Primary Hyperoxaluria, or PH, is a metabolic disorder that affects the Coton de Tulear dog breed. There is a deficiency of a liver enzyme needed to break down calcium oxalate crystals so that they can be eliminated from a dog's system. As the crystals build up in the body, the dog becomes progressively more and more ill.
An affected pup will show signs of the disorder at three to four weeks of age. This is when the accumulation of calcium oxalate begins to tax the system, especially the kidneys. The crystals can also build up in other areas including joints, bones, eyes, and other tissues. The disease eventually leads to kidney failure and death.
PH is an autosomal recessive genetic mutation, so a puppy will have PH only if both parents have the mutation. Carriers will not exhibit symptoms of PH, so DNA testing is useful to identify carriers of the mutation prior to breeding. Without testing before breeding, there is a chance that some puppies could become homozygous for PH and develop symptoms with eventual death.
|Affected: Dog has two copies of the Primary Oxaluria mutation and will be affected. The gene will be passed on to every offspring.
|Carrier: Dog has one copy of the Primary Oxularia mutation. Dog will not be affected by PH but may pass the mutation to offspring.
|Clear: Dog is negative for the mutation associated with PH.
Vidgren G, Vainio-Siukola K, Honkasalo S, Dillard K, Anttila M, Vauhkonen H. Primary hyperoxaluria in Coton de Tulear. Anim Genet. 2012 Jun; 43(3):356-61. [PubMed: 22486513]