There is a drug commonly used in anaesthetic protocols that should not be used for the Boxer.
The drug is Acepromazine - a tranquillizer, which is often used as a pre anaesthetic agent.
In the Boxer it tends to cause problems called "first degree heart block ", a potentially serious arrhythmia of the heart. It also causes “profound hypotension “( severe lowering of the blood pressure) in many Boxers that receive the drug. Recently on the Veterinary Information Network, a computer network for practicing veterinarians,an announcement was placed in the cardiac section entitled:

"Acepromazine and Boxers"

This described several adverse reactions to the drug in a very short time at a veterinarian teaching hospital. All the adverse reactions were in Boxers. The reactions included collapse, respiratory arrest, and profound bradycardia ( a slow heart beat rate less than 60 beats per minute ).
The announcement suggested Acepromazine should not be used for dogs of the Boxer Breed because of breed related sensitivity to the drug.

* Warning *

This drug is the most commonly prescribed tranquilliser used in veterinary medicine. It is also used orally and is prescribed for dogs whose owners wish to tranquillize their dogs for air and/or car travel.
I would strongly recommend that Boxer owners avoid the use of this drug, especially when the dog will be unattended and/or unable to receive emergency medical care if it is needed.

Submitted by Dr Wendy Wathner D.V.M July 1997

If your vet needs more than your word that you do not want your dog treated with this drug tell your vet to get out their “Handbook of Veterinary Drugs” (every vet has one) tell them to go to the section on Acepromazine. In this section ( 1993 Edition ) there is this section -

"Prolonged effects of the drug may be seen in older animals. Giant breeds as well as greyhounds appear quite sensitive to the clinical effects of the drug, yet terrier breeds appear more resistant. Boxer dogs on the other hand, are predisposed to hypotensive and bradycardic effects of the drug."