Tests are often needed to confirm a diagnosis or to determine the best mode or the effectiveness of treatment. Some of the most common tests that may be requested are stool sample, skin scrapings (for skin parasites or fungus), complete blood count, blood chemistry, urinalysis, bacteriology, and tissue biopsy.
Since cats like to examine their surroundings by licking both the ground and their peers’ private areas, and since they walk barefooted and eat things they shouldn’t (such as rodents), a stool sample should be checked once or twice a year. Most doctors will recommend that you bring it with you at vaccination time.A little is all that is needed, and it’s okay if the sample has kitty litter on it. If you are gathering an outdoor sample, try not to include any soil, because it contains some worms (harmless “soil” Strongyloides) that may confuse the examiner.
Confirming a fungus infection involves transferring skin scraping of the lesion to a container that contains “fungus food.” Confirmation may take one to two weeks. As the fungus grows and uses the “food,” the media in the coinfection.
Complete Blood Count
If firefighters are in a smoking building, you assume that there is a fire and that it will soon be under control. If there are smoke and flames and no firefighters, the building may burn to the ground. Your cat’s body has a remarkable “fire department” that consists of specialized cells, floating through miles and miles of blood vessels. Some carry oxygen (red blood cells), giving the blood its red color. Others can be mobilized to defend areas of tissue injury (from bacteria, trauma, chemicals, or heat, for instance) and inflammation by “eating up” the particles that invaded your pet’s body (white blood cells). These “firefighters” consist of erythrocytes (red) and leukocytes (white). The white blood cells are divided into neutrophils, lymphocytes, monocytes, eosinophils, and basophils. The bone marrow produces all red blood cells and the neutrophils, eosinophils, and basophils. Lymphocytes and monocytes are produced in the lymph nodes, the spleen, the tonsils, and the lymphoid cells of the intestine.
The number and type of “firefighters” may help your doctor determine the type of disease present. For example, the panleukopenia virus can stop a cat’s bone marrow from making neutrophils. The blood count for neutrophils and the total white blood count will then be vet), low. Therefore, a kitten or unvaccinated cat with the signs of panleukopenia, with a very low total white blood count, and with few neutrophils probably has the disease. The cat’s “firefighters” are not available, and its “building” (its body) is in grave danger. Parasites that attack the red blood cells, such as hemobartonella, can be identified by staining a blood smear and then looking for the parasite in the red blood cells.
The neck (jugular) and front leg (cephalic) veins are the two most common sites for venipuncture (literally, puncturing the vein) to obtain blood for tests. Gentle restraint and a sterile needle and syringe are used, and most pets tolerate the procedure very well. However, fat or hyperactive cats and those with rolling or unusual veins may make it difficult to get a blood sample on the first try. Every veterinarian and technician has dealt with “problem veins.” Reactions from the owner such as, “You mean you have to stick poor Ralph again?” will just add more stress to the job – so quiet, please!
The health of your cat’s body depends on the health of all its parts, and an unhealthy organ will eventually affect the other organs. In order to confirm a diagnosis or to monitor your pet’s return to health or its setbacks, various enzymes and products of metabolism found in the blood should be measured. An increase or decrease in their levels can be used to identify and monitor the organ (or organs) that is sick, and the proper treatment can begin. A blood test alone is not a substitute for a physical examination, but veterinary recognition of the importance of blood chemistries has made this commonplace for good veterinary care.
Most veterinarians use a reliable commercial laboratory that provides accurate results at a reasonable price or perform tests in their own clinics, since the results from commercial labs may not be available for twenty-four to forty-eight hours. Pets that are very ill also need immediate results. Even so, the tests require time. In fact, your veterinarian may have to institute basic treatment before the final analysis is known. (In serious cases, life-support care, such as antibiotics, fluids, oxygen, and any other treatment thought necessary, will be started before all the test results have come back.) If you call the office the day after your cat has been examined to find out what exactly is wrong, your doctor still may not be sure of the complete picture.
The commercial laboratories may run as many as fifteen or twenty different tests on your cat’s blood sample. This is called a biochemical profile.
Blood Sugar (Glucose)
Your doctor will run this test if diabetes is suspected.
Blood Urea Nitrogen (BUN) and Creatinine
Urea and creatinine are end-products of metabolism that are normally eliminated by the kidney in the urine. If the kidneys are not functioning properly, these products will be increased in the blood. This will not tell your doctor the cause of the kidney problem, but just that the kidneys are involved. Special radiographs, urinalysis, and even a biopsy may be needed to define the disease process.
