How do I know if my dog has bad breath from dental problems?

A healthy dog's breath is mild rather than pleasant, but it should not make you want to turn away. A sudden, strong odor that smells rotten, sour, or metallic is a different category and usually signals plaque, tartar, or gum irritation rather than something temporary.

Lift the lip and look along the gumline, especially on the back teeth, for a yellow or brownish film, which is tartar building up. Red or swollen looking gums alongside bad breath add weight to the idea that this is a dental issue rather than just diet related.

Breath that has been consistently bad for more than 2 to 3 weeks, especially if it is worsening rather than staying stable, is worth a dental check rather than assuming it will pass. Catching buildup early, before it progresses further, generally means a simpler fix.

Lifting the lip for a 10 second look and sniff once a week, even when brushing regularly, builds a mental baseline of what normal looks and smells like for your specific dog, which makes any gradual change, worsening breath, a new patch of tartar, far easier to notice than if you only check occasionally.

Comparing your dog's breath right after a meal, which naturally smells stronger temporarily, against its breath a couple of hours later gives a more accurate read of the underlying baseline than judging immediately after eating, when almost any dog's breath is briefly less pleasant.