[silkwoodzwartbles]

Sounds like you're on the right track, I'll be keeping everything crossed for her swift and full recovery

[Willowdale]

Jullienne, it's a parasitic nematode, Paralaphostrongylus tenius.  In the US it's hosted by white tailed deer and snails, and sheep / llamas/ alpacas / goats can get it by eating an infected snail while grazing.  We only have it in the Eastern half of the US and Canada.  It looks like it's not found in any other countries.

I'm not sure if you in the UK may have a parasite that can cause neurological symptoms like this.  The symptoms were very striking, almost like she had had a stroke now that I'm looking back.  She may always have some lingering neurological signs from damage the worms did before I was able to kill them, but will be otherwise normal.  And, you know, young animals like young humans bounce back pretty well.