Results of the Cambridge IVDD Conservative Treatment Recovery Trial
The much-awaited paper from the conservative treatment trial of IVDD has been released. Here is the paper in full:
Khan S, Jeffery ND, Freeman P. Recovery of ambulation in small, non-brachycephalic dogs after conservative management of acute thoracolumbar disk extrusion. J Vet Intern Med. 2024;1‐9. doi:10.1111/jvim.17149
My best attempt at translating it to normal speak.
The one or 2 liner: The study demonstrates a high proportion of dogs do recover from IVDD within 12 weeks when treated conservatively. This is more likely if they can feel their toes!
The brief summary of the trial:
The aim: to discover how many paralysed dogs treated without surgery for IVDD (acute thoracolumbar disk extrusion) recover mobility (ambulation) during the first 12 weeks of recovery. To assess the change in the compression (squish) to the spinal cord during this period of time.
The results:
49 of 51 dogs – that’s 96% of the dogs who had feeling in their feet (deep pain positive) were able to walk 10 paces within 12 weeks without having surgery.
10 of 21 dogs – that’s 48% of the dogs who DID NOT have feeling in their feet were able to walk 10 paces within 12 weeks without having surgery.
The average time taken to walk was between 11-25 days for both groups.
The level of “squish” (compression) to the cord (think jam doughnut) varied and appeared to be unrelated to their recovery.
Recruitment:
Cases were recruited between October 2020 to December 2022.
Paralysed (non-ambulatory) in hind limbs (in this case, unable to walk 10 steps unaided).
Dogs had to weigh under 15kg, suspected to have thoracolumbar myelopathy (TL IVDE)
Owners were unable to afford surgery but able to pay the study fee.
Cases were classified based on onset of paralysis and graded between 3 to 5 using the modified Frankel Scale.
The patients:
Dogs included:
57 miniature dachshunds
5 standard dachshunds
5 cross breeds.
Average age – 60 months (nearly 6 years old)
The process:
Dogs were hospitalized for a maximum of 2 days where they received pain management, cage rest, physiotherapy and where needed bladder management.
Once home, owners were supported remotely.
Recovery of the ability to walk 10 steps unaided was self-reported by owners and supported by video recordings.
All dogs were rested strictly for 4 weeks with on-lead toilet breaks 4-5 times a day.
After 4 weeks or if the dogs started walking before this short 10-minute walks 4 times daily were started. If dogs had not started walking in this time further rest was required.
No professional physiotherapy was provided. Owners were given basic guidance of exercises to do 3-4 times a day.
Bladder management was carried out every 6 hours during hospitalization. After this, owners were instructed to manage the bladder (where needed) 3-4 times daily until consistent voluntary urination had been seen.
After 12 weeks the dogs returned for a full clinical and neurological exam and a repeat MRI scan.
Results
95 cases were initially recruited. 19 of these were excluded as they either recovered (7 dogs), declined an appointment due to cost (6 dogs), transport restrictions (6 dogs) and sadly, euthanasia (6 dogs). Sadly a further 5 were euthanised due to suspected myelomalacia and 4 excluded as they had a different diagnosis to TL IVDE. This led to 67 cases being confirmed by MRI. Sadly 4 of these cases did not return for a repeat MRI scan after 12 weeks and had to be excluded from the study.
51 of 72 dogs had feeling in their feet (Deep pain positive)
21 of 72 did NOT have feeling in their feet (deep pain negative. This includes 5 with suspected myelomalacia.
Deep pain positive group (Can feel their feet)
39 of these were miniature dachshunds, 5 were standard dachshunds, 3 were cross breeds.
2 of the dogs failed to recover:
1 died with suspected aspiration pneumonia
1 showed no neurological improvement but remained deep pain positive.
Average recovery time was 11 days.
At the follow up, none of the dogs had persistent back pain, and those who had recovered their ability to walk also regained continence.
In 2 dogs clinical signs returned – 1 had a recurrence of back pain, and 1 had myelomalacia. Repeat scans confirmed a second disc extrusion at a different location for both dogs.
Deep Pain Negative group (Can NOT feel their feet)
18 of these were miniature dachshunds, 2 were cross breeds, 1 was a lhasa apso.
Of 21 dogs who were deep pain negative, 10 recovered ambulation at around 25 days.
7 dogs developed myelomalacia on arrival or later.
At the 12 week follow up, no dogs had persistent back pain, and those who regained walking also regained urinary continence.
4 dogs did not recover the ability to walk at the 12-week point.
Study discussion
Despite previous studies, a large proportion of dogs suffering from TL IVDE can recover within 12 weeks without surgery. 98% of dogs in the study who had feeling in their hind limbs (DPP) recovered, and 48% of those who could not feel their legs recovered. The results for Deep pain positive dogs reflect other studies, the results for deep pain negative is substantially better, although there is study reporting 60% recovery – the reason why they differ is unclear aside from the other study being retrospective (looking back) rather than this study which was prospective. These results are far more optimistic than most other previous studies.
Sadly, a higher number of dogs were reported to have myelomalacia than other cases. This may be because the dogs may have been eliminated in other studies and not counted in the data.
Compression?
This is where the cord is “squashed” by the disc matter.
This study is the first to report naturally occurring change in the “squish” material with time. The data does show overall there was a substantial reduction over the 12 weeks which varied between individuals. HOWEVER, the resolution was present in dogs that did and did not recover. This leaves an area of curiosity but suggests recovery is not based on the reduction of compression.
What does this all mean for you?
The results suggest that if surgical decompression is not possible conservative treatment is a valid alternative and should be assessed on a case-by-case basis. At a time when caregivers are being priced out of insurance, it offers some peace of mind that providing the appropriate care and rest can produce positive results.
It shows dogs who are more severely affected may take longer to recover.
It shows after 12 weeks there was no continuing pain or discomfort
It shows that those who did recover their mobility also regained urinary continence.
Professional physiotherapy and hydrotherapy is not required for recovery (side note: it may be helpful long term).
Notes of mention:
Myelomalacia is more likely to affect dogs with no feeling in their feet.
Recovery time is longer for dogs who can NOT feel their feet (deep pain negative).
Questions:
Did those dogs who did not recover within the 12 weeks
a) Show any improvements at all within the 12 weeks?
b) Show any improvement after the 12 weeks?
If so, how much improvement did they show? It would be interesting to see a scale of recovery rather than a fixed ‘black and white’ option.
Was the speed of onset of symptoms related to severity and recovery?
Was compression related to the speed of onset of symptoms?
How many of the dogs were able to cope with 4 10-minute walks per day after the 12 weeks?
What would be a better (more useful) definition of “recovery” than “able to walk 10 steps”?
Personal Thanks
Huge thanks to Sam Khan, Nick Jeffery and Paul Freeman at the Department of Veterinary Medicine, University of Cambridge for all the work they have put into this study. Thanks to all those who helped to fund this project, especially Dachshund Health UK and to all those who have contributed to the charity making this possible.
And mostly, huge thanks to all of those who participated in the trial. Your participation will help so many other people. For those of you who had to say goodbye, I am so sorry for your loss. Hopefully, one day, because of people such as those taking part in similar studies we may gain a better understanding of this awful disease. Thank you for your contribution. Run free little angels.
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