Browsing tag: MRI

Ask a Vet Online – ‘My vet says my poodle cross Pom, may have cushings disease what is this please?’

Question from Carol Fogerty

Hi my vet says my poodle cross Pom ,may have cushings disease whot is this please

Answer from Shanika Winters MRCVS, Online Vet

Hi Carol and thank you for asking about Cushing’s disease (HAC hyperadrenocorticism) which is a condition where the body makes too much of the steroid cortisol which can result in a variety of symptoms.  HAC is most common in middle aged to older dogs but does also affect cats, horses, hamsters and ferrets.

There are three different types of HAC:

Pituitary dependant HAC (PDHAC) is the most common type and this is when a tumour of  the pituitary gland in the brain is making too much of a hormone called adrenocotricotrophic hormone (ACTH)  this causes the adrenal glands to make too much cortisol.

Adrenal dependant HAC (ADHAC) is less common, this is when a tumour of the adrenal glands causes too much cortisol to be produced.

Iatrogenic HAC (IHAC) is when very high doses of steroid given as medication lead to symptoms of HAC.

What are the signs of HAC?

If your pet is showing some of the following signs then your vet may suspect HAC:

Increased drinking (PD polydypsia), increased urinating (PU polyuria), increased appetite (PP polyphagia), a large rounded low slung abdomen ( tummy), muscle weakness, hair loss on both sides (bilateral symmetrical alopecia), hard areas under the skin due to deposits of the mineral calcium (calcinosis cutis) and dark spots on the skin due to blocked keratin (hair protein) filled hair follicles  (comedones).

How do we test for HAC?

There are several blood tests, urine tests and diagnostic imaging tests than can be done to try and make a diagnosis of HAC:

    Routine blood tests in cases of HAC may show up increased levels of liver enzymes, increased cholesterol, increased blood glucose (blood sugar) and also changes to the white blood cell numbers.
    Routine urine tests may show an increase in glucose, white blood cells and protein.

More specific tests for HAC include:

    Urine creatinine: cortisol ratio, here a urine sample collected from your pet is sent to a laboratory for analysis, abnormal results are found in cases of HAC but can also suggest diabetes, liver disease or womb infection (pyometra).
    ACTH stimulation test, this is a set of blood tests in which a blood sample is taken from your pet, an injection of artificial ACTH is given into a vein (blood vessel) and 1-2 hours later another blood sample is collected. The laboratory results are abnormal in approximately 80% of dogs with HAC, this test is also often used to monitor dogs on treatment for HAC.
    Plasma cortisol level, this is a blood test which directly measure the level of cortisol in the blood , the blood sample has to be treated very carefully and sent to the lab quickly so as to get an accurate result.
    Ultrasound scan of the abdomen can be used to check the size of the adrenal glands (found next to the kidneys), look for a tumour and assess the other abdominal organs. IN PDHAC the adrenal glands are usually normal size or slightly enlarged with ADHAC the adrenal glands are usually different sizes, the large irregular gland being the one with the tumour.
    Low and High dose dexamethasone suppression test (LDDST & HDDST) are blood tests where the effect of artificial steroid on the adrenal glands is measured, the results can sometimes help tell apart PDHAC form ADHAC.
    Magnetic resonance imaging (MRI) scans and computed tomography (CT) scans can be performed at referral centres to help in the diagnosis of HAC and also tell which type it is.

How is HAC treated?

Trilostane is a tablet with blocks a step in the production of cortisol in your pet’s adrenal glands therefore decreasing the amount of cortisol in your pet’s body.

Mitotane is another tablet which works by destroying the parts of the adrenal glands that produce cortisol.

Surgery to remove the actual tumours can be performed usually at referral centres.

Trilostane and mitotane are the most commonly used treatments for HAC, they are effective on both PDHAC and ADHAC and your pet should have regular blood tests to monitor that the dose given is correct for your pet. Too much medication for HAC can lead to symptoms of Addison’s disease (Hypoadrenocorticism) where there is not enough cortisol which includes dehydration, depression, diarrhoea and lethargy (weakness).

I hope that my answer has given you some useful information about HAC, the exact test done on your pet will need to be discussed with your vet. The aim of treating your pet is to reduce the signs of HAC to improve your pet’s quality of life and is best achieved by working closely with your vet.

Shanika Winters MRCVS (online vet)

BEVA Congress 2012 – How Horse Vets Keep Up to Date

Equine Education (Part 1 – CPD)

As vets, we’re always trying to do the very best for our patients. However, veterinary medicine is constantly changing – every year, hundreds, even thousands of new papers are published, new drugs become available, and new machines and tools come on the market. What was the “gold standard” of treatment for a disease ten years ago might now be proven to be more harmful than helpful! At a recent conference (BEVA Congress – see below for more on that…), John Walmsey, one of the foremost and best respected members of the profession, gave the plenary lecture talking about the massive changes that have taken place in equine veterinary care in the four and a half decades since he graduated. The drugs we have now are far more effective, the machines and tools more robust and more useful. Even ten years ago, MRI in the horse was really rare and (to be honest) unreliable; now it’s a standard tool in working up a complex lameness. As a result, with the field of knowledge constantly changing, it’s more important than ever for vets in practice to keep up!

