Why do Lab Work?
Blood Profiles and Urine Analysis yield some of the best information for piecing together diagnostic clues and formatting a treatment plan.
When done as part of a Well-Pet Visit, these tests can pick up on problems before they are otherwise apparent. This means finding conditions at their earliest, and often most treatable, stages.
Some changes are “Normal” for that pet. For example, a liver enzyme called ALP (Alkaline Phosphatase) tends to elevate its levels as a dog ages, due to a non-illness-causing condition called Age-Related Hepatopathy. However, ALP can be a significant indicator of disease: liver disease, such as bile duct blockage; hormonal conditions related to adrenal gland malfunction; and bone degeneration due to cancer or arthritis. So, if I do a blood profile when your pet is ill, and we see an elevated ALP, is it significant or not? If we did a Well-Pet Profile 3 months ago, and the elevated ALP is at the same level it was then, I will probably disregard it as not pertinent to the current illness. If, however, it has increased greatly since the last blood profile, then it probably is significant to what is going on.
Some testing can be done right at my van, for results before the end of the visit.
Ear swabs are the best way to identify the causative factors in an ear infection. Is the infection bacterial, or yeast, or a mixed bag of both? Knowing what is down in the ear informs the treatment – different forms of ear infections are best treated by different means.
I can centrifuge and do microscopic analysis on a urine sample right away – urine samples yield the most accurate results when they are fresh, before sitting around causes chemical changes and allows bacterial contamination to proliferate.
Cell samples from a Fine Needle Aspirate can be assessed right away. Is a mass cancerous? If there is any question about whether the cells seen are significant, the prepared cell sample can still be submitted to the Referral Laboratory for assessment by a Board-Certified Pathologist.
Samples from my patients are sent to IDEXX Laboratories, a full service Lab offering the expertise of Board-Certified Pathologists. Valuable information can come from all sorts of samples:
Full profiles give an overall “snapshot” of the current state of organ health. There are also an assortment of specific tests targeting specific conditions: immunology, endocrinology, blood cell morphology, electrolyte levels, even specific markers of particular organ conditions such as pancreatitis and heart disease.
A basic Urinalysis can tell a lot about what is going on in the kidneys and in the bladder. Urine can also yield insight into other body conditions: sugar and ketones in the urine tell about the level of control in a diabetic, and urine cortisol levels can help identify adrenal gland disease.
Most people are familiar with the assessment of fecal samples for parasites, but did you know that there is a lot more to be learned? Fecal Occult Blood (blood residues not visible to the naked eye) can identify the presence of a stomach or intestinal ulcer. Stools can be assessed for digestive enzyme activity, to identify pancreatic insufficiency.
Small skin masses that can be removed with sedation and local anaesthetic can be submitted to check for the presence of cancer. Skin conditions can be better diagnosed by collecting a skin biopsy under local anaesthetic. Fluids building up in the chest or abdomen can be analysed to identify their cause.
Any of the above samples can be submitted for culture of bacterial or fungal elements. Culture allows not only for identification of a pathogen, but for insight into how to clear it up. The bacteria, after they are grown, undergo Sensitivity Testing: this means that the bacteria is swabbed onto a growth plate dotted with antibiotic-impregnated plaques. In this way we can see which antibiotics kill them, which just suppress them, and, most importantly, which they are able to resist!