CANINE GENETICS

Congenital and hereditary diseases are confusing but this list of over 300 genetic defects in purebred dogs is valuable information for dog breeders.  Genetic information reduces fear of inherited factors and can help determine whether it is a genetic problem (inherited disease) or environmental factor.

GUIDE TO CONGENITAL AND HERITABLE DISORDERS IN DOGS*

*Includes Genetic Predisposition to Diseases published by The Association of Veterinarians for Animal Rights (Ref #1) First printing: August 1994, revised August 1997 and November 2000 Special thanks to: W. Jean Dodds, D. Kay Inks - Reprinted with permission, edited by Kim Townsend, NoPuppyMills.com (Ref #2).   No portion of this guide may be reproduced in part or in whole. 

This is an excellent guide to inherited conditions but be certain to read the ii Disclaimer

Section I

A list of 148 purebred dog breeds, each of which is accompanied by a number or series of numbers that correspond to the genetic diseases identified and described in Section II.'

Section II

An alphabetical listing of genetically transmitted diseases that occur in purebred dogs. Each disease is assigned an identification number, and some diseases are followed by the names of the breeds known to be subject to those diseases.

How to use this webpage:  If you are thinking about acquiring a purebred dog, refer to Section I to find out the number of genetically transmitted diseases associated with the breed or breeds in which you are interested. Refer to Section II to find the names and definitions of those diseases.  TO FIND A WORD, use the Ctrl & F key, to bring up the "find" screen, then type in the word you want to find.

Section I:

Section II:

1.Aberrant cilia: eyelashes growing abnormally, such as rubbing against the eyeball (see #88,).

2.Abnormal copper metabolism: (usually Bedlington terriers or Doberman pinschers) an inability to utilize and store copper properly, resulting in liver disease and other problems.

3.Abnormal dentition: abnormal placement, number and development of teeth.

4.Acanthosis nigricans: (usually dachshunds) a skin disease where the skin becomes thickened and dark, primarily affecting the axillae (armpits).

5. Achondroplasia: abnormal development of cartilage leading to dwarfism (seen aberrantly in most breeds, but that's what makes a Basset hound and other achondroplastic breeds long and low).

6. Acne: same thing as in humans, affects the muzzle and lip areas.

7. Acral lick dermatitis: a skin disease caused by an animal's licking a localized area excessively, especially on the legs and paws.

8. Acral mutilation: a progressive self-mutilation of the feet and legs. Also known as peripheral sensory neuropathy in pointing breeds because they are born without pain sensation.

9. Acute moist dermatitis: known as "hot spots," a localized area of a severely itchy, inflamed and oozing dermatitis exacerbated by the animal's intense licking and chewing at the spot.

9a. Addison's disease (hypoadrenocorticism): a disease characterized by inadequate secretion of cortisone from the adrenal glands. More common in Old English sheepdogs, standard poodles and bearded collies. (See #159a,.)

10. Allergies: same as in humans. Dogs can be allergic to things they come in contact with, eat or inhale.

11. Amyloidosis: a condition where abnormal deposits of proteinaceous material called amyloid are laid down in tissues and impair their function. Common in Akitas and Chinese shar peis.

12. Anasarca: a condition where neonatal puppies have an abnormal accumulation of fluids in their tissues. Often seen in English bulldogs.

13. Anemia with chondrodysplasia: a condition of Alaskan malamutes where there is malformation and maldevelopment of cartilage and red blood cells. Also called stomatocytosis because of the mouth-like shape of red blood cells.

14. Anesthetic idiosyncracy: a condition where an individual has an abnormal response to commonly used anesthetics sometimes leading to death. Idiosyncratic means there is no good explanation or way to predict this.

15. Anomaly of third cervical vertebra: a malformation of one of the neck bones in the spinal column.

16. Anophthalmia: a condition where an animal is born without any eyes.

17. Aortic body tumors: a cancer that arises from a small organ at the base of the aorta, near the heart.

18. Apocrine gland tumor: a cancer arising from glands which secrete fluids (such as mammary glands).

19. Arteriovenous fistula: an abnormal connection that forms between arteries and veins.

20. Ataxia: (see #255, #288,.)

21. Atopic dermatitis: a skin disease caused by a dog's reaction to an inhalant allergy. (See #81,.)

22. Atopy: an allergy caused from things dogs inhale.

23. Atresia of nasolacrimal puncta: a condition where the holes on the inside of the lower eyelids (puncta) are too small or closed so tears spill over the lid instead of draining to the nose.

24. Atrial septal defects: a malformation of the dividing wall between two chambers of the heart, usually resulting in a hole which then causes blood flow abnormalities.

25. Avulsion fractures: fractures of the bones caused by a piece being ripped away, usually because of its strong attachment to a ligament or tendon.

26. Basal cell tumor: a cancer arising from a type of skin cell.

27. Behavioral abnormalities: a whole range of abnormal behavior patterns, such as aggression, panic disorders, etc.

28. Bithoracic ectromelia: a condition where the front leg bones are very small or absent.

29. Blepharospasm: an abnormal tightening of the muscles around the eyes, which causes repetitive blinking.

30. Blindness: an inability to see due to a large variety of causes.

31. Bloat: a condition where a dog's stomach produces excessive gas and enlarges severely enough to cause death without immediate treatment. Usually associated with gastric torsion (see #131,).

