View Full Version : Myasthenia Gravis?

26th April 2005, 03:00 AM
Is there anyone familiar with this? My little guy, Lester, is only 1 year old and suffering from frequent bouts of lameness. To be exact, he gets excited or exercises until his legs become useless. It started out as bunny hopping and has developed into all out tremors where his legs seize up as if he is having leg cramps and his back arches very abnormally as he tries to get around. Yesterday, he fell over and began shaking. I calmed him down and he was almost immediately better. I have taken him to 2 vets and together they ruled out syringomyelia, brain tumor and possibly he may have gotten a false negative on a blood test for myasthenia gravis. He needs yet another test for this which will might diagnose it or rule it out. I have spent all of my savings and currently swimming in vet bills trying to figure out what this is. He has had one MRI which was inconclusive and now needs another. I want to know if I am being swindled into needless testing and also what I can do to help my poor baby. Lester doesn't know there is anything wrong. He is quite alert during these episodes and doesn't seem to be in any pain. He had a bad day yesterday, today he is quite normal. He's my best bud, kind of a weirdo like me, silly, full of life and I would hate for anything serious to be wrong. He is an unusual animal; the most intelligent dog I have ever owned or met. It would be a crime to not have this thing at least diagnosed properly. If you could meet him...well, I'm sure all Cav owners think theirs is the best, but mine really is (for me)!! He rocks! If anyone has any suggestions on what my next move should be, please, please, please do not hesitate to reply.


Jen (and Lester the Molester) www.jencrowder.com/portfolio.html Click on pets and you'll see my little guy!

26th April 2005, 03:47 AM
Oh I feel so sad for you and Lester. On the other Cavalier site I frequent there is a pup named Penny with similar symptoms. She has been diagnosed with Episodic Falling Syndrome. Her Mom's posting name is Luv2Camp53. Maybe it is not the same but seems to have similar enough symptoms to connect you two. There seems to be some sucessful treatment. Good Luck! Keep us posted and many good wishes sent your way. Here is the web address

26th April 2005, 12:17 PM
Jen, just read this post after responding on your intro thread, and see you have done an MRI and have given much more info over here. This DOES sound like episodic falling syndrome; I have seen several cav owners describe this on other lists and boards. It is not something that would be picked up on an MRI. Listen to this -- it is exactly what you are describing:

Episodic Falling
Episodic falling or hypertonicity is a well-recognized paroxysmal disorder in Cavalier King Charles Spaniels in the UK [1,2], and has been seen in the United States and Australia [67]. After a variable period of exercise, affected animals develop a peculiar bounding, pelvic limb gait in which the limbs may be abducted and appear stiff. Other signs may include a bunny-hopping gait, arching of the spine, vocalization and collapse. There is no loss of consciousness. Some affected dogs assume a "deer-stalking" posture, with increasing limb stiffness, falling, and legs held in extensor rigidity [2]. Episodes appear to be triggered by stress, apprehension, and excitement. Signs are typically first observed between 3 and 7 months of age. Animals are neurologically normal between attacks, which appear to be a life-long event. Affected dogs do not respond to anticholinesterases, but slight, temporary improvement may occur following diazepam treatment. A greater clinical improvement is reported following following treatment with the benzodiazepine drug clonazepam which enhances GABA neurotransmission [67,70]. In one trial, clonazepam (at 0.5 mg/kg tid) resulted in almost complete remission of signs over a 2-year period [70]. Frequency of attacks is reportedly increased in some dogs using the antiepileptic drug carbamazepine (Tegretol) [1]. Results of hematology, blood chemistries, and electrodiagnostic testing are within normal limits. There is no evidence of lactic acidosis. No light microscopic lesions are seen in the central nervous system (CNS), peripheral nervous system (PNS), or viscera. Skeletal muscle appears normal microscopically, apart from presence of small vacuoles between myofibrils in some fibres stained with toluidine blue [2]. Histochemical staining using myosin ATPase, succinic dehydrogenase, and phosphorylase is normal. Ultrastructural alterations, however, have been reported in skeletal muscle, which include dilatation and proliferation of sarcotubular elements, mitochondrial swelling and degeneration of cristae, and tubular proliferations in the region of the triads [3]. Wright stated that she was uncertain if the morphological changes were causally related to the clinical signs [2]. The pathogenesis of this paroxysmal condition remains enigmatic, although both genetic and neuropharmacological factors may be involved. In one study, 7 of 8 dogs were males and 5 had a common male ancestor that suggested an inherited trait [2]. It has been suggested [67,70] that this disorder has some similarities to hyperexplexia (startle disease) in people, a hereditary (autosomal dominant) pathological exaggeration of the normal startle response to auditory, somesthetic or visual stimuli which sometimes results in falling [68,69].

