The Results are In - 1st Post

I've had trouble thinking of good ideas to blog about. So I've decided to spend a couple of posts talking about "lab results."

How many times have you heard, "We're going to run some tests," or, "the blood work all came back normal." WHAT DOES THAT MEAN?

Let's break it down and over the next few posts talk about some of the common tests that are run and what kind of information we can get. I will discuss the complete blood count, basic blood chemistries (including electrolytes), endocrine chemistries, urinalysis, stool analysis (see previous blog on this one), biopsy (histopathology) and cytology, and bacterial or fungal cultures.

For the first installment, I thought we would start with the Complete Blood Count (CBC). It is the most straight forward to discuss.

A complete blood count is just what it sounds like. We are trying to measure all of the types of blood cells and provide information about their age, distribution, and health. There are three main numbers we look at. Total white cell count, total red cell count, and platelets.

White cells got their name because when you get a bunch of them together, they look white (or kind of white - think pus which is a few billion white cells all together). There are 5 types of white cells we generally measure and the total white count (WBC) is simply all of these types added up.

• Neutrophils - these are the fast attackers. They are shortest lived of the white cells. They are the "first responders" to inflammation or infection and it's the neutrophils that are sacrificed in huge numbers (again, think pus). Typically, the neutrophils are the most numerous of the white cells - typically 60-70% of the total count. If the neutrophils appear young or have "toxic" changes, it helps tell us more about the type of response the body is mounting. Young, toxic neutrophils are usually in response to severe, systemic bacterial infections.
• Lymphocytes - The smaller, rounder white cell. They make up the second largest population. usually 20-40%. There are multiple "flavors" of lymphocytes. T-cells, B-cells, plasma cells. Basically all of the same family tree. Lymphocytes are responsible for various roles in managing the immune system. They don't eat stuff, they tell other cells to go work, go eat, or to make certain chemicals. They take control by using cellular contact chemicals (known as cytokines). For instance, Killer T-cells will tag a cancer cell and trigger it to die. The T-cell then tells the macrophages to eat the dying cell. B-cells are largely responsible for making antibodies.
• Monocytes - These are the biggest white cell and are responsible for much of the clean-up work. They can eat all kinds of stuff. If it needs to be cleaned up or eaten, monocytes are usually involved. They are usually about 5% of the total population. When monocytes leave the blood stream and enter a tissue that are re-named a macrophage. There are some highly specialized macrophages located in certain places in the body (like in the liver) that play a major role in regulating the immune system (kind of like the lymphocytes).
• Eosinophils - Similar to a neutrophil. These guys have large, reddish granules in their cytoplasm. Usually 1% or so of the total. Eosinophils have similar roles to the neutrophils, but they are primarily "turned on" when parasites are involved or in the case of allergic reactions/chronic allergies. Cats have a very interesting ability to mobilize eosinophils and the eosinophils can cause all kinds of problems when you get too many together all at once.
• Basophils - Very few are seen in the blood. It's actually kind of exciting to find one because they are typically fairly hard to find. They are in many ways just like an eosinophil.

If white cells are increased, we look at which ones. Neutrophils usually increase with infection of some kind (but any kind of stimulation to the immune system can cause increased numbers). Too few indicate life-threatening infection or that the bone marrow has been hit (as with parvovirus or chemotherapy). Increased monocytes can be seen in fungal infections or in cancer. increased eosinophils are usually associated with parasitic or allergic causes.

There are even some blood "parasites" that can be seen inside the white cells. Ehrlichia is one such infection.

Red blood cell counts:

The most common way to describe how many red blood cells an individual has is to use the packed cell volume (PCV) or hematocrit (HCT). PCV and HCT are basically percentages. If you take whole blood and spin it down (pack it) then you can compare the volume of red cells to the total volume of blood. Most blood is around 40-50% cells and the rest is all plasma.

Too few red cells = anemia.

PCV 30-40% - mild anemia

PCV 20-30% - significant anemia. Probably seeing "tired" pet.

