As a specialist in veterinary internal medicine, I (Perry Jameson) only see patients that are referred to me. This means you cannot call and make an appointment but must first see your family veterinarian or come in after hours as an emergency and be transferred to me in the morning.
This often means that a preliminary work-up has been performed already by the family veterinarian. This typically includes physical examination, basic blood work (complete blood cell count and chemistry), urinalysis, heart worm testing and a fecal evaluation. They come to me when these tests have not provided an answer.
As an internist, my job is then to review your pet’s history, familiarizing myself with the clinical signs specific to your pet, previous treatments and the response to those treatments, evaluate the previous diagnostics performed, as well as perform a complete physical examination. This usually takes me about 20 minutes as I like to “think out loud” with Mom and Dad as I process the information and get myself up to speed as to how we got to where we are.
Taking all of that information, I will then give advice as to what I think is the most likely problem or I will recommend additional diagnostics in a logical approach to try and determine the underlying cause.
With most of my patients being older cats and dogs, often I am concerned about the possibility of cancer. When I convey my concerns, I am frequently asked if cancer could still be an option because “the blood work did not show any signs of cancer." While I wish it was that easy to rule cancer out, unfortunately, it isn’t. For many patients, these preliminary tests are more important in telling us what is not going on rather than providing the answer.
The CBC (complete blood count) shows us what is going on with the three main blood cell lines: white blood cells, red blood cells and platelets. The only cancer we can diagnose on a CBC is leukemia. This is where there are circulating cancer cells. Cancers may alter these cell lines but so do many other noncancerous diseases.
We can never diagnose cancer with complete blood chemistry. Blood chemistry provides information about the liver, kidneys, electrolytes, calcium and blood proteins. While these levels can be affected by cancer, changes again are not specific for cancer.
The CBC and blood chemistry can actually be normal and your pet may have a very serious, terminal cancer.
The urinalysis tells us how the kidneys are concentrating the urine. This can be low with endocrine disease, kidney disease and some behavioral conditions. A high urine concentration is often seen with dehydration. We look for glucose in the urine to suggest diabetes, protein for kidney disease or other illnesses, and white blood cells and bacteria to indicate a urinary tract infection. Red blood cells in the urine can indicate bladder stones, cancer or a bleeding issue.
A heart worm test is essential for pets living in South Carolina as heart worms are a prevalent cause of both heart disease and respiratory disease in dogs and can cause respiratory signs in cats as well.
The fecal evaluation helps rule out basic parasites that can cause weight loss, blood loss and diarrhea.
It is also important to know what alterations are normal. For instance, puppies can have high phosphorus levels, and certain breeds, such as King Charles Cavalier Spaniels, can have low platelets.
Finally, there are several body systems that we don’t really have good blood tests to evaluate, and those include the intestinal tract and pancreas, lungs, heart and the central nervous system.
When we are concerned about the intestinal tract, we very often will recommend additional imaging (ultrasound, X-rays and endoscopy or colonoscopy). Additional blood work to check vitamin absorption and pancreatic function are often recommended as well.
For heart and lung disease, we will start with X-rays and an ultrasound of the heart. Evaluation of the central nervous system typically requires imaging of the brain (MRI) in combination with obtaining a sample of the fluid that surrounds the central nervous system (CSF).
In many of the patients who come to me, the initial blood and urine tests are completely normal. However, there is significant disease throughout their bodies. Fortunately, now we have veterinary specialists and advanced diagnostics for pets to aid us in figuring out the cause of these once-hidden diseases.