Does this sound like navicular?

[little_critter]

I’ll try to keep this short without missing out anything important
Horse went lame left fore 1/8/23, on the day of shoeing. Thought somehow he’d been made uncomfortable by being shod (not happened before though) gave him a week off but no improvement so called the vet. Suspected a bruise so shoes off for around 5 weeks (padded & duct taped). He was looking fairly sound other that being ouchy over stones (he has thin soles and is always sore without shoes)
Shoes went back on, looked ok for a week-ish then looked a bit off RIGHT fore which progressed over the course of 7-14 days to being almost non weight bearing. In that first week he went into the clinic for a work up, laminitis was suspected so hoof x rays were taken first but no laminitis showed up.
Referred for an MRI. That showed an inflamed collateral ligament in his right fetlock and some navicular changes in both feet. It was agreed we needed to fix the ligament before deciding whether the navicular needed treatment.
Went on box rest for 9 weeks, with hand walking rehab starting in week 5. Box rest ended in week 9 for both of our safety. At that point he was looking chipper and walking out confidently.
Week 10 and he looked more ‘reserved’ and I noted that his lameness looked to have switched back to LEFT fore. Vet checkup was scheduled for that week anyway, and she confirmed he’s now not quite right on left fore in walk and clearly ‘off’ on turns.
She’s wondering if this is the navicular raising its head. But I’ve not noticed him tripping or pointing.
The suggested next step is a navicular bursa block to try to pinpoint the location of the problem.

The swapping of the lameness and the lack of ‘classic‘ navicular symptoms is confusing me. Are we missing something?
Shout if I’ve missed any important info.

 

[ycbm]

It's a confusing one, and I'm sorry it's not clearer, for your sake, because not knowing is such a worry. My understanding is that the state of the bone, unless its crumbling or got spurs on it, is rarely responsible for the lameness. But you've had an MRI and that really should have shown up soft tissue injuries.

I'm afraid I can't help, except perhaps to reassure you that there isn't anything obvious you're missing, as far as I can see.

I would definitely want to be blocking the feet and make sure the lameness is from there. I hope you get some clear answers indicating an easy to fix problem in the new year.
.

 

[splashgirl45]

I may be wrong but I thought navicular was hardly ever diagnosed these days as it’s usually ligament damage, my mare had the symptoms that is usually associated with navicular but after x rays there was no damage to the bone so vet thought it was ligament damage mri was suggested but the treatment was the same as I didn’t want injections due to lami risk so rest then walking in hand then ridden but no jumping She recovered and went on for 6 years until Cushings got too bad to manage and she was close to having laminitis so I PTS

 

[little_critter]

It's a confusing one, and I'm sorry it's not clearer, for your sake, because not knowing is such a worry. My understanding is that the state of the bond, unless its crumbling or got spurs on it, is rarely responsibly for the lameness. But you've had an MRI and that really should have shown up soft tissue injuries.

I'm afraid I can't help, except perhaps to reassure you that there isn't anything obvious you're missing, as far as I can see.

I would definitely want to be blocking the feet and make sure the lameness is from there. I hope you get some clear answers indicating an easy to fix problem in the new year.
.

The left fore was blocked at the first workup and was a positive block when they did the abaxial block (May have misspelled that, the one that blocks the back half of the hoof and a bit of pastern, not the first one that only blocks the sole)
And I forgot to say, both fetlocks were medicated with steroids at the point he started the hand walking, after 4 weeks of box rest.

I have the mri report and it does say about changes to the navicular bone, lots and lots of long technical words I’m afraid so I struggled to understand it (and I’m not usually too bad on reading techie stuff) I can try to paste it here if that helps.

 

[little_critter]

MRI report:
These are the sections that seem to relate to the navicular, there is a separate section that covers the lateral collateral ligament.

In the left fore foot, there was mild diffuse STIR hyperintense signal of the spongy bone of the navicular bone, most pronounced in sagittal midline. There are several medium sized synovial invaginations along the distal horizontal border. Adjacent to the lateral sloping border is a small irregularly shaped hypointense fragment present. There is mild to moderate distal and proximal elongation of the palmar border. The dorsal border of the deep digital flexor tendon, at the level of the collateral sesamoidean ligament is mildy to moderately irregularly marginated with multiple T2W hypointense fibres and strands protruding dorsally within the navicular bursa. There is mild periarticular spur formation of the abaxial margins of the distal phalanx and dorsodistal margin of the middle phalanx. Mild irregular periarticular remodelling of the collateral fossae of the distal phalanx. There is mild distension of the distal interphalangeal joint. There is mild periarticular spur formation of the proximal abaxial margins of the middle phalanx. Mild diffuse and partly linear STIR hyperintense signal of the dorsodistal portion of the distal phalanx. There is mild heterogenous loss of signal of the trabecular bone of the lateral palmar process of the distal phalanx.

In the right fore foot, there were similar changes such as mild to moderate diffuse STIR hyperintense signal of the spongy bone of the navicular bone, most pronounced in sagittal midline. There are several medium sized synovial invaginations along the distal horizontal border. Adjacent to the medial sloping border is a small irregularly shaped hypointense fragment present. There is mild to moderate distal and proximal elongation of the palmar border. There is mild periarticular spur formation of the abaxial margins of the distal phalanx and dorsodistal margin of the middle phalanx. There is mild to moderate distension of the distal interphalangeal joint. Mild irregular periarticular remodelling of the collateral fossae of the distal phalanx. There is mild periarticular spur formation of the proximal abaxial margins of the middle phalanx. Mild diffuse and partly linear STIR hyperintense signal of the dorsodistal portion of the distal phalanx. There is mild to moderate heterogenous loss of signal of the trabecular bone of the medial palmar process of the distal phalanx.

 

[splashgirl45]

I’m not surprised you didn’t understand a lot of that , I would need the vet to explain it to me as well

 

[Highmileagecob]

A bit in depth for the average lay person! Maybe take a look at Pete Ramey's Hoof Rehab site, in particular, his views on navicular changes. My inclination would be to remove shoes, but it may be worth asking your vet/farrier if this would potentially put strain on the ligament, or encourage strengthening. Your vet should be sitting down with you and explaining this report.

 

[little_critter]

I know barefoot is often recommended for navicular but he is very sore without shoes. When he had shoes off initially back in August he was very sore and reluctant to move even with nappies duct taped to his feet. I couldn’t do that to him long term.

 

[maya2008]

I know barefoot is often recommended for navicular but he is very sore without shoes. When he had shoes off initially back in August he was very sore and reluctant to move even with nappies duct taped to his feet. I couldn’t do that to him long term.

I know this might sound odd, but I would want to blood test for insulin levels - low grade lami won’t show as changes on an x-ray. It does display as shifting lameness though and could be a contributing factor, especially since he is so crippled without the shoes. Our Shetland has EMS and without her levels being controlled she goes footy, gets shifting lameness, then full blown lami. It came on gradually over a number of years though and all we noticed at first was the footiness, then eventually she had periods of being lame on and off, before the official laminitis episode.