2 years since Homer's all clear results following his laminitis (due to EMS) in 2009, I wanted to check that we were still on the right lines, particularly since this year he has had quite a lot of access to grass, albeit with a grazing muzzle, on a track which is mostly under trees, and generally only first thing in the morning and and last thing at night, and only when he's in regular exercise.
I wanted to know how Homer was coping with his normal routine, so rather than fasting, he went out to graze in his muzzle as usual before the vet arrived. My equine vet practice has just invested in a mobile centrifuge and a handheld glucometer - great news for laminitic horse owners!
The vet drew a large syringe full of Homer's blood and then filled the appropriate tubes - purple topped (EDTA) for ACTH, grey topped (OxF) for glucose, red topped (dry) for insulin (according to Liphook's protocol - different labs may have different protocols depending on the assays they use). The ACTH and glucose samples were put straight in the centrifuge and separated, then the plasma drawn off with a needle and decanted into labelled plain tubes which were then chilled. The insulin sample had to clot before being centrifuged, so the vet did some vaccinations and then centrifuged the red topped tube and decanted the serum into a labelled plain tube, which was then chilled.
We took 2 EDTA samples for ACTH, 10 minutes apart - Liphook had offered to test both for the price of one, an offer we couldn't refuse!
As we are in France, the samples were frozen overnight (within the UK they'd normally only need be kept chilled) and then securely sealed and packed with frozen gel packs (supplied by Liphook), along with the completed submission form and cheque, and taken on a plane yesterday (in hand luggage accompanied by the DEFRA import licence) and then driven straight to the lab at Liphook. We had the insulin results for one pony within 3 hours of the blood's arrival at Liphook, and Homer's full results came first thing this morning.
We had tested a drop of whole blood from the first blood draw with 2 handheld glucometers - an Accu-Chek which gave a reading of 5.9 mmol/l (or 106.2 mg/dl), and the vet's glucometer which gave a reading of 116 mg/dl (or 6.44 mmol/l). I had been concerned by the vet's glucometer's high reading, and started to worry that this might indicate that Homer's insulin might be over 20 uIU/ml - and that my management of him wasn't strict enough. So it was with huge relief that I read Homer's results:
Insulin 4.4 uIU/ml (<20)
Glucose 5.7 mmol/l (2.3 - 6.8)
ACTH 16.4 and 14.6 pg/ml (10 mins apart) (<47)
I rushed out to give Homer a slice of apple (through his muzzle!) and a hug, and haven't yet been able to wipe the smile off my face!!
I chose to do a non-fasting insulin and glucose test - this was only because we had previously had negative results for both from a fasting test. Fasting tests are easier to interpret because they will not be affected by recent feed, and are recommended by many vets for initial diagnosis and for follow up tests at least until the horse tests negative.
I purposely wanted to compare the glucose results from glucometers and lab tests. Following these results, I'm not sure I would place too much faith in all glucometer results - they are likely to be useful for monitoring increases and decreases in glucose (using the same glucometer), but not necessarily for giving an accurate glucose concentration. I would want to know that a glucometer had had results in line with (correctly handled) lab results before accepting a glucometer result in lieu of a lab result.
I particularly wanted to have Homer tested for PPID during the peak of the seasonal rise (September), because according to the latest thinking, he could be said to be showing early signs of PPID:
- long hair on his chin/under his jaw, down his gullet and on the backs of his legs,
- early to get winter coat and later than my other "finer" horses to shed his coat in the spring, although no patchy shedding,
- decreased athletic performance and lethargy - he's never been the most enthusiastic chap to work, he's the sort of horse that tells you the way home out hacking, and keeps asking if it isn't time to stop or take a break in the school!
So it was great to have 2 resoundingly negative ACTH results - and I suspect it's changes in these symptoms that we need to watch out for, or starting to have them for the first time later in life, whereas Homer, who is a very easy keeping Irish cob who doesn't waste a scrap of energy and could easily be related to a yak, has always, since he came to us at the age of 7, been hairy, slow to lose his winter coat (which is much thicker than most other horses), and not too keen on work - no change there in over 10 years! So for the moment I am going to happily accept that that's "just how he is", and not go looking for PPID in every long hair (but I will keep monitoring him regularly, because if he does start to show signs, I'll be doing all I can to arrest the neurodegeneration for as long as possible)!
If your vet collects blood and takes it away to process it, you could easily underestimate the amount of work involved and therefore perhaps question their charges. The blood collection is (generally) the easy bit! Every tube of blood (for EMS/PPID tests) has to either clot and/or spin in a centrifuge to separate the plasma or serum from the cells. The plasma or serum then has to be drawn off using a clean needle and syringe for every tube, and put into a clean tube, which has to be labelled with the horse's name, the contents of the tube and usually the test required. And then submission forms filled in and the tubes packed up correctly and dispatched to the testing lab. A lab result is only as good as the sample submitted, so use the most experienced vet you can and be prepared to pay for good service. If you don't believe me, ask your vet whether it might be possible to watch your blood being prepared sometime - you may be surprised!
Finally, I cannot thank the lab staff at Liphook enough for their friendly and efficient service. Since I first contacted them over 2 years ago to ask them if they would test blood from France, they have helped us through every aspect of collecting and testing blood, and answered unending questions. We can rely on getting accurate results, reported by whatever means we choose (phone, email, text..) often within a few hours of the samples arriving at Liphook, 6 days a week, and at excellent prices, and enjoy knowing that our samples may be contributing to their research and helping horses in the future.
And I'd like to thank my vets here in France who are great to work with, very open to new ideas, have excellent horse handling skills, speak very good English and even pose for photos for the website! They are all equine specialists, are investing in equipment for the benefit of all horses in the area and appear to have made a huge difference to horse survival rates in the short time they have been in this predominantly beef-producing region of France - we are very lucky to have them!
For more about blood testing at Liphook, and the protocol in French and English, see: