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Canine Mendelian disease record

Hypocatalasia

Hypocatalasia. Autosomal recessive. Observed in 16 of 266 breeds tested in the Sniff Atlas, with measured carrier frequencies drawn from 242,660 dogs (Donner 2023). Per-dog phenotype outcome depends on penetrance, modifiers, and environment; the carrier frequencies below describe variant prevalence, not disease incidence.

OMIA identifier
OMIA:001138-9615
Autosomal recessive
Source dataset
Sniff Atlas v1.0.1 / DOI
The human connection

A model of human acatalasia

Dogs with this condition carry a change in CAT. In people, changes in the same gene cause acatalasia. That makes affected dogs a naturally-occurring model of the human disease, and it is part of why studying dogs moves medicine forward for everyone. It does not mean your dog has the human disease. It means the two share an underlying biology.

In people, the disease is described as: A congenital disorder resulting from a deficiency in erythrocyte catalase, an enzyme responsible for the breakdown of hydrogen peroxide.

In humans it is also called: acatalasemia, catalase deficiency.

MONDO:0013571 OMIM 614097

Mapped from OMIA via the human disease's OMIM entry to the Mondo Disease Ontology (Monarch Initiative, CC-BY 4.0). Sniff renders this as a model-of link; the canine disease remains the subject of this page.

About this disease

From OMIA's curated record

Documented in OMIA (Online Mendelian Inheritance in Animals). This describes the disease as recorded in the published literature, not a prediction for any individual dog. As of 2026-06-03.

Summary

Catalase catalyses the decomposition of hydrogen peroxide to oxygen and water. Reduced levels of catalase can lead to hypocatalasemia / hypocatalasaemia or hypocatalasia and absence of catalase activity results in acatalasaemia / acatalasemia.

Clinical features

Catalase is an enzyme responsible for breaking down reactive oxygen species. As there are other enzymes able to fulfil this role, hypocatalasia often has no clinical signs. Hypocatalasia has been associated with ulcers of the oral cavity leading to gangrene, a condition known as “Takahara disease” in humans (Fukuda et al., 1982). The pathogenesis of this disease is explained by some oral bacteria producing hydrogen peroxide, which is unable to be decomposed due to catalase deficiency (Ogata et al. 2008). IT thanks DVM student Joumana Quinn, who provided the basis of this contribution in May 2023.

Molecular genetics

By cloning and sequencing a very likely candidate gene (based on knowledge of the biochemical and physiological properties of the enzyme catalase in affected dogs), Nakamura et al. (2000) reported that the canine disorder in Beagles is due to a missense mutation [in the catalase gene (CAT),] leading to the substitution of alanine(327) (GCT) by threonine (ACT)".

Prevalence

Noting that the original discovery of the likely causal variant (c.979G>A; p.Ala327Thr) was in a Beagle colony, Donner et al. (2016) reported that "To our knowledge, presence and manifestation of acatalasemia due to the aforementioned CAT variant has not been previously documented in the pet Beagle population. We therefore note that we identified pet Beagle carriers, and a tenmonth-old mutant homozygous Beagle through panel screening. During this investigation, the genetically affected Beagle developed gangrene of the oral cavity leading to the removal of three teeth at the age of eighteen months, which could be a manifestation of acatalasemia". Donner et al. (2016, 2018) reported additional breeds in which the c.979G>A; p.Ala327Thr variant was present: American Foxhound (n=1), English Foxhound (n=1), Harrier 9 (n=6), Miniature Poodle (n=1), Treeing Walker Coonhound (n=2).

Human analog

OMIA links this condition to its human counterpart in OMIM (Mendelian Inheritance in Man), the place to read across to the deeper human literature for the same biology.

Disease · OMIM 614097 Gene · OMIM 115500

Source: OMIA (Nicholas, Tammen & the Sydney Informatics Hub), entry OMIA:001138-9615, doi:10.25910/2AMR-PV70 (CC-BY 4.0).

The evidence

Published references

The peer-reviewed papers behind this disease, curated by OMIA. Starred entries are OMIA-designated landmark papers. Showing 6 of 9.

  1. ★
    Genetic panel screening of nearly 100 mutations reveals new insights into the breed distribution of risk variants for canine hereditary disorders. · PLoS One · 2016 · PMID 27525650

    Why is this an OMIA Landmark paper? It is "the first large scale report of DNA panel screening across purebred dogs to date", involving the genotyping of 6,788 dogs from 233 breeds for 93 disease-implicated variants across 80 single-locus disorders, providing a very informative "snapshot" of the distribution and frequency of these variants. Importantly, the results indicated "15 risk variants in a total of 34 breeds in which their presence was previously undocumented", which will be very helpful in the provision of genetic counselling in those breeds. The detection of some of these latter variants led to "plausible molecular explanations" for disorders in some breeds.

References curated by OMIA (Nicholas, Tammen & the Sydney Informatics Hub), doi:10.25910/2AMR-PV70 (CC-BY 4.0). Full list at the OMIA entry.

