Catalase Deficiency

Common Symptoms

Catalase deficiency is an inherited disease affecting beagles. Catalase is a protein which plays an important role in a variety of metabolic reactions in the body including those involved in the prevention of cellular oxidative damage. Dogs affected with catalase deficiency lack adequate amounts of this protein in red blood cells. Though many dogs with this condition do not show clinical signs of disease, affected dogs are at increased risk of life-threatening ulceration and gangrene (tissue death due to loss of blood supply) of the oral cavity.

Breed-Specific Information for the Beagle

The Mutation of the CAT gene associated with catalase deficiency has been identified in beagles. Though the exact frequency in the overall beagle population is unknown, approximately 9.2% out of 119 beagles tested were carriers of the mutation and 0.8% were at-risk.

Testing Tips

Genetic testing of the CAT gene in beagles will reliably determine whether a dog is a genetic Carrier of catalase deficiency. Catalase deficiency is inherited in an Autosomal Recessive manner in dogs meaning that they must receive two copies of the mutated gene (one from each parent) to develop the disease. In general, carrier dogs do not have features of the disease but when bred with another carrier of the same Mutation, there is a risk of having affected pups. Each pup that is born to this pairing has a 25% chance of inheriting the disease and a 50% chance of inheriting one copy and being a carrier of the CAT gene mutation. Reliable genetic testing is important for determining breeding practices. Because symptoms may not appear until adulthood, genetic testing should be performed before breeding. In order to eliminate this mutation from breeding lines and to avoid the potential of producing affected pups, breeding of known carriers to each other is not recommended. Beagles that are not carriers of the mutation have no increased risk of having affected pups.

There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.

References

• Donner J, Anderson H, Davison S, Hughes AM, Bouirmane J, Lindqvist J, Lytle KM, Ganesan B, Ottka C, Ruotanen P, Kaukonen M, Forman OP, Fretwell N, Cole CA, Lohi H. Frequency and distribution of 152 genetic disease variants in over 100,000 mixed breed and purebred dogs. PLoS Genet. 2018 Apr 30;14(4):e1007361. doi: 10.1371/journal.pgen.1007361. [PubMed: 29708978]
• Nakamura K, Watanabe M, Takanaka K, Sasaki Y, Ikeda T. cDNA cloning of mutant catalase in acatalasemic beagle dog: single nucleotide substitution leading to thermal-instability and enhanced proteolysis of mutant enzyme. Int J Biochem Cell Biol. 2000 Nov-Dec;32(11-12):1183-93. [PubMed: 11137458]
• Nakamura K, Watanabe M, Takanaka K, Sasaki Y, Ikeda T. Purification and characterization of liver catalase in acatalasemic beagle dog: comparison with normal dog liver catalase. Int J Biochem Cell Biol. 2000 Jan;32(1):89-98. [PubMed: 10661897]