Sub-clinical laminitis

[Katy_Watts]

Laminitis is evident in the histology BEFORE the horse is noticeably lame.
IMO, it’s also evident from the outside, when one knows what to look for. Lots of horse feet shown in this forum shows signs of laminitis, but I’m not saying anymore, cause everyone thinks I’m a hammer and everything is a nail.

Karikoski NP, McGowan CM, Singer ER, Asplin KE, Tulamo RM, Patterson-Kane JC: Pathology of Natural Cases of Equine Endocrinopathic Laminitis Associated With Hyperinsulinemia. Vet Pathol; 2015 Sep;52(5):945-56

Pathology of Natural Cases of Equine Endocrinopathic Laminitis Associated With Hyperinsulinemia.
Laminitis in equids is a clinical syndrome usually associated with systemic disease.
Endocrinopathies recently have been recognized as the most common cause of laminitis, with hyperinsulinemia playing a key role.
Descriptions of laminitis-associated lesions have been confusing due to the wide range of experimental models used, failure of adequate clinical documentation for naturally occurring cases, lack of separate analysis of inflammatory and endocrinopathic laminitis, and uncertainty regarding normal morphological variation of lamellae.
In this study, lamellar morphology and pathology were described in 14 laminitic horses and ponies that had hyperinsulinemia (>20 mIU/l), with reference to 25 age- and breed-matched controls.
The lesions in these chronic cases of laminitis were similar to those described in some inflammatory laminitis models and contained features seen in developmental phases of hyperinsulinemic models.
These findings support the theory that repeated episodes of subclinical laminitis occur prior to clinical presentation.

[Pehsness]

Thanks for posting this. Having been through this horrific ringer and taking the (drastic?) step of becoming a certified trimmer solely because I wanted to help my own horse and spending countless dollars and years pursuing that education, it still amazes me how many times the absolutely obvious signs were missed by professionals. In hindsight it’s so obvious, now that I know. Could have save ten years of grief and gotten back ten years of riding time.

On the bright side, I am no longer reliant on others.

It’s also the downside of living in a rural area populated mostly by cash croppers and dairy farmers - the vets aren’t exactly top notch when it comes to horses. Or they are steeped in tradition recommending your laminitic horse be turned out on precisely the grass that is most harmful or living in a deeply bedded box stall. So when you attempt to have a conversation about things like sub-clinical laminitis you’re met with scorn or blank stares.

I’ve appreciated the safergrass website many times over the years Katy - it was instrumental in jumpstarting my education back in the day

[Diamontaire]

Agree completely. I saw it in oh so many horses when I was trimming; couldn’t get it through the owners’ heads that the horse was headed down that path. Or they would not take my recommendations for feeding, lifestyle changes, etc. I wanted to bang my head against the wall a LOT.

I love trimming, but can’t wait until the only horse I trim is my own; at least THAT owner will listen.

[jawa]

I ride with a lady whose horse has had 2 or 3 laminitic episodes in his 17 years. She tries to vigilant about his diet, but doesn’t like to see him ribby either. I sometimes think he is slightly foot sore due to a sub clinical laminitis. What are the things to look for?

[Katy_Watts]

Visual signs of laminitis- even when the horse is sound, and yes it might be something else and it might not.

• horizontal rings that turn down at the heel.
  -stretched white line, sometimes with specks of blood, sometimes not.
• dishing/flares
  -dropped flat sole
  -horse may be sound on good footing, but ouchy on hard footing
  -a good mover gets short and choppy
  -toe flipping at trot caused by exaggerated heel first landing

These signs are considered valid by the vets doing research on laminitis. Laminitis is such a big deal that a lot of people would rather deny it until the horse cannot walk. By then a lot of damage may be already done. Many, many vets are surprised when they radiograph and find P3 ready to punch through.
Laminitis is often incorrectly diagnosed as arthritis, navicular, laziness, or an abscess.
We know a lot more now. We can fix this BEFORE significant damage is done if you just take measures early. Removing all grain and taking a horse off pasture for a week can return a horse to soundess, and you’ve got your treatment and diagnoses all for free. No excuse for not having the money to have the vet out.

[Pocket_Pony]

Katy, do you have any pictures to share that might help us identify? Of course I understand the words you’ve typed out, but sometimes a picture is just so more of an “a-ha!” than a description.

