“Leukopenia” is a decrease in the number of total white blood cells found in blood, which for your cat can be rather bad news. After all, white blood cells comprise the defense team that protects against common illnesses and serious infections.
So what causes a low white blood cell count in cats? First it helps to understand the makeup of white blood cells, also known as leukocytes, and their functions:
- Neutrophils and Eosinophils are released into the bloodstream to destroy bacteria.
- Lymphocytes are produced in the lymph nodes and spleen.
- Monocytes are stored in the spleen and bone marrow.
- Researchers aren’t entirely clear as to the main purpose of basophils.
A normal white blood cell count in cats typically ranges from 5,500 to 19,500 per microliter of blood. To determine your cat’s count the vet will run a complete blood count. Low levels of neutrophils and lymphocytes circulating the blood indicate that these cells are at the site of an infection, or that sepsis has occurred. This drop is typically temporary, with counts rising to normal in a few days.
Why a Cat Would Have a Low White Blood Cell Count
Viral infections are the most common cause of a low white blood cell count in cats. Feline Immunodeficiency Virus (FIV) and Feline Infectious Peritonitis (FIP) are two such viruses. These viruses invade the white blood cells and use them to make copies of themselves, increasing the virus’ strength and reducing the number of white blood cells.
Other causes include:
- Bacterial infections. These infections can range from abscesses to respiratory infections to sepsis.
Essentially, any infection or inflammation causes a drop in white blood cells, particularly neutrophils. - Bone marrow diseases, or the panleukopenia virus, which destroys the marrow where white blood cells are produced.
- Pancreatitis. The inflammation of the pancreas will draw white blood cells from the bloodstream, lowering their count.
- Certain medications. Corticosteroids, which are used to treat arthritis can actually suppress the production of white blood cells.
- Stress. As a response to stress the cat’s immune system may begin to repress itself, resulting in a decreased production of white blood cells.
How Will I Know if My Cat is Sick?
Symptoms are typically related to the cause of the high white blood cell count.
- If the cause is a viral infection such as Feline Immunodeficiency Virus, symptoms will appear as fever, moodiness, swollen lymph nodes, lack of appetite, fatigue, inflammation of the gums, nasal and eye discharge, vomiting, bloody diarrhea, and hair loss. Feline Infectious Peritonitis symptoms include those of Feline Immunodeficiency Virus, as well as fluid buildup in the lungs, difficulty breathing, distended abdomen, frequent urination, and jaundice.
- If the cause is a bacterial 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. If the infection is internal, additional symptoms could include swollen lymph nodes, muscle and joint pain and stiffness, vomiting, and diarrhea.
- If the cause is a bone marrow disease such as panleukopenia, symptoms will be fever, lack of appetite, vomiting, diarrhea, and fatigue.
- If the cause is pancreatitis, symptoms will appear as trouble breathing, fatigue, lack of appetite, and lower than normal body temperature. Unlike dogs, cats typically do not vomit or exhibit abdominal pain.
- If the cause is a medication, the symptoms can vary. Your cat could exhibit anything from fever and moodiness to lack of appetite and diarrhea, which is why it’s best to discuss every new medication with your vet.
- If the cause is stress, symptoms will likely appear as aggression, decreased social interaction, lack of appetite, and hair loss.
Getting Your Cat’s White Blood Cell Count Back Up
If your cat’s white blood cell levels are low, your vet will recommend a treatment based on the cause of the issue.
- There are unfortunately no medications that can combat viruses. When it comes to a viral infection like Feline Immunodeficiency Virus or Feline Infectious Peritonitis, the main focus is supportive care, such as increasing fluids, devising a nutrient-rich diet, and administering antibiotics to prevent and treat secondary infections that may occur. Unfortunately, most cases of FIP lead to death, but there are reliable vaccines to prevent such viruses from taking hold.
- Bacterial infections can be treated with a variety of medications, particularly antibiotics.
- Bone marrow disease is incurable and care will be supportive. In severe cases, blood transfusions may be necessary. However, there is a reliable vaccine to prevent the condition.
- Hospitalization may be recommended for cats suffering from pancreatitis. During your cat’s stay, fluids and pain and anti-inflammatory medications will be administered.
It is import that you stay up to date with your cat’s wellness visits, in which your vet will run routine blood cell counts in an effort to spot any underlying health issues.
Knowing the aftereffects of such conditions can be especially beneficial for you as a pet parent. It doesn't only help you to put the correct practices in place but also take care of the appropriate measures to maintain their health.
