When is your pet ‘too old’ and ready to be put to sleep?

Q: My Shih tzu is 18 years old and everyone tells me she’s so old and that she should be put to sleep. I’d agree except she’s still alert and happy and eats like a horse every day. She walks with her head tilted and she can hardly see or hear but she’s cuddly and has a good quality of life. I don’t want to keep her alive for my sake, but I just don’t believe it’s her time yet. How old is too old? How will I know?

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Dr. Patty Khuly has a veterinary practice at Sunset Animal Clinic in South Miami.

A: Old age is not a disease. It’s normal and natural and every single dog is different with respect to how they age. Small dogs tend to live longer, it’s true, and while I’ve seen very few live beyond 18, it’s definitely not unheard of. Dogs can enjoy a reasonably good quality of life at this age.

How old is too old?

No age is too old as long as the dog’s quality of life is good. Luckily, we veterinarians have some objective parameters we can use to determine whether a pet’s quality of life is adequate or not. We have a quality of life scale that helps owners put a value on their pet’s comfort based on their levels of pain, anxiety and other factors.

Perhaps the most popular of these scales is the Quality of Life “HHHHHMM” scale owners can look up by themselves at The acronym stands for hurt, hunger, hydration, hygiene, happiness, mobility and “more good days than bad days.”

The scale asks owners to assign a value of 0-10 (10 is ideal) for each of these parameters so owners can assess their pet’s quality of life more objectively. A total over 35 indicates a good enough quality of life.

In my experience, anxiety and disorientation factor most heavily when it comes to happiness. Anxiety is perhaps the biggest factor, followed closely by their ability to recognize their people. When pets become disoriented due to normal geriatric changes, which are amplified by vision and hearing loss, they often eventually lose their ability to enjoy human company.

Which brings me to euthanasia. Now’s the time to consider whether you’d like her to have a peaceful assisted death or a “natural” death. The latter may be uncomfortable to watch and leave you wishing you’d made another decision. Hopefully, the quality of life tool will help tell you when it’s time so you can intervene appropriately, if that’s your wish.

Dr. Patty Khuly has a veterinary practice at Sunset Animal Clinic in South Miami. Her website is Send questions to