Hereditary Dog Diseases
Good dog health is important to all dog owners. All pet owners want to ensure their dog has a happy and disease-free life. Dog health problems are either hereditary/congenital or acquired through injury or environmental conditions. This article is about inherited dog diseases and is intended to help you understand some of the common canine health disorders.
Most breeders spend a lot of time and resources trying to get rid of genetic diseases in their lines. However, some amateur breeders and puppy mills are breeding dogs without screening the parents and perpetuating poor genetic health.
This article is not meant to be exhaustive but will attempt to describe some common hereditary diseases and indicate some of the dog breeds that have shown a tendency to inherit these diseases in the past. If you want to check on a particular dog breed you can go to a particular dog breed and search for its health issues.
1. Eye Diseases
There are a variety of inherited diseases of the eye that can be serious to your dog’s health and even lead to blindness. Fortunately the Canine Eye Registry (CERF) has a registry for dogs that will be used for breeding. Buyers of pure-bred puppies should ask to see this certification. Any dog that you plan to breed should have its eyes examined by veterinary ophthalmologist, and then be registered with CERF.
Cataracts result from a hardening of the lens that causes it to become cloudy and block light from reaching the retina. The usual cause is old age and/or diabetes but juvenile cataracts are almost always hereditary. In severe cases your veterinarian can remove the lens to somewhat improve eyesight. This disease can affect all breeds and a large number of breeds are subject to juvenile cataracts.
Collie eye anomaly (CEA) is a problem with the blood supply to the retina that can result in a detached retina. Retinal detachment usually occurs before two years of age and will cause blindness in the affected eye. This disease can affect all collie breeds, including the Border collie, Rough and Smooth Collie, and the Shetland sheepdog.
Ectropion is an inherited disease where the lower eyelid sags, droops and rolls out exposing the interior of the eyeball. This exposure can lead to inflammation and conjunctivitis Mild cases can be treated with drops and ointments, while severe cases should be surgically corrected. This disease can be found in the American Cocker Spaniel, Basset hound, Bloodhound, Boxer, Bulldog, Bull terrier, Clumber spaniel, English cocker spaniel, English Springer spaniel, Gordon setter, Labrador retriever, and Shih Tzu. Although less common, ectropion can be found in giant breeds such as the Great Dane, Mastiff, Saint Bernard, Newfoundland and Great Pyrenees.
Entropion is a condition where the eyelid, usually the lower, rolls or turns inward. This results in the eyelashes and fur irritating the cornea and can eventually cause vision problems. The problem is usually obvious by the time the dog reaches its first birthday and if it is severe should be surgically corrected. The problem is very common in the Chow chow, Bullmastiff, Mastiff and Shar-Pei. Entropion is also seen in the giant breeds such as the Bernese mountain dog, Great Dane, Great Pyrenees, Newfoundland and Saint Bernard. The condition is also seen in a wide range of hounds, spaniels, toys, sporting and working breeds that are too numerous to list.
Glaucoma is an enlargement of the eye caused by a defect in the eye’s drainage capability which allows pressure to build up and impair vision. Treatment of glaucoma must be started as soon as it is detected in order to save the eye. Mild cases can be treated by medications but severe cases are painful and will require the removal of an eye. Dogs can adapt quite well to living with one eye or even without eyes. Primary glaucoma is usually inherited and is common in the: Alaskan malamute, American cocker spaniel, Basset hound, Beagle, Boston terrier, Chow Chow, Dalmatian, Great Dane, Fox terrier (wire and smooth), Poodle (toy, miniature and standard), Samoyed, Siberian husky, and Welsh Springer spaniel.
Lens luxation is a disorder where the lens is positioned in the wrong part of the eye – either too far forward or backward. The primary or inherited disorder that occurs in younger animals is a forward displacement of the lens that can result in glaucoma. Symptoms are intense pain, tearing of the eye and reduced vision and can lead to blindness if not treated. This disorder is most commonly seen in the Border collie, Brittany spaniel, Cardigan Welsh Corgi, and in a number of terrier breeds including the: Fox terrier (wire and smooth), Bull terrier, Scottish terrier, Sealyham terrier, Skye terrier, Tibetan terrier and Welsh terrier.
Progressive Retinal Atrophy (PRA) is a hereditary disease which kills off the pigment cells in the center of the retina. Both eyes are affected and initially the dog cannot perceive stationary objects. As the disease progresses, the dog will experience night blindness and will not want to go outside at night and will start bumping into fixed objects. After a year or two the condition progresses until there is a complete loss of vision. There are two types of PRA – early onset which starts a few weeks after birth and later onset which starts after the dog’s first birthday.
Early onset PRA is common in the: Cardigan Welsh Corgi, Collie, Cairn terrier, Gordon setter, Great Dane, Irish setter, miniature Schnauzer, and Norwegian elkhound. Less common is day blindness in the Alaskan malamute and retinal degeneration in the male Borzoi. Later onset PRA is common in a large number of breeds which are too numerous to list here. There is a slower progressive disease called Central Progressive Retinal Atrophy (CPRA) in which the rate of vision is significantly slower than the other forms of PRA and may not deteriorate into total blindness. CPRA is usually restricted to dogs in the United Kingdom.
