Equine endocrine case decision Flashcards
19 y.o. pony mare, 200kg BWT
Quiet, but has always been
April – spring! Mare at pasture fulltime
Good doer, happy hacker
Last week progressively sore and now is not willing to move
The mare presents like the picture attached:
What is suggestive of laminitis in this picture?
Always collect a good history and then do a thorough PE before jumping to the detail
History
“Pony has always had good appetite
Owner does not think pony has lost weight
No history of laminitis previously but become pottery during last year
Currently on no medications
Pony lives out at pasture”
Physical Exam
- HR: 60bpm, RR:15brpm, RT: 37.8’C
- MM: pink, CRT<2
- Decreased but present borborygmi
- Mare has thin muscles but fat depots on tail base, shoulder and neck crest
Which is the most relevant part of the physical exam that was missing?
Assessment of digital pulses
Assessing digital pulsation is extremely important with laminitis – it will confirm also that feet are sore and also might provide some information as to whether one side is worse than the controlateral
Physical Exam
- HR: 60bpm, RR:15brpm, RT: 37.8’C
- MM: pink, CRT<2
- Decreased but present borborygmi
- Mare has thin muscles but fat depots on tail base, shoulder and neck crest
- Front limbs
- Pounding digital pulses
- Not willing to lift either limb or to move
- Hoof wall of front feet feel warm
- Painful at pressure over coronary band
- Hind limbs
- Warm but no digital pulses palpable
What would you do next?
Radiography of front feet
At this stage you should assess the feet – endocrine testing with a horse in severe pain is likely to affect the results of your testing
Physical Exam
- HR: 60bpm, RR:15brpm, RT: 37.8’C
- MM: pink, CRT<2
- Decreased but present borborygmi
- Mare has thin muscles but fat depots on tail base, shoulder and neck crest
- Front limbs
- Pounding digital pulses
- Not willing to lift either limb or to move
- Hoof wall of front feet feel warm
- Painful at pressure over coronary band
- Hind limbs
- Warm but no digital pulses palpable
Radiographs have been done showing rotation of pedal bone. What would you do next?
House in deep bedding, 2%BWT soaked hay diet, NSAIDs
No point in testing now, mare to sore, sort out feet and inflammation and recheck in few weeks
Why have we not tested for PPID, EMS?
- Pony is still very painful
- Pain induced endogenous glucocorticoid release
- Glucocorticoid induced IR
- Testing would likely give a false positive result
Case progression
Hx: 6 weeks later you see Clarabella again
Mare has been painful for 3 weeks
Mare is now much more comfortable but still on ½g phenylbutazone PO BID
PE: mare more comfortable, vital parameters wnl, digital pulses palpable but not pounding, BCS unchanged
What would you do next?
Basal ACTH, OGT, house in deep bedding, 2%BWT soaked hay diet, NSAIDs
- Mare in mild pain now so might be a better time for testing
- I would do both ACTH and OGT
- ACTH only might also be acceptable in this first instance
What treatment for PPID will you choose?
Pergolide mesylate
Start with pergolide only
Metformin not indicated in this case
After starting the treatment for PPID with:
Pergolide
Half-tablet Prascend PO SID (200kg horse)
Treatment for life
What would you do for this pony?
Want to keep in box rest at least 2-3 weeks after sound. (there will still be inflmation so want this to fully be okay)
Continue previous management:
- Phenylbutazone to control hoof wall inflammation
- Management (box-rest + diet)
- Remedial farriery – build relationship with farrier
Start with just this as you might solve the IR at the same time. Can add metformin later on if this doesn’t work
Metformin alone will only deal with the IR not the ACTH and downregulation.
How will you monitor pergolide treatment?
Recheck ACTH in 4-6 weeks
6 weeks later after initial pergolide treatment:
Pony doing ok but is still quite pottery on hard surface
ACTH
90pg/ml (normal <29pg/ml)
What would you do now?
- Increment dose to ¾ of a tablet SID
- This is to show that there are multiple options – chose one an stick to it. Ideally dose should be increased by 0.5µg/kg but Prascend is in tablets and pony is tiny so splitting tablet in small portions could be tricky - you need to use your judgment to see whether owner would be sensible enough to do this
- Continue with same dose – some improvement noted so might be a viable option in this case but need to recheck in another 6 weeks if no improvement then increase dose
- 0.5µg/kg – half tablet is already 2.5µg/kg for a 200kg pony – so increasing of 0.5 would mean giving 0.6 of a tablet which is a little unrealistic
- 3/4tablet – dose is increased to 3.75 although this might be also a difficult to achieve – I would probably attempt this one
Six weeks after increasing the dose to ¾ of a tablet ACTH is within the reference range and the pony is also clinically improved.
When will you check ACTH next?
Every 6 months
- Generally checking ACTH every 6 months would be acceptable at this point
- Stable condition. The horse is sound.
- Ever 6 weeks will be ££. Unless you have sudden deterioation
- Autumn – sensitive test. Once a year could be okay if there is a problem
- But you are likely to see the owner 2 a year to rasp teeth anyhow
- After a few years could reduce
