Myasthenia Gravis: Early Detection is Key to a Dog's Survival

by Jill Kruse

I’m destined to have mutant dogs.  Or perhaps I should say mutant dogs are destined to have me.  In 1999, I wrote about Dakota’s total hip replacement and her impending elbow surgery.  If you’ve seen us in Open classes at the Club, we’re the ones who jump 16 inches, at the most…we do the lessons for mental stimulation and fun.  Because the breeder guaranteed Dakota’s hips, I received a “free” puppy.  It didn’t take long to realize that he was also a mutant…both his testicles were un-descended and he had a severe undershot jaw.  Fortunately, a dog’s jaw continues to grow until about 10 months of age.  Although he still has quite an undershot jaw, to date it has not created a problem…other than making allowances for his method of eating and drinking.  Picture a shark’s snout/mouth and that’s my man, my Bogie Man.

If never making it into a “beauty show” was his albatross, then we’d be fine.  But like I said, that’s not our destiny.  Our story begins around the middle of July of 2002.  Bogie had been “throwing up”…not much and not every day.  It seemed to coincide with the weather.  When it was very, very hot he’d “throw up”.  As I learned later, the weather had nothing to do with his condition.  And he wasn’t “throwing up”, he was regurgitating food.  But little did I know at that time.

As we discovered, Bogie has a very rare (in dogs as well as people) and incurable, although treatable, disease called Myasthenia Gravis.  It is an autoimmune neuromuscular disease characterized by muscle weakness.  In essence, Bogie’s immune system is attacking his neuro-receptors.  Myasthenia Gravis can be either genetic or acquired, as in Bogie’s case, and is not life-threatening, in and of itself.  However, the symptoms and resulting effects can be, which is why early detection is key to a dog’s survival.  One of the symptoms is megaesophagus…an enlargement of the esophagus.  This can lead to aspiration pneumonia (caused by the regurgitation of food and water and then inhaling that crud), respiratory failure and death.  We came close.  This is our story.

Day 1 - On that Monday in late July (7/29) when I first took Bogie to the vet, I learned he had megaesophagus, for which there are several causes.  Metoclopramide was prescribed (to be given prior to eating) to aid in the stimulation of the lower esophageal sphincter so that food would make it to the stomach.  That was the plan.  It didn’t work.  Bogie continued to regurgitate … everything.  And, he developed a fever.

Day 3 - We were back at the vet’s office.  Antibiotics were prescribed and a blood test was taken, which later confirmed pneumonia.  Bogie was also given an injection of Metoclopramide and I was instructed to feed him baby food in small quantities eight times a day at an elevated level…letting gravity help in getting food to the stomach.

Bogie’s fever came down.  But, he kept regurgitating what he ingested.  Although he liked the Gerber Graduates, after regurgitating so many times, he lost the desire for food.  He just wanted to stay in his “den”, refusing everything I put before him.  And, he was losing weight.

Day 4 - Thursday morning was another call to the vet.  Bring the boy in.  Up to this point, symptoms were being treated, but the cause was not identified.  We had been dealing with an associate of our usual vet.  But, today we saw our usual vet.  And, to our good fortune, he had treated 2 previous cases of MG in his over 30 years of experience.  The rarity of the disease is such that very few vets have ever treated even one case.  Our vet recommended a blood test to determine Bogie’s acetylcholine receptor antibody level.  The normal range is <0.6 nmol/L.  This would definitively confirm his suspicions that Bogie had Myasthenia Gravis.  The trick to this blood test, though, is that it must be sent by overnight mail and refrigerated immediately upon arrival at the only lab in the entire United States that does this test…the Comparative Neuromuscular Laboratory at the University of California (also a very good website for information).  And, they only do this test on Tuesdays and Thursdays.  And, I got to mail the package (not cheap).

Day 5 - Friday was better as Bogie was getting some food down, as evidenced by his first bowel movement in days.  However, he was still regurgitating frequently. 