PCV 15-20% - severe anemia. Something needs to be done.

PCV 10-15% - life threatening anemia. Something HAS to be done

PCV less than 10% - incompatible with organ function. Rapidly fatal.

Red blood cells are first and foremost an oxygen delivery system. Too few means not enough oxygen getting to tissues. Too many (pretty rare) and the blood is too thick and can't flow.

Baby red blood cells are darker and larger. Really immature red cells still have a nucleus (something that the adult cells have lost). Baby cells aren't very good at transport of oxygen. They're not the right shape yet and don't have all of the hemoglobin they will have as an adult. If you see baby reds in any significant number, you know the bone marrow has been told to make more. Usually this means the body is responding to an anemia.

Platelets - these are actually little cell fragments of a cell called a megakaryocyte (found in the bone marrow). Platelets are responsible for making a clot. You are always leaking. Always. Platelets go around plugging up that leak. Without them, you bleed to death. Honestly. There are usually 200 thousand or so in each milliliter of whole blood.

I could continue discussing all of the interesting things about blood cells, but I've gone on long enough. At least you have an idea of what they are looking at when a CBC is done. Complete discussions on interpretation are entire books in and of their own.

Next post - The basic blood chemistry.

AMH

In Memoriam

I should probably try to find a picture of Daley when she was perky. She was such a mellow dog.

Right after Christmas, Daley lost her battle with cancer. She survived 6 months longer than she was expected to. I diagnosed her with Stage 4b lymphoma on July 4th. That's a tumor of the small white blood cells called lymphocytes. If lymphoma is circulating, it's called leukemia.

She responded WAAAAAY better to chemo than expected. I'm a believer in quality over quantity and I would only continue chemo if she felt well. Surprisingly enough, she felt really good during her chemo (for the most part). She had off days. It took creativity to find foods that she wanted to eat, but all in all, she kept doing all of the things she enjoyed doing.

Daley was at least 15 years old. Not bad for an old girl!

AMH

Retrievers Behaving Badly - aka My New Year's Resolution

Long time, no see! No excuse, just slow to post.

Nearly everyone has a New Year's resolution. Mine include the obligatory trips to the gym, not eating everything in sight, and actually trying to loose my "baby weight" (my girls are now 5yrs old, I guess it's about time to loose the baby weight).

It's also time to walk the dog.

Here's why I mention this. Kate, my yellow dog (she's supposed to be golden retriever, I don't think so), is a nut case. She's either the most wonderful dog in the universe, or I could just strangle her. She's the typical ADHD retriever dog. She has enough energy that I could probably use her to power a small house if I could only figure out how to plug her in.

So there's really only one way to help improve her behavior when she starts to act out. EXERCISE. If I walk her, even just once a day, it's like magic. She's so much better behaved. If I throw the ball for 10 minutes, she's a new dog! I can't tell you how many times I have an owner complain about a dog misbehaving (especially puppies!) and so much of it can be improved by just exercise! When they have too much energy built up, they find some way to burn it. If you don't find a constructive outlet, they will probably find something destructive to get your attention.

I have a friend who puts her dog on the treadmill. She tried it one day and her dog LOVED it. She actually begs to get up on the treadmill (she stands by the machine and stares at mom). I need to see if she will send me a video.

Yet again, I'll draw a parallel between raising dogs and raising kids. As any parent knows, rainy days are just the kind of thing to make a parent want to start drinking at noon when they are stuck in the house with their kids. Kids NEED to burn off excess energy. Their brains don't know what to do if they don't have physical exercise. Exactly the same with your dogs.

Don't forget cats! I'll post again with some suggestions on how to exercise your cat. It is possible. I'm not saying that your cat won't look at you, frown, and then fall back asleep when you suggest they get up and play, but it's POSSIBLE. Inappropriate urination, destructive behavior, aggression, and obesity are all things that are improved with exercise.

