Weakened hind legs

Hey vets! A little history on my boy, since a young age he’s always bunny hopped rather than ran properly. About 4/5 years ago, he done something to his back that left him unable to jump - It only lasted a week at tops and after a weeks rest he was back to being himself. He was assessed for Luxating patella at the time but that was ruled out. In the last year, he has been diagnosed with Mitral Valve Disease stage B2, Kidney Disease stage 2 and arthritis in his wrists. Within this year he has become weaker on his hind legs but maybe only mild muscle loss as he’s still got a fair bit of muscle to him - I have tested him for Degenerative myelopathy but he carries no mutated genes. He isn’t showing clinical pain, occasional paw knuckling, crossing of the hind legs when walking and turning around, he favours one side more than the other and has occasionally lost balance but has always managed to correct himself - no falling over yet. Recently I have noticed when he walks down the stairs, he extends his knee outwards. Kind of like a child would if they are bow legged. I can’t upload a video as it won’t allow me too. I know I won’t get an official diagnosis without the appropriate scans etc but I am holding off on sedation due to his age and health conditions. He still has good quality of life and I’m not risking that with sedation just to get an official diagnosis on something that isn’t bothering him and isn’t stopping him from doing what he wants. I just want to know what could be a possible cause so I know the direction to take when it comes to exercise etc. Sorry for the long post and thank you

Hello!   You sound from your phrasing as if you're in the States -is that correct?  What breed is your dog?  I am picturing a Jack Russel, but I think that's all conjecture; possibly your user-name put ideas into my head. Anyway, you sound to be seeing mild muscle reduction, favouring one side with occasional momentary balance loss, bow-legged stance on one side while descending stairs, occasional paw knuckling.  You don't think that there's any sign of pain.  At first glance that sounds like neurological change, possibly as a result of spinal disease e.g. disc disease, but the truth is that it could also be well-concealed hip or spinal pain (they do this!) or even, at a pinch, brain-related.  A full neurological exam - which is done in the conscious patient - can help your vet to give a fairly precise anatomical location for any abnormalities and may rule some of these in or out. Your vet might also pin-point whether that out-turned knee is related, or a secondary problem. Very often, a neurological exam will tell your vet where in the nervous or skeletal system, physically, the problem is - what it is can often be guessed at, from the location and the breed and the exact classification of of the signs (also, from the response to treatment).  Sometimes imaging is recommended to say for definite what it is, but it should be okay to say if that is something you have decided against.  We would still strongly recommend working it out this way round however, because guessing a diagnosis from the clinical signs is rarely effective and can result in your giving the wrong treatment. I hope that something here is useful.

Hi, sorry I am UK based. Jack is a border collie x cavalier - could be other breeds as he was from a backyard breeder (which I didn’t know at the time). I only know the border collie and cavalier are both definitely there as he herds like a collie and has the facial features/personality at home of the cavalier. We have ruled out arthritis in his hind legs as well - I forgot to add that bit in there. We are going to start him on gabapentin for pain relief as he could well be hiding the pain from us all - He shows mild signs at the vets but that’s only lip licking nothing else. If I can upload a video I will do. 

He is sweet.  What did the vet find on exam?

And how did they rule out arthritis in the hindlimbs?

Thank you. So the vet moved his legs about and said she felt no arthritic movement in his hind limbs. I’m trying to send you a video of how he walks down the stairs but it won’t allow me to post it

Thankyou - yes, it's troublesome on here.  Some people post on the Facebook group and we look across, but we are careful not to diagnose online because we may be missing out vital information, having not palpated the patient properly to the extent that your vet obviously has - we are in no position to offer second opinions to your vets'.  However, I am always interested!  Of course, there is a difference between not feeling arthritic movement and arthritis not being present - or no-one would ever need to x-ray for arthritis! - but it may be that the neuro findings explain everything that your vet is seeing.  Usually the signs will be neurological or orthopaedic or somewhere between the two (e.g. arthritis of the spine or joint pressing on a nerve, causing neuro signs) and pain relief is always a good idea for welfare reasons if there is any suspicion at all that an animal might be experiencing discomfort.  Your vet will normally have an opinion regarding how much exercise is appropriate, especially while pain meds are being used. Good questions include:  what are the most likely differentials (or 'possible diagnoses') or what diagnoses could still be true?  Is there any more you can do to tell between them - and how might it change what we do if we (e.g. take an x-ray to) find out?   We look forward to hearing how the case progresses from here - (I will check the Facebook group for the film tomorrow) wishing Jack as much comfort and stability as possible from all of us.  

Ah that would be brilliant thank you, I have posted the whole comment and video on the Facebook group so if you do have any sort of ideas or have seen something similar. Please let me know and I can raise any concerns with the vet when I see her next. I’m general, avoiding the heart disease and kidney disease. He is very healthy all things considered but sedation just seems so scary, he’s always been fine if he’s needed it but now he’s 10-11 this year and with the added diseases, my vet did say that adds a percentage to slimming his chances under sedation nowadays. So I may suggest a full physical exam and see if we can at least narrow down where the pain may be and what to do from there. She said short walks twice a day but I’m not sure what she would call short - Being that his collie personality takes over on a walk, I’m not sure how short I should cut his down. At the moment he’s only having about 10/15 minutes twice a day - Even though given the option he’d keep walking haha. Thank you for all your advice so far though and I know you couldn’t diagnose him. Just wondered if anyone had seen it before and in what scenario the other dog was diagnosed with so I’d know the route to take with the vet