32. Blue eyes: an adverse reaction to certain vaccines containing canine hepatitis virus (adenovirus 1) which produces a bluish discoloration to the cornea.

33. Bullous pemphigoid: an autoimmune (i.e., the body attacking itself) disease associated with the formation of painful blisters.

34. Bundle branch block: an abnormality of the electrical conduction mechanism of the heart.

35. Bundle of His degeneration: a condition where a part of the electrical system of the heart deteriorates.

36. Calcinosis circumscripta: the development of lumps of hard calcium deposits in the skin.

37. Cancer, bladder: as in humans, cancer arising from the bladder.

37a. Cardiac valvular disease: weakness of heart valves producing heart murmurs and leading to cardiac failure. Prevalent in Cavalier King Charles spaniels.

38. Cardiomyopathy: a disease of weakened heart muscles. Common in giant breeds, boxers, Doberman pinschers.

39. Carotid body tumors: cancer arising from a small organ located on the carotid in the neck.

40. Carpal subluxation: a condition where the "wrist" bones are loose and out of alignment.

41,. Castration responsive dermatosis: a skin condition characterized by loss of hair, thickened skin and inflammation which responds to castration (i.e., hormonally dependent).

42. Cataract: as in humans, a change in structure of the lens of the eye leading to cloudiness and usually to blindness.

43. Cataract with microphthalmia: a condition where a dog has cataracts along with abnormally small eyes.

43a. Cell-mediated immunodeficiency: a deficiency of t-lymphocyte function causing impaired immunity, chronic recurrent infections and stunted growth. Seen in Weimaraners and Dachshunds. (See #311b).

44. Cellulitis (folliculitis and furunculosis): inflammation and infection of the cells of the skin including the hair follicles and deeper structures.

45. Cerebellar cortical abiotrophy: malformation of the neurons in the cerebellum, a part of the brain.

46. Cerebellar degeneration: a condition where a part of the brain deteriorates.

47. 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.

48,. Cerebellar hypoplasia: a condition where the cerebellum, a part of the brain, is poorly formed (too small or absent) and doesn't function properly or at all.

49. Cerebrospinal demyelination: a condition where the neurons of the brain and spinal cord are malformed, lacking a specialized sheath, which causes malfunction.

50. Cervical disc disease: a degeneration or malformation of the cushioning discs between the spinal column bones (vertebrae) in the neck.

51. Cervical vertebral malformation or instability: a malformation of the vertebrae in the neck usually leading to nerve damage. Commonly seen in Doberman pinschers and causes a hackneyed gait (high stepping).

52. Choroidal hypoplasia: improper development of a part of the eye.

53. Ciliary dyskinesia: congenital trait in several breeds where all ciliated cells (those with hairs or moving appendages) are deformed and rigid. Also called immotile cilia syndrome and Kartagener's syndrome. Causes chronic pneumonia and sterility. Common in bichon frise and Doberman pinschers.

54. Cleft lip: a condition where the two halves of the upper lip do not join together. Cleft palate and cleft lip are often seen together.

55. Cleft palate: a condition where the roof of the mouth is not closed and the inside of the nose opens into the mouth.

56. Coliform enteritis: an inflammation of the bowel tract caused by a certain group of bacteria.

57. Collapsed trachea: a condition where the cartilage rings that make up the trachea are malformed and tend to collapse easily.

58. Collie eye anomaly: a condition of collie dogs where the narrow shape of the head causes the eyes to be malformed.

59. Coloboma: an abnormal development of the eye, usually seen in collies, which can lead to blindness (see #203,).

60,. Colobomas with aphakia: same as above but with congenital absence of the lens.

61,. Color mutant alopecia: a condition where certain colored areas of a dog's skin grows less or no fur. Commonly seen in Yorkshire terriers, blue Doberman pinschers and fawn Irish setters.

61a. Combined immunodeficiency: a severe combined deficiency of cell-mediated immunity (T-cell function) and low levels of serum immunoglobulins (IgA, IgG, and variably IgM). Affected puppies usually die from viral infectins by 12-16 weeks of age. Seen in Basset hounds. (See 343a, 168, 169, 170,.)

61b. Complement deficiency: a deficiency in serum levels of the third component of complement which impairs neutrophil function and causes recurrent infections. Seen in Brittany spaniels.

62. Conjunctivitis: an inflammation of the conjunctival membrane of the eye.

63. Conus septal defect: a developmental abnormality of the right ventricle of the heart.

64. Copper storage abnormalityin liver: (see #2,.)

65. Corneal dystrophy: an abnormality of the cornea usually characterized by shallow pits in the surface.

66. Corneal leukomas: an abnormal accumulation of a white material in or on the cornea.

67. Corneal ulcer, superficial: an erosion of the outer membrane and outer surface of the cornea.

68. Craniomandibular osteopathy: an abnormal development of the bones of the face and the jaw. Seen in West Highland white and Cairn terriers, among other breeds.

69. Cranioschisis: abnormal development of the skull characterized by openings between or in the bones.

70. Cryptorchidism: condition where one testicle does not descend into the scrotal sac.

71. Cushing's disease (hyperadrenocorticism): a disease characterized by an excess secretion of cortisosteroids from the adrenal glands. (See #156.)

72. Cutaneous asthenia: a condition where the skin lacks its normal strength, elasticity and sensation. Also called Ehlers- Danlos syndrome. Seen in several breeds, including English springer spaniels and boxers. (See #94a.)