AMH

Be Your Pet's Medical Advocate

I recently went through a spell of severe back pain and finally broke down and visited my physician. They were kind, listened to my concerns, prescribed some different pain management options, and then recommended that I go and have by back radiographed (x-ray).

Once I left the office, however, communication totally broke down. The doctor's office called the next day and said, "The X-rays are abnormal you need a MRI." I called the radiologist and was informed that the MRI was listed at $2,000.

I nearly pooped myself.

So I called back the doctor and I tried to get them to tell me what we were looking for, what was abnormal about the x-ray, and what kind of treatments we were going to consider. This was a lot of money. They were, unfortunately, totally unable to explain what they hoped to accomplish with this diagnostic, only to say that it was important and they needed to look at the "tissues." Seriously. $2000 and all I get from you is you want to look at the "tissues?" I was a bit upset.

I had the MRI (As it turns out, it was only $500 due to insurance negotiated discounts - who says our medical system of insurance ain't screwed up?). Afterwards my doctor's office called back to tell me that the MRI was abnormal and that I could be sent for injections for the bad disk if I wanted to. Seriously, that was the extent of the discussion. This left me even more frustrated.

I had to call back and insist that I talk to my RNP and discuss what the goals of thearpy were, what the expectations are for treatment, and what the actual diagnosis was. Point was, I had to GO AND SEEK OUT this information. I nearly had to drag it out of them.

I had to be my own medical advocate.

I have never had problems with this office, in fact I really like this group. I still like them, but they dropped the ball on this one.

I had seen the x-rays. I had a copy of the MRI made before I left the office so I was able to look through them and see what was up. I also had enough knowledge to know what we were looking for. What I did not know what how this would be handled in a human. I needed my physician's office to actually take the time to explain the plan. Why the recommendation for steroid injections? Surgery now? At what point do we consider it? Physical therapy?


Gee, Aaron, Why are you boring us with this long sob story about your back?

Because this experience was a reminder for me to NOT do this when I am working with my clients. I know this kind of thing happens every day both in human and veterinary medicine. It is easy to loose touch when the patient is not sitting in the room in front of you. I try very hard to keep up communication and take the time to explain, and I think I'm better than most. But I am sure that I have dropped the ball from time to time and have probably left some clients confused or with a feeling of being "out of the loop."

Your medical care and your pet's medical care is a TWO WAY STREET! It involves both the medical staff and you! I don't believe for a second that my doctor's office was trying to be lazy. But I do think that they did a terrible job this time communicating diagnostic findings, assesment of those findings, and a coherant plan with the patient. I had to take the responsibility to get the information.

You should handle your pet's medical care the same way. Hold your veterinarian and their staff responsible for giving you the information you require to make informed decisions. Make sure you are comfortable with the direction your pet's care is taking. If you don't understand something, call them back. Make for darned sure you have been given the information you need. We're all on the same team.


AMH

A Quick Influenza Update

I received an e-mail not long ago about a cat being diagnosed with H1N1 influenza. You will all remember that H1N1 is the "swine" flu as opposed to the H3N8 dog/horse influenza. I've checked into it and there have been a couple of cases of cats and a couple of ferrets with confirmed H1N1.

At risk of sounding redundant: DON'T PANIC!

We know that influenza virus can jump species. It's why we have the H1N1 epidemic to begin with, right? So it stands to reason that there would be instances where the virus jumps from people to cats.

Is it scary? Yes. It is. We always pay close attention when something like this happens. When there are inter-species jumps we always investigate and see if there is any difference in the virus, type of infection, or incidence.

Is it common? No, It's considered rare. I'm sure there are cases out there we don't know about, but if you consider there are two cat cases compared to many thousands of human cases, it's rare.

Has the virus mutated? NO. Genetic analysis says the virus has not changed, it just happened to infect a different species than we would have expected.

I assume we are going to see more of these. The cats and ferrets infected have all recovered from the infection and it is essentially the same story for them as it is in us or dogs.

Interesting...

AMH