Cyclic Neutropenia, Gray Collie Syndrome

Cyclic Neutropenia, also called gray collie syndrome, is a condition characterized by cycles of low white blood cell (neutrophil) counts leading to overwhelming infections. The disease is associated with silver/gray gene in Collies but can also occur in other dog breeds. In gray Collies the disease occurs in autosomal-recessive form. In dogs, the disease varies in duration of cycle and associated pigmentary defects but otherwise is very similar to the human disease.

The periods of cyclic neutropenia are usually brief. Between episodes, most dogs recover to almost normal neutrophil counts and are generally well, without systemic infections. The disease can be transmitted from affected to normal animals by bone marrow transplantation, and conversely, bone marrow transplantation of normal animal marrow to affected animals, results in cure. Untreated dogs die within several weeks mostly because of systemic infections. With antibiotic treatment, they survive only to succumb in early adulthood to enteritis (inflammatory bowel disease), pneumonia and other bacterial infections. Amyloidosis is often a complication in this terminal illness.

Signs of Cyclic Neutropenia

The affected pups are stunted and weak and less active at birth than their normal litter mates. Beginning within 12 days after birth, the pups show marked sign of cyclic neutropenia at 11- to 14-day intervals (human disease cycles at approximately 21 days).

Affected dogs bear a striking gray coat from the pigmentary defect and have eye defects such as microphthalmia and scleral ectasia.

References

1. Chris Walkowicz, Bonnie Wilcox. Successful Dog Breeding: The Complete Handbook of Canine Midwifery
2. Maxwell Myer Wintrobe, John P. Greer, John Foerster, John N. Lukens, George M Rodgers, Frixos Paraskevas. Wintrobe's Clinical Hematology
3. Nemi C. Jain. Essentials of Veterinary Hematology
4. Norman F. Cheville. Ultrastructural Pathology