Bone Scans the good....the bad (also in NL)

[NR99]

Hi

Also in NL.

As title says really, I have read quite a few posts where bone scans have not worked just wondered if anyone had any positive experiences where they have been useful as a diagnostic tool.

Basically our TB was showing signs of pain suspected Sacriolac/Pelvic problem, but on lameness work up showed lame in all 4 legs. Vet said if she had to put money on it, it would be sacrum or hock related but as there is so much to look at she thinks a bone scan would work out more cost effective than repeated nerve blocks.

Insurance will not authorise payment without a diagnosis and vet says needs scan to diagnose, so think I will bite the bullet and pay for it myself, but would be grateful for feedback good or bad.

 

[Halfstep]

The problem with bone scans is that they are almost too good! They can often reveal hotspots that are not clinically significant. But they also can be brilliant at pinpointing problem areas and are definitely a very good way of confirming sacro-iliac pain.

The problem basically is that a lot of working horses will have hot spots in the hocks (for example) which are caused by normal wear and tear on the joint but are not clinically important.

If the scan shows something that can be treated, the insurance should pay up. The risk you take is if the scan is inconclusive - you could have to foot the bill yourself in this case.

 

[lauraandjack]

The principle of bone scanning is that the horse is injected with a short acting radioactive isotope into the vein. First of all it is absorbed into the muscle and other soft tissues so depending on what suspicions your vet has they may decide to image the 'soft tissue phase.' If they are interested more in bone then the horse is put in the stable for a period of time to allow the isotope to reach the bone. Then they can be scanned for the 'bone phase.'

The idea behind it is that areas of the body that are damaged and undergoing active repair absorb more of the radioactive isotope than non damaged areas. The horse is scanned with a gamma camera (under sedation, it's a bit scary for most horses and the camera is vv expensive!). The results are interpreted by computer to give you a coloured picture of the horse. The brighter the colour, the more isotope has been taken up in the area, giving you so-called 'hot spots.'

Scintigraphy doesn't show you what the problem is, but it can help guide your vet to the likely problem area which is particularly helpful for difficult areas like the sacroiliac joint which is hard to assess in other ways. Obviously joints that are under a lot of stress such as the hock have constant bone remodelling going on and will also have increased uptake (but then again many horses have complex problems involving more than one area!)

Obviously some horses decide that they do not have any particular 'hot spots' so this is where a bone scan may be not so useful. This is maybe especially true for very longstanding cases where the repair mechanisms of the body are probably not so active.

Your horse will need to stay in at the clinic for a day or 2 while the radioactivity subsides.

I would probably go for the scan as your horse seems to have different problems going on, it may just help your vet to decide what is the most significant problem.

Hope this helps.

 

[NR99]

Thanks Halfstep that is really useful, that was my concern but I think on balance it is worth going with the scan as I am pretty convinced from the type of behavioural issues we have had and signs such as unable to develop his topline over lumbar region/rump and his hunters bump that has become more pronounced that there is something going on in that area.

Thanks for taking the time to reply, I'll keep everyone updated.

 

[Butterbean]

We have been unlucky with gamma scans, OH's horse had 2 (over 2 years) and my horse had one last year and each time they were inconclusive and didn't pinpoint anything.

 

[Tnavas]

How about trying Thermal imaging - a brillient means of finding the actual spots that are inflamed.

Inflamation = Heat so the thermograph picks up the hot spots.

Vet then knows exactly where the problem lies and can then work out why the areas are inflamed and then cinsider prognosis.

I had a horse done once that lost weight the moment it started working, never lame but weight would go down so fast. Thermograph picked out a hip/pelvis problem, sadly not treatable - horse became nanny to weanlings and is now in his late teens as plump as a broody.

 

[Angelbones]

I've just had my horse bone scanned. He obviously wasn't 'right' but nobody knew why, and he wasn't even lame. The scan showed hot spots in his hocks and in his sacroilliac region. Hocks were then xrayed but turned out to be fine. SI region was at the border between normal and problematic. The trouble is that even if it picks up a hot spot in the SI region there is no further imaging that can be done to narrow it down so you end up with a possible cause but nothing definite, and I believe it is almost impossible to say whether the SI injury is to the ligaments or the bones, and the treatment plan for each would be different, with a poor prognosis for both. My horse then had a local anaesthetic injected into his SI region, but still had his problem afterwards which said that it wasn't pain causing his problem, but again no further diagnosis could be made from there. It was all very frustrating. Now my insurance company has 'written off' the entire back despite the result being borderline. I have since taken my horse to see an equine sports therapist who did some work on him and lo and behold he is now able to do what he wasn't able to do before. I wish I'd taken him before sending him for the scan. Luckily he was insured but now I feel his is labelled as having a SI problem which I actually doubt was the problem all along. None of this probably helps you, but good luck with it all. x