Pet Columns, Office of Public Engagement, College of Veterinary Medicine at the University of Illinois at Urbana-Champaign

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Blood Work Reveals Your Pet's Problems

Pet Column for the week of May 8, 2000

Office of Public Engagement
2001 S. Lincoln Ave.
Urbana, Illinois 61802
Phone: 217/333-2907
By Carrie Gustavson
Information Specialist

Since sick animals canít describe to us precisely how they feel, veterinarians must use clues
revealed by clinical signs and diagnostic tests to diagnose the problem. Often one of the first
diagnostic tests a veterinarian will suggest is blood work. "There are two basic blood tests
we can do," says Dr. Chuck Wiedmeyer, veterinarian and former resident of clinical pathology at
the University of Illinois College of Veterinary Medicine in Urbana, "a complete blood
count, or CBC for short, and a blood chemistry profile." Both tests provide data to help the
veterinarian make a diagnosis.

One part of the complete blood count provides data about the number, size, color, and
shape of red blood cells. Anemia, or a decrease in the number of circulating red blood cells,
can occur for any number of reasons -- cancer, parasites, bleeding problems, chronic
illness, and vitamin or mineral deficiencies, to name a few. "From a CBC, we can determine
whether the animal is anemic, the possible reasons for the anemia, the type of anemia, and
how the animalís bone marrow is responding to the anemia," reports Dr. Wiedmeyer. "It is
very important for the veterinarian to know what type of anemia and whether the bone
marrow is working properly so proper treatment can be initiated."

Another part of the complete blood count offers information about the white blood cells. If
your pet has an infection, more white blood cells than normal are circulating to try to fight
off the infection. Furthermore, the veterinarian may be able to tell if the infection is bacterial,
parasitic, or fungal just by looking at the types of white blood cells that are increased. "We
can even go as far as telling if there is cancer of the blood or if the animal is experiencing
stress just by looking at the white blood cells circulating," says Dr. Wiedmeyer.

The last part of the complete blood count examines the platelets. "Platelets are necessary
for blood clot formation," says Dr. Wiedmeyer. "Without adequate numbers of platelets a
bloody nose or wound will not stop bleeding."

While a blood count does just that, count the cells, the blood chemistry profile measures
certain things in the plasma. Plasma contains proteins, glucose, electrolytes, cholesterol,
liver and kidney enzymes, hormones, and several other measurable constituents. "With a
blood chemistry profile, we can determine the overall health of an animal and whether there
is an abnormally functioning liver or kidney," says Dr. Wiedmeyer. "For example, irregular
values of urea, phosphorus and creatinine can signal kidney disease."

In fact, a blood panel can be so elucidating about the general health of a pet that many
practitioners will recommend a yearly or even bi-yearly screening as pets get older, even if
they appear healthy.

Dr. Wiedmeyer emphasizes that animals, especially cats, are characteristically stoic.
"Animals are very good at hiding disease," says Dr. Wiedmeyer. "As they grow older, they
may sleep more. It is hard to know if this is a natural pattern of aging or the result of an
underlying disease."

Veterinarians recommend a preventive approach to senior health care. A periodic blood
screening, in combination with a urinalysis and other basic, simple laboratory tests can
reveal early signs of disease. And early detection can be the key to a longer, healthier life
for your pet.