I probably can’t count the times that clients have asked me what they can do for their anemic pet. My immediate response is asking them what caused the anemia. Anemia is not a diagnosis. It is a clinical finding, a generalization, sort of like saying your dog is skinny? Why is it skinny? Is it not being fed enough? Can it process the food that it is being fed? Is there something that is competing for its food like a parasite and so on.
Anemia is defined as a red blood cell deficiency. Basically, the pet doesn’t have enough red blood cells. This is a very important finding because the red blood cells function to carry oxygen to the tissue. If there is not enough blood to do this, the tissue can’t get the oxygen required for the cells to function. No oxygen, no viability. Cells begin to die.
Depending on how anemic the pet is, there can be several symptoms seen. The pet can have pale gums and tongue, the small vessels in the eyes can no longer be seen and in time, even the skin becomes pale. The pet, when clinically anemic will breathe faster in an attempt to get more oxygen into the body and be sluggish in its activity. It will often refuse to move around at all because moving around requires more oxygen and the body just doesn’t have it.
Anemia is determined by blood assessment doing a CBC (complete blood count). A CBD will let us know what the red cell count is, the percentage of red cells in the blood (called hematocrit or packed cell volume), hemoglobin levels and a description of the red cells themselves, called red cell morphology. We use all of these indices in order to find out the cause of the anemia.
In hopes of eliminating the cause of the anemia, it is imperative to find out the cause. Many times this can be a life threatening situation. A dog may come into the vet clinic extremely anemic and on physical exam the vet may find evidence of a severe bleeding episode. Dogs with splenic hemangiosarcoma will often have the splenic tumor rupture and within a short period, the abdomen fills with whole blood. Emergency surgery is required to stop the bleeding or the dog will die. On the other hand, an anemic cat may come in and with a thorough investigation and lab assessment, we find that the cat has chronic kidney disease causing the anemia. To correct the anemia, we have to restore normal function of the cat’s kidneys.
When a veterinarian is presented with an anemic pet, she must not only determine how anemic it is, but also the cause of the anemia. If the cause is not obvious, we rely on lab work to help us look for potential causes. Basically, a pet can become anemic because of two general conditions. Either the pet is losing blood or the pet is not manufacturing its red blood cells normally. Hemorrhage can be simple to determine as in the example of the dog with hemangiosarcoma, but often it can be more difficult. Pets that have ingested rat poisoning (warfarin) will start to hemorrhage internally in many places that may not be obvious. A simple dark spot on the pet’s gums may be a petechial hemorrhage due to a clotting problem caused by the warfarin.
Other causes of insidious blood loss might be due to bleeding in the urinary system from tumors, chronic infection, etc. or bleeding in the gastrointestinal system due to erosions, ulcerations, tumors and more. Intestinal parasites in young puppies and kittens can cause anemia and in extreme cases even death. Primary blood diseases caused by infections is also common in pets. Blood parasites like Babesiosis, Ehrliciosis and Equine Infectious Anemia are common.
Blood loss anemias may also include diseases called hemolytic disorders. This is when a disease causes the red cells to be prematurely destroyed. Many autoimmune diseases such as autoimmune hemolytic anemia will cause anemia due to hemolysis. The net effect is the same as a blood loss anemia. Both cause overall blood loss for the pet. Some toxicities can cause hemolysis. Onions can cause hemolytic anemias in animals when ingested. It will be up to the vet to find the causes in hopes of stopping the blood loss and restoring normal health.
The other primary cause for anemia in pets is caused by red cell production deficits. If the red cells are not being produced by the pet, in time, anemia will occur. This can happen with several diseases or deficiencies. Deficiency caused by iron, copper, vitamin B12 and niacin are examples. Iron deficiency anemia is often caused by chronic blood loss causing the deficiency. Some diseases will often cause production red cell deficiency. As previously mentioned, chronic kidney disease will cause anemia. This happens because the kidneys are responsible for the production of the hormone, erythropoietin, which is required in the manufacturing of red cells. Cancer of the bone marrow can be another example.
By now, you can see that anemia is not a specific disease and treating all anemic pets the same will not likely have a good outcome. It is critical to find the cause of the anemia and address it in hopes of restoring normal health and well being.