The Risks of Anesthesia
   
Although all types of anesthesia involve some risk, major side effects and complications are rare.  Your pet's specific risks depend on its health, type of anesthesia used, and their response to those specific anesthetic drugs.  Individual risk factors include age, pre-existing heart, renal, or liver disease.

Complications from local anesthetics are few.  When used properly, they are safe and have few major side effects.  However, an individual can have an allergic reaction to a particular medication, which may not be discovered until that medication is administered.

Complications from general anesthesia can occur.  Serious side effects of general anesthesia are uncommon in pets that are otherwise healthy.  However, because general anesthesia affects the whole body it is more likely to cause side effects that local anesthesia.  Fortunately, most side effects are minor and can be easily managed.

General anesthesia suppresses the normal throat reflex of swallowing, coughing, and gagging.  These actions prevent aspiration.  Aspiration occurs when a foreign substance is inhaled into the respiratory tree (windpipe or lungs).  This is prevented during surgery by putting an endotracheal tube into the windpipe to prevent stomach contents from entering the lungs.  However, during recovery, when the tube is removed, patients can silently vomit and aspirate stomach contents.  The insertion of the endotracheal tube may cause coughing, gagging, swelling of the larynx, or hoarseness.  Other risks from general anesthesia include changes in blood pressure or heart rhythm or rate, heart attack or stroke.

Risks from reactions to anesthetics are rare.  If your pet has had an allergic reaction to a particular anesthetic drug, please advise our veterinary staff of this condition.  It is not uncommon for a pet to return home and be restless, vocal, or sedate after an anesthetic experience.  These are not allergic reactions.  A potentially fatal, rare condition is called malignant hyperthermia and may be triggered by some anesthetic medications.  The anesthetics most commonly associated with malignant hyperthermia are the inhalation anesthetics.

Common side effects and complications are: feeling sick and vomiting after surgery, sore throat, shivering, itching, aches and pains, pain during injection of drugs, and bruising and soreness around injection and catheter sites.

Uncommon side effects and complications are: chest infection, bladder problems (inability to urinate or temporary incontinence), depressed respiration, damage to teeth, and worsening of an existing medical condition.

Very rare side effects and complications are: damage to the eyes, serious allergy to drugs, nerve damage, death, and equipment failure.