From: http://www.ivis.org/special_books/Braund/braund29/chapter_frm.asp?LA=1#Episodic_Falling

More info: http://www.candog.com/cavaliers/Health/HEALTH%20POTPURRI96.htm

Where it says in part:

The descriptions of the syndrome in these articles suggest this is a transient and intermittently occurring condition, which was first identified in the 1960s. The article "Episodic falling..." documents nine clinical cases, seven of which were female. In fact, in most of the cases the first signs of the syndrome were seen when the dogs were between three and four months of age. The article on "Muscle hypertonicity..." describes eight dogs which had this syndrome; seven of the dogs were male. Their ages ranged from five-and-a-half months old to four years old. Dogs described in both articles were given thorough neurological exams before and after exercising, and none of them showed any evidence of neurological problems. Blood tests all came back with normal values. As with the club member’s dog, Tensilon was given and no improvements for dogs described in both articles were seen with the administration of the medication. Muscle biopsies were taken from five of the dogs, with some abnormalities of the muscles seen. It appears the disorder is a type of metabolic muscle disorder. It is probable that the disease is an inherited condition.

The description of what happens when Episodic Collapse occurs is as follows. After a period of exercise, which may be of variable length, animals that are afflicted develop a laboured, bounding gait in the hindlimbs which appear stiff and are partially turned out. The movement resembles the hopping of a rabbit. The dog’s back may become arched, with the head close to the ground and the rear high in the air, and the dog often cries out. With the lack of coordinated movement, the dogs collapse on their sides or pitch over on to their noses. There is no loss of consciousness or change in colour, although muscle tone in the legs was noted to be increased in the "Muscle hypertonicity..." article, and the legs were held in ‘extensor rigidity’. After a short time, which can vary, the animal gets back on its feet; some were noted to be quite distressed, while others acted as though nothing had happened. Stress, apprehension, and excitement can cause an episode. There is no known effective treatment, although if the owner picks the dog up, this seems to help with the recovery phase.

You should inform your dog's breeder that it has this if this is confirmed -- actually any odd condition should be reported to the breeder so that they do not do further matings with that dog.

It is now believed that it MAY be related to SM but isn't a progression or anything like that.

26th April 2005, 12:35 PM
Some further info on treatment and contacts:


Until recently, no medications appeared to remedy the condition, and there was no known effective treatment. However, in a study concluded in 2003, a group of affected Cavaliers was treated with Clonazepam, a drug used to treat humans for hereditary hyperekplexia ("startle disease"). With treatment, the episodes decreased in frequency from between 25 and 30 per week to as few as one every two to three months. After two years of treatment with Clonazepam, dogs in the study were described as clinically normal.

However, in a study currently being conducted by Dr Jacques Penderis, senior research neurologist at the Animal Health Trust in the UK, he has found that although some Cavaliers initially respond well to treatment with Clonazepam or Diazepam, the dogs tend to develop tolerance to the drugs after a while and the beneficial effect wears off. Dr. Penderis states that the current treatment options for CKCSs with episodic falling syndrome are extremely limited.

Current Research

The Animal Health Trust is conducting research to try to establish the pattern of inheritance of episodic falling in the Cavalier. It is collecting pedigrees from affected dogs for pedigree analysis, particularly where the disease status of related dogs (e.g. parents and litter mates) are known.

In an attempt to develop a more effective treatment for dogs that are severely affected, Dr. Penderis is conducting a trial of some other drugs that have been shown to be beneficial in human patients and to which the Cavaliers' tolerance does not develop. He advises that the initial results for one drug have so far been promising. The current trials are restricted to those dogs that have very frequent collapse episodes and are arranged through the owners' veterinarians.

Dr. Penderis also is collecting blood samples for DNA extraction to conduct genetic linkage analysis in order to determine the offending gene. In order to perform genetic linkage analysis, Dr. Penderis requires blood samples from known affected dogs and from as many normal related dogs as possible (particularly litter mates, parents, grandparents and offspring). The study's goal is to develop a genetic test to allow identification of the affected dogs and asymptomatic carriers, so that the disease may be totally eradicated from all tested breeding lines.