Day 6 - Bogie’s fever had spiked (by this time I had become proficient at taking his temperature and Bogie had become a reluctant but complacent victim).  And off to the vet we went, again, for stronger antibiotics.  Bogie continued to lose weight…he was down 5½  pounds from a high of 82.  Even at 82 pounds with a height of 28 inches, Bogie was, as my husband, Allen, described him, the “Barney Fife of Shepherds”…a long tall guy who, looking straight on, you saw huge ears and nothing of a body.  Now he was looking gaunt.

Day 9 - Vet’s office for a recheck and another blood test to check on the pneumonia…all clear.  Later that day we got the news.  Bogie definitely had Myasthenia Gravis.  His acetylcholine receptor antibody level was 0.83 nmol/L.  I picked up a prescription for Mestinon (the same medicine people would use) and had it filled at Walgreen’s.  I felt Bogie was given a death sentence.  Allen searched the internet.

What Allen found was encouraging.  Although MG only has a survival rate of 50%, this is due in large part to misdiagnosis of vomiting when in reality it is regurgitation and the presence of esophageal dilation, thus increasing the chances for aspiration pneumonia.  Allen also discovered that dedicated owners are essential in a dog’s survival as the average treatment time for acquired MG is six to eight months.  Feeding the dog at an inclined position (not just elevated) is crucial.  Keeping the dog in that position for 10 to 15 minutes after eating is also important…and a challenge.  But with proper therapy, Bogie could have an active and long life…even agility.  Better yet, remission was a strong possibility.

Day 11 - Bogie’s temperature increased and Prednisone was prescribed, increasing slowly from 20 mg daily to 40 mg daily.  From the information Allen found on the internet, we figured this was coming.

Bogie’s regurgitation continues, but improving.  Feedings were changed from eight times a day to five, thus Bogie was getting more to eat with each feeding (same amount for the day).  The timing of the Mestinon, 60 mg. (taken before meals) was important and it took some experimenting to get it right, especially with frequent feedings.  Time needed to be allowed for the Mestinon to start working and it only lasted for four hours.

 Day 16 - Back to the vet’s for a recheck.  Weight loss continues, now a total of 10 pounds.  Bogie’s diet was changed from the Gerber Graduates to pureed canned puppy food…still feeding five times a day at an elevated level.  Bogie’s regurgitation lessened in frequency (usually in the dead-of-night) and content (mostly saliva…he was keeping the puppy food down), but we still had yet to have two spittle free days in a row.  The water dish (also elevated) was removed in the evenings to help with this.

 Day 20 - Vet’s office just to weigh Bogie…down another pound…disappointing.  At least Bogie had a visit without any poking, prodding, and taking of blood.  Diet changed from pureed puppy food to Hill’s Prescription Diet P/D combined with water to make a gruel (1½ cans P/D and ½ cup water makes the perfect gruel consistency)…still feeding five times a day.

 Day 23 - Keeping food down, regurgitation of spittle getting less and less, BMs better on P/D, and he’s gained ½ pound.  Bogie was doing well enough to visit with his agility friends.  This was good for his spirits, but it was obvious he had feelings of vulnerability.

 Day 25 - Gain of two more pounds.  Feedings changed to three times a day.

 Day 32 - Gain of another 1½ pounds for a total gain of 4 pounds.

 Day 39 - Breakfast was made with a canned puppy food high in protein as we were out of P/D (so were all the vet offices I called looking for it…delivery this afternoon).  Two hours later, Bogie regurgitated his breakfast and he had a fever.  He’d gone six days spittle free…his longest.  But evidently, he managed to have the gruel go down the wrong pipe and end up in his lungs.  As a result, he was put on antibiotics and his diet was switched from gruel to meatballs.  No weight change.

 Day 40 - Given the O.K. to resume normal activities.

 Day 46 – Gain of 5½ pounds…in one week!  Must have been all those “stinky treats” Bogie had during Sunday obedience, Tuesday agility and Wednesday obedience.  Still has a touch of an infection in his lungs; antibiotics for another 10 days.  Begin slowly reducing dosage of Prednisone.

