What Are Monocyte Levels in Dogs?

By Betty Lewis

Reading your dog's lab results can be a mystifying experience. Packed with acronyms, abbreviations and a wide variety of numbers, the complete blood count provides your vet a wealth of information about your dog's health. Monocytes are one type of white blood cells measured in the complete blood count. Low levels don't indicate anything, but high levels point to inflammation, stress or infection.

The Work of Blood Cells

When the vet orders lab work for your dog, the complete blood count is often included because it offers a glimpse into your dog's body and how it's functioning. A sick body responds in routine ways to different threats. For example, the number of red blood cells, which ferry oxygen and carbon dioxide throughout the body, can indicate hydration level, parasites or bone marrow disease. White blood cells, also referred to as leukocytes, are an important part of the body's immune system, warding off infection. There are five types of white blood cells, accounted for in the differential, which measures values of the various white blood cells, including monocytes. The value of each type of white blood cell is a valuable diagnostic tool for the veterinarian.

The Role of Monocytes

Monocytes are manufactured in your dog's bone marrow and spleen and transform into macrophages in his tissues, where they "eat" unwelcome antigens. They also send the antigens to his T-cells so they're familiar with the offending organisms the next time they're encountered, meaning his body is ready for the invaders the next time they appear.

Monocyte Levels in Dogs

The typical monocyte count in a dog is between 100 and 1,800 per microliter of blood, however, occasionally a dog may have a monocyte count of zero, which doesn't indicate illness. If your dog's monocyte level is high, it could be due to a variety of causes, including something as simple as a stressful response to the visit to the vet. Other potential causes of an elevated monocyte level include:

  • Corticosteroid medications.
  • Bacterial infections.
  • Inflammation.
  • Hyperadrenocrticism.
  • Tissue damage or trauma.
  • Protozoal infection.
  • Chronic renal failure.

If your dog's monocyte level is out of the normal range, your vet will review his other differential numbers, as well as red blood cell values, medical history and symptoms to make a diagnosis.