What do Blood Tests Tell Your Veterinarian?

December 18, 2014

bloodwork vialsVeterinarians at The Animal Medical Center must say “Let’s send some blood to the lab” about 100 times a day. But what are we looking for in all those tubes of blood with the colorful stoppers?

CBC = Complete Blood Count
Your dog’s or cat’s blood contains at least four types of white blood cells, red blood cells and blood clotting cells, called platelets. A complete blood count analyzes what cells are present, how many cells of each type make up the blood sample, and identifies any unusual cells present. For example, the presence of increased numbers of immature white blood cells, called band neutrophils or bands for short, indicate a serious infection. Last week, one of my patients had an elevated total white blood cell count and 1,236 bands per microliter of blood; normal is less than 300. An abdominal ultrasound determined she had a gallbladder infection.

In addition to assessing the types and numbers of white blood cells, the CBC measures the number of red blood cells and several different features of them as well. A lack of red blood cells is called anemia, and too many red blood cells suggests a rare hematologic disorder called polycythemia. Size is a critical diagnostic feature of red blood cells – too big and we look for an increase in baby red blood cells responding to bleeding or anemia; too small and we worry about iron deficiency. The amount of hemoglobin (oxygen carrying protein) is measured as well. If there is too little hemoglobin, we worry about iron deficiency, and red blood cells are so smart they never synthesize too much hemoglobin. If the lab report indicates the hemoglobin is elevated, we scrutinize the sample for possible errors.

Chem Panel = Serum Biochemical Profile
The CBC looks at the whole blood sample in pretty much the same form as it circulates in the bloodstream. Serum is the liquid portion of the blood without the blood cells. Serum is produced in the lab by spinning the blood in a centrifuge and using a pipette to remove the liquid portion. The serum sample is used to run a serum biochemical profile, a series of 20 or so tests that come in a panel.

The chem panel can be divided up into several different organ systems. Some tests increase with liver disease like the alanine amino transferase, or bilirubin. When a patient has a kidney problem, we often see elevations in blood urea nitrogen and creatinine. Then there is a group of tests that analyzes the concentration of chemical elements like calcium, phosphorus, sodium, potassium and chloride in the blood. These analytes are important for cellular function and can be abnormal in a wide variety of diseases, like adrenal gland diseases, kidney disease and urinary blockage. Typically a chem panel includes measurement of the protein level in the blood. Protein is affected by a wide variety of conditions and is usually interpreted in concert with the other abnormalities found in the panel. Finally, the chem panel measures blood sugar when looking for diabetes or low blood sugar.

The Combination is Critical
Submission of a CBC and chem panel is so routine that it is test #1 in The AMC’s lab ordering system! When paired, these two tests become a powerful tool for veterinarians to assess the health of your pet or to direct further testing to identify the cause of your pet’s illness.

Fun Things Blood Tests Can Tell Us
Blood tests don’t only tell us about disease, but also can give us other little tidbits about your pet:

  • If you have a mixed breed dog, a blood test analyzing your dog’s DNA can tell you about his parents and what breeds are in his genetic makeup.
  • Avian specialists use a blood test to tell if your bird is a boy or girl.
  • A blood test can also be used to predict the birth of a litter of puppies. A rise in blood progesterone to 2-3 micrograms/ml occurs 63 to 65 days prior to whelping – the dog word for birth of puppies.

Anemia Tails: Dog and Cat Anemia

March 28, 2013

According to VetLearn, a company focused on continuing education for veterinarians and veterinary technicians, one of the top ten articles they published in 2012 was on anemia in dogs and catsIf an article on anemia tops your veterinarian’s reading list, then your pets are perplexing anemia cases. I would guess you have questions about anemia too.

Anemia: definition

Although the causes of anemia are complex, the definition is simple: if your pet is anemic, she doesn’t have the normal number of red blood cells speeding through her blood vessels carrying oxygen and nutrients to cells and removing cellular waste products. Without adequate oxygen, your usually peppy pup or cavorting cat acts dull and tired.

Liver and onions cause anemia?

You may think liver is a cure for anemia: not true. Last week we saw a cute wiener dog named Klauss. He came to The Animal Medical Center with dark brown urine. Although, Klauss didn’t seem sick to his owner, the color of the urine was frightening, provoking a trip to The AMC ER. The ER doctors found his urine contained a large amount of bilirubin, a breakdown product of red blood cells. They also found Klauss was anemic. Upon further questioning, the family reported of a raid on the trash can containing the leftovers of a of liver and onion dinner. Onions and garlic can damage the red blood cells of both dogs and cats, causing them to rupture and resulting in anemia. Klauss only needs to avoid eating onions and his body will shortly make new red blood cells.

Ironclad diagnosis

We take better care of our pets than ourselves, providing them with nutritious food while we snack out of the pantry. Because of their high level of nutrition, iron deficiency is rare in our furry friends. My patient Jackie, a Labrador with a jaw tumor, has developed a rare case of iron deficiency anemia. Three weeks ago, her tumor eroded a blood vessel and caused a major hemorrhage. When she lost blood, she also lost iron. On her most recent blood count, the red blood cells were tiny. The small size is a result of inadequate iron which keeps them from growing to normal size. An injection of iron will easily fix Jackie’s anemia.

Strange, but true

Hatshepsut, an Egyptian Mau cat, was not acting right. Because of a waning appetite, she came to the hospital for an evaluation. The radiologist saw an intestinal tract full of kitty litter when he reviewed her x-rays. Hatshepsut has a strange but true sign of anemia-pica – an appetite for eating non-food substances. Kitty litter is common, but I have seen dogs with anemia spend all day licking the grout between the bathroom tiles. The presence of kitty litter in the intestine made me suspect anemia, and a blood test confirmed it.

In conclusion

  • Blood loss, red blood cell destruction and faulty bone marrows are all causes of anemia. 
  • Is your pet tired, eating strange items or just not feeling well in general? See your veterinarian for a blood count. 
  • Does your pet’s skin or urine have a funny color? Take a urine sample to the veterinary clinic for testing. 
  • Does your pet’s stool have funny color? Take a sample for analysis.

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