72a. Cutaneous vasculopathy: a disease of autosomal recessive inheritance in which young puppies exhibit footpad swelling and depigmentation, with crusting and ulceration of the tips of ears and tail. Seen in German shepherd dogs.

73. Cyclic neutropenia: a condition characterized by periodic lowering of neutrophils, a type of white blood cell. Commonly seen in grey collies.

74. Cystic ovaries: a condition where the ovarian follicles become cyctic (fluid filled) leading to hormonal imbalances and other problems.

75. Cystinuria: an abnormal excretion of a substance (cystine) in the urine.

76. Cystitis and cystic calculi: infection of the bladder which often leads to formation of abnormal mineral deposits (bladder stones).

77,. Dacrocystitis: inflammation of a tear sac.

78. Deafness: an inability to hear, due to many different causes.

79. Deformed tail: a congenital condition where the tail is malformed.

80. Demodicosis: a kind of skin disease (mange) caused by microscopic Demodex canis mites living within the skin layers and producing an immunodeficiency syndrome.

81. Dermatitis, atopic: inflammation and subsequent infection of the skin due to atopy (see #21, and #22,).

82. Dermatomyositis: a disease affecting the skin and muscles, usually in collies or Shetland sheepdogs.

83. Dermoid cyst: a small growth composed of skin-like structures.

84. Dermoid sinus: similar to a dermoid cyst but usually larger. Seen in Rhodesian ridgebacks.

85. Diabetes mellitus: a metabolic disease caused by insulin deficiency and characterized by the inability to utilize sugars normally.

85a. Digital hyperkeratosis: a condition of Irish terrier puppies that causes marked thickening of the foot pads. Affected feet crack, become infected and painful.

86. Discoid lupus erythematosus: a form of autoimmune disease affecting the skin.

87. Dislocation of shoulder: a condition where the bones of the shoulder joint are out of proper position.

88. Distichiasis: abnormally growing eyelashes.

89. Dwarfism: an abnormality of the normal growth pattern resulting in an undersized individual.

90. Dystocia: complications of the birth process (difficult birth).

91,. Eclampsia: convulsions usually seen around the time of parturition (whelping).

92. Ectodermal defects: any of a multitude of abnormalities arising from maldevelopment of the fetal ectoderm (e.g., skin, nervous system, eyes).

93. Ectopic ureters: the ureters (tubes leading from the kidneys to the bladder) do not empty into the bladder in the normal location.

94. Ectropion: an abnormal rolling out of the eyelids.

94a. Ehlers-Danlos syndrome: a connective tissue disease characterized by loose, hyperextensible and very fragile skin that tears easily (see #72).

95. Elbow dysplasia: an abnormal development of the elbow joint.

96. Elbow joint malformation: (see #95.)

97. Elbow subluxation: a condition where the elbow joint is loose and out of alignment.

98. Elongated soft palate: the soft palate is abnormally long and causes breathing disorders.

98a. Encephalitis: an inflammatory condition of the brain causing signs of central nervous system dysfunction and epilepsy (seizures). A unique form of encephalitis is prevalent in the pug breed and is called "Pug Dog Encephalitis." (See #109.)

99, Endocardial fibroelastosis: an abnormal condition of scarring of the muscles of the heart.

100. Endometritis: inflammation of the internal layer of the uterus.

101. Enlarged foramen magnum: a condition in which the opening in the skull where the vertebral column begins is too large.

102. Enostosis: a bony growth within the hollow part of a bone.

103. Entropion: an abnormal rolling in of the eyelid.

104. Eosinophilic granuloma: an allergic reactive syndrome characterized by the plaque-like accumulation of eosinophils, a type of white blood cell.

105. Eosinophilic panosteitis: a painful inflammatory bone disease of young, rapidly growing dogs, often characterized by increased eosinophils in the blood. (See #231,.)

106. Epidermal dysplasia: abnormal development of the outer layer of the skin. Common in West Highland white terriers and begins in puppyhood. (See #331.)

107. Epidermoid cyst: a small growth consisting of tissues of the outer layer of the skin (see #274,.)

108,. Epidermolysis bullosa: an abnormal looseness to the skin characterized by large, deep, blister-like lesions.

109. Epilepsy: a disease characterized by convulsions (seizures) and/or disturbances of consciousness.

110,. Epiphora: abnormal draining of tears often due to overproduction.

111. Epiphyseal dysplasia: abnormal development of the epiphysis, a part of the long bones.

112. Esophageal achalasia: a functional stricture or spasm of the muscles of the esophagus where it joins the stomach.

113. Esophageal dilatation: an abnormally large and usually flaccid esophagus.

114. Eversion of nictitating membrane: a condition where the third eyelid is protruding.

115. Eye abnormality: any of a number of problems with the eye.

116. Facial fold dermatitis: an infection of the facial skin caused by unusual or excessive skin folds (seen in dogs such as the Pekingese or Chinese shar pei).

117. Facial nerve paralysis: a decrease or cessation of function of the facial nerve leading to a drooping of the affected side of the face.

118. Factor I deficiency or hypofibrinogenemia: a rare deficiency of a clotting factor (fibrinogen), which causes excessive bleeding.

119. Factor II deficiency or hypoprothrombinemia: a rare deficiency of prothrombin, a clotting factor needed to control bleeding.

