Low White Blood Cell Count in Cats

Low white blood cell count may or may not be a serious condition based on the underlying cause. However, if you suspect your cat has a low white blood cell count, you should take them to the vet immediately, as a low white blood cell count can be indicative of diseases such as feline leukemia.

Low white blood cell count in cats is usually secondary to disease or infection. There are many different types of white blood cells in cats. If the counts of all types of white blood cells are low, this is known as feline panleukopenia, which is also known as feline parvovirus. Low counts of certain types of white blood cells can be caused by other diseases.

Please note that the following is not a comprehensive list of symptoms; signs may vary depending on the underlying disorder. Seek immediate veterinary attention as soon as you notice any of the following symptoms:

• Vomiting and/or diarrhea
• Loss of appetite
• Weight loss
• Gingivitis
• Dehydration
• Ulcers in the mouth
• Mucus or cysts in the feces
• Greasy or matted coat
• Pale gums
• Lethargy and weakness
• Tumors or masses
• Changes in behavior
• Seizures

There are several causes of low white blood cell count in cats, including, but not limited to:

• Feline infectious enteritis caused by feline parvovirus
• Feline leukemia (FeLV)
• Salmonella infection
• Protozoan infection
• Acute toxoplasmosis
• Feline distemper
• Side effect of medications
• Autoimmune disease
• Cancer
• Stress

Some of these diseases, particularly feline parvovirus and feline leukemia, can be contagious to other cats. Any infected cats must be isolated to prevent spread of the disease.

Your vet may make a tentative diagnosis based on a physical examination and presentation of symptoms. Inform your vet of the nature, severity and duration of your cat’s symptoms, as well as any medications your cat is currently taking. Also, be prepared to provide your cat’s full medical history.

Your vet will make a definitive diagnosis by performing blood tests. These may include complete blood cell count and blood chemical profile. Additional diagnostic testing may be utilized based on the suspected underlying cause.

Treatment may vary depending on the severity of the underlying condition. 

Treatment methods for feline panleukopenia may involve intravenous fluid therapy, antibiotics, and anti-emetic drugs to decrease vomiting. Protozoan infections and toxoplasmosis are generally treated with antibiotics. 

Cancer may be treated with chemotherapy or radiation. However, radiation therapy can cause damage to the white blood cells, so chemotherapy is often the treatment of choice for cats with low white blood cell counts. Surgery or cytotoxic drug therapy may also be recommended to treat cats with certain types of cancer.

Unfortunately, feline leukemia is the second leading cause of death in cats. There is currently no curative treatment for feline leukemia, but the prognosis varies greatly depending on the signs that an affected cat is showing.  Your vet may recommend different treatments, based on your cat’s specific situation and your personal and financial preferences.

Recovery and prognosis may vary depending on the treatment method and the underlying condition. Always follow your vet’s post-treatment and/or post-operative instructions carefully. Always administer any medications, particularly antibiotics, exactly as directed for the full duration of the recovery period to prevent aggressive recurrence.

If your cat has been diagnosed with feline panleukopenia or feline leukemia, it is imperative that you wear protective clothing and wash your hands thoroughly after handling the infected cat. Keep your cat indoors to prevent further spread of infection. If you live in a multi-cat household, ensure your other cats have been vaccinated.

If your cat has had surgery, do not allow them to irritate the surgery site. An Elizabethan collar may be recommended. Check the surgery site daily to ensure there are no signs of infection.

Your vet may schedule follow-up appointments as needed to monitor the condition or administer additional treatment.