Adrienne is a certified dog trainer, behavior consultant, former veterinarian assistant, and author of "Brain Training for Dogs."
Understanding Anemia in Dogs
There are several signs of anemia in dogs, but these signs are not always readily recognized, which can lead to delayed treatment in a situation when every second counts. Anemia in dogs may lead to weakness and even serious complications such as incoordination and collapse if left untreated.
Anemia is the medical term used to describe a decrease in the number of red blood cells or RBCs (erythrocytes) circulating in the body. RBCs play an important role in the health and well-being of dogs and other animals. They are present in high numbers in the blood and are responsible for carrying oxygen to all of the body's tissues.
Red-blood-cell production starts in the bone marrow, which is stimulated by a special hormone produced by the kidneys known as erythropoietin. Once released by the bone marrow, the cells migrate from the lungs where they pick up oxygen from the air the dog breathes. Next, they travel to the dog's heart, which pumps out the blood containing all the oxygen-rich red blood cells so the oxygen can then be effectively delivered to all parts of the dog's body.
Anemia in dogs can be due to three different factors:
- Lack of RBC production (non-regenerative)
- RBC destruction (hemolysis)
- Blood loss
Lack of RBC Production (Non-Regenerative)
Lack of red blood cell production takes place when there is a problem with the bone marrow or the production of the hormone erythropoietin from the kidneys. Kidney issues (quite common in older dogs), chronic inflammation and chronic diseases may be some causes for lack of sufficient RBC production leading to anemia.
RBC Destruction (Hemolysis)
Sometimes, RBCs are being produced in normal quantities, but they are being destroyed. Red blood cell destruction can take place as a result of infection or some type of autoimmune disease. Autoimmune diseases are conditions where the immune system attacks healthy cells in the body by mistake. In this case, the RBCs are the victims.
Finally, the condition may take place as a result of RBC loss. In this case, RBCs are being normally produced, and although they are not being destroyed, the red blood cells are being lost due to internal or external bleeding.
For example, anemia may result in the case of a dog who has a spleen tumor that has ruptured, leading to chronic or acute internal bleeding. In this case, the dog ends up eventually losing red blood cells faster than his body can make them. Other causes include bleeding stomach ulcers, bleeding masses in the intestines and ingestion of rat poison (which prevents blood from clotting leading to potentially life-threatening blood loss).
Primary Signs of Anemia in Dogs
Regardless of the underlying cause, when there is a lack of sufficient red blood cells circulating in the dog's body to deliver oxygen, a variety of subtle and less subtle signs of anemia may emerge in dogs.
It's important to understand that in mild cases of anemia, the signs may not be evident but may be detectable through blood testing. Paying attention to signs of this condition in dogs is important so that a veterinarian can offer a proper diagnosis and method of treatment.
An older dog is more likely to have anemia associated with neoplasia and a middle-aged dog more often has immune-mediated disease.
— Kenneth R. Harkin, board-certified veterinarian specializing in internal medicine.
1. Feeling Weak and Tired
Weakness and lethargy in anemic dogs occur because there are not enough red blood cells to carry sufficient oxygen to the dog's heart, brain, muscles, and tissues. With less oxygen carried to vital organs, the result is less energy, which leads to feelings of fatigue.
Deprived of the gift of voice, dogs can't tell us they are feeling tired. Instead, they may manifest signs of low energy by lagging behind on walks, becoming slow to get up from lying down, and they may also sleep more. If allowed to progress, anemia may become severe, and the dog may reach a point of not even being able to lift the head.
Sometimes these signs may be initially chalked up to the dog just not temporarily feeling right (having an "off day") or perhaps getting old. Depending on the underlying cause of the anemia, these episodes of feeling weak and tired may manifest occasionally, and then the dog bounces back, or they may have a more ongoing, chronic nature.
Because feeling weak and tired is a non-specific symptom, anemia is not always readily diagnosed in dogs. It's a good idea to have bloodwork done in weak dogs to rule out or confirm anemia.
2. Pale Gums
Among anemic people, pallor is a common sign of anemia; however, pallor isn't noticeable in dogs for the simple fact that dogs are covered in fur. Instead, dogs with anemia tend to develop pale gums.
If you suspect anemia in your dog, one of the first things to do is to check the dog's gums. In a healthy dog, gums are normally a nice bubblegum pink. This gum color is a combination of melanin as well as blood flow in the superficial blood vessels.
Gum color can be challenging to assess in dogs with black, pigmented gums. In such a case, looking at the non-pigmented areas and the tongue may be helpful.
Pale gums or blue, grayish gums warrant a visit to the emergency vet as these are indicative of potential problems with oxygenation, perfusion, and red cell counts. Pale gums in dogs are not only a sign of anemia but can be indicative of dehydration, intestinal parasites, heartworms, or a heart problem.
3. Increased Heart Rate
An increased heart rate (medically known as tachycardia) may be observed in anemic dogs in an effort to compensate for the lack of oxygen to the tissues. With a faster heart rate, red blood cells can quickly travel back to the lungs where they receive oxygen and reach tissues that are in need of extra oxygen.
Because of this extra effort, anemia puts an extra strain on the heart because it must work harder and faster to pump blood to all the body. This increased workload can lead to a disruption in the rhythm of the heartbeat.
Affected dogs may develop a low-grade systolic heart murmur which takes place secondarily to the decreased blood viscosity associated with severe anemia. Since lower red blood cells alter the viscosity of the blood, this causes a slight murmur sound as it circulates.
4. Increased Respiratory Rate
Anemic dogs may be seen breathing more rapidly in an effort to compensate for the lowered amount of oxygen delivered to the tissues. The breathing may also become more shallow in depth.