The process of keeping up to date is known as CPD (Continuing Professional Development), and we are expected to do at least 5 days a year. It can be made up in a number of ways, including lectures, seminars, webinars, practical courses and reading journals and papers. Like most equine vets, I receive the big journals Equine Veterinary Journal and Equine Veterinary Education, which (respectively) publish papers on equine science and equine surgery and medicine. I also try to attend relevant courses and lectures as often as I can.

In September, I was at the BEVA (British Equine Veterinary Association) Congress in Birmingham. This is one of the biggest gatherings of horse vets in the world, and I try to go most years. Congress lasts for three days of lectures and seminars, as well as a large commercial exhibition. It’s a great place to go to pick up the latest ideas, new treatments and medicines, and catch up with colleagues from across the country. I sometimes think we learn almost as much from talking over cases with colleagues as we do in the lecture theatres!

This year was notable for…

  • The debate over firing of tendons. (Quick recap on that one – the Royal College, our regulatory body, does not permit firing of tendons etc; some equine vets think firing should be permitted again in certain circumstances; however, others disagree. The argument goes on!).
  • Andy Bathe from Rossdales in Newmarket had some hilarious stories about working at the Olympics, as well as a number of thought provoking points. For example, some of the showjumpers were receiving a wide range of different (legal) medications to keep them performing at their peak throughout the competition; and every single dose of every single medication had to be certified by an official vet on a separate form. That led to a HUGE pile of forms for the FEI vets to certify each day!
  • There was also a long session on current approaches to laminitis – unfortunately, none of the existing theoretical studies are an exact match for the real disease, and researchers are still plodding along, gathering information. Sooner or later, we will have a good understanding of the condition; however, at the moment we have to be content with identifying horses and ponies who are at high risk, and managing them to minimise the risk. There aren’t any easy tests available to measure how high the risk is, however, so it still comes down to the clinical judgement of the vet on the ground.
  • New work being done on RAO (Recurrent Airway Obstruction, what used to be called COPD). Almost all the vets in the audience, as well as the panel of experts, agreed that this year has been especially bad for summer pasture associated RAO, and that cases seem much more resistant to normal treatment than usual. No-one knows why, but it seems likely that the unusual weather has resulted in more pollen than usual (or at least, more of the particularly reactive pollens). One lecturer from Switzerland had a fascinating paper to present on the genetic basis of RAO – he and his team have identified at least 2 different genes that can cause it, one of which is also associated with extra resistance to worms and other parasites. Unfortunately, though, it looks like it will be a long time before there is a simple genetic test, because there are another 11 genes that are also involved… as usual with any horse disease, nothing is as simple as it at first appears! However, he did have one useful tip… In Switzerland, a horse with summer-RAO is routinely moved into the mountains, which seems to reduce the severity. Obviously, this isn’t always practical here, but one UK-based expert on the panel suggested moving to the coast for the same reason – to remove the horse from the source of the allergens that are causing the problem.
  • As well as the main lectures, there is always one lecture theatre devoted exclusively to Clinical Research – vets and scientists (and mostly people who are both) present their papers on all sorts of subjects, ranging from Soft Tissue Surgery to Reproduction to Imaging to General Medicine. If I tell you that papers presented include “Carbon Dioxide laser surgery with adjunctive photodynamic therapy as a treatment for equine peri-ocular sarcoid: Outcome and complications in 21 patients” and “Validation and reliability of orthoganal ultrasonographic projection dimensions of the kidney in the horse”, you should get some idea of the level of science being presented!

Of course, after Congress, every delegate takes home a copy of the Proceedings – a (big fat) book containing a summary of all the lectures and papers presented. In addition, all the lectures are recorded and vets can access them online, if there was a lecture in particular that they missed. For a lot of us, Congress is only the beginning – on the train home, or over the next few weeks, vets across the country will be reading up on papers and lectures in their particular areas of interest. At most practices – including mine – whenever anyone has been on a course or conference, they then have to boil it down into practical, “hands-on” information. We then present it to the other vets (and nurses etc, if it involves new techniques or machines), so that everyone’s patients can benefit from the new knowledge. Sometimes it’s hard – it can be very difficult for all of us to accept that a long-cherished treatment has been proven not to work! – but for the sake of all our patients, we work hard to use the most up to date information, and not to be trapped in old, comfortable ideas that aren’t as effective.

The other side of veterinary education, of course, is the education and teaching of students that happens in practice. I’ll be talking about that in my next blog!

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