Theo Marsh

Senior writer, Canine Years Explained

Theo Marsh is the senior writer at Canine Years Explained. Theo's beat is numbers: aging research, survival curves, biological age clocks, longevity trials, and the specs printed on the products dog owners bring home.

Theo measures before writing. When a box says a purifier suits a standard-size room, Theo runs a tape across the den to see where the room actually lands, and when a study reports a longer life, the article explains what was compared and for how long.

What Theo covers

• Canine aging research
• Dog Aging Project
• Biological age clocks
• Canine survival curves
• Dog longevity trials
• Healthspan in dogs
• Reading pet product specifications

How Theo works

Figures are quoted the way the source reports them, with a note when a study was small or early, and a link to the paper or the product page. Numbers get rechecked whenever a source updates, and corrections go through the Contact and corrections page. Read the full editorial standards.

Puppy Kind articles by Theo

• Puppy Kind Air Purifier: What I Found When I Checked the Size, Power, and Filter Layers
• What Does 216 Square Feet Look Like? Reading the Puppy Kind Box in a Real Room
• What the Room Size on an Air Purifier Box Really Means: ACH, CADR and 8 Real Examples
• Comfort for Older Dogs at Home: A Bolster Bed, Waterproof Layers and Fresh Air by the Bed

Theo writes from lived use under a pen name.