Cerebellar Abiotrophy in Dogs

Cerebellar abiotrophy is a degenerative disease of the central nervous system that has been found in both animals and humans. There are several types of cerebellar abiotrophy, which include neonatal (before birth), postnatal (after birth), and extrapyramidal nuclear abiotrophy, in which other cells besides Purkinje cells are destroyed. This disease has been reported in many different breeds such as the Beagle, German Shepherd, Old English Sheepdog, German Boxer, and Bullmastiff. The condition is usually noticed within the first few months of life, but in some dogs, it may not be seen for several years. In extrapyramidal nuclear abiotrophy, the disease progresses at a faster rate and includes symptoms not seen in neonatal and postnatal abiotrophy, like seizures and blindness.

The cerebellum is the part of the brain that controls movement and motor function. Those dogs with cerebellar abiotrophy usually show symptoms of exaggerated movements leg movements and goose stepping (overshooting or undershooting the intended step) as well as the lack of menace (blink) response. Cerebellar abiotrophy starts before birth when the cells (Purkinje cells) in the cerebellum mature before they are supposed to and then die, which creates the signs of lacking balance and incoordination. This is a degenerative and progressive disease that lowers the quality of life in most dogs that are affected. Most often, the owner chooses to euthanize to end the suffering within the first year of life.

If your puppy has cerebellar abiotrophy, the signs may be obvious at birth or may not be seen until weeks or months later, depending on whether the condition is neonatal or postnatal. Also, there is a third type of cerebellar abiotrophy that affects other brain cells besides Purkinje cells so there are other symptoms if your dog has that type (extrapyramidal nuclear abiotrophy). The most often reported symptoms are:

Neonatal Cerebellar Abiotrophy

• Seen at birth
• Inability to nurse
• Falling
• Cannot walk or walks with goose stepping
• Muscle tremors

Postnatal Cerebellar Abiotrophy

• Seen weeks or months after birth
• Stiff walking
• Wide stance
• Incoordination
• Falling
• Head shaking
• Hyperactivity and aggression
• Overreaching and overstepping
• Muscle tremors
• Knuckling feet
• No menace reflex
• High stepping

Extrapyramidal Nuclear Abiotrophy

All the above symptoms as well as:

• Confusion
• Blindness
• Seizures

Types

• Neonatal cerebellar abiotrophy (very uncommon) – Purkinje brain cells are spontaneously destroyed before birth, causing the symptoms to be noticeable at birth
• Postnatal cerebellar abiotrophy – The Purkinje brain cells are normal at birth but start to spontaneously degenerate within a few weeks to months
• Cerebellar and extrapyramidal nuclear abiotrophy – Affects other brain cells besides the Purkinje cells

The cause of cerebellar abiotrophy is not known, but it is presumed to be congenital in certain breeds such as:

Neonatal Cerebellar Abiotrophy

• Samoyed
• Beagle

Postnatal Cerebellar Abiotrophy

• Old English Sheepdog
• Lagotto Romagnolo
• Gordon Setter (about 6-12 months of age and progresses slowly)
• German Shepherd (about 6 months of age)
• German Boxer
• English Springer Spaniel
• English Pointer
• Bullmastiff
• Bull Terrier
• Brittany Spaniel (starts in later age, about 10 years old)
• Border Collie
• Bernese Mountain Dog
• Bern Running Dog
• Australian Kelpie
• American Staffordshire Terrier (uncommon)
• Airedale Terrier (uncommon, 12 weeks of age)
• Labrador Retriever (uncommon, 6-12 weeks of age and progresses rapidly)

Cerebellar and Extrapyramidal Nuclear Abiotrophy

• Miniature Poodle (4-8 weeks of age and progresses rapidly)
• Rough Coated Collie
• Kerry Blue Terrier (2-12 weeks of age)

Because there are no exclusive tests to diagnose cerebellar abiotrophy, the veterinarian will most likely perform various tests to rule out other conditions that have similar symptoms such as cerebellar hypoplasia and other central nervous system disorders. Also, the veterinarian will need to know your dog’s medical history and what symptoms you have noticed. A complete physical examination will be done including vitals, palpation, and auscultation. Your dog’s reflexes will be tested to determine if his menace reflex is working properly. Blood tests may be ordered, such as a biochemical analysis, complete blood count, bacterial and fungal cultures.

In addition, the veterinarian will probably want to get some tissue samples for biopsy. Histological results will likely show thinned cerebellar folia and lack of normal Purkinje cells. The cells that are found will be damaged and shrunken. A cerebral spinal fluid analysis should be done to rule out infections such as distemper, encephalitis, toxoplasma. A magnetic resonance imaging (MRI) is used to check the size of the cerebellum. Other imaging may be necessary to get a more detailed view.

There is no effective treatment for cerebellar abiotrophy, but there are ways to help your dog be more comfortable and have a better quality of life while he is still able.

Medications

There are certain medications that can relieve the pain and may help slow the progression of the disease. Some of these are amantadine for pain, buspirone for anxiety, coenzyme Q-10 for protecting cells from damage, and carnitine for improving nerve impulse transmission.

Therapy

To help relieve pain and improve circulation, aqua therapy and massage therapy can both be effective.

The prognosis for cerebellar abiotrophy is grave. The majority of dogs will become so crippled that at some point the owner will have no other option but to choose euthanasia to relieve his suffering. However, the length of this disease varies greatly from one breed to another. Some breeds such as Gordon Setters, Brittany Spaniels, Old English Sheepdogs, and American Staffordshire Terriers do not show any symptoms until adulthood from 10 – 12 years of age. Continue to see your veterinarian for supplemental treatment and advice.