CHD? We have that in dogs: canine hip dysplasia.
If you mean congestive heart disease, dogs do not have it as in humans, and
Dr. Rath uses that phenomenon to argue that it's because non-primates can make their own vitamin C.
However, dogs can have signs of heart disease similar to humans because of blockage of their pulmonary arteries due to heartworms (does not occur in humans), or due to heart muscle weakness due to taurine deficiency (also in cats), which only occurs in those fed commercial diets.
I hope I got what you meant by CHD right.
Gerry