[csaper58]

Yes, Yes, pictures would be great. Are you describing ‘sugar rings’? And thank you for your web site. Safer Grass has been very helpful.

What are the Histology changes? Which value changes are key? Thank you!

[Katy_Watts]

here’s a full text on histology:
http://www.laminitisresearch.org/downloads/0910/2009_Equine_Laminitis_model_-_lamellar_histopathology_7_days_after_induction_with_oligofructose_41_735-740.pdf

and a different abstract:
Equine Vet J. 2010 Nov;42(8):700-6. doi: 10.1111/j.2042-3306.2010.00111.x.
Histopathology of insulin-induced laminitis in ponies.
Asplin KE1, Patterson-Kane JC, Sillence MN, Pollitt CC, Mc Gowan CM.
Author information
Abstract
REASONS FOR PERFORMING STUDY:
Ponies with laminitis associated with insulin resistance and hyperinsulinaemia lack systemic and/or intestinal inflammatory signs, suggesting a different pathogenesis potentially reflected in differing histopathology.
OBJECTIVES:
To describe the histological appearance and quantify morphological changes in primary and secondary epidermal lamellae (PEL and SEL) of laminitis lesions from ponies with insulin-induced laminitis.
METHODS:
Equine hoof lamellar tissue was obtained from 4 control ponies and 5 ponies with laminitis induced following infusion of insulin (1036 ± 55?µU/ml) while maintaining euglycaemia for 55.4 ± 5.5?h. Sections from all 4 hooves were stained and examined by a veterinary pathologist. Measurements of lamellar length (PEL and SEL) were made in mid-dorsal sections of the right forefeet by 2 blinded observers. Immunolabelling for calprotectin was performed using a monoclonal antibody.
RESULTS:
No lesions were detected in normal ponies. Lesions detected in ponies with laminitis were variable in severity between ponies. Within ponies, SEL lesions were more severe along the axial region of PEL. Lesions included swelling, disorganisation and abnormal keratinisation of epidermal cells, increased mitotic activity and apoptosis. Separation of basement membranes was minimal. Immunostaining revealed inflammatory cells within the lamellar dermis. SEL were significantly elongated in laminitic hooves relative to controls, with the greatest elongation in those attached to abaxial and middle regions of PEL.
CONCLUSIONS:
Laminitis induced by prolonged infusion of insulin lacked widespread basement membrane disintegration, and increases in epidermal cellular proliferation at axial aspects were marked for this acute stage of disease.
POTENTIAL RELEVANCE:
Defining equine laminitis entirely in terms of separation of the basement membrane may not be appropriate for laminitis associated with hyperinsulinaemia.

[Katy_Watts]

googling ‘laminitis horse rings’ ho bunch.

https://www.google.com/search?q=laminitis+horse+rings&espv=2&biw=911&bih=429&source=lnms&tbm=isch&sa=X&ved=0CAcQ_AUoAmoVChMImLDW3-CXyAIVAZANCh2imQ4Z

[Katy_Watts]

Perhaps some translation would be useful.

The individual lamina grow like crazy, stretch and split in 2. Some parts grow so fast they split off and form separate globs of tissue not attached to the structure. This causes the whole structure to weaken. Some recent work is suggesting that the insulin is triggering receptors for insulin-like growth factor ( the stuff that makes feet grow)

I have many times seen horses that needed their feet trimmed every 4-5 weeks previously can go 8-10 weeks, even 12 when the diet is corrected by removing excess sugar and starch.

[Katy_Watts]

Here’s a great photo of pre-clinical laminitic changes in the white line.
By Dr. Walsh, head of a foundation that funds laminitis research. Not a ‘crazy barefooter’. Read the whole page.

http://www.ahf-laminitis.org/2013/02/spring-grass-laminitis-insulin-cushings-horse-prevention.html

[Ambitious_Kate]

[QUOTE=Katy Watts;8334157]
googling ‘laminitis horse rings’ ho bunch.

https://www.google.com/search?q=laminitis+horse+rings&espv=2&biw=911&bih=429&source=lnms&tbm=isch&sa=X&ved=0CAcQ_AUoAmoVChMImLDW3-CXyAIVAZANCh2imQ4Z[/QUOTE]

Wow, there are some reall sad photos there. And you’re right - how often do we see this in photos on this forum.

