Tessie Almost Died Monday!

[Guest GreyKat]

Yikes- so scary! I was bad about regular brushing, but I decided to make it a habit. A few times a week was hard to do, so I decided to force myself to do it each night for 21 days. It worked- became a habit that I rarely skip these days! Also, I give various types of chews (CET lately), and I just recently started turkey necks. I'm looking forward to seeing the difference the turkey necks will make!

 

Not only is it nice to keep their teeth clean to avoid dangerous anesthesia experiences, it's also nice to save money by avoiding costly dentals. When doing all three at once, we spent $1,200 one time. UGH! Never again...!

 

Our Max had trouble after his last dental (about 3 years ago). They said he had a spike in temp and that they had to bathe him in ice to get the temp down. Poor guy. It's another reason I'd like to avoid anesthesia at all costs.

 

 

[Guest Winterwish]

Thank goodness Tessie is going to be alright! you must have been so scared! Feel better Tessie.

[Jiffer]

A muscle biopsy can be performed to determine susceptibility in humans; I don't know as it's cost-effective in dogs.

 

My vet wouldn't do a biopsy because it means putting the dog under again and risking another MH episode.

[Guest Tessiegirl]

My vet didn't know what to think either.

 

 

 

Shouldn't it happen immediately and not two hours later?

 

Merck says 5-30 minutes:

 

"Clinical signs include tachycardia, tachypnea, pyrexia, muscle rigidity, and cardiopulmonary failure. Signs develop 5-30 min after exposure to the anesthetic agent. Treatment consists of immediate cessation of anesthesia and hyperventilation with oxygen. IV fluid therapy, corticosteroids, and ice packs are also used. Dantrolene, a muscle relaxant, may be given at 2-5 mg/kg, IV. Prognosis is poor in severe cases. Urinary output, serum potassium levels, and cardiac function should be monitored."

 

A quick Google search shows Domitor is well-tolerated in greyhounds. I'm at a loss.

 

[feemandvm]

Worse, malignant hypothermia doesn't always happen with every exposure to gas anesthesia, so a dog can present with malignant hyperthermia (in some cases) even after having been spayed or neutered (frequently the first time a dog undergoes general anesthesia).

 

 

Not true. If a dog has MH it will produce a life threatening hypERthermia every time it is exposed to the gas anesthesia triggering the episode. A lot of GHs are misdiagnosed as having malignant hyperthermia when they truly have non-MH. See below for the difference:

 

http://animalmedicalcentreofmedina.com/lib...yperthermia.pdf

 

Is the mechanism different in dogs than in humans? I'm not challenging you; I thought the mutation was the same in humans as in other animals. The reason I ask (emphasis mine):

 

http://anes.usuhs.mil/mh_primer.htm

 

"The ability to recognize a clinical episode of MH is complicated by its rare occurrence, nonspecific signs, lack of non invasive screening test and by the fact that susceptible patients may not trigger with every exposure to triggering agents." (Sheila M. Muldoon, M.D. Professor, Department of Anesthesiology, Uniformed Services University of the Health Sciences)

 

From the NIH:

 

http://www.ncbi.nlm.nih.gov/books/bv.fcgi?...ene.chapter.mhs

 

"Of note, an MH episode may not occur with every exposure to "trigger" agents. Clinical manifestation may depend on genetic predisposition, dose of trigger agents, or duration of exposure." ( Henry Rosenberg, MD, Professor, Saint George's University, President, Malignant Hyperthermia Association of the United States)

 

From the J. Anesthesiology:

 

"Some of the complexities in the presentation of MH may be caused by the heterogenetic nature of the disorder. [7-10] Not only have several mutations been identified in RYR1 that may cause various phenotypes of MH, but as many as five chromosomes have been suggested to encode proteins that potentially cause MH. [10] Furthermore, certain factors can modify the expression of the syndrome, because heterozygous humans, [11] and even swine homozygous for the porcine MH mutation, [12] do not exhibit the syndrome at every exposure to a triggering anesthesia." (May, 1999: ATX II, A Sodium Channel Toxin, Sensitizes Skeletal Muscle to Halothane, Caffeine, and Ryanodine.)

I really can't say anything about humans as I don't know much about MH in other species. However, in dogs we do know that the underlying cause is an autosomal dominant trait and should trigger with each anesthetic episode.