Pet Care Corner
Dr. Becky Marks
Tiny
Exams
The microscope is a
marvelous
invention. In the 1700s our ancestors discovered how to magnify an
image using
very simple principles. Two lenses and a light source could open up a
new world
of tiny structures.
Today the light
microscope is
still a vital piece of equipment in any lab.
In order to identify cell tissue changes the microscope must be
used. In
the veterinary lab samples include blood, urine, feces, ear wax and
tissues.
The blood exam is a
very
important procedure. Much information can be derived from blood
analysis but
the blood smear is critical. One drop of
blood is smeared and stained for information. The health of the red
blood cells,
white blood cells and platelets can determine if the animal is fighting
new
infection versus old infection. The cells may give indicators of
stress,
cancer, parasites and anemia. An organism called Mycoplasma
in cats is only identified in a sample that is immediately examined.
The
organism is transmitted by fleas and attaches to the red blood cells
causing
red blood cell death. Without the microscope there is no diagnosis.
Urine samples
contain a
plethora of insights. In the animals world many problems occur in the
urinary
system. The contents of the is examined in
two ways.
The chemical analysis is a screening for pH, infection, sugar etc. The
actual
exam of the urine is done before and after centrifuging. The exam
checks for
white and red blood cells, slough of cells from the kidneys and abnormal cells
(CANCER). The exam also
picks up crystals which are precursors to bladder stones. Many cats
have
crystals which a like pieces of sand. OUCH! The sand is passed and is
likened
to urinating glass. Without knowing what type of crystals exist the
therapy can
not be chosen.
The stool sample of
your pet
may seem like a big waste. However, in the veterinary hospital the
sample is
goal mine. A small amount of the sample is directly examined under the
scope
for bacteria sizes, shaped and numbers. The centrifuged sample is
examined for
large parasite eggs such as hookworm, whipworm and roundworm. Many
parasites
are zoonotic (can give people disease) and
without
the microscope you would never know they exist. In
If your dog has
itchy ears
the Veterinarian will get a “juicy sample” on a Q-tip. Ear samples are
examined
microscopically for
yeast, bacteria and mites. There is no other way to identify the ear
problems.
Finally, cells from
tissue(skin, tumors, organ) can be examined
for the normal
versus abnormal. The in-house lab can often determine if the lump you
have been
worried about is a fatty tumor or a serious tumor. Each type of tumor
has a
unique cell(s) type and the appearance of the cells can be determined
to be
normal or abnormal. For example a lymph node biopsy may yield lymph
cells that
are reacting to infection . Some lymph cells may
simple be larger in
size but if there are changes in the cell cytoplasm and nuclei the
diagnosis
can change from infection to cancer. Only the human eye has discern
these changes. In all of these examples
the human eyes are tools in the diagnostic process.
After hundreds of
years the
microscope remains a very important tool in everyday practice. Thanks to our ancestors we have advanced in
the world of microscopy. The trained eye, the microscope and
a tiny exam give big information.