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Bandera's Neonatal Ataxia

Bandera's Neonatal Ataxia (BNA), discovered in the Coton de Tulear, is a severe brain problem that affects a puppy's ability to move its body properly.

Key Signs

Problems standing and walking, Head nodding, Intention tremors

Age of Onset

0 to 2 yrs

Juvenile onset


Autosomal Recessive

For autosomal recessive disorders, dogs with two copies of the variant are at risk of developing the condition. Dogs with one copy of the variant are considered carriers and are usually not at risk of developing the disorder. However, carriers of some complex variants grouped in this category may be associated with a low risk of developing the disorder. Individuals with one or two copies may pass the disorder-associated variant to their puppies if bred.

Likelihood of the Condition

High likelihood

At risk dogs are highly likely to show signs of this disease in their lifetime.

What to Do

Here’s how to care for a dog with BNA

Partner with your veterinarian to make a plan regarding your dog’s well-being, including any insights provided through genetic testing. If your pet is at risk or is showing signs of this disorder, then the first step is to speak with your veterinarian.

For Veterinarians

Here’s what a vet needs to know about BNA

First signs are observed as soon as the puppies start to move at around 2 weeks of age. Usually, affected puppies are unable to stand or walk on their own and they appear to move as if they were swimming. Other signs are nodding of the head, intention tremors, and jerky movements of the eyes. Clinical signs do not usually progress, but due to their severity affected puppies are usually euthanized.

For affected dogs clinical sign progression should be carefully monitored, ensuring the dog is as comfortable as possible. Affected dogs are usually euthanized on welfare grounds, although some dogs may live longer with significant support.

For Breeders

Planning to breed a dog with this genetic variant?

There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.

This disease is autosomal recessive meaning that two copies of the mutation are needed for disease signs to be shown. A carrier dog with one copy of the BNA mutation can be safely bred with a clear dog with no copies of the BNA mutation. About half of the puppies will have one copy (carriers) and half will have no copies of the BNA mutation. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. Please note: It is possible that disease signs similar to the ones caused by the BNA mutation could develop due to a different genetic or clinical cause.

Technical Details

Gene GRM1
Variant Insertion
Chromosome 1
Coordinate Start 37,564,500
Coordinate End 37,564,501

All coordinates reference CanFam3.1

References & Credit

Credit to our scientific colleagues:

Zeng, R., Farias, F. H. G., Johnson, G. S., Mckay, S. D., Schnabel, R. D., Decker, J. E., … O’Brien, D. P. (2011). A Truncated Retrotransposon Disrupts the GRM1 Coding Sequence in Coton de Tulear Dogs with Bandera’s Neonatal Ataxia. Journal of Veterinary Internal Medicine, 25(2), 267–272. View the article

Coates, J. R., O’Brien, D. P., Kline, K. L., Storts, R. W., Johnson, G. C., Shelton, G. D., Patterson, E. E., & Abbott, L. C. (2002). Neonatal cerebellar ataxia in Coton de Tulear dogs. Journal of Veterinary Internal Medicine. View the article