It has also been observed in the Curly horse, Miniature horse, the Gotland Pony, one Eriskay Pony, and possibly the Oldenburg. Most foals appear normal at birth, with symptoms noticeable at an average age of four months, though there have been cases where the condition is first seen shortly after birth and other cases where symptoms are first recognized in horses over one year of age. Breeds DNA tested that reveal some carrier lines, but to date no affected animals, include the Welsh pony and the Trakehner. However, other breeds heavily influenced by Arabian breeding, such as the Thoroughbred and the American Saddlebred, do not appear to carry the mutation. In horses, cerebellar abiotrophy is believed to be linked to an autosomal recessive gene. This means it is not sex-linked, and the allele has to be carried and passed on by both parents in order for an affected animal to be born. Horses that only carry one copy of the gene may pass it on to their offspring, but themselves are perfectly healthy—without symptoms of the disease. Because it is recessive, the allele for cerebellar abiotrophy may pass through multiple generations before it is expressed. Cerebellar abiotrophy is sometimes misdiagnosed. Though the symptoms are quite distinguishable from other neurological conditions, it has been confused with Wobbler's syndrome, equine protozoal myeloencephalitis, and injury-related problems such as a concussion. A DNA test which identifies markers associated with cerebellar abiotrophy became available in 2008. The test was refined to identify the most likely mutations, and retesting of earlier samples based on an earlier indirect marker test developed by UCD, indicated a 97% accuracy rate for the old test relative to the newer version, with no false negatives. The causative mutation was identified in 2011. Research on cerebellar abiotrophy and the DNA test was led by the Veterinary Genetics Laboratory at the UC Davis School of Veterinary Medicine. Researchers working on this problem include Drs. Cecilia Penedo and Leah Brault. Ann T. Bowling made significant early contributions to the genetics research on cerebellar abiotrophy. Cerebellar abiotrophy has been seen in the Australian Kelpie, Gordon Setter, Border Collie, Labrador Retriever, Airedale, English Pointer, Scottish Terrier, Kerry Blue Terrier, Miniature Schnauzer, Lagotto Romagnolo, and other dog breeds.