Amylase and Lipase
More cases of acute pancreatitis (inflammation of the pancreas) are being diagnosed and treated properly, thanks to the availability of these tests. If your pet has abdominal pain and sudden and severe vomiting and is very weak and depressed, these tests may be beneficial. The cells of an inflamed pancreas release the amylase and lipase enzymes into the bloodstream, so their number is markedly elevated.
Liver Profile Tests
The liver has so many functions that to see how it is functioning overall, the aliver profile has to be done. The blood tests include bilirubin, protein, SGPT, SGOT.cholesterol, and alkaline phosphatase. Sometimes this still is not enough to tell your doctor the cause of the liver problem, so other tests. such as a liver biopsy, may be necessary.
Feline T-Lymphocytic Virus Test (FTLV)
The feline T-Lymphocytic virus (FTLV), discovered in 1987, is similar to the human AIDS virus and attacks the cat’s immune system. A simple blood test is available and is recommended whenever a cat shows signs of chronic infection(mouth sores, weight loss, anemia, chronic intermittent diarrhea, skin sores, respiratory infection, or abortion). Test a “new cat” before bringing it into a home.
An important “new” disease in cats over seven years of age is hyperthyroidism. It is caused by a benign growth of the thyroid gland, which makes the “body-engine” go faster. The most common signs are weight loss, increased appetite, hyperactivity, rapid heart rate (over 200 beats per minute at rest), increased water intake and urination, and occasional vomiting. Less common signs are diarrhea, panting, and muscle weakness.
A simple blood test for thyroid hormone (T5) is used for diagnosis of this problem. The enlarged thyroid glands can usually be felt in the neck area.
This is an extremely helpful test for diagnosing diseases of the urinary tract and other problems, such as diabetes mellitus and liver disease. Your doctor will check to see if your pet is concentrating its urine (specific gravity) and will study the chemical analysis for such abnormalities as sugar in the urine, which may indicate diabetes or a kidney defect. Microscopic examination of the urine can be used to spot cells that may indicate inflammation. infection, or degeneration any-where along the urinary tract.
Bacterial infections are very common in bite-wounds (abscesses)and in problems involving the ear, eye, and urinary tract. Your doctor may suggest culture and sensitivity tests, which involve transferring a small amount of the infected material to a container filled with “food” in which the bacteria can flourish. Small paper disks, each containing a different antibiotic, are placed in the container at even intervals. The antibiotics that are effective against the bacteria will produce zones of inhibition areas around the disks where no bacteria will grow. The bacteria will also be identified by their growth pattern and microscopic features. Using a general antibiotic may cure the infection, but performing culture and sensitivity tests especially in chronic infections is better practice and may be cheaper in the long run.
Removing a tissue section for microscopic examination is often an excellent way to make a proper diagnosis, determine if the disease process can be reversed, and suggest the best therapy. Of course, biopsy of the internal organs is more difficult and has more risks than biopsy of the skin, but in skilled hands and with the proper instruments, tissue can be studied from the kidney, liver, or any other organ. Often, a local anesthetic and the appropriate biopsy instrument are all that is needed to obtain the sample. A biopsy is a good tool for determining the chance for your cat’s recovery and the type and cost of the best therapy.
Radiographs have become another important tool for diagnosis. The radiographic equipment in many veterinary hospitals is equivalent to that in human hospitals – and just as expensive. Modern X-ray equipment provides excellent “pictures” of the bones and internal organs and the spaces between them. The procedure of taking X-rays is painless and relatively harmless, but your pet may be sedated because any movement may cause blurring. Two or more views are needed to get a three-dimensional “picture” of the area under investigation.
To get the “picture,” X-rays are directed through your cat’s body. They travel very rapidly and then penetrate a plate containing film. X-rays pass through air easily, but solid masses, such as internal organs and bones, will stop some of them. Those that hit the film turn it black when it is developed. The areas on the film not touched by the rays remain white. So a chest X-ray has white areas (such as the heart, backbones, and ribs) and black areas (lung tissue, containing air). Your doctor will study the X-rays under a bright light, looking for changes in the normal shape, size, and density of the organs.
An electrocardiogram (ECG) is a graphic measure of the electrical activity of the heart. It is an inexpensive, safe, and painless technique for determining if your pet has heart disease. It is also helpful for diagnosing and monitoring treatments of illnesses not originating in the heart, such as urinary obstructions and Addisons disease. To obtain the ECG, your pet is placed on its right side, and leads are attached to its legs and body using clips. Cats rarely need to be sedated. The various leads are recorded, and the heart rate and rhythm and changes in the heart size are evaluated.
Bone Marrow Aspiration or Biopsy
If the blood-forming cells need to be studied, bone marrow may be aspirated from the tibia (leg bone) or ilium (hip bone). Bone biopsies may be collected under local or general anesthesia.