Ongoing problems with itchy mare

[Dizzykizzy]

I have posted about this mare belonging to my friend before but things are now getting more serious as her pony has started exhibiting similar symptoms.
This is a brief summary

My friend keeps her horse on our land which was previously grazed by our own horses without problem up until December 2012. Her horse arrived in good health after passing a full vetting in September 2013. After about 2 months she started to get very itchy, her coat wasn't shiny and she was lacklustre and reluctant to work. Vet has been numerous times, they diagnosed lice then allergies and she has been on a heavy dose of steroids since last Autumn but really hasn't improved at all. Now waiting for a second more detailed cushings test. Vet bill standing at £2500.
We have been in touch with the previous owner who seemed genuinely shocked and unaware that there were problems.
Friend has been feeding turmeric and zeolite as well as the steroids and a general feed supplement.
My friend bought a pony for her daughter in June and 2 months later he too is exhibiting the start of the same symptoms, dull itchy coat, getting grumpy. The only common factor is the grazing so the vet has told her to move them off asap. This is fine but not what either of us wants long term
Do you think this could be some sort of deficiency or something horrible in the land? We are surrounded by arable fields which do get sprayed.
Both are kept on extremely restricted grazing because of the fear of laminitis and are given hay to supplement.
Would you recommend a soil analysis and does anyone know where to get it done?
Thanks for any help

 

[Tnavas]

Are they grazing together? Are they losing any coat? Has she tried stopping all supplements? Have they been well wormed?

Try bathing them both a couple of times with Nizoral shampoo. If there is any underlying fungal or bacterial cause Nizoral will sort it.

Nizoral can be bought at the chemists. Dilute the shampoo in hand hot water and work well in to the coat. I make up the mix in a 4litre pump spray, the sort used to spray weed killer. The spray means you waste little.

Work well into the coat and leave for 20mins before rinsing out.

Try to feed the real basic feeds, nothing processed or commercially mixed. Beet pulp, meadow chaff, linseed (will do coat good) and oats for energy. Don't forget to add some salt.

 

[Dizzykizzy]

Thank you for your advice, I will pass it on.
She has recently had hair and skin tests and there was only a normal amount of bacteria which the vet said does not need treating.
It is not just a skin problem, the mare is completely listless and unwilling to move out of walk.
Zeolite has only just been started as has supplement, she has been on turmeric for some months and initially it seemed to help.
Thyroid was swollen (has been tested and cushings test done earlier in the year) but today seems to have gone down since taking the zeolite.