[Ambitious_Kate]

Good education, though.

[Katy_Watts]

another full text
http://www.scielo.br/scielo.php?pid=S0102-09352015000501226&script=sci_arttext

Laminitis in horses is often associated with endocrine disorders, especially the pituitary pars intermedia dysfunction (PPID) in older animals. Morphologic exams of the laminar tissue of the hoof were performed in two horses with suspected PPID, with no clinical signs of laminitis. Changes compatible with laminitis of endocrine origin were observed, such as rounding of the nuclei of the basal cells, thinning and stretching of the secondary epidermal laminae and tissue proliferation. PPID horses with no clinical signs of laminitis may be affected by lesions of the laminar tissue of the hoof that compromise the integrity of the dermal-epidermal junction and may develop clinical symptoms of the disease. It has been suggested that the development stage of endocrine laminitis is longer, but further studies should be conducted to confirm it.

[ChocoMare]

As a trimmer, I see it too. Alas, we only have 1/4 of the Equine Care Square: Diet, Environment, Exercise, Trim. I do what I can to help educate (often pointing them to Safergrass.org) and help evaluate what the horse is eating. Those who have taken it to heart, have seen positive changes. Those who chose not to, are no longer my clients. I do it part-time, so can afford to do that

[Katy_Watts]

It costs nothing to soak hay and remove all grain. No horse is going to get dangerously thin in the 2-3 weeks it will take to confirm that the diet works to improve soundness. Maybe a month to see new better grow coming down, or the abnormal fast growth slowing. There is no reason NOT to try this on ANY horse with flat soles, dished toes, stretched white line and/or rings on the outside of the hoof.
If the diet works, you have all the confirmation you need that the horse needs to stay on the diet.

[Pocket_Pony]

Katy, speaking of soaking hay . . . when I was recently hay shopping, one farmer (not the person I ended up getting my hay from) had just done a third cutting and it was scheduled to rain. He said that the rain would wash the sugars away, just as if you soaked it (of course he would rake it and dry it before baling). I thought, ummmm okayyyyy? But I have no knowledge of whether or not this would be true. Do you have any opinions or studies about that?

[Hermein]

Thank you, Katy. The pictures are particularly helpful.

Pocketpony–I’d think you’d need a mighty rain storm to equate 1 hour’s soak in cold water. And then, it would take some effort to get your haying equipment into (and out of) the field.

You were too polite to mention that to the farmer, I’m sure. :winkgrin:

[Dune]

[QUOTE=Katy Watts;8334163]
Perhaps some translation would be useful.

The individual lamina grow like crazy, stretch and split in 2. Some parts grow so fast they split off and form separate globs of tissue not attached to the structure. This causes the whole structure to weaken. Some recent work is suggesting that the insulin is triggering receptors for insulin-like growth factor ( the stuff that makes feet grow)

I have many times seen horses that needed their feet trimmed every 4-5 weeks previously can go 8-10 weeks, even 12 when the diet is corrected by removing excess sugar and starch.[/QUOTE]

How is that long of a trimming cycle good/better for the horse than more often? As a rider, I feel that the feet are at their best from trimming/shoeing day to about 4 weeks, then I start to feel the little imbalances in their work. I’ve always been happy that my horses/ponies grow a good amount of foot in 5-6 weeks. I had to go 7 weeks recently on one because of the farrier’s schedule and I was not happy about that. :-/ ???

[Katy_Watts]

[QUOTE=Dune;8408345]
How is that long of a trimming cycle good/better for the horse than more often? As a rider, I feel that the feet are at their best from trimming/shoeing day to about 4 weeks, then I start to feel the little imbalances in their work. I’ve always been happy that my horses/ponies grow a good amount of foot in 5-6 weeks. I had to go 7 weeks recently on one because of the farrier’s schedule and I was not happy about that. :-/ ???[/QUOTE]

The amount you need to trim off is related to the speed of growth, is it not? I know some barefoot metabolic ponies that NEEDED to be trimmed every 4-5 weeks, but after getting the metabolism normalized their feet stayed in balance and they did not need to be trimmed nearly as often. If the heels grow faster than the toe in a laminitic horse ( evidenced by the downward turn of the rings at the heel) it makes sense that the foot will also stay in balance longer as it grows.