Predict a litter

Set each parent's status for Hypocatalasia and see the odds for their puppies. Single recessive variant, exact Mendelian math.

Parent A
Parent B
NNClear
NmCarrier
NmCarrier
mmAffected
Clear25%
Carrier50%
Affected25%

These are the genetic odds for one known variant, not a promise: a real litter varies around them, and penetrance or other genes can change whether the condition ever appears. Use it to avoid pairing two carriers and to keep a line healthy, not to engineer a dog. Inheritance mode per OMIA.
Your breed

See what Hypocatalasia looks like in your dog's breed.
Carrier frequency by breed

Top 14 well-sampled breeds (n ≥ 50)

Maximum per breed across variants in the Donner 2023 cohort, with . The list below is split into well-sampled breeds (n ≥ 50 tested) and small-sample breeds (n < 50, where the Wilson CI typically spans more than 20 percentage points and frequencies should not be compared directly to the well-sampled entries). Frequencies are population-level, not per-litter or per-line.

0%10%20%
American Foxhound14.8% · n 574
Beagle6.9% · n 5,292
Treeing Walker Coonhound0.45% · n 336
Basset Hound0.15% · n 990
Chihuahua<0.1% · n 4,273
Australian Cattle Dog<0.1% · n 982
Cocker Spaniel<0.1% · n 1,880
Pug<0.1% · n 5,154
American Staffordshire Terrier<0.1% · n 42,792
French Bulldog<0.1% · n 13,113
Pembroke Welsh Corgi<0.1% · n 4,371
Bulldog Standard<0.1% · n 4,815
German Shepherd<0.1% · n 15,648
Labrador Retriever<0.1% · n 16,856
n = 117,076 dogs · Donner et al. 2023 carrier-screening cohort · Sniff Atlas
Each bar is one well-sampled breed; the whisker is its Wilson 95% CI, and fainter bars have wider intervals. Frequencies are population-level, not per-litter. Carrier status for Hypocatalasia is measured; phenotype outcome depends on penetrance and modifiers.
▸ Full table with Wilson 95% confidence intervals
Breed Carrier frequency n tested
American Foxhound 14.8% 574
Beagle 6.9% 5,292
Treeing Walker Coonhound 0.45% 336
Basset Hound 0.15% 990
Chihuahua <0.1% 4,273
Australian Cattle Dog <0.1% 982
Cocker Spaniel <0.1% 1,880
Pug <0.1% 5,154
American Staffordshire Terrier <0.1% 42,792
French Bulldog <0.1% 13,113
Pembroke Welsh Corgi <0.1% 4,371
Bulldog Standard <0.1% 4,815
German Shepherd <0.1% 15,648
Labrador Retriever <0.1% 16,856
▸ Also observed in 2 small-sample breeds (n < 50)

Frequencies in this section are statistical estimates with wide Wilson 95% confidence intervals (typically >20 percentage points). Treat these as "carriers observed but the true population frequency is not yet measurable" rather than as comparable to the well-sampled entries above.

Breed Estimate n tested
Plott 8.0% 25
Rat Terrier 6.3% 8

250 additional breeds in the Donner 2023 cohort were tested but showed no carriers.

Penetrance

From genotype to phenotype

Carrier status is not the same as disease status. Penetrance is the fraction of at-risk dogs that develop the phenotype. The Donner 2023 S4 table tracks this for 1 variant(s) underlying this disease in the cohort.

At-risk dogs evaluated
6
Phenotype confirmed
4
Penetrance range
not yet quantifiable

Fewer than 20 at-risk dogs evaluated; too few to state a penetrance figure.

Predicted disease relevance at the per-dog level is UNPROVEN. The carrier frequency is measured; phenotype outcome is governed by penetrance, environment, and modifier loci. Consult a veterinarian for clinical interpretation.

How to cite this record

Citations

If you use this record in published work, cite the Sniff Atlas (the published dataset that carries the breed-level carrier frequencies) and the upstream sources:

  • Sniff Atlas v1.0.1 for the per-breed carrier frequencies:

    Gehring, M. (2026). Sniff Atlas v1.0.1. Zenodo. https://doi.org/10.5281/zenodo.20566358. CC-BY 4.0.

  • OMIA for the disease definition, inheritance, and gene assignment:

    Nicholas, F. W., & Tammen, I. (2024). OMIA. Sydney Informatics Hub, The University of Sydney. https://doi.org/10.25910/2AMR-PV70. Entry: OMIA:001138-9615.

  • Donner et al. 2023 for the breed × variant carrier-frequency cohort:

    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. https://doi.org/10.1371/journal.pgen.1010651.

Full citation formats (BibTeX, RIS, CITATION.cff) at sniff.world/cite.

Related

Related

Last updated
Sources: Sniff Atlas v1.0.1 · OMIA OMIA:001138-9615 · Donner et al. 2023