosis, Systemic Histiocytosis) A proliferation of nodules in or under the skin or ulcers on any part of the body, with metastatic lesions in the lungs and other organs. Mode of Inheritance - Polygenic / Age at Onset < 7 years - Mastocytoma (Mast Cell Tumor) Masses in the skin and subcutaneous tissue. Lesions may ulcerate or spread and metastasize to other parts of the body. Mode of Inheritance - Polygenic / Age at Onset < 7 years Endocrine Hypothyroidism An autoimmune destruction of the thyroid gland. Mode of Inheritance - Undetermined / Age at Onset < 2 years - Hypoadrenocorticism (Addison's Disease) Autoimmune or other causes of destruction of the adrenal glands resulting in a deficiency in production of corticosteroids. Mode of Inheritance - Undetermined / Age at Onset < 5 years Blood and Lymphatic Dysfibrinogenemia (Factor I Deficiency) A rare deficiency of a clotting factor (fibrinogen), which causes excessive bleeding. Mode of Inheritance - Recessive / Age at Onset < 6 months - Von Willebrand's disease (vWD) (Type I vWD) A common inherited bleeding disorder caused by a lack of von Willebrand factor (vWF), which plays an essential role in the blood clotting process. Mode of Inheritance - autosomal recessive trait with variable penetrance / Age at Onset < 6 months Heart and Vascular Mitral Valve Defect (MVD, Mitral Stenosis) Abnormalty of the mitral valve of the heart. An excess of valvular tissue that limits proper valve movement. Mode of Inheritance - Undetermined / Age at Onset < 1 year - Patent Ductus Arteriosus (PDA) Failure of the vessel remnant joining the aorta and pulmonary artery to close properly at birth, thereby shunting blood away from the lungs. Mode of Inheritance - Polygenic / Age at Onset birth - Subaortic Stenosis (SAS) A tightening of the outflow opening for blood to go from the heart into the aorta. Causes murmurs, weakness, and sudden death. Mode of Inheritance - Autosomal Dominate or Polygenic / Age at Onset < 1 year - Tricuspid Value Dysplasia (TVD) Malformation of the tricuspid valve results in regurgitation of blood back into the atrium. Symptoms include cardiac murmur, exercise intolerance and right-sided congestive heart failure. Mode of Inheritance - Undetermined / Age at Onset < 1 year Immune System Atopic dermatitis A skin disease caused by a dog's reaction to an inhalant allergy. Mode of Inheritance - Undetermined / Age at Onset < 1 year - Autoimmune Hemolytic Anemia (AIHA) The immune system attacks its own red blood cells, causing severe anemia and possibly death. Mode of Inheritance - Undetermined / Age at Onset < 4 years - Systemic Lupus Erythematosus (SLE) An autoimmune disease where antibodies form against the nuclear protein of cells. Characterized by skin lesions as well as other organ dysfunctions and blood abnormalities Mode of Inheritance - Undetermined / Age at Onset < 9 years Hair and Skin Color Dilution Alopecia (CDA) Color Mutant Alopecia (CMA) A form of follicular dysplasia (FD) symptoms include bilateral balding, hair loss in areas covered by pigmented hair, while the nonpigmented or lightly pigmented areas are not affected. Mode of Inheritance - Recessive / Age at Onset < 6 months - Pemphigus Foliaceous Skin disease caused by autoimmune destruction of tissues. Lesions usually begin on the face and ears, then spread and may be generalized. In rare cases only the footpads are involved. Mode of Inheritance - Undetermined / Age at Onset < 4 years - Primary Seborrhea Skin disease with excess scaling of the skin and often an excess of sebum (oil-like substance) and odor. Mode of Inheritance - Undetermined / Age at Onset < 1 year - Sebaceous Adenitis (SA) A disease of sebaceous (sweat) skin glands characterized by reactive tissue growth and autoimmune destruction of the sebaceous glands. Hair loss occurs and is poorly responsive to treatment. Mode of Inheritance - Undetermined / Age at Onset < 1 year - Snow Nose (Nasal Hypopigmentation) A decrease in pigmentation of the nose, usually during winter. Mode of Inheritance - Undetermined / Age at Onset < 1 year - Umbilical Hernia A break in the abdominal muscle wall at the point where the umbilical cord enters the body. May contain abdominal viscera and sometimes regresses spontaneously. Mode of Inheritance - Recessive or Polygenic / Age at Onset < 6 months Liver Diseases Chronic Active Hepatitis Chronic Canine Inflammatory Hepatic Disease (CCIHD) A slow, progressive inflammatory disease of the liver, cirrhosis of the liver results. Mode of Inheritance - Undetermined / Age at Onset < 5 years - Hepatic Portosystemic Shunt (Liver Shunt) A malformation of blood vessels in the liver or an abnormal communication between the arteries and veins in the liver. Mode of Inheritance - Undetermined / Age at Onset < 1 year Neurologic Diseases Cerebellar Degeneration Cerebellar and Extrapyramidal Abiotrophy A condition where the neurons in the cerebellum part of the brain and parts of the spinal cord are malformed and eventually malfunction. Results in progressive neurologic signs, including incoordination, ataxia, paralysis and generally death. Mode of Inheritance - Recessive / Age at Onset < 20 weeks - Degenerative Myelopathy (DM) Degenerative myelopathy is a progressive disease of the spinal cord in older dogs. The disease has an insidious onset between 5 and 14 years of age. It begins with a loss of coordination (ataxia) in the hind limbs. Mode of Inheritance - autosomal recessive with variable penetrance / Age at Onset > 5 years

