Euthanasia is performed using a very large dose of an anaesthetic drug, causing unconsciousness within a few seconds, followed by death. The route chosen depends upon the species and medical condition of the pet, but in every case the procedure is quick and painless. The drug may be administered by any of the following routes:

• Injection into a vein in the forelimb (cephalic vein).
   
• Injection into a vein in the hindlimb (saphenous vein).
   
• Injection into an indwelling intravenous catheter (if the animal is on a drip for example).
   
• Injection into the liver, kidney or heart (this may be necessary if the animal has very poor circulation).
   
• Injection into a vein in the ear (usually the case with rabbits).
   
• Inhalation of a volatile agent (usually the case with small rodents such as hamsters, rats and gerbils since a vein is very difficult to visualise).

Every animal is assessed individually, and the method chosen will be that which causes the least stress. If a pet is particularly nervous, then a tranquillizing drug may be given prior to the procedure.

Consciousness is lost within a few seconds, but it is important to advise the client that there may be some reflex actions evident. These include gasping, sighing, urination or defecation, and the client must be assured that although these signs may be distressing, the pet is unaware of any pain or discomfort.