120. Factor VII deficiency: a mild bleeding disease primarily of beagle dogs.

121. Factor VIII deficiency or hemophilia A: the most common severe inherited clotting disorder of humans and nonhuman animals. Inhereited as a sex-linked recessive trait (carried by females and manifested in males). Affects most dog breeds.

122. Factor IX deficiency or hemophilia B: same as hemophilia A, but more rare and involves a different clotting factor. Affects about 20 dog breeds.

123. Factor X deficiency: a rare clotting disorder primarily of American cocker spaniels. An autosomal trait (affects both sexes).

124. Factor XI deficiency: a rare clotting disorder of several dog breeds. Protracted bleeding from surgical procedures is a feature. Affects both sexes.

124a. Factor XII deficiency: a clotting factor deficiency that rarely produces clinical signs. Seen in toy and standard poodles and occasionally in other breeds. Usually diagnosed incidentally during blood testing for potential bleeding disorder.

124b. Familial amaurotic idiocy: deposits of fatty pigments in the brain produce loss of vision, stuppor, and seizures. Seen in English setters, Germn short-haired pointers, and Australian cattle dogs. (See #177, 193a, 214,.)

124c. Fanconi syndrome: a kidney tubular dysfunction of basenjis which leads to glycosuria (see #268).

125. Fibrosarcoma: a cancer arising from certain types of fibrous cells.

126. Fibrous histiocytoma: a type of fibrous tumor arising from cells called histiocytes.

127. Flank sucking: a behavioral problem common in Doberman pinschers and exhibited as a continually wet patch on the flank (from sucking the skin).

128. Fold dermatitis: an inflammation of skin folds especially in dogs with loose skin (e.g., Chinese shar pei).

129. Folliculitis: an infection of the hair follicles.

129a. Fragmented coronoid process: osteochondrosis of the elbow joint. (See # 221a.)

130. Furunculosis: an infection of the deeper structures of the skin.

131. Gastric torsion: a condition where the stomach twists, thereby impeding input and output. (See #31,.)

132. Generalized myopathy: a condition affecting all the muscles of the body which produces weakness.

133. Genu valgum: malformation of the knee joint ("knock-kneed").

134. Gingival hyperplasia: overgrowth of the gum tissues.

135. Glaucoma: abnormally high pressure in the eye.

136. Globoid cell leukodystrophy: abnormal development and/or function of certain types of white globoid cells in the brain. (See #193a.)

137. Glycogen storage disease: a syndrome characterized by an inability to store and utilize carbohydrates. (See #193a.)

138. Goiter: a swelling of the thyroid gland.

138a. Granulocyte dysfunctin or adhesion defect: an impairment of neutrophil function or adhesion which causes chronic recurring infections, stunted growth and secondary increase in immune globulins (hypergammaglobulinemia). See in Irish setters and Doberman pinschers.

139. Granulomatous colitis: a type of chronic inflammation of the colon characterized by reactive tissue growths.

140,. Granulomatous sebaceous adenitis: 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. Common in standard poodles, Akitas, samoyed and vizslas.

141. Hair follicle tumors: abnormal growths of the hair follicles.

142. Hairlessness: also called alopecia or loss of hair. Can be a normal pattern for breeds like the Mexican hairless dog.

143. Hanging tongue: a syndrome where the tongue does not retract into the mouth properly, due to neurologic or anatomic defects. Commonly seen in Cavalier King Charles spaniels.

143a. Hemangiosarcoma: a cancer of blood vessels involving liver, spleen or skin.

144. Hemeralopia: inability to see in daylight.

144a. Hemorrhagic gastroenteritis: an acute disorder characterized by bloody diarrhea, elevated hematocrit and shock. Common in miniature schnauzers.

145. Hemivertebra: a particular kind of malformation of the vertebra where only half of the structure is formed.

146. Hemolytic anemia: anemia caused by the destruction of the red blood cells by an autoimmune process. Particularly common in cocker spaniels and Old English sheepdogs, as well as several other breeds.

147. Hemophilia A: a blood clotting disorder due to deficiency of coagulation factor VIII (this is the most common type of hemophilia in dogs). (See #121,.)

148. Hemophilia B: a blood clotting disorder due to lack of coagulation factor IX. (See #122,.)

149. Hepatic portosystemic shunt or arteriovenous fistula: a malformation of blood vessels in the liver or an abnormal communication between the arteries and veins in the liver.

149a. Hepatic lipidosis: an abnormal accumulation of lipids in the liver which leads to liver failure. Common in miniature schnauzers and Shetland sheepdogs.

149b. Hereditary nephritis: also called "Samoyed hereditary glomerulopathy," a sex-linked disease of young males. Affected dogs have renal glomerular disease which rapidly progresses to kidney failure and death. Female carriers have abnormal glomerular basement membrane as well, but usually remain healthy until later life when renal failure may occur.

149c. Hereditary spinal muscular atrophy: an autosomal dominant degenerative disease of motor neurons characterized by weakness and muscle atrophy with a typical gait, and progressing to dangling of the head and a drooping, paralyzed tail. Severely affected dogs become paralyzed and die by  3-4  months of age. Seen in Brittany spaniels.

149d. Hepatocerebellar degeneration: a syndrome of progressive cerebellar and hepatic disease of 6-8 week old Bernese mountain dogs with lesions of cerebellar abiotrophy and coexistant hepatic lesions. Autosomal recessive inheritance.

