Progressive hindlimb ataxia JRT

Re: Progressive hindlimb ataxia JRT

Hannah Wynne Richards — Thu, 13 Sep 2012 17:00:29 GMT

I've had 2 PTSs and another to do later

Wynne

Re: Progressive hindlimb ataxia JRT

Bob Russell — Thu, 13 Sep 2012 15:40:17 GMT

The day started with me being liberally sprayed with anal gland secretions and has gone progressively downhill from there!

Re: Progressive hindlimb ataxia JRT

Mark Lowrie — Thu, 13 Sep 2012 15:38:24 GMT

Hi Bob, I do not doubt you are correct and I accidentally deleted the first part of my post that should have said “Sorry to pick up on this Bob but you raise a very interesting point about gait abnormalities in dogs and establishing whether they are wobbly due to weakness or wobbly due to incoordination”.

I would very much agree that hypothyroidism would cause wobbly weakness very much as you state in your post and a neurological examination of the dog would help to pick up symptoms of this. However, based on the OP (and of course without a video), I would not consider hypothyroidism to be a differential diagnosis for ataxia in this dog.

I see lots of referrals for patients that are reportedly ataxic but on examination are actually only paretic. This was effectively all I was trying to highlight. Apologies if my post seemed a bit blunt as it certainly wasn’t meant to but your posts have raised an interesting discussion point that I picked up on. And I don't normally use these but I think one of these is indicated...

Re: Progressive hindlimb ataxia JRT

Bob Russell — Thu, 13 Sep 2012 15:18:49 GMT

I am not saying that this case is hypothyroid but the JRT I referred was inco-ordinated, weak and scuffing its back nails. It was showing other symptoms of hypothyroidism that I admit were missed and I was not particularly suggesting this is the diagnosis in this case. It almost certainly is not!

We do not have a video and my post was only a reminder that not all 'wobbly' dogs have obvious lesions on imaging. Perhaps I am getting a little defensive but stand by basic blood work being sensible in an old dog prior to referral. I am pretty sure this will be one of the first things a referral practice is likely to do anyway!

Re: Progressive hindlimb ataxia JRT

Mark Lowrie — Thu, 13 Sep 2012 14:36:46 GMT

[quote user="Bob Russell"]

Last time I looked a T4 took about 15 minutes to run. It will not delay referral but my case was referred, had MRI the works but if I had been on the ball could have saved the owners insurance company a bomb by looking on that case as 'medical' rather than 'neurological'!

This is a dog with a chronic, progressive lameness over a period of months, not an acute 'wobbly' dog. Clearly a space occupying lesion is possible (perhaps likely) but in what way is checking the T4 a poorly targeted test?

[/quote]

The OP mentioned the dog was ataxic (uncoordinated and wobbly) not weak/lame. This would suggest a problem in the sensory pathways (sensory nerves, dorsal tracts of the spinal cord or brain). Hypothyroidism is reported to cause peripheral neuropathies and usually affects the motor nerves only therefore only causing weakness and not ataxia – as Bob says, a dog with a clinical hypothyroidism will have a chronic progressive lameness or weakness over a period of months. Having said this pathological specimens do show some sensory nerve involvement but this doesn’t seem to be evident clinically. Therefore dogs with hypothyroidism tend to be paretic (i.e. weak) and not ataxic (i.e. uncoordinated).

I agree T4/TSH should be considered in an older weak dog but if obvious ataxia is present I think a spinal cord or brain disease is more likely depending on the neurological exam. This would be my main reason for considering a video to establish whether the dog truly is ataxic, how severe it might be, and if it is not ataxic, is the dog weak, or does it have an orthopaedic reason for having an abnormal gait.

I also agree with Bob that rushing into an MRI in a chronic progressive case is not always necessary... I think it is difficult from the OP to establish how badly affected this dog is and therefore I think referral is very acceptable in this situation – this doesn’t mean an MRI is inevitable but I am sure it will be done if indicated.

