Myasthenia Gravis (need some help and information)
So it looks like one of my Shibas (Toby) may have myasthenia gravis. We've been having a hard time getting a diagnosis on his problems, and my vet, after running some tests and doing a consult with some other vets who work in endocrine issues, believes he may have myasthenia gravis. It does describe his problem (trembling in the back legs and weakness but no loss of muscle mass, and no apparent pain).
The thing is, in 30+ years of vet practice, she's never seen a case. Turns out, neither has the endocrinologist who she talked to, so she would like to get some more information on it from people who have experienced it, whether that is breeders or other vets. One of her med journals (which she's loaning me this afternoon so I can read about it) says 89% of cases improve on their own, and she's wondering how accurate that, and what a bad case of MG looks like (and mild cases, etc).
I'm going to do some more research on it too, but we're also looking for people who have actually seen cases. If anyone has any suggestions/tip/knows anyone, this would be really useful for us. (or even links! I just found out about this last night so haven't even gotten far enough to do a good google search--all I've done is read about it Bouyet book on Akitas).
It is something that shows up in Akitas, mostly, so it may be Akita people who might have encountered it.
(And as for Toby....well, it does explain his weakness and inability to tolerate exercise. It does not explain some of his other health problems, which my vet still thinks is a boderline case of Cushings, though the lab is insisting its not. So while this will not solve his problems knowing about MG, we now think there might be two things going on, and I'm thinking he's just having problem with his endocrine system in general, as he is also hypothyroid).
The thing is, in 30+ years of vet practice, she's never seen a case. Turns out, neither has the endocrinologist who she talked to, so she would like to get some more information on it from people who have experienced it, whether that is breeders or other vets. One of her med journals (which she's loaning me this afternoon so I can read about it) says 89% of cases improve on their own, and she's wondering how accurate that, and what a bad case of MG looks like (and mild cases, etc).
I'm going to do some more research on it too, but we're also looking for people who have actually seen cases. If anyone has any suggestions/tip/knows anyone, this would be really useful for us. (or even links! I just found out about this last night so haven't even gotten far enough to do a good google search--all I've done is read about it Bouyet book on Akitas).
It is something that shows up in Akitas, mostly, so it may be Akita people who might have encountered it.
(And as for Toby....well, it does explain his weakness and inability to tolerate exercise. It does not explain some of his other health problems, which my vet still thinks is a boderline case of Cushings, though the lab is insisting its not. So while this will not solve his problems knowing about MG, we now think there might be two things going on, and I'm thinking he's just having problem with his endocrine system in general, as he is also hypothyroid).
Comments
I hope someone here might be able to help you on this soon.
An ultrasound of the adrenals would give you the best idea about Cushings at this point, IMO.
You can also ask at the vet school if they had a case like yours they studied on.
The golden I remember with MG, initially presented with some neurological problems with eye movement and mega-esophagus.
It's surely possible in Shibas, given the weirdo autoimmune issues in all NK. Usually the most obvious answer is the correct one, but sometimes not.
Right now, we're not doing anything at all, but we would like to know more. We don't have a local vet school to ask, but my vet is on her way to a conference in the next couple of weeks where she's going to see if she can find anyone that's dealt with it.
And for the other issue, he's not at the level that would make him a clear case of Cushings, but his resting cortisol levels are elevated every time we've tested, and it's clearly not just stress (as the lab keeps insisting). He did react fairly normally to the dexamasone test--ie. his cortisol levels went down--but they were still slightly elevated. I wasn't really keen on the treatment for Cushings anyway, and now that we think he's not clearly Cushings (but still has something going on with cortisol levels) I'm not willing to treat him for it, and my vet isn't thrilled by the idea either.
According to Barbara Bouyet's Akita book, some of the autoimmune disorders seen in Akitas are immune mediated uveitis/dermatitis....this shows up in the skin and eyes (and is something my vet and I talked about today as something she's seen in autoimmune diseases). There is something called Pemphigus, which is seen, according to Bouyet, more often in Akitas than any other breed. It's a skin disorder. There is Lupus. There is a disease that shows up in Akitas called Sebaceous Adenitis. There is autoimmune hemolytic anemia. And there is MG.
Those are just the autoimmune diseases. Of course, there is also a tendency to hypothyroidism (this one is showing up a lot). There are seizure disorders (I've noticed a bit more of this on the Shiba forum). There is a serious worry about glaucoma, which is not uncommon in Akitas. There is hip displaysia in the larger breeds, and luxating patella is common in the smaller breeds. There are clotting disorders (including Von Willebrand's) which has been seen in Akitas and Shibas. In another thread, Lindsay linked this page, which had some links to some disorders, including clotting disorders, that have showed up in Shibas: http://www.shiba-dog.de/ShibaDog-en.htm
I'm very much of the opinion that is important for us, as NK people, to be aware of the conditions that effect any of these breeds, even ones we may not have.
We were talking about mega-esophagus on the Kai Ken FB page, because an imported Kai had it, and thus had been neutered. It doesn't have to be related to MG, of course, and is usually diagnosed in puppies, because it is noticed, first, when puppies are weaned. (per my conversation with my vet today).
Anyway, that's a long answer, but the point is, NKs, like any other types of dogs, do have certain conditions that show up, and some are more rare than others, but it's useful to know what they are. When my vet said MG, I knew exactly what it was, though neither she nor I have any actual experience with it. I knew what it was, though, because I've read a lot about the kinds of things that show up in Akitas....
http://www.akitaclub.org/health/health/mgshelton1.html
http://www.vetmed.ucdavis.edu/vsr/Neurology/Disorders/Myasthenia Gravis.html