In order to reduce the incidence of the disease and eventually develop a genetic test, Dr. Penderis is interested in information from as many affected dogs as possible from the Cavalier King Charles Spaniel breed. He states that what is essential to the research is that no dogs that do not have episodic falling syndrome are inadvertently included in the study (e.g. have similar appearing stiffness or collapse episodes that are not due to episodic falling) as this could severely hamper the genetic analysis. The disease will therefore need to be confirmed by video footage of an episode or examination of the dog at the Animal Health Trust. Please contact Dr Jacques Penderis at the Animal Health Trust if you wish to participate in the research project. He may be reached at Animal Health Trust, Lanwades Park, Kentford, Newmarket, CB8 7UU, UK. Telephone: (+44) (0)1638 552700; Fax: (+44) (0)1638 555600; email: Jacques.Penderis@aht.org.uk

From: http://www.cavalierhealth.org/episodic_falling.htm

26th April 2005, 02:13 PM
WOW.....Sure sound like the same symptoms to me....
Jen, Please keep us updated as to what your vet says...Im interested to see if it is the same thing that little Penny has.

26th April 2005, 03:04 PM
Jan, so sorry to hear about little Lester - this must be heartbreaking for you to watch.

It does sound very like Episodic Falling - there is some more information here too:



If they are not too severly affected, they can lead a very good quality of life, so hopefully that will be the case for Lester.

Sending lots of positive, healing thougths for you both, and please keep us posted as to how he is doing.[/url]

26th April 2005, 03:22 PM
Thanks Nicki, I thought you would also have some links. icon_thumbsup

26th April 2005, 10:01 PM
Sounds very much like Penny who has been definately diagnosed with Episodic Falling Syndrome. She has had all the tests you have mentioned, and then some. We started her on Clonazepam last Wednesday. So far, we have not yet gotten the dosage correct, and she is still having attacks, although they are not so frequent (maybe I am just doing some wishful thinking). She is currently getting 1 mg four times aday. Today is her first day on that dosage. According to my vet, we can go up to 9mg per day, so we have a ways to go before we hit the maximum dosage. I know what you are going through, and my prayers and good thoughts are with you. You are in Minnesota. I got my Penny from a breeder in Minnesota. Maybe you could PM me and we could talk. Donna

27th April 2005, 03:34 AM
So happy to see that Karlin and others on these Cavalier sites brought Jen and Donna together on this. I know that if Audrey ( and I hate to say it but when) has problems there are such great folks to come to. Our best of luck for the help you and your sweet babies need right now comes forth.
Many prayers and fond wishes,
Dee and Audrey

27th April 2005, 10:57 AM
That's great that Donna and Jen can be in contact, I know how much it helped me having contact with other Cavalier guardians whose doglets sadly have the same conditions as my two.

Sending healing thoughts and prayers to Penny and Lester.

28th April 2005, 04:18 AM
Oh yes, it sounds very much like what he is going through! I have never heard of this, but am going to contact my vet(s) first thing in the morning. Meanwhile, Lester enjoyed his first taste of BARF diet today and then proceeded to bury some chunky leftover bone in my clean clothes hamper! Again, he is still a rowdy, little mischief maker who doesn't know he's "handicapped!" I will definately keep you posted!

By the way, how is this diagnosed? If not through blood, MRI (or other x-ray)...what should I ask the vet to do to rule out or diagnose this? I'll look more into this FOR SURE. It matches his symptoms to a T. But if anyone knows, I would greatly appreciate and again THANK YOU soooo much for all the wonderful information and resources!

Thanks again!


28th April 2005, 09:50 AM
Jan, I think they do a muscle biopsy. I would guess that would be under anaesthetic.

When you have a minute, check the links above, there is a LOT of information there.

Hopefully this is Lester's problem, it sounds like it is something that can be controlled and he can have a very good quality of life despite it.

28th April 2005, 11:47 AM
Oh, I'm so glad you have seen these posts and now hopefully have ended your search for WHAT is wrong (which is so frustrating when you can;t pin something down) and can move on towards treating it. My understanding from reading the above info is that it is diagnosed mainly by clinical signs. Why not send a PM or email to Donna as she has already gone through this with a dog? She too is in the US.

29th April 2005, 02:54 AM
Here's the crazy part...Donna and I have the same breeder!! Wow! Small world! Donna informed our breeder today and I also spoke with the breeder twice today. I'm going to move forward and try to find (or start) some professional or educational research on this matter. I think starting with tracking down the offenders in her stock is a great place. I believe she said she purchased some dogs from Ireland a while back, but it could really have come from anywhere. I think the first step is for the breeder to inform every person she sold a pup to and make damn sure those pups are ALL fixed and possibly try and find out if any others are affected. I think it is a strange coincidence that Donna and I found each other, but certainly seems meant to be! From what I have read over the past couple of days, as far as the levels of severity, Lester probably has it pretty bad, but again he is a scrappy little guy and just isn't having any part of being lame. I am confident he can live a VERY long time and have good quality of life. Treatment will certainly help if it gets unbearable, but again, he's indifferent to his problem and is unstoppable. There will certainly be expense, but hopefully we've got it diagnosed and can move on with treating it!

