By Dr. Karen Burgess
What is a urinalysis?
A complete urinalysis is made up of chemical (commonly called a dipstick) and microscopic or sediment examination. The dipstick portion looks for the presence of red and white blood cells, glucose, ketones, protein and bilirubin in the urine. It also quantifies the concentration and acidity of the urine. The sediment portion of a urinalysis involves physically looking at a sample under the microscope in search of red blood cells, white blood cells, crystals, bacteria, and abnormal kidney or bladder cells. The urine is one of the first ways that kidney disease can be identified in pets. If a bacterial infection is suspected a culture and sensitivity (C&S) may also be performed to identify specific bacteria and the appropriate antibiotic choice for treatment.
By Dr. Karen Burgess
What is blood chemistry testing?
Blood chemistry testing uses the serum or non-red blood cell portion of blood to evaluate how a variety or organs and systems work in the body. Often a variety of tests are combined to form a profile that is specific for a pet’s age or medical situation.
What tests are commonly performed in a blood chemistry profile?
- Glucose-often also referred to as blood sugar, glucose provides energy to all of the body including the kidneys, brain, and muscles. Low blood sugar can cause seizures or collapse while persistent elevations of blood sugar may be indicative of diabetes.
- Kidney testing-the kidneys are responsible for filtering the blood and regulating sodium (salt) and water concentrations in the body. Ultimately the kidneys produce urine. BUN (blood urea nitrogen) and creatinine are waste products that are filtered by the kidneys and elevations can occur with kidney disease or dehydration. A sample of the urine is necessary to fully evaluate kidney function. Electrolyte values are also often performed and further help determine kidney function.
- Liver testing-the liver serves many functions in the body including waste removal and nutrient breakdown. ALT (alanine aminotransferase) is a direct measurement of liver cell damage. This value goes up and down very quickly allowing real time evaluation of damage to the liver. ALP (Alkaline phosphatase) is a less specific test and can be elevated with liver disease, stress, or secondary to hormonal diseases. GGT, AST, and bilirubin are all additional tests of liver function.
- Protein values-the body requires protein as building blocks and in fighting off disease. Albumin, globulin, and total protein are all measures of protein in the body. Low values of albumin in particular can lead to life threatening fluid accumulation in the body.
- Electrolytes–Na (sodium), K (potassium), Cl (chloride), TCO2, and anion gap are all related to electrolyte balance. The body keeps electrolyte values in very narrow ranges. Abnormally high or low levels can lead to collapse, heart failure, or other signs of disease.
- Minerals–Ca (calcium) and Phos (phosphorous) are minerals that are tightly controlled in the body. Elevation in calcium can be associated with cancer and elevations of phosphorous with kidney disease.
- Thyroid testing-thyroid hormone impacts the metabolism of a pet. Elevations, commonly seen in cats, can lead to heart disease, weight loss, and eventually death. Abnormally low levels, more common in dogs, can cause abnormal weight gain, behavior changes, and skin disease.
Complete Blood Count
By Dr. Karen Burgess
What is a CBC (complete blood count)?
A CBC quantifies the number of red and white blood cells and platelets a pet has. It also describes the cells qualities including how they physically look (ex. too small, too large)
What are red blood cells and what tests are done on them?
Red blood cells make up almost half of the blood’s volume. They give blood its red color and contain hemoglobin which is responsible for carrying oxygen from the lungs to all of the cells in the body. Common tests performed include:
- RBC (red blood cell count), HCT (hematocrit), Hgb (hemoglobin)-measures red blood cell mass and quantity. A decrease in these counts would be suggestive anemia, a potentially serious medical problem.
- MCV, MCH, MCHC, RDW-measurement of red blood cell size. The size of the red blood cells can give clues about specific disease processes.
- Retic-quantification of reticulocytes or immature red blood cells. Helps determine whether the bone marrow is working properly.
What are white blood cells and what tests are done on them?
There are five types of white blood cells. These cells respond to bacteria, viruses, and foreign material in the body. White blood cell types include:
- Neutrophils-most common white blood cell, typically fight bacterial infections. Can also be elevated with stress.
- Lymphocytes-components of immune system
- Monocytes-are involved with damaged tissue typically
- Eosinophils-often involved with parasitic and allergic disease
- Basophils-also related to parasitic and allergic disease, uncommon.
What are platelets and what tests are done on them?
Platelets are the body’s first line of defense in the body’s clotting process. Low platelet counts can be indicative of potentially life threatening bleeding problems in a pet.
FAQ’s About Laboratory Work
By Dr. Karen Burgess
Why should laboratory work be performed on a pet?
There are many reasons to perform testing on a pet, some of the more common include:
- As part of a wellness examination-our goal with annual labwork is to prove that a pet is healthy and not find abnormalities. The idea is to establish a baseline so that if and when a problem develops there is a “normal” reference point to refer back to. This becomes increasingly important with age, thus why it is recommended that senior pets have labwork done twice a year. In some situations a pet may seem healthy and an unknown medical condition may be identified thus allowing earlier intervention and possibly a better prognosis.
- With illness-labwork allows further evaluation of the sick pet in an effort to further isolate the problem, assist with treatment, and provide prognosis.
- Prior to anesthesia-the key to safe anesthesia is to plan ahead. A key component of this is preanesthetic labwork which helps to determine safe drug and dose selection.
How are labwork samples obtained?
Bloodwork is performed on a blood sample. This sample is drawn from a neck or leg vein using a syringe and needle. Urine is either collected in a clean container while a pet is naturally voiding or while being restrained using a syringe and needle.
Where are blood tests performed?
Bloodwork can be done either by an automated analyzer in the hospital providing results within the hour or at a commercial laboratory yielding results within a day or so. Urine evaluation is done by automated analyzers and under the microscope visually. Some samples are also evaluated by trained personnel under the microscope.