Feline Anemia Causes
You are probably familiar with anemia because it is a fairly common condition in humans. But did you know that cats can suffer from it too? Feline anemia develops when there are not enough red blood cells in the body to deliver the adequate amount of oxygen to the tissues. This is either because the body is not producing enough red blood cells, or because the red blood cell count is lowered through blood loss or blood cell destruction. Either way, these irregularities and the resulting anemia are typically caused by underlying medical conditions. Let’s take a look at the causes.
Types of Feline Anemia
There are two types of feline anemia -- nonregenerative and regenerative.
Nonregenerative anemia is the result of insufficient production of red blood cells by the bone marrow. In many cases, an underlying medical condition displaces or eliminates the red blood cells, and the bone marrow cannot keep up with the heavy demand for new cells.
Regenerative anemia is either the result of blood loss or hemolysis, which is the atypical destruction of red blood cells. Immune-mediated hemolytic anemia (or IMHA) -- a form of regenerative anemia -- occurs when a cat’s body is tricked into seeing red blood cells as foreign, and the immune system kicks into action to destroy them.
Nonregenerative Anemia Causes
Conditions that can cause inadequate red blood cell production are:
- Feline leukemia (FeLV)
- Feline immunodeficiency virus (FIV)
- Cancer
- Kidney disease
- Liver disease
- Autoimmune disease
- Hormonal disorders
- Various chemicals and poisons
- Any chronic illness
- Poor nutrition
Regenerative Anemia Causes
Conditions that can result in blood loss are:
- Injury or trauma -- either external or internal
- Intestinal, kidney, or bladder tumors
- Clotting conditions
- Severe parasitic infections from ticks and fleas, such as Cytauxzoon felis and Mycoplasma haemophilus. Cytauxzoon felis is an often fatal infection passed to cats by ticks, usually in rural areas. Mycoplasma haemophilus is a parasite passed to cats through tick and flea bites. It can also be passed through cat bites or from an infected mother cat while the kitten is in utero.
Conditions that can result in red blood cell destruction (hemolysis):
- Feline Leukemia (FeLV)
- Blood parasites
- Cancer
- Autoimmune disease
- Various chemicals and poisons
- Reactions to medications
- Reactions to blood transfusion
Is Anemia Hereditary?
Anemia itself is not hereditary, and all cats are at equal risk for developing it. However, there are some rare genetic disorders -- such as neonatal isoerythrolysis and the blood disorder porphyria -- that can cause anemia. Your veterinarian may check your cat for these and other genetic disorders if they discover that your cat has anemia.
See Your Veterinarian
If your cat is suffering from any of the above conditions, or if you notice symptoms of anemia, contact your veterinarian. They will perform a series of tests to determine if your cat is suffering from a low red blood cell count. If so, there are a number of treatment options available, and for many cats the recovery prognosis is very good.
Symptoms of Anemia in Cats
Anemia -- a condition which means there are not enough red blood cells in the body to deliver sufficient oxygen to the tissues -- can affect any cat at any age. The symptoms can either be mild or severe depending on your cat’s degree of illness, and unfortunately, many of the symptoms of anemia mimic those of other health conditions, so it can sometimes be difficult to spot.
However, knowing the classic symptoms of anemia in cats can help you to begin putting the pieces together, especially if you already know that your cat is suffering from one of the underlying conditions that can cause anemia.
Common Anemia Symptoms in Cats
Not all cats with anemia will exhibit the same symptoms, and the severity of your cat’s symptoms will depend on just how sick they are. Here are some of the most common symptoms of anemia in cats.
- Lethargy and Weakness: Because oxygen is required for normal bodily functions and anemia reduces the amount of oxygen delivered to body tissues, it can result in lethargy and weakness. You may see your cat sleeping a lot and looking frail, and they may not be interested in regular activities like playing or exploring.
- Lack of Appetite and Weight Loss: When a cat is sick, their appetite is often the first thing to go. Because they are not eating normally, they may also lose weight. These serious symptoms are seen with many health conditions, and they should never be ignored.
- White or Pale Gums or Tongue: These are perhaps the most obvious symptoms of anemia. These mucus membranes often turn white or pale because the oxygen that gives those tissues their healthy red or bright pink color is not being delivered in adequate amounts. Your cat’s nose or the bottom of their eyelids may also appear pale.
- Rapid Breathing and Increased Pulse: In severe cases of anemia, if the cat’s body is going into shock, you may see rapid breathing or an increased heart rate. These are also common symptoms of heart disease and sometimes the conditions are confused.
- Eating Dirt or Litter: Some cats with anemia develop an iron deficiency. It is somewhat rare and typically only seen in cats on very poor diets or those who are experiencing severe blood loss. Cats who have an irony deficiency may attempt to eat dirt or litter to ingest the iron that their body is telling them they need.
- Fever: Cats suffering from anemia caused by a parasitic infection may develop a fever.
