The Studies Behind the Numbers You Keep Hearing — Research Index

Last updated: August 15, 2026

"Eight in ten dogs over three have periodontal disease." "Senior dogs need more protein." Certain numbers circulate among owners and keep getting repeated. Going back to look, we often could not find the number in the original study at all — or found the researchers themselves noting that it does not stretch that far.

The articles

• Is an oxygen cage proven to help?

  There is research on acute care in hospitals. For the oxygen cages families rent for home use, we found no study testing the thing itself.

  A read for the daily care stage

• Can more walks prevent dog dementia?

  Dogs that move less really do have more dementia. But the researchers added that the same numbers appear if the order runs the other way.

  A read for the daily care stage

• Has she stopped jumping up because of her age?

  Of 100 cats over 12, 90 had joint changes on X-ray. Only 4 had been noticed.

  A read for the daily care stage

• Should senior dogs be fed extra?

  Dogs fed 25% less of the same food lived 1.8 years longer. Joint pain also showed up a year and a half later.

  A read for the everyday life stage

• The dog left behind has lost her spark

  Of 426 owners, 86.6% reported changes. For three in ten, it settled within two months.

  A read for the after the goodbye stage

• Do big dogs live less because they are big?

  Lifespan drops about a month per 2kg of body weight. They do not die early so much as age faster.

  A read for the everyday life stage

The range a number covers

Every study has a boundary. What was found in 48 Labradors was found in 48 Labradors; it is not a statement about all dogs. A study that counted cats after they arrived at a clinic does not represent cats doing fine at home. Strip that away and keep only the number, and it can turn into material for blaming yourself.

What to look at when you meet a number

1. Who was counted

"Nine in ten senior cats" means something entirely different depending on whether the cats were counted at a clinic or picked at random from homes. The first group is weighted toward cats brought in because something was wrong, so of course more findings turn up than in cats at home.

A skewed sample does not make a study worthless. It only changes how far the finding can be extended.

2. A snapshot, or a study that followed along

A study that captures one moment in time (a cross-sectional study) can show that two things occur together, but not which came first. "Dogs that do not move have more dementia" might mean lack of exercise caused it, or it might mean the dementia is why they stopped moving. The same number reads both ways.

A study that followed the same animals for years (a longitudinal study) can speak to sequence. Those take time and money, so there are fewer of them.

"Associated with" and "causes" are different words. Headlines swap them constantly.

3. How many conditions differed

Most food comparisons look at groups that ate different products. Ingredients, formulation, kibble size, price, how attentive the owner is — many conditions differ at once, so there is no way to isolate what did the work.

When a study changes one thing only, like feeding the same food in different amounts, the result means something specific. That is one of the things worth checking as you read.

What you can get here is how far a given study reaches, and no further. It cannot settle treatment or medication. Use it as one piece of material when you talk to your own vet.

If you spot an error

If you notice a misreading of a paper or a mixed-up citation, please write to [email protected]. We will check it and correct the article with a dated note.