150. Hermaphroditism: a syndrome where the individual has anatomical features of both sexes.

151. Heterochromia, iris: the presence of different colors in the same or both irises.

152. Hip dysplasia: a developmental malformation or subluxation of the hip joints.

153. Histiocytoma: a tumor composed of certain skin tissue cells (i.e., histiocytes).

154. Hydrocephalus: a condition where there is an abnormal accumulation of fluid in the ventricles of the brain.

155. Hygroma: a fluid-filled sac usually occurring on the elbows of large breed dogs such as the Great Dane or Irish wolfhound.

156. Hyperadrenocorticism or Cushing's disease: a disease where the adrenal glands are overactive. (See #71.)

157. Hypercholesterolemia: a disease where the animal has too much cholesterol in the blood system. Commonly associated with hypothyroidism.

158. Hypertrophic osteodystrophy: a condition of rapidly growing giant breeds where there is an abnormal inflammation of bones with pain and development of excessive bony growths.

159. Hypertrophy of nictitans gland: a condition where the gland of the third eyelid is abnormally large.

159a. Hypoadrenocorticism: a disease where autoimmune or other causes of destruction of the adrenal glands produces a deficiency of corticosteroids. (See #9a,.)

160. Hypoglycemia: a syndrome where the animal has an abnormally low blood glucose.

160a. Hypomyelinogenesis: failure of the nervous system to form myelin, seen at birth.

161. Hypopigmentation, lips and nose: a condition where an animal lacks pigment (color) in areas where it is usually present. (See #328,.)

162. Hypoplasia of dens: a condition where part of the second vetebra fails to develop fully and leads to instability.

163. Hypoplasia of larynx: a condition where the larynx (cartilage of the "voice box") fails to develop fully.

164. Hypoplasia of trachea: a trachea that fails to develop fully.

165. Hyposomatotropism: failure of the body growth hormones (somatomedins) to develop fully. Also known as growth hormone- responsive dermatosis. Common in Pomeranians.

166. Hypothyroidism: a common endocrine disease where the body produces an abnormally low amount of thyroid hormones. An autoimmune destruction of the thyroid gland which affects more than 50, dog breeds. (See #192, #312.)

167. Hypotrichosis: a condition where there is an abnormally small amount of hair growth.

168. Immunoglobulin A deficiency: a condition where levels of secretory immune globulins are low. Common in Chinese shar peis and beagles. (See #187,.)

169. Immunoglobulin G deficiency: a condition where circulating antibody levels are low. Produces immune deficiency and susceptibility to infections.

170. Immunoglobulin M deficiency: a condition where antibodies produced in early stages of an immune response are low, producing susceptibility to infection. Seen in Doberman pinschers.

171. Inguinal hernia: a break in the muscular layer of the body wall occurring at the inguinal canal (where the back leg meets the body).

172. Intestinal malabsorption: a disease where the intestinal tract does not absorb nutrients properly. Also known as protein- losing enteropathy as a consequence of inflamatory bowel disease. In Irish setters there is also a wheat-sensitive enteropathy.

173. Intervertebral disc disease: a disease where the discs between the vetebra are abnormal and prone to rupture and misplacement.

174. Intussusception: a serious condition where the intestinal tract telescopes in on itself.

175. Iris atrophy: a condition where the iris (the colored part of the eye) shrinks and becomes non-functional.

176. Iris heterochromia: a condition where one iris is a different color from the other or has more than one color to it.

177. Juvenile amaurotic idiocy: a syndrome characterized by early onset blindness and low mental capacity.

178. Juvenile cellulitis: an inflammation of cells (usually skin cells) occurring in the young animal.

179. Keratitis sicca: a condition where one or both eyes do not produce a normal amount or type of tears.

180. Keratoacanthoma: a small growth, usually on the face, filled with keratin material.

181. Keratoconjunctivitis sicca: (see #179.)

182. Kidney aplasia, unilateral: a developmental abnormality where one kidney fails to develop. Also called renal agenesis.

183. Kinked tail: a developmental abnormality where the tail has a pronounced kink.

184. Lacrimal duct atresia: a condition where the duct draining tears from the eye is too small or not formed.

185. Legg-Perthes disease: a disease where the blood vessels feeding the femoral head (top part of the thigh bone) shrink, leading to starvation and death of the femoral head (the ball of the ball-and-socket joint of the hip). Also called Legg-Calve'- Perthes disease.

186. Lens luxation: a condition where the lens in the eye is displaced into an abnormal position.

187. Linear IgA dermatosis: a type of skin disease resulting from an abnormality of the secretory immune system. Common in Chinese shar peis.

188. Lip fold dermatitis: a skin infection caused by redundant skin folds around the mouth.

188a. Lipidosis: a form of lysosomal storage disease where lipids accumulate in nerves. Called GM- 1 gangliosidosis in Portuguese water dogs. (See #193a.)

189. Lissencephaly: an abnormal brain development where the surface lacks gyri (the grooves).

190. Lung torsion: a condition where one or more lung lobes twist upon themselves.

191. Lymphedema: a disorder where valvular blockage of lymph flow or twisted lymphatic ducts causes an acumulation of fluid to swell tissues with edema.

192. Lymphocytic thyroiditis: an autoimmune disease causing inflammation and destruction of the thyroid gland, which becomes infiltrated with lymphocytes (white blood cells) and leads to hypothyroidism. This is the most comon endocrine disease of the dog and has an inherited predisposition (see #166, #312).

