This is the third in a series of articles about anemia in pets. In the last two, Dr. Palazzolo laid out the anatomy of a blood cell and discussed the physiology of anemia itself. This article covers the disease’s diagnosis.
A dog or cat that is anemic oftentimes has a history of lethargy, weakness and poor appetite. There might also be blood from the nose or mouth, dark stool (called melena), or blood in the urine. It all depends on the degree of anemia and the specific cause.
During an exam of an anemic dog or cat, we might notice blood externally. Looking at the gums (mucous membranes), we might note them to be pale or even white. If the anemia is severe enough, there might even be a heart murmur.
Pale gums are one sign of anemia, like the ones of this fox brought to our Wildlife Program after being injured in a fire. Notice how long the canine teeth are. Photos courtesy of Long Beach Animal Hospital (LBAH).
A blood panel is important in the diagnosis of anemia. The part of the blood panel that checks the RBCs directly is called the CBC. It stands for complete blood count because it checks the RBCs and the white blood cells (WBCs).
Reptiles and birds can become anemic also, although the diagnosis of the cause and the treatment can be different because of a vastly different anatomy and physiology compared with dogs and cats. This reptile is severely anemic. Did you notice there is no HGB (hemoglobin) level or RBC count in this report?
In animals, three parameters are checked for anemia. They are RBCs, hemoglobin and packed cell volume (PCV). A decrease in any one of the three is technically anemia. When anemia is detected, it is important to know whether the anemia is regenerative or nonregenerative.
Before we can figure out the cause, we need to determine if it is a regenerative or a nonregenerative anemia. The reticulocyte (immature red blood cells) aids us in determining this.
In regenerative anemia, the body has lost RBCs because of blood loss, internal parasites or an immune-system dysfunction, but the bone marrow can make up for the loss by producing more RBCs.
A nonregenerative anemia occurs when the bone marrow cannot make adequate red blood cells. There are several diseases that can cause this, and it tends to be more serious than a regenerative anemia.
Another way we diagnose anemia is with a bone marrow biopsy. In this test, we use a special needle to obtain bone marrow from the hip or one of the legs, and have a pathologist look at the marrow. This gives us substantial information about the anemia and often the actual cause.
This pet is anemic. The RBCs, HGB and HCT (hematocrit) are all low. Now that we have confirmed anemia, we need to figure out the cause.
Once we diagnose a pet with anemia, we then need to figure which of the many diseases that can cause anemia is actually occurring. There many causes, and I will only cover the basics of the two primary ones we encounter at Long Beach Animal Hospital in my next article.