Genetic
Health of Rhodesian Ridgebacks |
This information is designed to
elucidate the known genetic diseases associated with Rhodesian Ridgebacks
to enthusiasts of the breed. The aim is to educate owners and breeders
in order to reduce the occurrence of genetically inherited diseases
such as Hypothyroidism and Dermoid Sinus among others.
The breeder’s ethical responsibility is
to discuss dogs with defects or those that produce defects and to appropriately
breed away from such genetic traits. As an owner of a Rhodesian Ridgeback,
it is also your responsibility to report the development of any genetic
anomaly that presents itself during the course of your dog’s lifetime
to the breeder of that dog. The breeders aim is to produce the healthiest
and most correct conformation puppy possible. This cannot be achieved
successfully without open knowledge of genetic problems that are present
within any line of Ridgebacks.
By developing pedigrees to illustrate genetic
inheritance the breeder is able to interpret the genetic status of dogs
used to produce a litter. This knowledge allows the breeder to more
carefully select breeding stock. Every Rhodesian Ridgeback carries genes
for approximately 6.6 genetic defects which is similar to the amount
of genetic defects you and I carry. By knowing which 6.6 genetic defects
are carried by a breeding dog or bitch and breeding away from those
defects is the key to controlling genetic disease in Rhodesian Ridgebacks.
Adwera Rhodesian Ridgebacks is committed to
the welfare of our beloved breed. We are developing genetic pedigrees
and are committed to discuss them with other breeders and to use them
to improve the genetic quality of Rhodesian Ridgebacks. If you are interested
in beginning a genetic pedigree or would like more information about
control of genetic traits Adwera Rhodesian Ridgebacks recommends the
book “Control of Canine Genetic Diseases” by Dr. George
A. Padgett, DVM |
Disease
Name |
Description |
Megaesophagus
(Esophageal Achalasia) |
Clinical symptoms are regurgitation of undigested
food. This occurs due to the failure of esophageal muscles to force swallowed
food through to the stomach.
Mode of inheritance is undetermined
Age of onset < 6 mos. |
Hypothyroidism
(Autoimmune thyroiditis, Hashimoto’s Disease, Lymphocytic thyroiditis) |
Destruction of the thyroid gland due to an attack
from the animal’s own immune system. Symptoms are rough, scaly skin,
hair loss, and weight gain.
Mode of inheritance is recessive
Age of onset is < 2 yrs. |
Deafness |
Inability to hear, may be unilateral or bilateral.
Mode of inheritance is undetermined
Age of onset is < 6 mos. |
Alopecia (Idiopathic
Flank Alopecia or Cyclical Flank Alopecia) |
Clinical symptoms include hair loss on flanks
with little or no scaling or any inflammatory changes. Hyperpigmentation
may occur.
Mode of inheritance is undetermined
Age of onset < 5 yrs. |
Myotonia |
Muscles continue to contract after voluntary
movement ceases causing a stiff gait.
Mode of inheritance is recessive
Age of onset < 6 mos. |
Dermiod Sinus
(Arachnoid cyst, Meningeal cyst) |
Cavities or cysts may develop within the meninges
separated from the spinal cord by pia mater. They may compress the cord.
Mode of inheritance is undetermined
Age of onset birth. |
Rhodesian Ridgeback
cerebellar degeneration and color dilution syndrome |
All affected puppies show coat color dilution
and cerebellar signs, including growth retardation, ataxia, inability
to stand and tremors.
Mode of inheritance is recessive
Age of onset < 4 wks. |
Cataracts |
Lens opacity that obscures vision and may cause
blindness.
Mode of inheritance is undetermined
Age of onset varies. |
Entropian |
Turning in of the eyelids causing the eyelashes
to rub the eyeball.
Mode of inheritance is undetermined
Age of onset is < 1 yr. |
Eversion of
the nicitating membrane (Eversion of the third eyelid) |
The cartlidge in the third eyelid
is abnormal, causing the third eyelid to roll away from or toward the
globe.
Mode of inheritance is undetermined
Age of onset < 3 mos. |
Pannus (Superficial
Stromal Keratitis) |
An epithelial growth over the cornea causing
a gray haze that may obscure vision.
Mode of inheritance is undetermined
Age of onset < 1 yr. |
Persistent Pupillary
Membranes (PPM Mesodermal dygenesis) |
A failure of blood vessels in the anterior chamber
of the eye to regress normally; there may be impaired vision or blindness.
Mode of inheritance is undetermined
Age of onset < 3 mos. |
Progressive
Retinal Atrophy (PRA) |
Degeneration of the retinal vision cells which
progresses to blindness.
Mode of inheritance is undetermined
Age of onset varies |
Calcinosis Circumscripta |
Abnormal deposits of calcium in the skin and
subcutaneous tissue.
Mode of inheritance is undetermined
Age of onset < 1 yr. |
Hemivertebra |
Abnormal formation of he body of the vertebrae,
which can cause posterior ataxia and paralysis.
Mode of inheritance is undetermined
Age of onset < 1 yr. |
Hip Dysplasia |
Abnormal formation of the hip socket; causes
rear-limb lameness.
Mode of inheritance is polygenic
Age of onset < 2 yrs. |
Osteochondritis
Dessicans (OCD) |
Aseptic necrosis of bone under joint cartlidge;
causes lameness.
Elbow Joint (Elbow Dysplasia): OCD of the medial humeral condyle, fractured
coronoid process and nonfusion of the anconeal process.
Mode of inheritance is polygenic
Age of onset < 1yr.
Shoulder joint Undetermined < 1 yr.
Tarsocrural Joint Undetermined < 1 yr. |
Spondylosis
Deformans |
Abnormal fusion or bridging between vertebrae,
may cause pain and/or paralysis.
Mode of inheritance is polygenic
Age of onset > 1 yr. |
Transitional
Vertebral Segments (Lumbosacral) |
Clinical signs associated with this disorder
relate to damage to the cauda equina and include paresis, paralysis, denervation,
atrophy and atonia.
Mode of inheritance is polygenic
Age of onset varies |
Wobbler Syndrome
(Cervical Spondylolisthesis, vertebral instability) |
Abnormality of the neck vertebrae causing rear
leg ataxia that may progress to paralysis. The main vertebrae affected
are 5, 6, and 7.
Mode of inheritance is polygenic
Age of onset < 1yr. |
Renal Dysplasia |
Failure of normal development of the renal parenchyma
causing malfunction and death. Clinical signs are those of renal failure.
Mode of inheritance is undetermined
Age of onset < 1 yr. |
