Is your dog slowing down? Have you noticed that his or her gum color looks a little pale? Does your furry friend just not seem like his or herself? Could s/he be anemic? Anemia is a common disease that we treat in veterinary medicine and can be caused by Immune-Mediated Hemolytic Anemia (IMHA). IMHA is caused by the immune system attacking the patient’s own red blood cells, which can lead to an acute loss of circulating red blood cells causing shock and even death.
Defined, anemia is a condition in which the body lacks enough healthy, circulating red blood cells. Like many health problems, anemia may be acute (severe, sudden in onset) or chronic (long-developing). It can develop due to a lack of production of red blood cells from the bone marrow, destruction within the periphery or due to excessive bleeding.
Further, anemia is commonly broken into two classifications: regenerative and non-regenerative.
- Regenerative anemia is caused when bone marrow produces an increased number of red blood cells to adequately make up for the lack of red blood cells produced by the condition. As the disease progresses, it may develop into blood loss or hemolysis (immune-mediated).
- If a dog suffers from the non-regenerative type, the bone marrow does not produce the correct number of red blood cells to combat anemia. Non-regenerative anemia can be due to bone marrow disease, chronic kidney disease or an iron deficiency.
If your dog suffers from anemia, he or she may show these clinical signs:
- Exercise intolerance
- Pale to icteric gums
- Increased heart rate
- Low blood pressure
- Increased respiratory rate
If you notice that your pet is showing any of these common symptoms, schedule an appointment with your veterinarian or ask for a referral to an internal medicine specialist. Initially, your vet must determine if your pet is suffering from acute or chronic anemia. Veterinarians commence diagnosis by digging into a patient’s history. For example, has the patient gotten into anything; is s/he currently taking a heartworm/flea/tick preventative; is s/he on any other medications; has s/he recently received vaccinations?
The veterinarian will also perform a thorough physical examination. Essentially, your veterinarian will look for any secondary cause that could be the underlying reason for the anemia/hemolysis before diagnosing primary IMHA. Tests include:
- During examination, your veterinarian will complete a slide agglutination test, which tests for “sticky” red blood cells. These are indicative of the immune system attacking red blood cells.
- The vet also looks at overall organ function.
- Thoracic and abdominal x-rays can assist in looking for obvious masses, tumors or metal foreign bodies (objects that could contain zinc, most commonly pennies post-1982).
- Your veterinarian may perform an abdominal ultrasound.
- Lastly, the vet will run infectious disease testing, primarily tick-borne diseases which are common in the South.
Blood work includes complete blood count (CBC) and a blood smear to evaluate for any blood parasites or spherocytes. Spherocytes, which are formed due to the immune system attacking the red blood cell, are a classic type of red blood cell seen in IMHA.
Primary IMHA Versus Secondary IMHA
If your pet is diagnosed with Primary IMHA, his or her immune system no longer recognizes its own red blood cells. In response, his or her body creates antibodies against them, which causes their destruction. Dogs seem to be more susceptible to Primary IMHA than other patients.
Pets who suffer from Secondary IMHA experience immune response to a foreign entity such as an infectious disease, cancer or toxins/drugs. Cats are most commonly diagnosed with Secondary IMHA. Patients may also be diagnosed with non-immune hemolytic anemia due to zinc, onions/garlic, moth balls, skunk musk or acetaminophen.
Treatment Options For Anemia
Veterinarians treat patients depending on the type of conditions as well as the severity. First and foremost, if your pet is having difficulty breathing, is severely lethargic or has a distended abdomen, seek emergency care. Further, in acute cases, blood products and, sometimes, immunosuppressive drugs are needed. Subsequently, this warrants a trip to the emergency room or specialty veterinary clinic.
However, if your pet has pre-diagnosed chronic anemia, he or she likely will not need emergency treatment as patients tend to adjust well to therapy and medications. That being said, your pet may still need blood products. In these situations, make an appointment with your specialty veterinarian.
Long-term prognosis depends on the underlying cause (Primary IMHA versus Secondary). In patients with Primary IMHA, the prognosis may be poor in the beginning. However, if your pet responds to therapy, s/he may live a good life. Once the underlying cause is treated in patients with Secondary IMHA, the projection is typically fair to good.
Though they vary, common treatments include:
- Blood transfusions
- Immunosuppressive drugs
- Antibiotics to treat for any tick-borne diseases
- Anti-clot medication: patients with IMHA are prone to forming clots most commonly in the lungs (pulmonary thromboembolism)
Once getting through an IMHA crisis, patients are commonly on drug therapy for 6 to 9 months to completely calm the immune system down to prevent further attack on the red blood cells. The goal is always to come off all medication, though some patients may be on medication for life. When patients are on immunosuppressive therapy, they are closely monitored for secondary infections.
Unfortunately, IMHA is not always a preventable disease. There are, however, good health tips to help prevent Secondary IMHA:
- Consistently administer heartworm/flea/tick preventatives.
- Keep a log of medications your pets have received.
- Do not neglect your pets’ annual veterinary examinations.
- Always closely monitor your pet within the first 2 weeks after vaccines. Patients who are diagnosed with IMHA after a recent vaccination may not need to receive that vaccine anymore. Discuss this with your pet’s veterinarian.
How CARE Can Help
Our Emergency team is available 24/7/365 for all of your pets’ urgent healthcare needs. Call ahead to let us know you are on your way – 704-457-2300. We also have three Internal Medicine specialists on staff for diagnosis, treatment and any other long-term needs associated with your pet’s case of anemia. If your pet does not have urgent needs, ask your family vet for a referral.