Epilepsy

A disease characterised by convulsions (seizures) and/or disturbances of consciousness

Mode of Inheritance – Undetermined / Age at Onset < 1 year - Hepatocerebellar Degeneration Affected Bernese Mountain Dog puppies develop signs of progressive cerebellar disease, including progressive ataxia with strength and head bobbing. Puppies are unable to walk without falling backwards or sideways. Mode of Inheritance - Recessive / Age at Onset 12 weeks - Hydrocephalus A condition where there is an abnormal accumulation of fluid in the ventricles of the brain. Mode of Inheritance - Polygenic / Age at Onset < 3 months - Hypomyelination (Trembler) A series of Bernese Mountain dogs developed a tremor starting at 2-8 weeks of age. This is a fine tremor which affects both the limbs and head. It becomes worse with excitement and disappears with sleep. There is also mild weakness, high tail carriage and a stiff action of the hind legs. Mode of Inheritance - Recessive / Age at Onset < 10 weeks - Meningitis-Vasculitis Steroid-Responsive Meningitis-Arteritis (SRMA) Aseptic Meningitis Immune mediated vascular lesions in the meningeal and coronary arteries. Symptoms include chronic fever, anorexia, stiff neck and paralysis. Mode of Inheritance - Undetermined / Age at Onset < 2 years Ocular Disease Cataracts A change in structure of the lens of the eye leading to cloudiness and usually to blindness. Mode of Inheritance - Undetermined / Age at Onset Varies - Ectopic Cilia (Aberrant Cilia) Eyelashes on the inner surface on the eyelid (most often upper eyelid). Mode of Inheritance - Undetermined / Age at Onset birth - Ectropion An abnormal rolling out of the eyelids. Mode of Inheritance - Undetermined / Age at Onset < 6 months - Entropion An abnormal rolling in of the eyelid. Mode of Inheritance - Undetermined / Age at Onset < 1 year - Optic Nerve Hypoplasia A condition where the optic nerve going from the eye to the brain is too small. Mode of Inheritance - Undetermined / Age at Onset < 3 months - Progressive Retinal Atrophy (PRA) A disease where the retina slowly deteriorates, progressing to blindness Mode of Inheritance - Undetermined / Age at Onset Varies - Uveodermatological Syndrome A syndrome of bilateral depigmentation may affect the iris, nose, lids, lips, mouth, foot pads, and anus. Ocular pain due to uveitis. Possibility of acute blindness. Mode of Inheritance - Undetermined / Age at Onset < 3 years Reproductive Cryptorchidism A condition in which one or both testicles do not fully descend into the scrotum. The condition may be presented in two forms: 1.) Unilateral cryptorchidism refers to the normal descent of a singular testis. 2.) Bilateral cryptorchidism results in the retention of both testes. Mode of Inheritance - Undetermined / Age at Onset < 3 months Skeletal Calcinosis Circumscripta Abnormal deposits of calcuim in the skin and subcutaneous tissue. Mode of Inheritance - Undetermined / Age at Onset < 1 year - Cleft Lip/Cleft Palate Cleft lip: the two halves of the upper lip do not join together. Cleft palate: the roof of the mouth is not closed and the inside of the nose opens into the mouth. Cleft palate and cleft lip are often seen together. Mode of Inheritance - Undetermined / Age at Onset Birth - Kinked Tails Abnormal bend or crook in the tail Mode of Inheritance - Undetermined / Age at Onset < 3 months - Elbow Dysplasia An abnormal development of the elbow joint, includes ununited anconeal process (UAP), fragmented medial coronoid process (FCP) and osteochondrosis of the medial condyle of the humerus (OCD). Mode of Inheritance - Polygenic / Age at Onset < 1 year - Hip Dysplasia Abnormal formation of the hip socket; causes rear-limb lameness. Mode of Inheritance - Polygenic / Age at Onset < 2 years - Intervertebral Disc Disease (IDD) The discs between the vetebra are abnormal and prone to rupture and misplacement; causes back pain, rear-end weakness and paralysis. Mode of Inheritance - Undetermined / Age at Onset 1 year - Luxating Patella A condition where the knee caps slide in and out of place. An affected dog may appear knock-kneed or cow-hocked. Lameness may be evident. Mode of Inheritance - Polygenic / Age at Onset < 1 year - Osteochondritis Dissecan (OCD - Shoulder) Developmental diseases resulting in abnormal formulation of joint cartilage. Mode of Inheritance - Undetermined / Age at Onset < 1 year - Panosteitis (Pano, Enostosis) A painful inflammatory bone disease of young, rapidly growing dogs, typically 6-18 months of age. Mode of Inheritance - Undetermined / Age at Onset < 18 months Urinary Familial Glomerulonephropathy A renal disease which has been identified in Bernese Mountain Dogs aged between two and seven years that have been suffering from weight loss, anorexia, apathy, vomiting, polydipsia and polyuria. Chronic kidney failure can result.