Biology Reference
In-Depth Information
peritonitis (FIP), but alone is not diagnostic. Any positive test should be
confirmed by other means.
FeLV is initially screened through an ELISA (enzyme-linked
immunosorbant assay) test for viral antigens in the blood.The confirming
test is an IFA (immunofluorescent antibody) that detects viral antigens
associated with cells. When both tests are positive, the cat is likely to be
persistently infected with FeLV.When there is a discrepancy in the results
(one positive, one negative), the tests should be repeated in 60 days and
then annually until they concur. Discordant results may reflect the stage of
infection.
FIV is initially screened through an ELISA test that detects antibodies
against the virus in the blood. Most cats develop antibodies within 60 days
of infection. A western blot test confirms the diagnosis of FIV by show-
ing that the antibodies are specific to FIV structural proteins. There are
PCR (polymerase chain reaction) tests for FeLV and FIV viral RNA or
DNA, but currently these tests have not been standardized or validated.
FIP cannot be definitely diagnosed by any blood test.The tests used
that may support a diagnosis are an antibody titer test to FCV, FIP 7B
ELISA and FIP PCR, but none of these are conclusive blood tests.
X RAYS
X rays are diagnostic images, also called radiographs.They are produced
on film, and now also digitally, when a beam of electromagnetic ener-
gy is transmitted through part of the body and the image it creates is
captured.The density of various tissues affects the way the energy beam
relays the image. X rays are very good for evaluating bony structures
and of variable usefulness for soft tissue structures. They are excellent
for detecting metal and rubber objects inside a cat's body.
X rays provide a two-dimensional image of a three-dimensional
animal, so at least two views are needed to properly assess a body part.
X rays are a relatively inexpensive test and are readily available in vet-
erinary hospitals.
When patients are fairly cooperative, animal technicians wearing
protective aprons and gloves position and hold the animal during expo-
sure. Fractious animals, or those in pain, require sedation or anesthesia
for proper images to be recorded.
Contrast materials make visualization of certain body parts clearer
on X rays. In a barium upper GI series, a cat is made to drink a chalky
liquid that outlines his esophagus, stomach and intestines as it passes
through. Some abnormalities in the lining of the tubular GI tract and
obstructions are found this way.
