Entries Tagged 'Pet Health' ↓

How Diagnostic Tests Work…

I have just had a good friend have all sorts of trouble with her lovely old Labby- He suddenly got sick, really unwell, and in a matter of weeks they had to help him along to spirit… He suddenly developed Diabetes, and then they thought he had developed Cushings disease as well. However- the tests they did came back as negative, even though he had the symptoms!

This was confusing and painful…

The thing is- Diagnostic, or Laboratory tests are not perfect! I always tell my clients this- even the very best tests have some False results- both False Negatives (so they tell you your pet doesn’t have some problem, when really he does)- and False Positives (so they tell you your pet does have some problem, when really he doesn’t!)

Confused yet?

Stay with me- and I will show you what I mean.

There are two important measurements of diagnostic tests- SENSITIVITY, and SPECIFICITY..

Sensitivity tells you how good a test is at detecting when your pet has a given dis-ease. So- If a test has a Sensitivity of  %95, then it will detect 95 out of every 100 patients with the given dis-ease.

Specificity Tells you how accurately a Positive Test identifies patients who actually have the given dis-ease… So if a test has %90 Specificity, then 10 times out of 100, if your pet tests positive to the dis-ease  with that specific test, he doesn’t actually have the dis-ease.

Or Don’t Work?

So- When you are testing for diseases that are harder to diagnose with Laboratory or blood test (and Cushings is one of these)- it gets really tricky.

Let’s take a quick look under the hood- for Cushings, there are several tests you can use-

1. The Low Dose Dexamethasone Response Test is about %95 Sensitive, but only around %70 Specific (so it will detect 95 out of 100 pets with the disease, BUT  out of 100 positive tests, 25 patients will not have the disease)
2. The ACTH Response Test is about %80 Sensitive, But it’s Specificity can vary from %35-%80
3. The Urine Cortisol:creatanine ratio Test is about %90 Sensitive, but it’s Specificity is only  around %25 (so only about a 1/4 of dogs with abnormal levels in this test actually have Cushings disease, BUT it will pick up %90 of dogs tested that do have the dis-ease.)

I hope that makes some sort of good sense

So What do You Do then?

Please remember that this is confusing- even for your Vet- who I am sure is doing their level best to find out what’s up, so he can help you out, and find an effective treatment. I just think it will help if you know that all diagnostic tests are not created equal, and neither a positive, nor a negative test result will give you absolute certainty most of the time. This is why we sometimes need to do more tests,and sometimes what we don’t find in a test is as meaningful as what we do find. (So no test is wasted!- they all help by increasing our knowledge of the case…)

And it might help you understand just how hard it sometimes is for your vet to work out what is wrong with your pet.

Happy pets until next time, Dr Edward

I have been thinking about this a lot for the past few days…

As a practicing veterinarian, I see a lot of unwell pets- and then I also see a lot of healthy pets who are simply due for a checkup, or a vaccination booster, or maybe a yearly heart-worm prevention injection. The funny thing is- quite a few of the supposedly “healthy” pets don’t look that way to me!

Often they are overweight, have yucky teeth, or are dull in the coat, or stiff in their movement, or somehow don’t seem quite to be in the pink of good health. This is often subtle, hard to define, and hard for me to explain- but If I were to show you a truly healthy animal beside one who is not, it would leap out to you.

Maybe I can offer you a list of some of the things that really strike me when I meet a truly healthy pet…

A Healthy Pet Will Have:

• A Glossy Coat. You can tell a lot about how healthy your pet is by this! I would invite you to start checking out as many different pets as you are able, with all of these points in mind- (as this will give you something to compare your own pet with). Watch your pet, and you may even see this change from day to day- I have seen this change even during sessions of special hands on work I do with my patients! Of course- some breeds are naturally glossier than others, so bear this in mind.

• A Happy Demeanor. Check out your pet’s body language… Your pet has an emotional life, very much like yours. They have good days, bad days, and in between. As they can’t talk English (well- I am sure some of will tell Your pet sure can!), so watching how your pet moves and behaves will give you deep insight into how healthy he is.

• Free, Comfortable Movement. Your pet should have a nice open gait, sit to both sides, be able to get up and down easily, and exercise happily (not so much with Cats, of course). Back pain is very common in animals, and drastically under-diagnosed! I can speak from experience here- When I graduated, I knew next to nothing about how to tell if a pet had back pain, and less than nothing about what to do to help relieve it! (Apart from prescribing anti-inflammatory drugs, of course… As you will find the more you enjoy this blog, I am very much interested in using natural treatments wherever possible- and at the same time, I understand that drugs have their place, and I use them too, when I judge it necessary.)

• Healthy Weight. I see so many FAT pets… You should be able to gently run your fingers along the side of your pet’s ribcage, and distinctly feel the little bumps of the ribs flick under your finger tips. If you can’t, please consider a diet- I will share my magic diet in a future post. I know, I know- they are so good at looking at you when they want food!

• Clean Teeth. Modern pet food diets ain’t generally great for the health of the digestive system in general- and where you will see this most clearly is in the mouth. The teeth should be clean, clear of any buildup of tartar, no really stinky foul breath (not that even healthy pet breath smells like roses…)

• Healthy Toilet. Your pet’s poo should be nice and firm, and regular. The urine should not be too strong, or stinky, or (especially) have any blood in it. If you see blood, or your pet is wanting to urinate unusually often, please see your veterinarian as soon as possible.

***An Important Point- In my opinion, your pet can be unhealthy without necessarily being unwell…***

I better explain a little more about exactly what I mean here…

I am going to define “unwell” as something your Vet will be able to diagnose, and hence treat… i.e. a recognisable dis-ease (the comfort zone of Western Medicine in the mainstream!) You know how it goes- Your vet will find some clearly defined symptoms on the Physical Exam (eg fever), or may run some diagnostics such as blood tests, X-rays, Ultrasound or the like, and reach a “diagnosis”.

So then- What does unhealthy mean?

For a start- If you were to bring an unhealthy pet to me, I can be fairly certain that a reasonable amount of the time, I could spend a large chunk of their Mum or Dad’s money on Blood Tests, Xrays, Ultrasounds- or any number of other diagnostic tests… and often find nothing remarkable, nothing “to treat”, so to speak.

Sometimes we would find something that really helps- like organ malfunctions with blood tests.

But what do you do when you and your vet can’t find a problem, but your pet is clearly unhealthy?

Come back and learn some simple, effective things you can do to keep your pet “Better than Well” in my next post.

Cheers For now,

Dr Edward

Hi- I am Dr Edward… This blog is still “under construction”- but there will be much to follow, as I get my head around the techie side of this blog adventure-

I am a home visit vet, based in Townsville, Nth Queensland, Australia. I have a strong interest in natural and complementary health care for all pets.

It’s raining as I type, we are in the middle of the big wet (and everything is going moldy)

Every word I share will be entirely focused on helping you keep your pet “Better Than Well”- as naturally and gently as possible. Our pets give us so much, and it’s only fair that we give back to them in any way that we realistically can. Be patient, and come back, or even subscribe (see the options over to the right)- it will be well worth it!

Why?- because you will find out all about many ways to help your pet! You can even ask me any questions via the comments section below, and I will post in reply…

Cheers for now,

Dr Edward