2. Musculoskeletal Disorders
There are a number of common inherited diseases for which reputable breeders screen their breeding stock. The Orthopedic Foundation for Animals (OFA) has specialists evaluate x-rays, DNA, thyroid, cardiac and other tests and register the results. A prospective buyer should ask to see the OFA results for the dog’s parents.
Chondrodysplasia or dwarfism in the legs is a disease that causes malformation of the carpal and radius bones of the front legs resulting in a stunted and bowed look. Puppies born with this disease do not show any signs until they grow older. The disease can be painful and often the only choice is to euthanize the dog. This disease is most common in the Alaskan malamute and the Beagle.
Elbow dysplasia is a hereditary disease in which the elbow joints of the front legs are malformed. Lameness usually makes its appearance around 7 to 10 months of age and is treated by anti-inflammatories and also surgery. All breeds are susceptible to the disease but it is most common in large male breeds. These breeds include the: Basset hound, Bernese mountain dog, Bloodhound, Bouvier des Flandres, Chow Chow, German shepherd, Golden retriever, Great Pyrenees, Irish wolfhound, Labrador retriever, Mastiff, Rottweiler, Saint Bernard and Weimaraner.
Hip dysplasia is a disorder that results when there is a loose fit of the ‘ball and socket’ hip joint and the ball may continuously slide part way out of the socket. Over time this will cause osteoarthritis in the joint and the dog will become lame and weak in the hind end. Some relief can be found with the use of nutriceuticals such as glucosamine and chondroitin, and anti-inflammatories. Some cases are so bad that the dog must have surgery or be euthanized. Ensuring that your dog isn’t overfed and overweight can delay the onset of hip dysplasia. Hip dysplasia is the most common inherited orthopedic disease in large and giant breeds and many medium-sized breeds as well.
Panosteitis or ‘pano’ is a common condition which suddenly causes lameness in a growing puppy or adolescent dog. The lameness is a result of inflammation of the long bones of the front and hind legs and can be mild to severe. A veterinarian will probably prescribe pain medication and ask you to restrict exercise. Affected puppies usually grow out of the condition as they mature. It is most common in male medium- to giant-sized dog breeds which include the: Basset hound, Doberman pinscher, German shepherd, Labrador retriever and Rottweiler.
Luxating Patella (Patellar luxation) or slipped stifle is a hereditary condition where the knee cap slips out of its groove. In some cases, the kneecap will slip back into place while in other cases; a veterinarian may need to put it back in place. If it is not corrected through surgery, then osteoarthritis will usually result. It is commonly seen in the Affenpinscher, Australian terrier, Basset hound, Boston terrier, Chihuahua, Cavalier King Charles Spaniel, English Toy Spaniel, Maltese, Papillon, Pekingese, Pomeranian, Poodle (miniature and toy) and Lhasa Apso.
3. Heart Disease
Aortic Stenosis (AS) and Sub Aortic Stenosis (SAS) are caused by a narrowing of the aorta (main blood vessel) as it leaves the left side of the heart. The heart must work harder to push the blood through the opening and this can cause problems and even death. This condition is hard to detect but with moderate to severe stenosis, it is necessary to restrict exercise. This disease is one of the most common heart conditions seen in large breed dogs. It is quite common in Newfoundland dogs and also fairly common if Boxers, Golden retrievers and Rottweilers.
Mitral valve disease is a heart condition resulting from a leaky valve causing a backflow of blood into the left atrium of the heart. This is one of the common forms of heart disease seen in older dogs. However some early development of mitral valve dysplasia is inherited in small dogs such as the Bull terrier, Cairn terrier, Cavalier King Charles spaniel and Miniature poodle.
Tricuspid valve dysplasia is a heart condition resulting from a leaky valve causing a backflow of blood into the right atrium of the heart. Mild cases will allow the dogs to live normal lives, while severe cases will cause early death. The most commonly affected breed is the Labrador retriever.
Cardiomyopathy is a disease of the heart muscle where there is a loss of the normal contracting abilities of the ventricles. The heart is forced to work harder which can result in irregular beats and even death. The disease is most common in Doberman pinschers but is also seen in giant breed dogs such as the: Great Dane, Irish wolfhound, Saint Bernard and Scottish deerhound.
4. Endocrine Disorders
Diabetes mellitus is the inability of the dog’s system to correctly process carbohydrates and sugars. In some dogs diabetes doesn’t develop until middle age and can be associated with weight gain. In the inherited form of diabetes, the disease is usually apparent by 6 months of age and is indicated by puppies that drink and eat more than normal but do not gain weight very quickly. Breeds that show early signs of inherited diabetes can include the: Alaskan malamute, Chow chow, Doberman pinscher, English Springer spaniel, Golden retriever, Labrador retriever, Miniature Schnauzer, Old English Sheepdog, Poodle, Schipperke and West Highland white terrier.
