Causes of Low White Blood Cell Count in Dogs What Does This Mean For Your Dog's Health?

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A low white blood cell count is never a good thing for your dog since white blood cells are there to help fight off illnesses. Learn more about what a low white blood cell count means.

White blood cells are crucial when it comes to your dog’s health. After all, they are the defense team that protects against common illnesses and serious infections. Unfortunately, their numbers aren’t always high. A low white blood cell count in dogs, known as neutropenia, can leave your dog susceptible.

This article will discuss what causes a low white blood cell count and what you can do about it. First, it helps to understand the makeup of white blood cells and their functions. There are five different types of white blood cells -- neutrophils, eosinophils, basophils, lymphocytes, and monocytes.

  • Neutrophils and eosinophils are released into the bloodstream to destroy bacteria.
  • Researchers aren’t entirely clear as to the main purpose of basophils.
  • Lymphocytes are produced in the lymph nodes and spleen.
  • Monocytes are stored in the spleen and bone marrow.

A normal white blood cell count in dogs typically ranges from 6,000 to 17,000 per microliter of blood. To determine your dog’s count the vet will run a complete blood count. You can have a low count among the neutrophils and lymphocytes, but it is impossible to come up with a low to zero level of eosinophils, basophils, and monocytes. Low levels of neutrophils and lymphocytes circulating in the blood indicate that these cells are gathered at the site of an infection, or sepsis.

Why a Dog Would Have a Low White Blood Cell Count

Bacterial infections are the most common cause of a low white blood cell count in dogs. Ehrlichiosis is one such infection, which results when bacteria found in the saliva of brown dog ticks is spread via a tick bite

Other causes include:

  • Fungal infections such as histoplasmosis. Histoplasmosis is common in Mississippi, Missouri, and the Ohio River Valley areas.
  • Viral infections such as parvovirus. Parvovirus is a deadly virus that destroys cells within the bone marrow -- where white blood cells are produced.
  • Breed-specific genetic disorders. Giant Schnauzers are genetically unable to absorb sufficient quantities of B12. In turn, such vitamin deficiencies can cause white blood cell levels to drop. Collies with Gray Collie Syndrome, which is characterized by the color of the nose, are unable to produce a sufficient amount of white blood cells due to a defect in the stem cells of their bone marrow. Belgian Tervurens can also inherit this condition, but it’s typically more dangerous in Collies.
  • Certain medications. Phenobarbital, which is used to treat seizure disorders, is one among many.
  • Chemotherapy. This is because the therapy holds up the production of white blood cells in the bone marrow.

How Will I Know if My Dog is Sick?

Symptoms are typically related to the cause of the high white blood cell count.

  • If the cause is an infection symptoms will appear as fever, lack of appetite, moodiness, and fatigue. If the infection is external there may be a rash, wound, or abscess. As for ehrlichiosis, all of the above apply, as well as nosebleeds, bruising, enlarged lymph nodes, muscle and joint pain and stiffness, inflammation of the eye, discharge from the eyes and/or nose, vomiting, and diarrhea.
  • If the cause is a fungal infection such as histoplasmosis, symptoms will appear as fever, lack of appetite, yellowing of the gums, vomiting, diarrhea, enlarged lymph nodes, moodiness, and fatigue.
  • If the cause is a viral infection such as parvovirus symptoms will appear as fever, moodiness, lack of appetite, dehydration, fatigue, vomiting, and bloody diarrhea.
  • If the cause is a genetic disorder symptoms will typically appear as lethargy and an inability to gain weight. Collie puppies with Gray Collie Syndrome will have a grey nose and be smaller and weaker than the others in their litter. They’ll exhibit recurrent fevers, diarrhea, and possible joint pain as they age.
  • Medications could cause anything from fever and moodiness to lack of appetite and diarrhea.
  • Chemotherapy can result in a lack of appetite, nausea, vomiting, and diarrhea. Increased susceptibility to infection may also occur. These symptoms typically appear a few days after beginning treatment and may resolve several weeks later.

Getting Your Dog’s White Blood Cell Count Back Up

If your dog’s white blood cell levels are low, your vet will recommend a treatment based on the cause of the issue.

  • Ehrlichiosis, histoplasmosis, and other bacterial or fungal infections will be treated with medications, and likely a regimen to prevent infection in the future.
  • Parvo is incurable and care will be supportive.
  • Supplement may be recommend for vitamin deficiencies.
  • Unfortunately there are few effective treatment options for Gray Collie Syndrome. A bone marrow transplant surgery is costly and involved, which is why most vets recommend managing the symptoms of the disorder, typically with supplements that will boost the immune system and antibiotics that will fight secondary infections.

It is import that you stay up to date with your dog’s wellness visits, in which your vet will be able to run routine complete blood cell counts in an effort to spot any underlying health issues, or monitor the progress of existing issues. 

More on Dog Health

How to Prevent Ehrlichiosis in Dogs and Cats
5 Simple Pet Supplements to Consider
How to Treat Eye Infections in Dogs and Cats

This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis or treatment by, your veterinarian with respect to your pet. It has, however, been verified by a licensed veterinarian for accuracy.

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