Hi, I'm new to this site, only joining today 28/04/19. I joined this site to register my interest in finding a PYRANEAN puppy, but whilst here I thought I'd make some owners aware of the horrible reason that I've found myself here. On Friday my best and loyal friend had to be put to sleep, he was a PYRANEAN mountain dog called Rossi, he would have been 6 years old on July 23. On wednesday evening my wife and i thought rossi had pulled a muscle in his back leg, a trip to the vets that evening resulted in the vet finding nothing wrong, but gave an anti inflammatory injection just in case, that evening his condition worsened, so a trip at 11.00PM to emergency vets, who again could find nothing wrong, a trip back to our vets Friday morning resulted in a referral and trip to The Royal vetinary college in London, here they discovered he had a rare disease called MYASTHENIA GRAVIS which affects the throat and muscular system, at 15.30 PM, he had to be put to sleep (one of the worst days of my life) less than 48 hours since he appeared to have hurt his leg he was dead. The disorder is congenital and would have laid dormant since birth. We bought Rossi from a breeder in wales called Maelgwn, it would be highly unlikely that the breeder would be aware of this disorder, and we in no way hold the breeder responsible for not informing us of this disorder. What I would like is for any person who obtained a puppy from this breeder 6 years ago, to perhaps take their dog along to the vets and have them checked to see if they are carrying this disorder. Sorry for the long letter, but it is truly horrendous to see your dog go from perfect health to dead in less than 48 hrs and most vets don't now what's wrong.

I am sorry for your loss.  What an awful thing to discover, and such a sudden shock.

Have you notified the breeder directly?  That would be an excellent step as they should have contact details for most (if not all) of the buyers of the litter so would be able to let them know about Rossi.

I am very sorry for your loss
. Mg can also be acquired as an  adult an autoimmune disease so may not be congenital.  But still a good idea to let the breeder know so they can consider any ursting that may be available.
With humans it can be tested for by bloods

My daughhters best friend has this condition. 

She had been complaining of being unwell, but sent away by her GP.  She collapsed and ended up in hopital where she had to be put into an induced comas and later had surgery on her neck.

If you no longer have contact detaisl for the breeder then you couold write a letter to the kennel club to pass on to them, and or the puppy owners assumign they have their detaisl up to date (many owners never transfer the registrations to their names, my account shows me owning around 50 dogs, though at least half due to their ages must be deceased by now).

If you register for a MYKC account with the Kennel club and input yoru dogs regsitered name you wil be able to find sibling and parents details, including other offspring.

How very distressing.   As I didn't know exactly what this is, I did a search and thought it might, or not, be helpful to post it here.

https://www.pethealthnetwork.com/dog-health/dog-diseases-conditions-a-z/myasthenia-gravis-dogs