Hyperthyroidism occurs when the dog’s thyroid produces insufficient thyroid hormone which can result in lower energy levels and weight gain. Other symptoms can include changes to the dog’s coat – dull, dry and hair loss and intolerance to cold. A number of middle-aged mid- to large breed dogs can acquire hypothyroidism but are too numerous to list here. The inherited form or congenital hypothyroidism is much less common and will result in stunted growth in the puppy and in other abnormalities.
5. Blood Disorders
Auto-immune hemolytic anemia (AIHA) results when the new red blood cells are destroyed by the immune system faster than new ones are produced. This results in anemia and is most common in the English cocker spaniel, old English sheep dog, and Poodle.
Von Willebrand’s disease (VWD) is a common inherited bleeding disorder or hemophilia. It is caused by a reduction of the Von Willebrands factor in the blood and is usually fairly mild. Affected animals are usually prone to nose bleeds and care must by taken during any surgery. The disease is most common in the Doberman pinscher breed and fairly common in the Scottish terrier and the Shetland sheep dog. The disease is also occasionally seen in most other breeds.
6. Other diseases
Bloat which is also called canine gastric delation- volvulus (CGDV) is a dangerous and life-threatening condition. The stomach swells with gas and fluid, then begins to twist and traps the gas inside. This twisting will shut off the blood supply to the digestive organs and if the dog is not rushed to a veterinarian he can go into shock and die. The exact cause is unknown but certainly swallowing air while quickly eating a large meal and exercising soon after a meal are contributing factors. The condition can be detected in the initial stages when you see him in distress and pain and his stomach is taut and swollen soon after eating. The best treatment for bloat is prevention:
a. Feed your dog several smaller meals rather than one large one
b. Don’t exercise your dog for an hour after eating
c. Don’t let your dog drink excessive amounts of water all at one time
e. Don’t overfeed your dog and encourage him to eat slowly
f. If you are feeding your dog a dry food then add water to it to encourage faster digestion
All large, deep-chested dog breeds are susceptible to bloat. This includes the: Labrador retriever, Bloodhound, Bullmastiff, Doberman pinscher, Greyhound, Great Pyrenees, Great Dane, German shepherd, Irish setter and Weimaraner.
Congenital deafness is inherited and occurs in one or both ears due to the degeneration of the inner ear structure after a few weeks of age. Deafness seems to be linked to coat colors in breeds with piebald or merle color genes or breeds with more white in their coats. Congenital deafness is very common in the Dalmatian but is also prevalent in Australian shepherds, Border collies, Bull terriers, Doberman pinschers, English setters, Pointers, Rottweilers and Shetland sheepdogs.
Epilepsy is a hereditary disease that occurs in all breeds and mixed breeds. The symptoms vary in severity but the dog will usually foam at the mouth and appear to be chewing on something. This will be followed by the dog collapsing, legs going rigid, leg movement, and uncontrolled bladder or bowel movement. Seizures can last for several minutes and during recovery the dog appears dazed and wobbly. Frequent epileptic seizures can be treated by drugs similar to those used for humans but your vet will first want to rule out other causes. You should not breed a dog with this condition. While this condition can be present in all breeds, it is most prevalent in American cocker spaniels, Australian shepherds, Beagles, Border collies, Golden retrievers, Italian greyhounds, Irish setters, Miniature pinschers, and Shetland sheepdogs.
Kidney diseases include many inherited disorders ranging from renal dysplasia to an inability to process protein correctly. While the underlying problem varies between breeds, the kidneys start to deteriorate by the end of the first year and will fail before middle age. These diseases affect many breeds but the most common are the: Bernese Mountain dog, Bull terrier, Cairn terrier, Chinese Shar-Pei, Doberman pinscher, English cocker spaniel, Golden retriever, Lhasa Apso, Norwegian elkhound, Pembroke Welsh Corgi, Samoyed, Standard Poodle, and Soft-coated Wheaten terrier.
Respiratory disorders are most commonly seen in brachycephalic breeds and range from tracheal narrowing to respiratory difficulties because the face is very short. Tracheal narrowing is most common in the English bulldog and Boston terrier while respiratory difficulties occur in the same two dogs as well as the Cavalier King Charles spaniel, Chinese Shar-Pei, French bulldog, Lhasa Apso, Pekingese and Shih Tzu.
Zinc-responsive dermatosis occurs when the dog fails to absorb enough zinc from its food because it has a higher than normal requirement. The condition results in scaling and crusting of the skin which can be seen on the dog’s nose, paw pads and stomach. Treatment usually consists of zinc supplements added to the dog’s diet. The most commonly infected breeds are the northern ones such as the Alaskan Malamute, Samoyed and Siberian Husky. Young and rapidly growing Doberman pinschers and Great Danes sometimes have a transient zinc deficiency and exhibit similar symptoms.
There are many more hereditary diseases that are prevalent in a number of dog breeds and can seriously affect your dog’s health. Contact your breed’s national breed club for a list of the most common inherited genetic diseases.