193. Lymphosarcoma: a cancerous condition involving the lymphatic system. One of the more common canine cancers.

193a. Lysosomal storage diseases: a group of progressive multifocal neurologic disorders caused by specific enzyme deficiencies leading to death of nerve cells and accumulation of their respective enzyme substrates in cells. (See #299a,.)

194. Malabsorption syndrome: (see #172.)

195. Malocclusion: a condition where the teeth do not meet properly.

196. Mastocytoma: a rare cancer developing from a type of tissue cell known as a mast cell.

197. Melanoma: a rare cancer developing from the type of skin cell which produces pigment (melanin).

198. Metabolic bone disease: any of a number of diseases affecting the bones due to an abnormality of metabolism.

199. Microphthalmia: a condition where one or both eyes are too small.

200. Missing teeth: a condition where there are too few teeth.

201. Mitral valve defects: a group of abnormalities of the mitral valve of the heart.

202. Mononephrosis: a condition where only one kidney is present.

203. Multiple colobomas: a developmental abnormality of the structures of the eye.

204. Multiple epiphyseal dysplasia: a condition where many of the long bones develop abnormally due to changes in the growth plates.

204a. Muscular dystrophy: a congenital and often inherited form of generalized muscle dysfunction which causes signs such as poor growth, weakness, abnormal gait, dificulty eating and swallowing, and muscle atrophy. Affected animals have serious health problems and may die or be euthanized. Inheritance is sex-linked in Golden retrievers, Irish terriers, Samoyeds, and Belgian shepherds.

205. Muzzle pyoderma: an infectious skin disease on the muzzle of an animal.

206. Myasthenia gravis: a syndrome characterized by muscle fatigue due to an autoimmune disease which produces chemical abnormalities of the muscles and nerves. An enlarged esophagus called megaesophagus can result and causes regurgitation of food.

206a. Narcolepsy: a neurological disorder characterized by falling asleep suddenly (collapse) which can occur during periods of activity and last for varying lengths of time. Seen in Doberman pinschers and Labrador retrievers.

207. Narrow palpebral fissure: an abnormally small opening between the upper and lower eyelids.

208. Nasal pyoderma: a skin infection of the nose.

209. Nasal solar dermatitis: a skin disease of the nose and muzzle which is greatly affected by exposure to sunlight. Common in collies.

210. Nasolacrimal puncta atresia: (see #23,.)

211. Necrotizing myelopathy: a condition where the spinal cord gradually dies.

212. Necrotizing panotitis: a severe infection of the ear and surrounding tissues.

213. Neuromuscular atrophy: a condition where the muscles waste away due to lack of proper nerve supply.

214. Neuronal ceroid lipofuscinosis: a congenital disease where fatty pigments are deposited in the brain and cause brain dysfunction. (See #193a.)

215. Neurotropic osteopathy: a disease of the bones due to abnormalities of the nerves.

216. Nodular panniculitis: a skin disease characterized by nodules of inflammation under the skin.

217. Oligodendroglioma: a cancer arising from a type of cell found in the brain and spinal cord.

218. Oligodontia: an abnormally small number of teeth.

219. Open fontanel: a condition where the suture lines between bones of the skull do not fuse together properly.

220. Optic nerve hypoplasia: a condition where the optic nerve going from the eye to the brain is too small.

221. Osteochondritis dissecans: a specific form of inflammation of the cartilage of certain joints which causes arthritis. (See # 221a.)

221a. Osteochondrosis: a group of developmental diseases resulting in abnormal formulation of joint cartilage. Commonly involves the shoulder, stifle, hock or elbow. (See # 221.)

222. Osteodystrophy: any of a number of diseases involving the development of the bones.

223. Osteogenesis imperfecta: imperfect development of the structure and/or mineralization of the bones.

224. Osteopetrosis: a condition where the bones are abnormally dense and hard.

225. Osteosarcoma: a cancer arising from the cells of the bones.

226. Otitis externa: an infection of the external structures of the ear.

227. Otocephalic syndrome: a developmental abnormality where the animal lacks a lower jaw, and the ears meet below the face.

228. Overshot jaw: a condition where the upper jaw is too long for the lower jaw.

229. Pancreatic insufficiency: a condition where the pancreas does not produce the proper enzymes for digesting food.

230. Pannus: an immunologic eye disease characterized by abnormal growth of tissue over the cornea.

231. Panosteitis: (see #105,.)

232. Parosteitis: inflammation of tissue around a bone.

233. Parotitis: inflammation of the parotid salivary gland. Also called parotiditis.

234. Partial alopecia: some loss of the normal haircoat.

235. Patella luxation: a condition where the knee caps slide in and out of place.

236. Patent ductus arteriosus: failure of the vessel remnant joining the aorta and pulmonary artery in fetal life to close properly at birth, thereby shunting blood away from the lungs.

237. Pattern alopecia or baldness: hair loss occurring in certain patterns. Common in dachshunds.

238. Pemphigus erythematosus: one of many skin diseases caused by an autoimmune mechanism.

239. Pemphigus foliaceous: another skin disease caused by autoimmune destruction of tissues.

240. Perianal adenoma: a cancer arising from a cell of a gland found near the anus.

241. Perianal fistulas: a condition characterized by abnormal communications from deeper tissues to the skin surrounding the anus.

242. Perianal gland tumor: (see #240,.)

243. Persistent right aortic arch: a developmental abnormalitiy where one of the fetal blood vessels near the heart does not atrophy as it should.