Re: Progressive hindlimb ataxia JRT

Bob Russell — Thu, 13 Sep 2012 11:17:58 GMT

Re: Progressive hindlimb ataxia JRT

Busybee — Wed, 12 Sep 2012 18:39:45 GMT

Dog off to referral centre early next week with instructions for strict rest in the mean time! Will keep you posted :)

Re: Progressive hindlimb ataxia JRT

Hannah Wynne Richards — Wed, 12 Sep 2012 17:55:44 GMT

I'm with you Malcolm By all means try T4 if the owners refuse a referral-this sounds as though it could be serious-and if it's on record that you've suggested referral at an early stage-then any ill consequences of a delay are definitely the owners fault-not yours

Wynne

Re: Progressive hindlimb ataxia JRT

Malcolm Ness — Wed, 12 Sep 2012 17:51:22 GMT

[quote user="Mark Hedberg"]t may be time to progress to the next step and refer[/quote]

If these signs are caused by a space occupying lesion, for example a disc extrusion, early referral for diagnosis and appropriate treatment is advisable. Further delay while you radiograph or perform other poorly targeted tests might result in the prognosis deteriorating beyond the point of no return.

Re: Progressive hindlimb ataxia JRT

Bob Russell — Wed, 12 Sep 2012 15:22:57 GMT

One thing to check would be T4!

We had a JRT with weak back legs and after a lot of investigation someone had the bright idea to check the thyroid. It was low and provisional diagnosis of thyroid related neuropathy was made.

The improvement on thyroid supplements was impressive (within a month or so). At least check this before referring!

Re: Progressive hindlimb ataxia JRT

Mark Hedberg — Wed, 12 Sep 2012 07:33:01 GMT

I think you'll be hard pressed to get better advice than what you got from Mark Lowrie above...if the client's keen to refer and you haven't found significant pathology, it may be time to progress to the next step and refer.

Re: Progressive hindlimb ataxia JRT

Busybee — Tue, 11 Sep 2012 18:51:09 GMT

Bit of a bump to this thread...

No change in the clinical presentation having been on previcox for nearly a week. Owner keen for referral. I'm hoping to see the dog again first and consider radiographs prior to referral to ensure we're not missing anything. Does anyone have any more ideas?

Re: Progressive hindlimb ataxia JRT

Busybee — Thu, 06 Sep 2012 21:27:57 GMT

Questions are fine Mark! I really enjoy neurology but as you say, this one doesn't fit perfectly in my head. Certainly the thing that stood out to me was the stiff legged mildly swinging gait.

No video yet I'm afraid, it was a busy evening surgery. I did wonder about concurrent orthopaedic disease in this dog as seemed resistant to hip manipulation (but was getting very fidgety by this point anyway) so have started it on Previcox over the weekend with a view to review early next week. If still the same (which I suspect it will be), I will try and video then.

No pain over caudal lumbar region. No medication prior to me seeing it. Problem seems to be very gradually getting worse than at onset but isn't severely affecting the dog at present. Owner didn't think was acute onset but was unsure.

Re: Progressive hindlimb ataxia JRT

Mark Lowrie — Thu, 06 Sep 2012 21:09:37 GMT

This sounds about right, but a few things to mention. The first question to always ask is “is it neurological?”. If it is ataxic (i.e. incoordinated) as you said then yes, it probably is. Any chance of posting a short video of the dog’s gait? Sometimes it is very easy and obvious to say it is neurological, other times it can be a little more complicated.

Once you have confirmed how many legs are affected, I check the reflexes in the affected legs – as you have done. You mention a decreased withdrawal in both affected limbs. This would suggest the reflex arc to the back legs is affected and hence an L6-S1 localisation exactly as you said. Some people would refer to this as ‘lower motor neuron’ (LMN) signs. However, in addition you would anticipate decreased tone in the affected limbs and not increased tone as you observe which doesn’t fit so well. This is why I mention a video as the gait seems key in this case for determining whether it is neurological or not. Is there pain over the caudal lumbar region? Has the god had any medication so far? Is the problem getting worse, better or remaining the same? Was the problem acute in onset or did it occur insidiously? Sorry for all the questions…