Sacrocaudal Dysgenesis in Dogs

Sacrocaudal dysgenesis is a congenital disorder of the spinal cord most often seen in dogs who were bred to be tailless, such as Bulldog breeds and Pugs. Many cases of sacrocaudal dysgenesis are asymptomatic. However, on rare occasions, this disformity can lead to an inability to control portions of the hind end. This can result in incontinence or paralysis and is usually apparent within the first few weeks of the animal’s life. Badly afflicted animals are frequently euthanized.

Sacrocaudal dysgenesis is a disorder in which a dog is born with a malformation causing a truncation of the spine, and is most common in dogs bred to be tailless.

Sacrocaudal dysgenesis is a congenital disorder. When this disorder is severe, it will affect a puppy’s ability to move its back legs, as well as inhibiting its capacity to control its bladder and bowels. Muscle tone in an afflicted puppy will be lacking, and the animal may appear to be in pain or discomfort. 

• Lack of muscle tone
• Lack of bladder and bowel control
• Appearance of pain

Types

Sacrocaudal dysgenesis is one of only a few similar types of congenital spinal malformations. Other inborn malformations that can affect the functionality of the hind end include:

Hemivertebrae - Dogs with this disorder have wedge-shaped vertebrae that cause an angle to be formed in the spine; this disease also causes a narrowing of the spinal canal as well as increases the chances of spinal fracture and is the most likely of the congenital spinal disorders to be associated with neurological problems 

Spina Bifida - This disorder results in the improper fusing of the vertebrae and in some cases portions of the spinal cord squeeze out through gaps in the spine; this disorder is often found concurrently with sacrocaudal dysgenesis

Sacrocaudal dysgenesis is a congenital disorder and is most common in dogs bred for the feature of taillessness, such as Bulldogs and Boston terriers. Some of the breeds that are somewhat more prone to developing spinal disorders like sacrocaudal dysgenesis include:

• Boston Terrier 
• English Bulldog
• French Bulldog
• Old English Sheepdog
• Pugs

A puppy who is unable to walk normally as compared to his brothers and sisters should be evaluated by a veterinary professional. When you transport the afflicted puppy to the veterinary clinic for evaluation, it is important to remember that very young puppies cannot regulate their body temperatures, and their eyes may be too sensitive to handle bright sunlight. Your veterinarian will get as much medical and developmental history from you as she can and will manually inspect the puppy. 

In order to make a final diagnosis, imaging techniques including x-rays will be used to better visualize the spinal column. The x-rays, also known as radiographs, will show the defect and will help to uncover if concurrent disorders such as spina bifida are also present. Computer tomography (CT) scans and magnetic resonance imaging (MRI) may help your puppy’s doctor pinpoint not only where the sacrocaudal deformity is, but also where any other spinal abnormalities may be lurking.

There is no effective treatment for this or other deformities of the spinal column. Attempts to surgically correct congenital disorders of the spine have been unsuccessful, and drug management and dietary changes have no meaningful impact on sacrocaudal dysgenesis or similar malformations. In situations where no outward symptoms develop, no treatment may be needed. In the event that the damage affects the puppy neurologically, the decision to treat or to euthanize will be guided by the projected quality of life and the owner’s willingness to take on the extra care that may be required. 

If severe signs of sacrocaudal dysgenesis are present, then the puppy may be in a great deal of pain and discomfort. Many caring pet owners chose euthanasia instead of subjecting a dog to the lifelong disability and discomfort associated with a severely limiting deformity of this nature. In situations where the disability is not so severe, adjustments in lifestyle can be made to accommodate the animal and make its life more comfortable and enjoyable.

Dogs who are afflicted with this disorder may require specialized care, depending on the amount of disability that it has caused. In some cases, only a minor weakening of the hind legs occurs and the dog is able to live a relatively normal life. In other cases, the dog’s owner may need to assist them in standing, or they may require diapers or a strict feeding and eliminating schedule if incontinence is an issue. Standing and walking may be achieved even for paralyzed dogs, using either a harness and sling that allows you to hold up the hind end for your dog, or a specially designed wheelchair for dogs.