Blood tests for your pet may include blood chemistries
to see if there is any underlying liver problem, kidney problem, electrolyte
abnormality or diabetes. A blood cell count will give information
about anemia, infection or a possible immune system problem. Looking at
the blood cells may sometimes reveal cancerous blood cells.
A separate thyroid hormone level can help determine if your dog has a deficiency
in thyroid hormone or if your cat is sick because its thyroid gland is
producing too much hormone. Special tests may also be indicated to
determine if your dog has too much cortisone (Canine Cushings disease)
or too little cortisone (Addison's disease).
ALT--a liver enzyme that
is released from damaged liver cells. Some increase may be normal
in old dogs as the liver
ages.
BUN--blood urea nitrogen--tells
us if the kidney is filtering properly, or if the liver is functioning
Creatinine--another kidney
test, tells us if there is active cell damage.
Most animals can have a blood sample taken easily
from their jugular vein.
ECG
An ECG measures the electrical conduction of the
heart muscle. The heart beats because electrical pulses spread through
the heart muscle in a co-ordinated fashion. If there is a defect
in the conduction, the heart will not function normally. The ECG
can also give us information about heart size and heart rate. In
dogs with heart disease an ECG may be used to determine when to use certain
drugs like digitalis. Many times an ECG is coupled with a radiograph
and possibly an ultrasound.
Most dogs tolerate an ECG without any sedation.
Sometimes cats need to be tranquilized so they will lie still with little
clips attached to their elbows and knees.
RADIOGRAPH
A radiograph uses x-rays to give images of body
tissues. In geriatric animals a radiograph of the chest gives information
about the lungs and heart. There can be changes, especially in the
lungs that are normal for old dogs. One may sometimes find tumors
in the chest with a radiograph which were not evident with a physical exam.
That is why a routine chest xray may be suggested by your veterinarian
in your old pet especially if there is unexplained weight loss.
A radiograph of the abdomen may reveal abnormal
liver or spleen size, tumors in the kidney or bowel area, or stones in
the kidney or bladder. Radiographs of the elbows, pelvis and spine
can reveal degenerative changes (arthritis) in the joints.
Taking a radiograph of your dog or cat may require
them to be tranquilized so they lie still. Any movement during the
xray will ruin the radiograph.
ULTRASOUND
Ultrasound uses sound waves to give images of body
tissues in a more detailed manner than we can get with a radiograph.
It is especially useful to assess heart size and function since we can
see the heart muscle thickness and into the heart chambers to assess blood
flow. In the abdomen, the ultrasound can give us better detail of
the liver itself. We can determine if there is an abnormal mass in
the abdomen and possibly which organ is involved. It lets us see
the kidney tissue and tell if there are cysts, stones or other problems.
The bladder can be visualized to determine if there is a tumor in the bladder
wall. Adrenal glands and the pancreas can be assessed for tumors.
The ultrasound does not help us assess bone tissue.
Many animals tolerate an ultrasound without any
need for tranquilizers. They are held on their backs or side and
the probe is moved across the area to be examined. There is no heat
or pain involved. Hair interferes with the sound waves so we sometimes
have to shave areas of the pet's body to get a good view.
URINALYSIS
A urinalysis can tell us if the animal is having
good kidney function by analyzing the concentration of the urine.
When kidneys begin to fail, the first thing that happens is the urine is
more dilute. A chemical analysis of the urine tells us if there is
diabetes (sugar in the urine), protein loss, pH changes (seen in infection
many times) and blood. A microscopic analysis of urine tells us if
there are cellular problems in the kidney, infection in the kidney or bladder,
and sometimes reveals cancer of the bladder.
Urine collected when the animal urinates is okay
to use to assess concentration but to get a sample to accurately assess
infection and microscopic analysis it is best to have the doctor collect
the sample directly from the bladder by inserting a needle into the abdomen
and into the bladder. The majority of animals do not exhibit discomfort
with this procedure, which is called a cystocentesis.
NEEDLE ASPIRATE
A needle aspirate is a specific procedure to get
a sample from body tissue. It can be a simple procedure to take a
tiny amount of cells from a lump in the skin, to a more elaborate procedure
of getting a sample of liver tissue while ultrasounding the abdomen.
Most animals do not seem to feel discomfort with a simple skin needle sample.
We can get very valuable information about skin lumps to be able to sometimes
quickly determine that the lump is nothing more than fat. We can
sometimes get a diagnosis of cancer from a simple needle sample of an abnormal
liver or kidney, avoiding more invasive surgery. Sometimes we use
a biopsy needle to get a larger sample. Most animals tolerate an
abdominal needle biopsy with mild sedation.