Medical Mystery (Theories are Welcome)

I am publishing this page in the hopes that someone reads it and recognizes the symptoms and pattern of whatever has befallen the Tonka Dog.

This all started in October 2011 with Tonka starting to defecate while walking  instead of squatting. He then he developed a slight limp in his left hind leg. He does have some mild hip dysplasia on that side so they put him on a pain killer and a course of strict rest.  The limp became worse and his foot started knuckling under and dragging, so he went to see a neurologist. The exam found neurological deficits that would be consistent with a problem in the lumbar (lower back) area of the spine. He was also seen by an orthopedic that day to rule out any possible problem coming from the hip or knee. No definitive diagnosis was produced from either the orthopedic or neurology exam. An MRI of the lumbar and thoracic area s and a spinal tap were done and the MRI showed nothing significant, and the spinal tap results were within normal ranges.

He soon became semi-incontinent and would dribble urine upon standing or stretching and would sometimes defecate in his sleep. He could not stand for any length of time without his hindquarters sinking towards the floor. He could not get his feet right under him to rise from a lying position and would have to be helped up. Nights were hard on him and he did not want to be left alone, so I mostly slept on the floor with him.  He could not walk very far on concrete without something to protect his dragging toenails from bleeding. I had to use dog socks and wrap duct tape around the toe area because I could not find a boot light enough to allow him to walk. At this point I had him measured and fitted for a cart with the hope of keeping him mobile longer and to build up his muscle so maybe he could go to the park to “see” his friends. Mentally and emotionally he needed to get out and be social, but the support rings on the cart for the hind legs put pressure on the affected nerves and made things worse.

With no clear cause, it was decided that some rehabilitation might be helpful.  Tonka started acupuncture, B12 shots and canine rehabilitation therapy. He has had therapy every week for six months now.

During the first month his mobility slightly improved and he started lifting his foot a little higher to try and clear things. It was no longer a constant scuffing sound when he walked. He stopped dribbling upon standing and would semi squat to defecate and would even stay in one spot if I would hold his leg in place. He could now feel that he had to go and started barking again to be let out. By April he could walk in a straight line fairly well and could even manage a jog when very excited.  Then his right leg started with a limp and it has been all downhill from there.
He has been on an anti-inflammatory (Metacam) for eight months and Gabapentin for the last 2, he takes Soloxine for thyroid and azopt and pred. acetate drops to control glaucoma in his remaining eye. Tonka was born blind with retinal detachment and at age 3.5 he had heart surgery to fix a hold in his heart all of that is easier to deal with then this.

I have had three orthopedists and three neurologists evaluate Tonka with no concrete diagnosis. In May I had an MRI of his head and neck done –it was the last place to look and the results came back with nothing. It is now June and this leg is following the same course as the other one. Right now he cannot walk without knuckling under and dragging that foot. No-one has an answer and after 8 months of dealing with this I am struggling to make sense of this. We are continuing Physical therapy with the hope that this leg will eventually come around.. Has anyone seen these symptoms before?

It is not a stroke or FCE since it was a slow decline and nothing shows on MRI.

It is not DM since he has recovered on the left side and in 8 months the progression would have been worse. It is not a virus or tick borne illness since all the blood work is great.

It is not a disk problem, not a spinal fluid (too much, too little) issue nothing shows on MRI. 

It is not orthopedic – nothing on x-ray or present during physical exam.

Anyone have any ideas?

UPDATE:
We are now heading into 11 months with this overall problem and 5 months with this side. Additional tests have been run and he has now seen 4 neurologists and still nothing. I have weaned him off of the Metacam and the Gabapentin as they seemed to be doing nothing for him. We started him on a course of prednisone at a very low dose and he seemed to really improve the first 3 days and then slipped back to the ups and downs that define our days. We gave it 2 weeks and I am now weaning him off of that.
It's not Myasthenia Gravis- as once again his blood work is normal.
I am losing hope that this side is going to improve. He is fecally incontinent once again and this time it has lasted longer than before and is dribbling urine again. He now has a difficult time rising on his own and on bad days has no interest in even attempting to go for a walk or go out in his wagon. the following videos were taken to show the difference in one day. The bad day was taken the evening of August 25th and the good day was the morning of August 26th.

Video of a bad day

Video of a good day