Cyclic Hematopoiesis

Cyclic Neutropenia (also known as Gray Collie Syndrome)


Cyclic hematopoiesis (formation of blood cells) in color-dilute gray collie pups is characterized by frequent episodes of infection with failure to thrive and early death. Clinically, the pups may appear normal for the first 4–6 weeks and then develop diarrhea, conjunctivitis, gingivitis, pneumonia, skin infections, carpal joint pain, and fever. A frequent cause of death of the pups is intussusception (blockage) of the small intestine. 

Episodes of illness, varying from inactivity accompanied by fever, to life-threatening infection, repeat at 11- to 14-day intervals. The gray pups are usually smaller than their litter mates at birth, weak, and often pushed aside by the bitch. Cyclic hematopoiesis has been observed in many collie bloodlines in the U.S. and in other countries; however, experienced collie breeders do not attempt to raise the affected pups and frequently will not acknowledge the presence of the responsible gene in their bloodline. As a result, gray collie pups are not commonly observed.Cyclic hematopoiesis in the collie breed is present only in the color-dilute pups. The color dilution and bone marrow disorder are inherited as an autosomal recessive trait (presumably the same gene). The bone marrow disorder and color dilution was present in pups resulting from a collie/beagle cross and could occur in any mongrel with collie bloodlines in both parents, if both parents had the recessive gene. Clinical signs occur as early as 1–2 weeks of age and are always apparent by 4–6 weeks of age.

 An apparently similar disease was reported in normal-colored pups in two Border collie litters in the UK. Single cases of cyclic hematopoiesis have been reported in Pomeranians and cocker spaniels; the disease is not well characterized in these breeds.


 Coat color is diluted gray

  • Smaller and weaker than litter mates
  • Weakness
  • Failure to thrive
  • Conjunctivitis, may be symptomized by watery eyes, crusted discharge on eyes
  • Gingivitis, symptomized by reddened and/or swollen gums
  • Diarrhea
  • Pneumonia
  • Skin infections
  • Carpal joint pain, observed during the initial recovery phase of the disease cycle
  • Fever

 This cellular disease is inherited genetically.

You will need to provide a thorough history of your puppy's health leading up to the onset of symptoms. Any details that you can provide about the pregnancy, birth, and infancy stages will be helpful for your veterinarian in determining the appropriate course of action. Your veterinarian will perform a complete physical exam on the puppy, including a blood chemical profile, a complete blood count, an electrolyte panel, and a urinalysis.

If the complete blood count shows an abnormally low number of neutrophils at two week intervals, and the collie shows expression of genes for a dilute coat color along with a nasal epithelial color dilution, this is strong support for a diagnosis of cyclic hematopoiesis.

Cyclic Neutropenia (CN)

Canine cyclic neutropenia, also known as 'gray collie syndrome' (GCS), is an autosomal recessive disease. Both parents must carry the abnormal gene for the offspring to be affected. Carriers are perfectly healthy and do not manifest the disease, but if bred to another carrier there is the risk of producing an affected puppy.

This is a disorder in which the number of neutrophils, (the types of white blood cells that are primarily responsible for gobbling up invading bacteria and other infectious organisms) drops dramatically in a cyclical pattern, usually about every 10 to 12 days. During the time of a low neutrophil count, there is an increased susceptibility to infection. Affected dogs develop clinical signs such as fever, diarrhea, joint pain, or other signs associated with eye, respiratory, or skin infections. They are also prone to bleeding episodes.

GCS is a serious genetic disorder and affected puppies are smaller and weaker, with a noticeable pale gray or pinkish/gray or beige color. These puppies rarely live beyond a couple of days and when they do survive, they are susceptible to all sorts of infections. With proper treatment they can be kept alive, but few have lived beyond 2 to 3 years of age.


The dog has 2 copies of the normal gene and will neither develop the disease,nor pass a copy of the cyclic neutropenia gene to any of its offspring.


The dog has one copy of the normal gene and one copy of the mutantgene that causes cyclic neutropenia. It will not develop the disease butwill pass on the mutant gene to 50% (on average) of its offspring.


The dog has two copies of the cyclic neutropenia mutation and is affected with the disease

Liquid Life Aid - available from online veterinary chemists - Amazon or your Vet. The Life aid must be diluted ie: 6ml Life Aid to 75 ml water. Mix the diluted life aid (75ml) to 25ml of Carnation Evaporated Milk. 

When the puppies are a week old you can change the mixture to half/half Carnation/Life Aid. 

If puppy is having no milk from the dam, add 3 drops of Abidec and 3 drops of liquid calcium per bottle of feed.