Off Balance

The vet says one of my puppies has cerebellar hypoplasia. What is that?

Cerebellar hypoplasia in dogs is a condition where the cerebellum, which is the part of the brain that controls balance and coordination, does not develop completely. The cerebellum is also known as the hindbrain. It is located at the back of the head, just above and behind where the spinal cord connects to the brain itself.

The cerebellum is responsible for maintaining a dog’s balance by detecting subtle shifts in balance and sending signals to the rest of the body to adjust and move to keep upright. It also coordinates muscles to work together so the body moves smoothly. The cerebellum will coordinate eye movements and help the body learn gross and fine motor skills.

The term “hypoplasia” means the under development of an organ. When the cerebellum does not develop properly, dogs become uncoordinated and do not have the ability to perform fine motor skills.

What causes cerebellar hypoplasia?

Cerebellar hypoplasia occurs when something negatively impacts the development of the cerebellum while the puppy is in utero, which means before birth while still inside the mother. It can be caused by genetic mutations and is known to be an inherited disorder in Airedale Terriers, Chow Chows, Boston Terriers and Bull Terriers.

Other factors that may cause cerebellar hypoplasia include poor nutrition of the bitch and infectious diseases, including canine herpesvirus, canine distemper, fungal diseases, tick-borne diseases and accidental migration of intestinal parasites into the brain. Exposure to toxins and brain injury or trauma can also cause abnormal underdevelopment of the cerebellum.

What are the signs of cerebellar hypoplasia?

The signs of cerebellar hypoplasia in dogs are associated with movement, especially intentional movement. They may exhibit head bobbing, abnormal head swaying, or flinging upward and backward of the neck and head. Dogs can display “intention tremors,” where a stretched-out limb or head shakes more and more violently as it approaches its target, like eating out of a bowl. Some dogs have an uncoordinated, or ataxic, gait with stilted, high-stepping “toy soldier” leg movements.

At rest, dogs sometimes display a “truncal sway.” This happens because their spinal muscles have lost their fine-tuning. The spine and everything attached to it are pulled back and forth in a struggle to maintain balance. These dogs may stand with their legs spread wide in order to steady themselves. The muscles surrounding the eyes have also lost this fine-tuning, leading to a rhythmic flicking of the eyes known as nystagmus.

Affected puppies are abnormal from birth. They show signs of cerebellar disease, including intention tremors and truncal sway, before they even open their eyes. As they begin to walk, they show uncoordinated gait and poor balance. They have poor judgment of distance and fall frequently.

Signs of cerebellar hypoplasia do not tend to get worse over time. They stay the same, or in some milder cases, the dogs seem to get better as they adjust to their balance challenges.

How is cerebellar hypoplasia diagnosed?

In order to diagnose cerebellar hypoplasia, veterinarians rely on a combination of clinical signs and breed disposition. Information about the dog’s birth and mother is particularly helpful, as this condition develops in utero.

Symptoms can be similar to some metabolic or toxicological conditions. Examples of these would be tremors due to poisoning with strychnine, extremely low thyroid levels or unregulated diabetes mellitus. Diagnostic testing to help confirm the diagnosis involves a variety of tests to rule out other diseases. Such tests can include cerebrospinal fluid analysis, complete blood cell (CBC) analysis, blood biochemistry, thyroid testing, urinalysis, brainstem auditory-evoked response, and CT or MRI scans of the brain.

Is there treatment for cerebellar hypoplasia?

There is no treatment or cure for this condition. Certain medications may be prescribed to control certain symptoms. Mildly affected dogs can lead a long life, but you may need to restrict what the dog is allowed to do to help prevent accidents or injury. You may have to help your dog eat, or you may need to prevent your dog from climbing stairs or swimming to avoid injury.

Dogs with cerebellar hypoplasia are not good candidates for group activities, such as visits to the dog park or doggy daycare. However, this decision should be made on an individual basis with the advice of your veterinarian.

Are there ways to prevent cerebellar hypoplasia?

Since cerebellar hypoplasia happens while the puppies are in utero, the only way to help prevent it is to make sure the pregnant bitch is healthy and safe. She should be fed a complete and balanced diet that is formulated for growth and lactation. Check with your veterinarian before giving any new or additional supplements to a pregnant bitch.

Make sure all vaccinations are up to date and boosted before the dog gets pregnant. Check for and treat any internal or external parasites. Verify that products used are labeled safe for pregnant or nursing dogs.

Prevent access to any household or backyard toxins. Provide a secure enclosure to prevent trauma or injury.

What are DINGS?

DINGS is a term used by the Doberman Pinscher breed community to describe puppies affected with deafness and vestibular dysfunction (DVD). This disease is both congenital (meaning the puppies are born with it) and inherited (meaning the parents pass the genes to their offspring). DINGS was first reported in Dobermans in the early ’80s and was characterized as a disease in 1992. It is estimated to affect 13 percent of all Dobermans.

Puppies affected with DINGS display head tilting and loss of balance. They are often described as “bobble-headed.” The signs become evident when the puppies are one to two weeks old. DINGS-affected puppies may struggle to find their mother’s nipples and are often pushed away by their mothers. These puppies cry constantly and have a hard time getting comfortable.

Why are the DINGS puppies in distress?

The cochlea, which is the part of the inner ear that produces nerve impulses in response to sound vibrations, does not function properly in DINGS puppies. The vestibular system, which is located in a dog’s inner ear, can malfunction and cause vertigo, dizziness, imbalance, vision problems, hearing problems and problems with spatial orientation. Puppies with these symptoms who cannot hear can suffer severe distress. They express that distress by constant crying and disoriented movement.

How is this condition treated?

There is no treatment for this disorder.

Is there a test to see if my dog will produce DINGS puppies?

Reliable genetic testing is important for determining optimal breeding pairings. These tests are usually cheek-swab tests that are easy for owners to do at home. Genetic testing of the PTPRQ gene in Doberman Pinschers will determine whether or not a dog is a genetic carrier of DVD. The DINGS genes are inherited in an autosomal recessive fashion. This means that puppies must receive two copies of the mutated gene — one from each parent — to develop the disease.

In general, carrier dogs do not have features of the disease, but when bred with another carrier of the same mutation, there is a risk of having affected puppies. To avoid the possibility of producing affected puppies, matings between known carriers is not recommended.