In mild cases of anemia, a cat may show no symptoms, and the condition will only be discovered through blood testing.
When To Seek Help
Any of the above symptoms -- especially if there is no other explanation -- warrant a trip to the veterinarian. Your vet will run a series of tests to determine if your cat is suffering from anemia, and if they are, will suggest treatment options. Many cats respond very well to anemia treatments, and the sooner you can get started, the better off your cat will be.
Frequently Asked Questions
What does low white blood cells mean in cats?
There are many types of white blood cells, and the lack of each can be caused by an underlying disease. However, the lack of all white blood cells could indicate the presence of the feline panleukopenia virus, also known as panleukopenia or feline distemper, a highly contagious, life-threatening infectious disease in cats. According to Dr. Katie Grzyb, DVM, the disease is closely related to canine parvovirus. The virus suppresses the production of all white blood cells in the bone marrow, which is crucial for the immune system. Without white blood cells, the virus can spread throughout the body quickly. Feline distemper mostly affects kittens and unvaccinated cats. The virus enters a cat’s body through the nose or mouth. Usually, the virus invades the bone marrow and intestines within two to seven days of a cat encountering the virus. It infects and kills the rapidly growing and dividing cells in the body. Feline distemper is ubiquitous in the environment and can endure for years. The virus can survive on various surfaces like shoes, paws, bedding, bowls, and litter boxes, as well as in freezing and room temperatures. Disinfectants like iodine and alcohol may not be able to eliminate it. Feline panleukopenia virus is among the deadliest cat diseases in the unvaccinated cat population. Kittens, cats with compromised immune systems, and pregnant cats are most susceptible to severe symptoms, so vaccination against this virus is considered essential for all cats.
What causes low blood count in cats?
According to Dr. Veronica Higgs, DVM, The causes of anemia can be categorized into three main groups: blood loss, destruction of RBCs, and failure to produce new RBCs. Blood loss can be internal, external, or both, with various potential causes such as trauma, fleas/ticks, hookworm infestations, bleeding tumors, severe stomach ulcers, diseases impairing blood clotting, anticoagulant rodenticide toxicity, and post-surgical complications. Destruction of RBCs (hemolysis) can result from immune-mediated hemolytic anemia, feline leukemia virus (FeLV) infection, feline infectious peritonitis (FIP), certain blood parasites transmitted by ticks, exposure to toxins and chemicals like onions, zinc, copper, or acetaminophen, adverse drug reactions, genetic diseases, neonatal isoerythrolysis, low phosphate levels, and cancer. Failure to produce new RBCs may occur when the bone marrow cannot meet the demand for new RBCs, often due to underlying conditions such as chronic diseases, chronic kidney disease leading to decreased erythropoietin production, severe nutritional deficiencies, viral infections like FeLV or FIV, autoimmune diseases or inflammation affecting the bone marrow, and exposure to chemicals or toxins or cancer affecting the bone marrow or RBCs directly.
Is low white blood count serious?
Yes, low white blood cell count in cats can be serious. The white blood cells are what your cat's body uses to fight off infections, so if you see a low white blood cell count, it means your cat is not fighting off infections as well as it should. Low white blood cell counts could lead to severe and life-threatening illnesses like pneumonia or sepsis. There are lots of reasons why a cat may have low white blood cell counts, including exposure to a virus or bacteria, injury or trauma to the body, certain medications, and more. As verified by Dr. Michele K., DVM, Low white blood cell count may or may not be serious, depending on the underlying cause. A low white blood cell count in cats often indicates an underlying disease or infection. Feline panleukopenia, also known as feline parvovirus, occurs when all types of white blood cells are low and is a contagious, life-threatening condition. Other causes of low white blood cell count in cats include feline leukemia, Salmonella infection, protozoan infection, acute toxoplasmosis, feline distemper, medication side effects, autoimmune disease, cancer, and stress. Certain diseases like feline parvovirus and feline leukemia can spread among cats, necessitating isolation of infected cats to prevent contagion. If your cat has low white blood cell counts and isn't getting better after a few days of antibiotics or other treatment, talk with your vet about other treatment options.
What are the symptoms of low white blood cells?
The most common symptom of low white blood cells in cats is a fever. In addition, if the cat has a bacterial infection, which is more likely to occur if its white blood cells are low, it may experience diarrhea and vomiting. If your cat's white blood cells are low because of a viral infection, it may have an enlarged spleen or liver. When white blood cell count drops, various symptoms may arise, although these signs can vary depending on the underlying condition. Seek immediate veterinary attention if 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, a greasy or matted coat, pale gums, lethargy, and weakness, tumors or masses, changes in behavior, or seizures. These indicators could signal a serious health issue that requires prompt medical intervention.
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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.