DISEASES FOUND IN GREAT DANES

Great Danes as a breed have the potential for over 68 known diseases. Some are devastating, others are mild. Some appear common, some not so common. Don't let this scare you, a breeder with any knowledge of genetics knows the vast majority (if not all) dogs are carriers for 4 - 5 (or more) defective genes (diseases). These unfavorable genes can range from mild to severe. Many breeders only breed for what they can see (conformation) whereas more important are health and temperament. The appearance is of little use if the dog is aggressive or dies early in life from a genetic disease.

Don’t be surprised by this list, all breeds of dogs have many diseases they are prone to as a breed; some have very long lists (like the Labrador Retriever is prone to over 100 known diseases!) The most important step in eliminating diseases from any breed begins with the breeder. This is why health screenings of breeding animals is so important.

This seems to be the “hard to find” topic in dog breeding (of any breed) and potential owners should be informed about the predisposition to genetic diseases of their particular breed. Below, you will find a list of all 68 separated into the different body systems.

As a breed, Danes are susceptible to 68 genetic diseases. According to the recent survey done by the Great Dane Club of America (GDCA) the most commonly reported are Hypothyroidism, Bloat, hip Dysplasia, and Cardiomyopathy.  Go to : http://www.gdca.org/health/healthsurvey.htm to download the survey from the GDCA.  

CARDIOVASCULAR DISORDERS

1. AORTIC STENOSIS: is a congenital heart disease involving a narrowing or stricture just below the aortic valve. The ventricle responsible for pumping blood through the stenotic valve is frequently enlarged to a degree proportional with the tightness of the stenosis.

2. DILATED CARDIOMYOPATHY (DCM): is defect of the heart muscle in which it becomes thin and stretched. Affected dogs eventually succumb to heart failure. A nutritional mechanism, autoimmunity, defect in L-Carnitine and taurine or virus have been implicated in the development of DCM. Although a genetic tendency is suspected, long term studies are not yet available.

3. MITRAL VALVULAR DISEASE: A chronic valvular disease that typically involves the atrioventricular valves and results in mitral regurgitation, rupture of the chordae tendineae and potential left-sided heart failure. There is thought to be a genetic tendency to experience degeneration of the collagen in the heart valves.

4. PATENT DUCTUS ARTERIOSUS (PDA): occurs when normal fetal communication between the nonfunctional lungs and the aorta fails to close after birth. Surgery before 5 months of age has a success rate of 90%, uncorrected, 50% die within the first year.

5. TRICUSPID VALVE DYSPLASIA: A congenital malformation of the tricuspid valve complex resulting in insufficiency and regurgitation of blood into the right atrium.

6.     PERSISTANT RIGHT AORTIC ARCH: A developmental anomaly in which the aorta is formed by the right 4th aortic arch instead of the left 4th aortic arch. The esophagus and trachea are encircled by a vascular ring resulting in aspiration pneumonia and regurgitation. 

ENDOCRINE DISORDERS

7. HYPOADRENOCORTICISM (Addison's Disease): causes primary atrophy of the adrenal cortex or secondary pituitary insufficiency. Signs include weakness, depression, vomiting, diarrhea, and abnormal cardiac function.

8. HYPOTHYROIDISM: Results in a progressive deficiency of thyroid hormone. Increased susceptibility to infection and lower energy levels are common, as is alopecia, weight gain, intolerance to cold, reproductive failure, anemia and poor hair re-growth.

NERVOUS SYSTEM DISORDERS

 9. AGRESSION: Extremely assertive or forceful with other dogs/people, may attack or bite without reasonable provocation. Aggression cannot entirely be controlled through genetics but it is recommended that no dog that demonstrates unprovoked aggression towards people be bred.

10. CEREBELLAR DEGENERATION: Diseases of the cerebellum that tends to be breed specific, resulting in progressive neuralgic signs including in coordination, ataxia, paralysis and generally death. Mode of inheritance thought to be recessive.

11. CERVICAL VERTEBRAL INSTABILITY (Wobblers Syndrome): is instability in the intervertebral disks of the neck area. Preliminary research suggests that excess dietary calcium, genetic factors, injury and overfeeding may all be involved. Most commonly appears from 10 – 18 months of age. Mode of inheritance is recessive.

12. DEAFNESS: a loss of hearing that may be partial or complete resulting from degeneration of the inner ear structures and neurons of the spiral ganglion. Deaf dogs are not born this way; they lose hearing between 3 to 4 weeks after birth. Mode of inheritance is thought to be dominant. Studies have shown that deafness is strongly associated with parental hearing status, breed only animals from families in which deafness is not a problem.

13. SEIZURE DISORDERS: Partial seizures are a manifestation of a focal epileptogenic event in the cerebral cortex. Generalized seizures can be subdivided into convulsive (grand-mal).

GASTROINTESTINAL DISORDERS

14. ESOPHAGEAL HYPOMOBILITY: Regurgitation, weight loss, recurrent respiratory infections, and retarded growth rate due to the esophagus failing to push food into the stomach. Mode of inheritance is not known.