244. Persistent hyaloid artery: as #243, however, involving a blood vessel inside the eye.

245. Persistent pupillary membrane: a developmental abnormality where the membrane forming the iris does not form properly.

245a. Phosphofructokinase deficiency: a deficiency of a specific red blood cell enzyme in English springer spaniels. Causes chronic anemia, exercise-induced acute hemolytic crises and enlarged spleen.

246. Pigmentary keratitis: an inflammatory condition of the cornea characterized by abnormal pigmentation.

247. Pituitary dwarfism: a developmental abnormality resulting in an undersized animal due to a defective pituitary gland.

248. Pituitary tumor: a cancer arising from the pituitary gland.

249. Platelet disorder: a group of abnormalities of small blood cells necessary to control bleeding. (See #311,.)

250. Pododermatitis: a skin infection of the paws.

251. Polyostotic fibrous dysplasia: a type of bone disease where the bones are composed of improper fibrous tissues.

252. Polyradiculoneuritis: an acute inflammatory disease of several groups of nerves causing fever.

253. Posterior retinal atrophy: a deterioration of the part of the eye which translates light to electric impulses (the retina). Produces night blindness. (See # 256.)

254. Primary peripheral retinal dystrophy: a certain type of developmental disease affecting the retina.

255. Progressive ataxia: a condition where the animal's sense of coordination deteriorates.

256. Progressive retinal atrophy: a disease where the retina slowly deteriorates, producing night blindness.

257. Prolapsed rectum: a condition where the inside of the rectum protrudes outside the anus.

258. Prolapsed uterus: a condition where the uterus protrudes into the vaginal canal or through the vaginal opening.

259. Pseudohermaphrodism (pseudohermaphroditism): a condition where the animal has the gonads of one sex but the appearance is ambiguous or is of the opposite sex.

260,. Pulmonic stenosis: a condition where one of the valves of the heart does not open properly.

261. Pyloric stenosis: a condition where the opening leading from the stomach does not function properly.

262. Pyometra: an bacterial infection of the uterus where it fills with pus.

263. Pyruvate kinase deficiency: a deficiency of a specific red blood cell enzyme. Most commonly seen in basenjis; also in beagles and Cairn terriers.

264. Quadriplegia with amblyopia: a syndrome characterized by weakness of all four limbs, as well as of vision.

264a. Rage syndrome: sudden unprovoked aggression of serious nature. Seen in English springer spaniels. (See #27.)

265. Recessive retinal dysplasia: a developmental disorder resulting in an abnormal retina, carried by a recessive gene.

266. Renal cortical hypoplasia: a condition where the cortex of the kidney(s) develops incompletely.

266a. Renal dysplasia: a condition where the kidneys form abnormally. Renal failure develops with protein loss in urine.

267. Renal hypoplasia: a condition where the kidney(s) do not develop completely.

268. Renal tubular dysfunction: a condition where the tubules of the kidneys (the filtering structures) do not function properly. (See #124b,.) In basenjis, glycosuria develops and is called Fanconi syndrome.

269. Retinal detachment: where the retina is unattached to the back of the eye.

270. Retinal dysplasia: a condition where the retina is malformed.

271. Schnauzer comedo syndrome: a skin disease of schnauzers where the skin forms comedones ("blackheads").

272. Scotty cramp: a condition fround in Scottish terriers where the animal has periodic, generalized cramping of the muscles.

273. Screw tail: a birth defect where the tail is twisted tightly on itself.

273a. Sebaceous adenitis: (see #140,.)

274. Sebaceous cyst: a small mass in the skin with a secretory lining and filled with a yellow waxy-like material (see #107,).

275. Sebaceous gland tumor: a tumor arising from sebaceous glands of the skin.

276. Seborrhea: a skin disease with excess scaling of the skin and often an excess of sebum (oil-like substance) and odor.

277. Sertoli cell tumor: a tumor of the testicles which secretes estrogen and causes feminization.

278. Short skull: a skull that is abnormally short for the breed in question.

279. Short spine: a spine that is abnormally short for the breed in question.

280. Short tail: a tail that is abnormally short for the breed in question.

281. Shoulder abnormalities: a group of disorders of the shoulder joint due to malformation or subluxation.

282. Shoulder dysplasia: a looseness of the shoulder joint.

283. Silica uroliths: stones which are composed primarily from silicone that form in the bladder.

284. Sinoatrial syncope: a condition where the electrical impulses of the heart are abnormal and the animal has episodes of syncope (fainting).

285. Skin disorders: any of a number of abnormalities of the skin.

286. Skin neoplasms: any number of tumors arising from cells of the skin.

287. Spina bifida: a developmental abnormality where some vetebra are malformed thereby exposing the spinal cord.

288. Spinal cord demyelination (ataxia): an abnormality of the nervous tissue of the spinal cord leading to incoordination.

289. Spinal dysraphism: a developmental abnormality where the spinal cord does not form completely.

290. Spinal osteochondrosis: a specific type of developmental abnormality of the vertebrae.

291. Splenic torsion: a condition where the spleen twists upon itself.

292. Spondylolisthesis (Wobbler's syndrome): a condition where the vertebrae of the neck slip out of joint and are malformed causing progressive incoordination of the rear legs. Commonly seen in Doberman pinschers. (See #51,.)

