Hereditary Vitamin D-Resistant Rickets in Dogs

Category: Bone & Joint
Breeds documented: 3
Published sources: 4

Overview

A faulty response to active vitamin D disrupts normal bone hardening in this rare inherited disorder. The problem lies in the vitamin D receptor, which normally helps the body respond to the hormone. Growing bones can remain poorly mineralized and become deformed. In the published Pomeranian case, low blood calcium, hair loss, bowed forelegs and later seizures accompanied the bone disease.

Signs to watch for

Hair loss that is not itchy
Bowed front legs
Tiring easily during play
Episodes of limping
Seizures

In the reported Pomeranian, hair loss appeared at 2 months and bone changes by 4 months.

Emergency Go to an emergency vet now if your dog has a first seizure.

Diagnosis and tests

Vets investigate suspected rickets with blood tests and X-rays of growing bones. The reported dog had low blood calcium, abnormal hormone results and poorly mineralized growth plates. Further genetic and laboratory work identified a defect in the vitamin D receptor, explaining resistance to the active hormone.

Breeds with documented risk

3 breeds

By breed size

1 Toy
1 Small
1 Medium

PomeranianToy · Toy Group
KeeshondMedium · Non-Sporting Group
German SpitzSmall · Miscellaneous Class

Inheritance

Not yet known
None of the sources we use states how this is inherited in dogs yet.

We've gathered what published sources say about this condition, so you can talk it through with your vet. It isn't veterinary advice: you and your vet know your dog best.