We love our companion animals so much, it can be really challenging to contemplate saying goodbye, but the reality is we have to at some point.
And the truth is that most veterinarians have been through this more than once with their own animals.
We know it hurts to lose them.
The average lifespan of a dog is 12 years, while the average lifespan of a cat is longer at 15 years.
Due to accidents, illness and the influence of genes, some animals live shorter lives.
But some animals live longer. The average maximum reported lifespan of a dog is 17, and 18 years for cats.
Nonetheless, it is highly likely that we will outlive our companions.
What do you wish for your companion, at the end of their life?
Many of my clients tell me that they would prefer if their companion died peacefully and painlessly in their sleep, with minimal suffering preceding those final moments.
While this would be wonderful, and relieve us of the burden of decision-making on the behalf of our companions, such an end-of-life experience is very rare for animals.
A recent retrospective study of the medical records of 29,676 dogs registered at general practices in the United Kingdom found that the vast majority - 89.3 per cent - were euthanased by a veterinarian, while just 8.3 per cent died unassisted.
A smaller study from New Zealand reported a similar rate, with 91 per cent of 68 dogs and 130 cats being euthanased, while nine per cent died unassisted.
Not all unassisted deaths are peaceful.
Deaths classified as "unassisted" in the above studies were not performed by a veterinarian, but they included deaths due to motor vehicle trauma and accidents.
Not all assisted deaths involved animals with a terminal illness. In the UK study, undesirable behaviour was the fourth-most common reason for euthanasia, accounting for over seven per cent of cases.
So what does this all mean?
It means that while some animals may die a "natural", unassisted death, the majority of companion animal owners are likely to have to make the decision to euthanase an animal at some point.
In most cases, euthanasia is performed in an animal that is approaching or exceeding the average lifespan, if their quality of life deteriorates.
The UK study revealed that the main reason for euthanasia was poor quality of life.
Of course, animals change as they age. A dog that used to love playing as a youngster may be content to sleep most of the day. A cat that used to jump may avoid doing so.
Veterinarians can do so much these days to improve the quality of life of unwell or ageing animals.
But there is a limit.
Ageing is an irreversible process. Many diseases cannot be cured - only managed.
To ensure minimal suffering for our companions, it is important that steps are taken to keep them comfortable, and that their quality of life is regularly assessed by a veterinary team.
Even if you hope that your animal will die peacefully, the reality is that isn't always the case.
It is important to talk to your vet about what to do if your pet's quality of life deteriorates, or what to do in an emergency (for example, a dog with well-managed heart disease that begins to have trouble breathing).
Choosing when to say goodbye to a companion animal is hard, but your veterinary team is there to support you.
One thing we can do is ensure those final moments are peaceful and painless.
Gates, M.C.; Hinds, H.J.; Dale, A. Preliminary description of aging cats and dogs presented to a new zealand first-opinion veterinary clinic at end-of-life. N Z Vet J 2017, 65, 313-317.
Pegram, C.; Gray, C.; Packer, R.M.A.; Richards, Y.; Church, D.B.; Brodbelt, D.C.; O'Neill, D.G. Proportion and risk factors for death by euthanasia in dogs in the UK. Scientific Reports 2021, 11, 9145.
Dr Anne Quain BVSc (Hons), MANZCVS (Animal Welfare), Dip ECAWBM (AWSEL) is a lecturer at the Sydney School of Veterinary Science and a practising veterinarian.