15. ESOPHAGEAL ACHALASIA (Congenital Mega-Esophagus): presents as regurgitation in puppies, failure to thrive, excessive saliva, and respiratory distress second to aspiration pneumonia.

16. EXOCRINE PANCREATIC INSUFFICIENCY: Usually results from pancreatic atrophy. The condition is progressive and results in weight loss and semi-formed stools in the face of a ravenous appetite.  

17. GASTRIC DILATATION VOLVULUS (GDV/Bloat): occurs when the stomach becomes distended with air. The air gets swallowed into the stomach when susceptible dogs exercise excessively, gulp their food/water or are stressed.

18. PTYALISM: A hyper secretion of saliva characterized by profuse drooling. It occurs when there is a normal quantity of saliva but an increase in drooling secondary to conformational abnormalities or swallowing disorders.

IMMUNOLOGIC DISORDERS

19. PEMPHIGUS (Pemphigus Vulgaris): is characterized by bulbous lesions along the mucous membranes of the mouth, anus, prepuce, vulva and oral cavity. Bacterial infections often complicate lesions.

20. BULLOUS PEMPHIGOID: A complex of blistering conditions characterized by auto antibody deposition at the junction between the epidermis and dermis, with blister formation immediately deep into the dermis.

OPHTHALMOLOGIC DISORDERS:

21. CATARACTS: opacity of the lens of the eye. Cataracts can be divided by stages; incipient, immature, mature, hyper mature. By location; anterior or posterior capsule or cortex, equator or nucleus. Mode of inheritance, and age of onset; congenital, perinatal, juvenile, adult onset, or senile.

22. DISTICHIASIS: Eyelashes that may project toward the surface of the eye from abnormal locations. May not be problematic if the hairs are soft and fine.

23. ECTROPION: Eyelids are turned out and often have the appearance of drooping. Animals may be prone to conjunctivitis.

24. ENTROPION: Eyelids are turned in, often resulting in abrasive damage to the cornea.

25. ENOPHTHALMOS: Eyeball is recessed into the eye socket.

26. EVERSION of the NICTITATING MEMBRANE: Cartilage in the third eyelid is abnormal, causing the third eyelid to roll away from or towards the globe

27. GLAUCOMA: Caused by an increase in fluid pressure within the eye leading to blindness.

28. HEMERALOPIA: Day blindness due to progressive degeneration of the cone photo receptors. Sight returns when the dog is returned to dim lighting.

29. MICROPHTHALMIA: The condition of a congenitally small eyeball. Usually associated with partial albinism and deafness.

30. PERSISTENT PUPILLARY MEMBRANES: Strands of fetal eye tissue appear visually within the eye, typically spanning the pupil. Usually does not cause a vision problem.

31. PROGRESSIVE RETINAL ATROPHY: Visual impairment occurs slowly but progressively with atrophy or degeneration of the retinal tissue.

32. PROLAPSED GLAND of the NICTITANS: Cherry eye refers to an enlarged gland at the base of the nictitating membrane that is displaced from its normal position

33. PROTRUSION of the THIRD EYELID: Third eyelid extends over the globe with no obvious pathology. It may or may not interfere with vision.

34. RETINAL DYSPLASIA: Abnormal development of the retina which can cause visual impairment and blindness. Can be caused by secondary events such as; viral infections, certain drugs, and intrauterine trauma.

 HEMOLYMPHATIC DISORDERS

35. LYMPHEDEMA: Caused by developmental defects in the lymphatic and lymph nodes. Characterized by pitting edema, typically in the limbs and abdomen, or pleural cavities.

36. VON WILLEBRAND DISEASE (vWD): is the most common bleeding disorder found in dogs. Mode of inheritance is recessive.

URINARY SYSTEM DISORDERS

37. RENAL DYSPLASIA: Abnormal differentiation of kidney tissue such as inappropriate or anomalous structures appearing within the renal parenchyma.

38. UROLITHIASIS-CYSTINE: A kidney disorder that allows cystine crystals and stones to form in the urine and potentially to block the urinary tract.

REPRODUCTIVE PROBLEMS

39. CRYPTORCHIDISM: Testicles that have not descended into the scrotum. Can be one or both testis. As a general rule, if the testicles have not descended fully into the scrotum by 4 months of age, they are unlikely to do so.

MUSCULOSKELETAL DISORDERS

40. ABDOMINAL HERNIAS: Refer to defects in the wall of the abdomen that may allow the protrusion of abdominal contents. Most umbilical hernias only trap fat in the umbilical ring and are of little clinical significance. Inguinal hernias result from a congenital inguinal ring anomaly.

41. CORE MYOPATHY: Affects skeletal muscle fibers and causes muscle atrophy. Mode of inheritance is not known.

42. CRANIOMANDIBULAR OSTEOPATHY: Proliferation of bone that typically affects the lower jawbone and occasionally other bones of the head. Mode of inheritance is recessive.

43. ELBOW DYSPLASIA-FRAGMENTED CORONOID PROCESS: Most common form of elbow dysplasia in which part of the elbow joint breaks away from the bony anchor. Characterized by stiffness, stilted gait, or lameness.

