Anemia in dogs
Anemia is a fairly common clinical problem in dogs that can be seen in the decrease in red blood cells. Red blood cells are made in the bone marrow, and they are known to carry oxygen to all the living tissues in the body.
Dogs might display signs of anemia in many different ways, depending on its cause, severity, and duration. As anemia advances, dogs might show clinical signs of shock and even failing cardiovascular and respiratory systems.
Anemia could become extremely severe and life-threatening. If you notice that your pet has pale gums, you should immediately seek veterinary care, especially if he also has trouble breathing, is actively bleeding, or shows signs of unusual bruising. Generally, there are three ways in which a dog can become anemic:
- RBC loss – The bone marrow still produces normal amounts of RBCs. However, they get lost easily or leak outside the blood vessels.
- RBC destruction – The body is destroying RBCs too soon.
- RBC decreased production – The bone marrow doesn’t make enough RBCs.
Besides the usual types, anemia could also be described by the responsive or unresponsive bone marrow. For instance, in regenerative anemia, the bone marrow responds positively to the decreased RBC count and starts making brand new ones, while in nonregenerative types, the bone marrow doesn’t produce enough RBCs.
Important symptoms
Clinical signs depend on many factors, such as cause, severity, and even the length of the disease. For instance, dogs with chronic conditions might show vague signs or no clinical signs whatsoever, not until the anemia becomes really severe.
These dogs might acclimate to lower RBC counts longer, compared to a dog with acute blood loss, which will show immediate signs of distress and illness. Some of the most common signs of anemia are:
- Weakness
- Lethargy
- Decreased appetite
- Pica (eats anything, even non-food items)
- Weight loss
- Pale mucous membranes
- Increased heart rate
- Increased respiratory rate
- Trouble breathing
- Collapse
- Bruising over the body, which is also known as petechiae or ecchymoses
- Jaundice, or the buildup of yellow coloring in blood and tissue
- Blood loss from the nose, mouth, and urogenital and gastrointestinal systems
Causes of anemia
All dogs risk anemia, no matter the breed, age, or gender. It seems that some breeds might be predisposed to a specific type of anemia, known as immune-mediated hemolytic anemia, or IMHA, more than others, and these are:
- American Cocker Spaniel
- Miniature Schnauzer
- Collie
- Doberman Pinscher
- English Springer Spaniel
- Poodle
- Bichon Frise
- Miniature Pinscher
- Old English Sheepdog
- Maltese
In serious situations, blood loss usually occurs secondary to trauma, surgery, poor clotting (also known as coagulopathies), rodenticide toxicity, a ruptured spleen, or even bleeding cancers (hemangiosarcoma).
Even more, chronic blood loss might eventually lead to anemia, especially in cases of long-term gastrointestinal ulcers, parasites (whether it’s hookworms or fleas), tumors, poor nutrition, and even some drugs.
Also, it’s worth noting that red blood cell destruction usually appears when normal red blood cells are completely removed from the system in a faulty manner or way too soon, because usually, red blood cells last up to 115 days in dogs, and they can be removed by the spleen, liver, or bone marrow when they are too old.
Common examples of anemia:
- IMHA usually occurs when the immune system decides to attack the red blood cells. It might happen in various circumstances, such as drugs, infections, cancers, or even inflammatory diseases. It could also appear without a clear cause.
- On the other hand, there are red blood cell parasites, also known as Babesia, that can easily induce anemia.
- In some cases, oxidative stress might also cause anemia, as it usually occurs in onion or garlic toxicities, acetaminophen toxicities, or even benzocaine toxicities. Another potential risk could be zinc toxicosis as well. Generally, oxidative stress makes the normal oxygen-carrying hemoglobin change its course to methemoglobin, which can’t bind or deliver any oxygen to the cells.
- Red blood cell mechanical damage might occur because of heartworm diseases, vasculitis, cardiac diseases, liver diseases, disseminated intravascular coagulation, and even some cancers.
- Other common causes of red blood cell destruction might include infections, some incompatible blood transfusions, genetic RBC abnormalities, and disorders, but also diabetic ketoacidosis, propofol administration, or hypophosphatemia, which refers to low phosphorus.
Decreased RBC production
It can occur when the bone marrow is incapable of making enough RBCs. This is also a nonregenerative type, and here are some of the main reasons why your body can’t produce RBCs:
- Chronic inflammatory disease
- Chronic kidney disease
- Hypothyroidism
- Addison’s disease
- Immune conditions
- Infection
- Cancer
- Bone marrow suppression, caused by infectious agents, drugs, and other toxicities
How veterinarians usually diagnose anemia in dogs
Oftentimes, vets suspect anemia depending on the pet’s history and clinical exam findings. If your dog has pale gums, bruising, and obvious abdominal tumors, it’s much easier to find the right diagnosis of anemia.
Even so, they need to perform the standard bloodwork to successfully assess the RBC count, as well as other RBC factors like size, shape, and color, which could indicate the severity, chronicity, and even what caused the anemia.
A complete blood count, or CBC, is a test that looks at various red blood cell factors. All these tests help the vet figure out the best plan of treatment. Also, there’s PCV/TS, which is a relatively rapid and efficient diagnostic tool used to look at the packed cell volume, which is another efficient way to monitor the RBCs.
Besides this, there’s the reticulocyte count, which is a test that focuses on the increased numbers of young RBCs, showing if there’s a regenerative response. In the end, the vet might want to perform some tests known as cytology and blood smear, slide agglutination test, and bone marrow evaluation, besides the classic radiographs and ultrasounds that might be needed.
Treatment
The most important goal for dogs with anemia is to find efficient ways to treat the condition. Treatment usually depends on the chronicity and severity of the illness. Some of the most common treatments include:
- Surgery to remove all bleeding masses and repair traumatic wounds
- Vitamin K therapy to treat the rodenticide poisoning
- Antiparasitic medication to treat internal parasites
- Antibiotics to treat all infectious agents
- Discontinuing harmful drugs
- Steroids and immunosuppressing meds that are meant to treat autoimmune diseases
- Blood products provide red blood cells and other important blood cells
- Supportive care, such as intravenous fluids
Recovery and management
The majority of vets prefer using a serial complete blood count to carefully watch the dog’s response to the treatment, besides watching for other diseases that might cause the disease. Usually, if the underlying disease is successfully treated, anemia might pass in multiple weeks, even if clinical improvement can be easily spotted in a couple of days.
These dogs might need lifelong medical management. Luckily, some cases of anemia can be cured for good, such as trauma, infectious agents, and parasites. Even so, more severe cases might be too advanced for complete treatment, even with the most aggressive therapy.
Management usually varies depending on the predisposing factors, and sometimes it lasts a lifetime. For instance, dogs with IMHA are more at risk for flare-ups. Even so, care should always be taken to decrease the chances of recurrence in those dogs.
If you want to know how to properly take care of your pup, here’s what we recommend: 16 Tell-Tale Symptoms You Should NEVER Ignore in Your Dog