Euthanising Rats Humanely

pet rat with tumour and cataract
A difficult decision – Image courtesy of Silver Frost Rodents

Every pet owner at some point has to face the difficult decision to euthanise their pet The decision is very personal and each owner will feel differently about the point at which an animal with an afflication should be euthanised.

Once the decision has been made to euthanise, it is a very good idea to discuss with your vet the method that will be used. It is important to make those final moments with your pet as stress and pain free as possible, and to make it as positive an experience as possible for both rat and owner.

There are a few different methods generally employed by vets in Australia, some are by far more humane than others;

Carbon Dioxide

Gassing by CO2 can be humane if the correct technique is used. If the chamber is filled with CO2 gas prior to placing the rat into the container, the rat will asphyxiate immediately and will understandably panic, gasp and choke, much the same way a human would if a plastic bag was placed over the head and the air removed.

To humanely euthanise using CO2, the rat should be placed into the container before any gas has been released. Once the rat is inside and the lid is safely secured, a short burst of CO2 should be released into the container (approx 10% volume).

This will cause the rat to literally slip into a sleep, without panicking, gasping or choking. Once the rat is unconcious the container can then be filled to full capacity with CO2. As the rat is already unconcious he will not suffer during this final stage and will simply not wake up

Lethal Injection

The most popular method employed by Australian vets to euthanise pets is by injection of a euthanasia drug, (often a product called Lethabarbâ„¢).

Larger pets, such as cats and dogs, are euthanised by injecting the euthanasia drug directly into a vein. Rats are unfortunately too small for this method of delivery to be used, and therefore the euthanasia drug has be to injected directly into the heart or peritoneal (stomach) cavity.

The injection into either location is excrutiatingly painful and extremely inhumane if done without prior sedation. Imagine a needle to scale being injected into a human heart or stomach cavity, it is tantamount to being stabbed.

Whilst it is necessary to perform this injection, it should NEVER be used as the sole method and should be used in conjunction with one of the following;

Sedation using anesthetic gas (Isoflurane) and oxygen

The rat is sedated using a mix of anesthetic gas and oxygen, which is administered by placing the rats head into a mask. Once the rat is unconcious, the lethal injection is administered into the heart or peritoneal cavity. The rat does not feel this whilst unconcious, and passes peacefully.

Sedation using anesthetic liquid under the skin

The rat has anesthetic liquid injected under the skin. This takes a few minutes to absorb into the system, after which time the rat will slip into unconciousness. At this stage the lethal injection is administered into the heart or peritoneal cavity. The rat does not feel this whilst unconcious, and passes peacefully.

As small animals are not often taken to the vet, being considered ‘throwaway pets’, it isn’t uncommon for vets to be inexperienced in treating small animals such as mice and rats. It seems to be general practice to administer the lethal injection directly into the heart or stomach without prior sedation UNLESS they are instructed differently by the owner. Prior sedation will inevitably cost more, which is perhaps why it isn’t standard practice.

Having heard first hand accounts of the agony caused when the rat is not sedated, we believe it is worth the extra cost. Discuss the procedure with your vet prior to saying goodbye, it could save your rattie distress in his last moments.