 Over the past week, Bogie’s meatballs slowly went from being made entirely of P/D to predominantly his dry food with ½ can of P/D.  And, he went eleven days without spittle.

 Day  53 - Gain of another 3½ pounds for a total gain of 13 pounds.  X-ray of lungs…all clear.

 Over the next week, we experimented with switching to dry food only.  Per the vet, it’s a matter of what Bogie can keep down.  He’s been having small biscuits with no problem.

 Day 60 - Successful transition.  Feedings three times a day…dry food only.

 Day 66 - Feedings twice daily…dry food only…still at an inclined level.

 Day 69 - Prednisone reduced to 20 mg every other day.

 Day 71 (October 7^th) - Acetylcholine receptor antibody titer.  Good news!  Bogie’s number was 0.07 nmol/L (remember, the normal range is <0.6 nmol/L).  Next would come the slow reduction and ultimate elimination of all meds to determine if Bogie would go into a true remission, not just a clinical remission.

 November 1^st - Prednisone reduced to 10 mg every other day.

 December 9^th - Prednisone reduced to 5 mg every other day.

 January 6^th - X-ray of esophagus.  It’s shrinking!  Our vet was ecstatic and surmised that Bogie had been “reading the book” and following all the rules.  Continue Prednisone at 5 mg every other day.

 February 3^rd - X-ray of esophagus…completely back to normal!

 February 5^th - Acetylcholine receptor antibody titer.  Bogie’s number was now 0.05 nmol/L.

 March 8^th - Last dosage of Prednisone.

 April 5^th - Last dosage of Mestinon.

 May 5^th - X-ray of esophagus…perfect.  Officially declared in remission!

 June 7^th & 8^th - Bogie’s in his very first trial…our agility trial.  He takes 2^nd Place in Novice Agility Jumpers with Weaves on Saturday and 1^st Place in NAJ on Sunday.

 Bogie may come out of remission, or he may stay in remission forever.  One thing is for certain.  He will always have my watchful eye for signs.  Besides megaesophagus and regurgitating food and water, other signs include droopy eyelids (looking back, Bogie had that), excessive drooling (he had that, too…got worse with the Mestinon) and muscle tremors (had that only once in the thigh).

 Knowing the difference between vomiting and regurgitation is also essential.  If there is yellow bile in what the dog upchucks, then it is vomit.  What Bogie regurgitated was foamy, when it wasn’t food that looked coming out just as it did going in.  Regurgitation is also spontaneous whereas with vomiting, the dog will do that all-too-familiar sound and mindless walking.  There were many times when Bogie would just be lying down and all of a sudden…surprise!  Sometimes I knew it was coming when Bogie would drop his head, ears back, get a sick look on his face, and drool excessively.  In the beginning, Bogie’s regurgitation came so often and with such little notice that we had strategically placed stacks of paper towel throughout the house and if we were quick enough, we could slip several sheets under Bogie’s mouth and save on clean-up.  We were using it so much that Allen wanted to buy stock in Scott Towels. 

 I hope that our story illustrates the importance of early detection, and that you understand survival is dependent upon the dedication of the owner.  Bogie was fortunate that I was able to be there for him ‘round-the-clock.  I was fortunate to have people in my life who understood my devotion to Bogie.  The prayers on Bogie’s behalf by friends and members of this Club, I believe, contributed to his recovery.  I will always be grateful for this and for the unselfish act of one friend (and member) in particular who built a water stand that both Dakota and Bogie could use and an incline feeding stand for Bogie, which he will use for the rest of his days.  (Commercial elevated dog dishes are 16 inches high, at the most.  With Bogie at 28 inches in height and Dakota at 27 inches, custom made was the only way to go.)

 As I said, mutant dogs are my destiny.  But when I watch Bogie when he’s happy, which is most of the time, and not only does his tail wag, his whole butt wags, I know that it will always be worth it.