Thanks again and I'll keep everyone posted!

29th April 2005, 03:23 AM
Hi Jen, I applaud your attitude for your little hero Lester.
I have a ruby boy who suffers with this condition, although very mildly - he has only ever had four attacks in his life and he was eleven last January.
He had his first when he was just four months old and we soon recognised it was stress/heat/exercise related. He is always conscious during an attack, but his eyes are 'staring', his limbs go rigid like steel rods. I just sit quietly reassuring him until it has passed, then he gets up and gets on with his life.
If Lester's breeder doesn't already know, there is strong evidence that this is an hereditary condition.
Best wishes,

29th April 2005, 03:40 AM
Thank you! I'm glad I'm not alone. It has been a whole year. The more I read about this, the more I realize how bad Lester has this thing. He's a very brave boy. His legs go almost every day. I count it as a good day if he doesn't fall down. I'm starting to see that this is not a mild form of it. Was yours very active? Did it get worse over time?

30th April 2005, 01:51 AM
Hi Jen, my boy suffers only mildly. Initially however we (including my vet) were totally stumped at what was happening, it was before this condition was well known about. Because of this Teddy has never had treatment, so maybe that is a plus for Lester that there is treatment available out there for him. Keep positive, try and eliminate any stress for him. I also watch Teddy never overdoes the exercise or become too heated.
Thinking of you both.
Best wishes,

30th April 2005, 04:15 AM
I'm going to move forward and try to find (or start) some professional or educational research on this matter. I think starting with tracking down the offenders in her stock is a great place. I believe she said she purchased some dogs from Ireland a while back, but it could really have come from anywhere.

You should contact this pathologist who was doing research on it. Having 2 affected dogs from the same lines is a great place to start research!

Here is a link to her website w/ her research on this a few years ago:
p.s. Lester is adorable!!! :D

10th May 2005, 04:18 PM
How is Lester doing? Have you had the chance to get him in to see anybody; or try any medication?

3rd June 2005, 12:35 AM
Hello Jen
I am so sorry to hear about your boy. I have already had contact with Donna and she did tell me she had found another affected one. Jacques Penderis, who is doing the research on EF, has recently moved to Glasgow University and at present I am waiting for a contact address from him. However is he working in conjunction with Dr Ned Patterson at the University of Minnesota, so it might be worth your while trying to contact him. They are working on a new drug but will only divulge the info to your veterinarian. Please take a look www.cavalierepisodicfalling.com
I have been collecting data on this condition for nearly 30 years and I wonder if you might be able to supply me with a copyof your pedigree please. You can email me privately if you like.

Best of luck

3rd June 2005, 05:17 AM
It appears this is much scarier to you than Lester....We pray for Lester to get better and for you to find peace over it.
This is such an interesting disorder. I truly appreciate all who provide their input and knowledge. Hang in there!

3rd June 2005, 02:12 PM
Hi Jen,
How is Lester doing? Any updates?

I hope all is well,

Jen & Abbey

23rd June 2005, 08:59 PM
i am in the market for buying one but after reading these problems it seems this breed have many problems. Do these peoblems happen in most dogs or?

24th June 2005, 02:52 AM
All breeds have problems of one sort or another.
However the gene pool for Cavaliers is extremely small and in attempting to eradicate one health problem it has been reduced further and along the way another extremely serious problem has arisen.
My own opinion is that Cavaliers have more than their fair share of health problems, and you need to research your Breeders very carefully.
Warm wishes,

24th June 2005, 04:06 AM
All breeds have problems of one sort or another.
However the gene pool for Cavaliers is extremely small and in attempting to eradicate one health problem it has been reduced further and along the way another extremely serious problem has arisen.
My own opinion is that Cavaliers have more than their fair share of health problems, and you need to research your Breeders very carefully.
Warm wishes,

I agree with Ruth. But know that even w/ the best, most responsible breeder, there are no guarantees that your dog won't still have some problem.

24th June 2005, 01:13 PM
Sadly very true Rory.

Warm wishes,

7th July 2005, 09:15 PM
How is Lester now? Is he on medication? He's got to be one of the most gorgeous Tri's I have ever seen. If you ever get bored of him then send him over here to me ;)