Bone Deformity and Dwarfism in Dogs

Osteochondrodysplasia is an abnormality in the growth and development of bone and cartilage leading to decreased bone growth and bone deformities. Achondroplasia is a form of osteochondrodysplasia commonly known as dwarfism, in which the bones fail to grow to the expected size based on breed conventions. These conditions are caused by mutations in the growth factor receptor gene.

As these disorders are caused by genetic mutations, they are hereditary. Bone deformity and dwarfism can be detected very early in life. Dwarfism may be detected as early as fourteen days if a dog is not gaining weight at the same rate as its littermates, and skeletal deformities will begin to be visible around eight to twelve weeks of age. In extremely severe cases in which the deformity impedes bodily functions, dogs can die as early as days after birth.

Some breeds of dogs have been bred through the selective encouragement of achondroplasia to achieve short limbs, such as the Dachshund, Skye Terrier and Welsh Corgi.

Dogs of the Great Pyrenees, Alaskan Malamute, Samoyed, Scottish Deerhound, Labrador Retriever, Basset Hound, and Norwegian Elkhound breeds are predisposed to osteochondrodysplasia, while dogs of the Bulldog, German Shepherd, Basset Hound, Boston Terrier, Pug, Pekingese, Japanese Spaniel, Shih-Tzu, Beagle, English Pointer, Scottish Terrier and Cocker Spaniel breeds are predisposed to achondroplasia.

• Abnormally large head
• An underbite accompanied by a short nose
• Spinal deviation
• Bowing of forelimbs
• Constricted nostrils
• Enlarged joints
• Poor growth, lack of growth
• Abnormal bone shape
• Crooked teeth (caused by short jaw)
• Larger than normal head shape

Bone deformity and dwarfism are an autosomal dominant genetic disorder, which means that it is passed on equally through male and female dogs, and can occur in dogs for which only one parent carries the gene.

Knowing your dog’s genetic background is extremely helpful in aiding diagnosis. Additionally, a thorough report to the veterinarian will include the onset of the symptoms or your noticing them, as well as any relevant medical history. A complete blood count, chemical blood profile and urinalysis will be conducted in order to rule out possible other causes for your dog’s symptoms; however, if your dog has a form of osteochondrodysplasia, these tests will come back normal.

X-rays will need to be taken of the affected limbs and likely the entire body. These will show abnormalities in the bone structure and provide insight on bone growth, as well as determine the extent of any spinal deviation. A small tissue sample from your dog’s bones may be taken for extensive testing by a veterinary pathologist.

Treatment options will depend upon the severity of the deformity. In a minority of cases, surgical correction may be attempted. However, the results of surgery have not been positive enough to make this a likely treatment option. Pain as a result of deformities may be treated with pain relievers and/or anti-inflammatory medications. Your dog’s comfort and ability to lead a healthy life will depend upon the severity of the deformity and how it impacts your dog’s functionality. Many dogs will be able to live a normal life with proper management; however, in severe cases accompanied with overwhelming pain and reduced functionality, euthanasia may be considered.

Because the overwhelming majority of cases cannot be treated, your dog’s prognosis depends upon whether or not she can function and achieve comfort with her deformity. If your dog has been prescribed pain medication for comfort, always follow the instructions and consult the veterinarian if you believe that your dog may require an increased dose—never determine this for yourself.

The veterinarian may prescribe a reduction in your dog’s activity, and this will be something you must adapt to in order to not strain your dog. Additionally, your dog will be more likely to develop arthritis and obesity. Keep your dog on a healthy, nutritious, diet and continually monitor his weight and physical well-being. Always consult the veterinarian if you notice changes in your dog’s health, functioning, or weight.

To avoid passing this trait on, you should not breed your dog. The veterinarian will advise that you get your dog spayed or neutered in order to prevent accidental breeding. Additionally, your dog’s parents and siblings should not be bred for this reason. It is important that you notify owners of these dogs of your dog’s condition if possible.

The symptoms of genetic conditions can be expensive to treat. Fortunately, some insurers cover genetic conditions. To avoid high vet care expenses, secure pet health insurance today. The sooner you insure your pet, the more protection you’ll have from unexpected vet costs.