Presa Canario
The tested variant with the highest allele frequency is Canine Multifocal Retinopathy 1, at 9.4% among the 64 Presa Canarios tested (Donner 2023; gene copies, not dogs), then Degenerative Myelopathy (9.4%) and Chondrodystrophy and Intervertebral Disc Disease Risk (6.3%).
Which disease variants turn up in Presa Canarios?
From a panel of 250 Mendelian-disease variants screened in 1,054,293 dogs (Donner et al. 2023), 7 turn up in Presa Canarios at observable frequency. The figure beside each is its allele frequency. Of the gene copies tested in this breed, the share that carry the variant. Every dog carries two copies, so this is not the share of dogs. It is not clinical risk. Most recessive variants require two copies for disease expression; many dominant variants show incomplete penetrance. Read this as a population fingerprint of what's in the gene pool, not a per-dog prediction.
FGF4what this gene does
FGF4 influences leg length by affecting bone growth, leading to shorter legs in certain breeds.
For your dog: If your dog is from a breed known to carry this gene, it's worth discussing spinal health with your vet, but being a carrier doesn’t guarantee problems.
BEST1what this gene does
BEST1 is a gene that helps maintain the health of the retina, the light-sensitive layer at the back of the eye. It plays a role in keeping the cells in the retina functioning properly.
For your dog: If your dog is from a breed known to carry BEST1 variants, it’s worth discussing retinal health with your vet, especially if you notice any vision changes.
SOD1what this gene does
SOD1 is a gene that helps protect cells from damage caused by harmful molecules called free radicals.
For your dog: If your dog is a carrier of SOD1 variants, it's worth discussing with your vet, but remember carrier status doesn't mean your dog will get the disease.
SLC3A1what this gene does
SLC3A1 is a gene that helps transport certain amino acids in the kidneys. It plays a key role in preventing the buildup of cystine, which can form stones.
For your dog: If your dog is from a breed known to carry SLC3A1 variants, it’s worth discussing cystinuria risks with your vet, especially if urinary issues arise.
ANO6what this gene does
ANO6 is a gene that helps regulate how blood cells expose certain signals on their surface, which is important for normal blood clotting.
For your dog: If your dog is from a breed known to carry ANO6 mutations, it’s worth discussing with your vet before any procedures to ensure bleeding risks are managed.
RPGRIP1what this gene does
RPGRIP1 is a gene involved in the function of photoreceptor cells in the eye, which help dogs see in different light conditions.
For your dog: If your dog belongs to a breed known to carry RPGRIP1 mutations, it’s worth discussing with your vet to understand the risks and monitor eye health.
SLC2A9what this gene does
SLC2A9 is a gene that helps regulate uric acid levels in a dog's body. It plays a role in how the kidneys handle this substance.
For your dog: If your dog is one of the breeds known to carry this gene variant, it’s worth discussing with your vet to understand any potential urinary health concerns.
What these results mean for a Presa Canario
About 6 in every 100 copies of this gene in the 64 Presa Canarios tested carry this change (Donner 2023).
- Extra copies of a growth gene called FGF4 shape a dog's legs and back. The copy on chromosome 12 is the one linked to disc disease. The copy on chromosome 18 makes legs shorter.
OMIA 000157-9615
“Two FGF4 retrogenes (FGF4L1 on chromosome 18 and FGF4L2 on chromosome 12) have been identified to cause dwarfism across many dog breeds.” OMIA 000157-9615
“Brown et al. (2017) reported that an FGF4 retrogene insertion in chromosome CFA12” OMIA 000157-9615
- Carrying it raises the risk, but it can't tell you which dog will have a disc problem. In Dachshunds, researchers found the test on its own isn't a reliable guide.
OMIA 000157-9615
“the FGF4 retrogene insertion on CFA12 is not a valid risk indicator on its own” OMIA 000157-9615
What to do
Ask your vet what the result means for your dog. The sources here don't say what lowers the risk for a dog that carries it.
Not tested, or a mix
Without a test, no one can tell. Short legs don't tell you either: the disc copy and the short-leg copy are different.
About 9 in every 100 copies of this gene in the 64 Presa Canarios tested carry this change (Donner 2023).
- DM slowly damages the spinal cord in adult dogs, until the back legs stop working. Nothing yet can stop it.
OMIA 000263-9615
“This is an adult onset degeneration of the spinal cord that progresses to paraplegia and tetraparesis. There is no successful treatment. A genetic test is available.” OMIA 000263-9615
- Two copies of the SOD1 gene change mean a dog is at risk, not that it will get sick. Some dogs with two copies never do.
OMIA 000263-9615
“some homozygous mutant dogs had no signs of degenerative myelopathy, which suggests incomplete penetrance or other causative loci” OMIA 000263-9615
- One copy makes a dog a carrier. In the study that found this change, every dog with DM that was tested had two copies.
OMIA 000263-9615
“All affected dogs tested were homozygous mutant.” OMIA 000263-9615
What to do
A DNA result isn't a diagnosis. If the way your dog walks changes, take that and the result to your vet.
Not tested, or a mix
Without a test, no one can tell how many copies your dog has. How common it is in a breed says nothing about one dog.
About 3 in every 100 copies of this gene in the 64 Presa Canarios tested carry this change (Donner 2023).
- The kidneys can't hold on to cystine, one of the building blocks of protein. It can form crystals and stones that block the flow of urine.
OMIA 000256-9615
“Cystinuria, type 1 - A is an inherited defect that causes failure of reabsorption of cystine in the proximal renal tubule, leading to cystine precipitation in the urine. Formation of crystals and calculi lead to urolithiasis and urinary tract obstruction.” OMIA 000256-9615
What to do
If your dog is straining to pee, or passing little or none, see a vet the same day.
Not tested, or a mix
Without a test, no one can tell how many copies your dog has.
For researchers Population genetics, disease models and every recorded condition Open the research detail for the Presa Canario
Where every number on this page came from.
This page draws on one primary data source. Allele frequencies and sample sizes come from Donner et al. 2023 (CC-BY-4.0), a direct-to-consumer screening cohort, graded Limited as a study design because the dogs were tested at their owners' choice. No genotyped research dogs of this breed are in the three open releases the atlas reads, so the population-genetic sections other breed pages carry are absent here for that reason, not hidden. Conditions recorded for the breed come from OMIA.
What this page does not yet have. Inheritance modes and per-disease penetrance evidence from Donner 2023 are in the structured data for every variant the panel covers. Mondo, OMIM, Ensembl, and HGNC cross-references live on the gene and disease pages this page links to, rather than being repeated here. What is still absent from this breed page is anything not in the cited panel, and each such gap carries its cause where it appears.
How to cite this page. Cite Donner et al. 2023 (doi:10.1371/journal.pgen.1010651) for every frequency on this page, and OMIA for each condition, with the sample size shown beside the figure.
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- Donner J, Freyer J, Davison S, Anderson H, Blades M, Honkanen L, et al. (2023). Genetic prevalence and clinical relevance of canine Mendelian disease variants in over one million dogs. PLOS Genetics 19(2):e1010651. doi:10.1371/journal.pgen.1010651
- Brundage DM (2026). CanVAS: A Harmonized and Imputed Canine Variant Atlas. bioRxiv. doi:10.64898/2026.04.13.718238
- Nicholas, F.W., Tammen, I., & Sydney Informatics Hub. (2026). Online Mendelian Inheritance in Animals (OMIA) [dataset]. The University of Sydney. https://omia.org. doi:10.25910/2AMR-PV70 (retrieved April 2026).