44. ELBOW DYSPLASIA-OSTEOCHONDROSIS of the MEDIAL CONDYLE: (OCD) of the medial humeral condyle is similar to the disorder seen in the shoulder. It involves the lower end of the humerus rather than the upper part.

45. ELBOW DYSPLASIA-UNUNITED ANCONEAL PROCESS (UAP): occurs when the bone growth center in the anconeal process of the elbow fails to unite with the ulna of the foreleg

46. HIP DYSPLASIA: An abnormal development of the hip joint. It is actually a genetically transmitted tendency for the hips to develop laxity of the joints. Several factors combine to determine if a predisposed animal will develop hip dysplasia. These include body size, conformation, growth patterns, pelvic muscle mass, caloric load, and electrolyte balance in dog foods. All supplements should be avoided, especially calcium, phosphorus, and vitamin D.

47. HYPERTROPHIC OSTEODYSTROPHY (HOD): A developmental condition that affects young rapidly growing large-breed dogs. Variable lameness and pain on palpation, fever, anorexia, and depression, affects the distal radius, ulna, and tibia.

48. MYTONIA: Disorder of the skeletal muscles characterized by delayed relaxation of the muscle fibers causing the muscles to continue to contract after voluntary movement ceases.

49. OSTEOCHONDROSIS (OCD): causes flaps of cartilage to be exposed in the joints with inflammation resulting. It is most common in the shoulders, elbows and hind legs of Great Danes. Factors that cause OCD are many, trauma, poor nutrition and hereditary have all been explored.

50. PANOSTEITIS (Pano): refers to an inflammatory condition that affects the leg bones, characterized by excessive bone remodeling, and lameness that appears to migrate between legs.

51. PATELLAR LUXATION: Condition in which the kneecaps slip out of their usual resting places and lodge on the medial aspects or lateral aspects of the knee.

52. CROOKED TAILS: An abnormal bend or kink in the tail.

53. LATERAL TORSION of the HIND FEET: The anterior surface if the foot is directed to the side to varying degrees.

54. MULTIPLE CARTILAGINOUS EXOSTOSES: A silent disease that may produce pain on occasion if pressure is put on the protuberances. There may be lameness intermittently. Bony nodules can be felt on the ends of the long bones or ribs, but may be found anywhere on the body.

55. PREMATURE CLOSURE of the ULNA: The ulna stops growing sooner than the radius causing wrists to turn in and the front feet to turn out.

DERMATOLOGIC CONDITIONS

56. ACNE: Muzzle folliculitis and furunculous; follicular papules of various sizes, which are generally hairless. May ulcerate and produce purulent exudate.

57. ACRAL LICK DERMATITIS (Lick Granuloma): is a disorder in which the dog continues to lick at their limbs, abrading the skin and creating ulcers and raw, weeping areas.

58. ANASARCA: Refers to a generalized edematous condition seen in newborn puppies. This trait can be lethal; other cases may be mildly affected.

59. CALCINOSIS CIRCUMSCRIPTA: A condition characterized by dystrophic mineralization of tissue, and abnormal deposits of calcium in the skin and subcutaneous tissue. Appears as well circumscribed, non painful, subcutaneous swellings with occasional ulceration and fistulation.

60. COLOR DILUTION ALOPECIA: A condition that describes the patchy, poor hair coat that can develop in animals bred for unusual hair color.

61. DEMODECTIC MANGE: An inflammatory disease of the hair follicles that is part from the presence of Demodex mites and part inherited or acquired immune defect.

62. EPIDERMOLYSIS BULLOSA (EB): refers to a group of diseases that causes blistering and structural defects at various levels of the basement membranes.

63. FOLLICULAR DYSPLASIA: Abnormal hair loss or defective follicle formation of hair shaft. Findings are hair loss, changes in coat quality and hyper pigmentation of the skin in affected areas.

64. ZINC RESPONSIVE DERMATOSIS: A scaling and crusting disorder that does not result from a dietary deficiency of zinc. Affected dogs have crusting on the nose, eye areas, footpads, elbows and hocks. 1/2 develop itching. Some ingredients in dog foods can interfere with zinc absorption; these include calcium, fiber, and iron, tin and copper.

 DENTAL DISORDERS

65. BRACHYGNATHISM: Also known as an overshot jaw is a condition in which the mandible is significantly shorter than the maxillae.

66. MALOCCLUSION: Denotes any abnormality in how the upper and lower teeth meet. Level bite is a malocclusive disorder in which the front teeth meet end to end. Reverse scissors bite occurs when the upper incisors fall just behind the lower incisors. Open bite occurs when a gap of at least 5mm is present between the top and bottom incisors when the mouth is closed. Wry mouth is a version of either brachygnathia or prognathia that affects only one side of the head.    

67. MISSING TEETH (Anodontia): is the complete absence of teeth, and oligodontia refers to several missing teeth.

This information was compiled from :

"Control of Canine Genetic Diseases By: George A. Padgett, DVM                         

Dane Art provided by: Danes-R-Us