293. Spondylosis: a malformation of the vertebrae.

294. Squamous cell carcinoma: a cancer arising from the squamous type of skin cell.

295. Stenotic nares: a condition where the openings of the nose (nares) are too small.

296. Sterile pyogranuloma syndrome: a disease of the deeper layers of the skin characterized by formation of abnormal tissues, with no infectious organisims involved.

297. Sternal callus: a thickened, hairless area forming on the chest of an animal.

298. Stockard's paralysis: a degeneration of parts of the spinal cord causing paralysis.

299. Stomach torsion: (see #131,.)

299a. Storage disease: (see #193a and #188a,.)

300. Subaortic stenosis: a tightening of the outflow opening for blood to go from the heart into the aorta. Common in golden retrievers and Newfoundlands.

301. Subcorneal pustular dermatosis: a skin inflammation occurring between certain layers of the skin.

302. Subcutaneous cysts: small fluid-filled masses accumulating under the skin.

303. Subvalvular aortic stenosis: as #300, but the tightening occurs below the aortic valve.

304. Swimmer puppies: a developmental defect which causes a flattening of the body so that newborn pups are unable to place their feet under them for proper locomotion.

304a. Syncope: a brief period of fainting or collapse.

305. Syringomyelia: developmental abnormalities causing cavities within the spinal cord, probably just an effect of #289. Common in Rhodesian ridgebacks.

306. Systemic lupus erythematosus: 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.

307. Tail abnormalities: any number of problems associated with the tail.

308. Tail fold dermatitis:a skin infection caused by abnormal tissue folds around the tail.

309. Teeth abnormalities: any number of problems of the teeth.

310. Tetralogy of Fallot: a specific four-way developmental abnormality of the structures of the heart and associated great vessels.

311. Thrombocytopathy: a functional abnormality of small blood cells (thrombocytes or platelets) which are needed to control bleeding. (See #249,.)

311a. Thrombocytopenia: a reduced number of platelets in the blood which causes pinpoint hemorrhages in the skin and mucosa. Often accompanies #146 as an autoimmune syndrome called Evans syndrome. (See #249,.)

311b. Thymic atrophy: a deficiency of cell-mediated immunity expressed by decreased T-cell function and low levels of growth hormone. Occurs in Weimaraners. (See #165,.)

312. Thyroiditis: an autoimmune inflammatory disease of the thyroid gland. (See #166, and 192.)

313. Tracheal collapse: (see #57,.)

314. Trembling of the hindquarters: a condition where the rear legs tremble due to muscle weakness or other pathologies.

315. Type II muscle fiber deficiency: a deficiency in form and/or function of a specific type of muscle fiber.

316. Ulcerative colitis: an autoimmune inflammation of the lining of the colon characterized by formation of ulcers.

317. Ulcerative keratitis: an inflammation of the cornea characterized by the formation of ulcers.

318. Umbilical hernia: a break in the abdominal muscle wall at the point where the umbilical cord enters the body.

319. Undershot jaw: a condition where the lower jaw is too long for the upper jaw.

320. Ununited anconeal process: a developmental abnormality of one of the bones of the elbow joint causing pain. (See # 221a.)

321,. Uric acid calculi: bladder stones which are formed primarily from urates. Common in Dalmatians.

322. Uric acid excretion abnormalities: an abnormality in the process of the excretion of the uric acid formed during metabolism. Common in Dalmatians.

323. Uterine eclampsia: (see #91,.)

324. Uterine inertia, primary: a condition where the uterus does not have the muscular strength to proceed with the birth process, and not due to any acquired problems (e.g., malnutrition).

325,. Vaginal hyperplasia: an overgrowth of tissues of the vagina.

326. Vasculitis: an inflammatory condition of the blood vessels.

327. Ventricular septal defect: an abnormality (usually a hole) in the wall between the two chambers of the heart.

327a. Vitamin B12-responsive malabsorption: a disease of young Giant schnauzers in which there is selective inability to absorb vitamin B12 from the bowel. Affected puppies have chronic nonregenerative anemia, low white blood cell counts, low serum vitamin B12, metabolites (methylmalonic acid) in the urine, and failure to thrive.

328. Vitiligo: a lack of pigment in the skin (called vitiligo in man and hypopigmentation in nonhuman animals). Common in rottweilers, Doberman pinschers, Old English sheepdogs and dachshunds. (See #161,.)

329. Vogt-Koyanagi-Harada-like syndrome: an autoimmune disease common in Akitas and the "sled" dog breeds where the eyes, blood and other tissues are progressively destroyed leading to blindness and death.

330. von Willebrand's disease: a type of bleeding disorder caused by defective blood platelet function. Occurs in 59 dog breeds but most often in Doberman pinschers. An autosomal trait affecting both sexes.

331. Westie armadillo syndrome: a condition of West Highland white terriers where the skin becomes very thickened. Related to atopic (inhalant) allergies. (See #106.)

331a,. White dog shaker syndrome: a disorder mainly of white dogs having muscular tremors over entire body, incoordination and rapid eye movements. Episodes occur with stress or excitement.

332. Wobbler's syndrome: (see #51, and #292,.)

333. Zinc deficiency: can be caused by dietary problems, but also from an inability to utilize and store zinc properly. Seen as a lethal problem called acrodermatitis in bull terriers.

334. Zinc-responsive dermatosis: a condition where the skin is abnormal (scaly, hair loss, etc.) but which responds to the administration of zinc in the diet.