Pelger-Huet Syndrome is an observed abnormality in the formation of the nucleus of white blood cells. Whereas a typical white blood cell nucleus would have a generally round appearance, cells affected by Pelger-Huet Syndrome acquire a shape more like two round shapes held together by a thin bridge. It is often described as being shaped like a peanut. Though Pelger-Huet Syndrome is defined as a congenital abnormality, it can and often is developed post-birth and in such cases is termed "Acquired Pelger-Huet Syndrome" though for all intents and purposes, it remains the same defect.
This particular type of cellular defect is significant not because of any real problem that it causes in and of itself but because it acts as herald to much more serious diseases such as leukemia.
Although any breed may develop Pelger-Huet Syndrome, Australian Shepherds have by far the highest tendency to contract the disorder. Other breeds in which it is more frequently sighted include the basenji, the border collie, the Boston terrier, the Cocker spaniel, the German Shepherd, and the Samoyed.
Diagnosis of Pelger-Huet Syndrome can prove somewhat problematic since similar nuclear abnormalities can be caused by different matters altogether, such as infection or neoplastic change. They can even be induced by the use of drugs.
Once Pelger-Huet Syndrome has been diagnosed with certainty, however, several things become clear. Constant observation of the dog's white blood cell count must be conducted to keep at eye on their numbers. If their development grows out of hand, these immature leukocytes can quickly proliferate and have an adverse effect on otherwise healthy bone marrow cells. What this means for you and your dog is that his or her bones will likely become brittle, and even small injuries could become very significant as the blood clotting process is severely compromised.
As the white blood cells produced in a dog with Pelger-Huet Syndrome are largely dysfunctional, unwanted autoimmune reactions may also occur. This could produce an emergency state in which the dog's own immune system begins to attack healthy tissue, compounding the need for healthy white blood cells that just aren't present.
If the number of white blood cells observed during routine observation goes into a highly abnormal state, an emergency procedure in which the number of dysfunctional leukocytes in the dog's body is drastically reduced can be taken. Once the white blood cells reach a "critical" stage through this process, there is a change that a higher percentage of the new ones produced to replace the deficiency will be healthy and normal. This process can be repeated quite often as long as it yields somewhat promising results.
There is no cure for Pelger-Huet Syndrome, but it's important to remember that it is not in itself a disease. It is merely a sign that you must keep a close eye on your dog's white blood cell count so that should any more serious problems arise, you'll be ready and able to stop them.