Isoflurane vs Sevoflurane


New member
Jul 15, 2011
Phx, Az
Bulldog(s) Names
Arwen Undomiel
Please know the following is from my own research and study of veterinary medical research and study publications.
I am not a Vet, nor in the profession... Just my

So, Arwen will be getting spayed in a about 6-7 weeks, so I “interrogated” my vet about his experience and procedures. One thing that popped out to me was the fact he uses Sevoflurane and not Isoflurane. Red Flag!

He noticed my reaction and explained that for any dog (especially bulldogs) that a fast induction and system dissolution of any anesthetic is paramount. Sevoflurane is actually quicker in both instances, and has a much more precise control over the depth of the anesthesia. He has also been using it for about 8 years, after using ISO before the SEVO. So the dog goes under quicker with SEVO and recovers faster than with ISO. I told him I would do some research... Little did he know what that means with me!

After reading numerous articles (only a few listed below), I found this great summary by Nora Matthews from Texas A&M vs Sevoflurane.pdf
I Strongly suggest everyone read this article.

So, I am opting for Sevoflurane for Arwen, and probably for all future procedures & dogs. This is just my choice, and I am not suggesting that anyone opt for any specific anesthetic for their Bullies. I do suggest that you read, read, read & discuss with your own Vet on what you may want vs what they can do safely. One BIG plus for me is the experience that my vet has with Sevoflurane.

One thing I did note a few times in all my reading was the fact that Sevo is more expensive than Iso, so a lot of vets save the Sevo for the most critical animals only... I have No Problem pushing for the best anesthetic for my Arwen!!!!! I want her around for a LONG time!!!!

Anyway, since I dropped a ton of time in researching this, thought I'd share the basics of what I found out.

Feel free to search & read up like I did... if you dare!

  • Sevoflurane is a less potent coronary arteriolar dilator than Isoflurane, and that neither has a direct effect on the diameter of large coronary arteries. [SUP]1[/SUP]
  • Both Sevoflurane and Isoflurane significantly decreased arterial pressure in a dose-dependent manner, but neither drug significantly altered cardiac output. [SUP]2[/SUP]
  • Movements during RII (rapid inhalation induction) were minimal in Sevoflurane group comparing to the other groups. [SUP]3[/SUP]
  • Sevoflurane seemed to be the best inhalational anesthetic for RII in dogs without significant problems in respiratory and/or cardiac functions. Isoflurane also induced rapid induction with some degree of the movements. [SUP]3[/SUP]
  • Sevoflurane reduces myocardial infarct size by activating KATP channels and reduces the time threshold for ischemic preconditioning independent of hemodynamic effects in vivo. [SUP]4[/SUP]

  1. A comparison of coronary hemodynamics during isoflurane and sevoflurane anesthesia in dogs - Department of Anesthesiology, Nagasaki University School of Medicine, Japan.
  2. CEREBRAL EFFECTS OF SEVOFLURANE IN THE DOG: COMPARISON WITH ISOFLURANE AND ENFLURANE - 1. Neuro-anaesthesia Research Laboratory, M-029, Department of Anaesthesiology, University of California San Diego, La Jolla, Ca 92093, U.S.A.
  3. Rapid inhalation induction of anesthesia by halothane, enflurane, isoflurane and sevoflurane and their cardiopulmonary effects in dogs. - Department of Veterinary Surgery, University of Tokyo, Japan.
  4. Sevoflurane Reduces Myocardial Infarct Size and Decreases the Time Threshold for Ischemic Preconditioning in Dogs - Toller, Wolfgang G. M.D., D.E.A.A.*; Kersten, Judy R. M.D.†; Pagel, Paul S. M.D., Ph.D.†; Hettrick, Douglas A. Ph.D.‡; Warltier, David C. M.D., Ph.D.§
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Mar 25, 2011
Southern California
Bulldog(s) Names
Great info! My vet... well her anesthesiologist, also uses the Sevoflurane...he feels the same way..but he does use the Iso on pups...he uses a combo of Valium and another relaxer in order to tube for the gas. I am actually not sure why he prefers the iso for pups..At least male pups..the females are more complicated and it could be he uses the Sevo on them.I didn't pursue because I was fine with the iso...with either of these.,they are instantly awake with zero side effects like the general anesthesia.. sounds like you have a great vet and you are a great Bully Dad!


Aug 12, 2010
Milwaukee, WI
Bulldog(s) Names
HRH Princess Gracie, aka: HRH; Princess Amelia Pond, aka: Amy
Thank you for the time you spent compiling this information. It is articles like this that make English Bulldog News such a wealth of information for those lucky enough to be owned by a bully.


"Slug Assassin" and PBS Gardening Dweeb
Jun 23, 2011
Mukilteo, Washington State
Bulldog(s) Names
Beefeater's Buxom Beatrice and Lord Harrington's Bodacious Beauregaard
Thank you for the time you spent compiling this information. It is articles like this that make English Bulldog News such a wealth of information for those lucky enough to be owned by a bully.

Well said.


Staff member
Community Veteran
Jan 28, 2010
Tucson, Arizona
Bulldog(s) Names
The Home of the Desert Sky Pack
Thank you for this info!! This is excellent information for all the bulldog community. Both of these types of anesthesia are the only ones I will ever allow and every bully owner should read this. Too many senseless deaths on bullies who were given other types of anesthesia.

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