To help your veterinary surgeon to reach a diagnosis of your pet’s illness laboratory tests are often required.
These can take many forms but generally involve taking a sample of blood, urine, faeces, skin, etc from your pet and examining it microscopically and chemically. We can perform a wide variety of laboratory tests on our own premises and we send samples to a range of external laboratories if a more detailed work-up is required. To give you an idea of what is available; here are some tests that we can carry out in-house and some that we send away.
Blood
We can measure the packed cell volume (PCV) of your pet’s blood which tells us how many red blood cells it contains and also if he or she is dehydrated. We can also examine a blood smear under the microscope which can tell us about the relative numbers of white blood cells (those that fight off infection) and allow us to identify some intracellular parasites. Biochemical tests include: urea concentration which can indicate kidney function; plasma proteins concentration which can give us further relevant information and glucose to diagnose diabetes.
We offer in-house testing for Feline Immunodeficiency Virus (FIV) and Feline Leukaemia Virus (FeLV) which are two of the most serious viral diseases affecting cats.
Urine
Tests include specific gravity, pH (acidity), the presence of glucose, red and white blood cells and bilirubin; these can tell us about many diseases eg kidney failure, diabetes and bladder infections. Centrifuging a sample of urine and examining the sediment under the microscope will show any crystals that may be present in the urine.
Faeces
If your pet has a problem with its bowels then we may request a faecal sample. These are usually sent away to an external laboratory although there is one test that we have to do in house. We will provide you with a pot to collect the sample into and some gloves if you require them. Always remember to wash your hands after handling faeces.
Skin
The most important test here is a scrape of the top layers of the skin to identify ectoparasites such as mites. Other preparations can show the presence of fleas, lice and fungi.
Blood pressure monitoring
We use this more and more frequently especially in the diagnosis and monitoring of cats suffering from heart and kidney disease.
ECG (electrocardiogram)
This involves recording the electrical impulses produced as the heart beats and can tell about the rate, rhythm and size of the heart.
External laboratory tests
Many diseases are caused by bacteria and a swab or sample from the affected organ can be sent off to identify the type of bacterium involved and also which antibiotics it is sensitive to. This information is very useful in the diagnosis and treatment of skin, eye, ear, urinary tract and intestinal conditions.
Metabolic disease caused by organ dysfunction (eg liver, kidney, pancreas, thyroid gland) is best diagnosed by a range of biochemical tests.
The biopsy of affected organs either via a needle or by surgical excision is another commonly performed procedure.
What will happen to your pet?
In some cases (eg faeces) you will be asked to bring in the sample yourself; more often we will need to collect the sample from your pet.
Blood samples are collected from either the jugular vein in the neck or a vein in the front leg so you should expect your pet to be shaved in one or both of these areas. Just like in people taking blood is only mildly uncomfortable and serious problems are very rare.
For some biochemical tests (eg diabetic monitoring or liver function tests) we will need to keep your pet in the practice for the day so that we can collect multiple samples.
A skin scrape can be a little painful so we may sometimes suggest administering a sedative prior to the procedure.
A word of warning
No laboratory test is 100% accurate; there may be false positives or false negatives. Testing is most accurate when it is targeted at a particular organ or condition, if preliminary tests are inconclusive it is frequently necessary to perform further investigations (which may include x-rays, ultrasound scans, ECG, etc) or repeat the initial test at a later date.
In particular there is no single test for cancer, in fact there are very few blood tests that are appropriate as part of the diagnosis of this disease. More usually most types of cancer are identified by taking a biopsy of the affected tissue.