Increased respiratory rate in anemic dogs may be more noticeable during times of increased activity. During exercise, the increased activity in the muscles triggers an increased need for oxygen-rich blood. The dog will be breathing faster as to deliver more oxygen to the tissues.
Exercise may, therefore, be more challenging for anemic dogs. Despite the dog's breathing effort to accommodate for the low oxygen supply, the lowered levels of hemoglobin (a red protein responsible for transporting oxygen in the blood) make it difficult to carry any additional oxygen to compensate for the hypoxia (deficiency in the amount of oxygen reaching dog's tissues).
Affected dogs often have a hard time during exercise, which may cause dog owners to assume the dog is just "out of shape" or perhaps just getting older.
Dogs with significant anemia may breathe rapidly in circumstances that shouldn't normally warrant such increased respiratory effort. For instance, an anemic dog may be breathing heavily even after just getting up and walking around or after having a bowel movement.
5. Unusual Food Cravings
Iron deficiency due to an unbalanced diet is not seen as often in dogs as in humans, explains board-certified veterinarian Dr. M.G. Weiser in Textbook of internal Veterinary Medicine. This is because most dogs eat a meat-based diet and most commercial dog food approved by the Association of American Feed Control Officials ensures that adequate amounts of iron are added to food to ensure it meets the dog's nutritional requirements.
Among adult dogs, iron deficiencies may, therefore, be seen in dogs who are fed an unbalanced homemade diet, such as vegetarian or vegan diets. Young puppies may be predisposed as well to iron deficiencies because they are prone to parasite loads (especially hookworms) and ingest milk which contains relatively little iron.
Dogs who are affected by iron deficiency anemia tend to develop unusual food cravings or they may start eating substances that are largely non-nutritive, a medical condition known as pica. Affected dogs may start eating soil or rocks as a strategy to replenish iron stores.
Iron supplementation under the guidance of a vet and blood transfusions can tackle the deficiency, and the symptoms should subside. In dogs, chronic blood loss rather than diet is the most common cause of iron-deficiency anemia.
We are not sure why dogs exhibit pica, it may be that the body is asking for building blocks for red cell production, but we do know that it commonly is a sign of anemia.
— Dr. Kara, veterinarian
Other Signs of Anemia in Dogs
There are several other signs of anemia in dogs. Of course, all signs of anemia may be indicative of other disorders which is why it's important to run some tests to confirm anemia or rule it out. Anemia is not a diagnosis per se; rather, it occurs secondary to other conditions. A finding of anemia, therefore, warrants further diagnostic tests.
6. Cold Extremities
The body takes important measures when life-threatening conditions such as severe anemia take place. As a survival mechanism, blood flow to the extremities will be reduced to ensure that the vital organs are well oxygenated. Dogs may, therefore, develop cold paws, and sometimes the tips of their ears may also become colder to the touch.
7. Reduced Appetite
Dogs suffering from anemia may suffer from loss of appetite. Some dogs may become picky eaters, or they may categorically refuse food. Reduced appetite is a vague symptom and can be indicative of various other conditions such as digestive issues or diseases of organs.
Anemia should be a possible consideration, which is why many vets will request bloodwork anytime a dog with a history of previously eating well presents with an unexplainable reduction in appetite.
Jaundice, also known as icterus, is the medical term for depicting yellowing of the skin. In the case of dogs suffering from anemia, the yellowing is an indication of hemolysis. Hemolysis is the medical term used to depict the destruction of red blood cells. When red blood cells are destroyed, an orange-yellow pigment known as bilirubin is excreted by the liver.
Hemolytic anemia, an anemia developing as a result of hemolysis, can therefore cause jaundice in dogs. This can take place due to autoimmune diseases (IMHA- immune-mediated hemolytic anemia) or secondary to an underlying disorder such as a tick-borne disease. Jaundice in dogs may also appear as a result of liver failure, or gallbladder obstruction or rupture.
9. Mental Changes
Along with feeling sluggish and depressed, some anemic dogs develop behavior and cognitive changes. Dogs may feel woozy, and disorientation can take place due to low oxygen levels in the brain.
10. Lack of Coordination
As a dog with anemia becomes weak, it's not unusual for the dog to become wobbly and unstable. The dog's legs may shake and give out. This lack of coordination is due to the severe blood loss and the associated drop in blood pressure.
As seen, when dogs have a drop in the number of red blood cells in circulation, they are prone to lethargy and depression. When dogs do not have sufficient time to grow accustomed to the drop in red blood cell numbers, they may collapse and faint due to low blood oxygen levels in the brain.
This is seen in the quick onset of acute anemia when affected dogs fail to realize that they must take it easy at least until their concentration of oxygen in circulation ameliorates.
12. Miscellaneous Findings
Finally, it's worth mentioning that dogs may develop a variety of other signs of anemia, but these signs may be more tied to the secondary, underlying causes.
- Abdominal distention may be seen in anemia dog due to bleeding from the spleen.
- Melena, the presence of dark-digested blood in the dog's stool may be suggestive of bleeding stomach ulcers.
- Hematemesis, the vomiting of blood, can take place as well from bleeding stomach ulcers.
- Blood in the urine and blood from the nose can be seen in blood clotting issues as seen in dogs that ingested rat poison.
- Petechiae, small, pinpoint red or purple spots found on the dog's skin, or mucous membranes can also be indicative of bleeding as seen in coagulation disorders.
- Bruising under the skin (ecchymosis)is often noticed on the dog's belly and too may be due to underlying bleeding disorders.
This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.
© 2018 Adrienne Farricelli
susan barbara on June 30, 2018:
Our dog is vomiting evvery drop he drinks and he is not eating .what can i do .the vet. Gave him 2 injections and some pills .but the dog did nt make any progress. Are there some home remmedies pls ?