You looked away for 10 seconds in the garden. Now your dog is chewing, you know exactly what it is, and they would like to lick your face about it.
This is common in adolescence. Our disgust is a human value and not one your dog shares, which matters, because it explains why telling them off does not land.
Manage it before you train it
Pick up in the garden straight after every toilet trip, with a torch after dark. Nothing left out means nothing rehearsed.
Go out with your dog rather than sending them out. For 2 weeks, every garden trip is a supervised one.
On walks, spot it early and take a wide arc past. A shorter leash for 20 paces beats a wrestle in a hedge.
Consider a well-fitted headcollar or a 4 foot leash for pass-bys if your dog reaches things before you see them.
For a dog who eats genuinely risky things, a basket muzzle introduced with food over 2 weeks is management, not punishment.
Teach a paid leave it
Indoors, put something boring on the floor. Say your cue once, and feed 3 pieces of cheese the moment your dog turns away.
Do 6 reps and stop. Repeat for 5 days before you use the cue on anything real.
Outdoors, use the cue on worthless things first, so it is not a word your dog only ever hears in an emergency.
Pay for coming away every single time, generously, for as long as this is a problem.
Never punish after the fact
A telling off arrives far too late to teach anything about the decision. What it does teach is swallowing faster and moving away from you, which is a worse problem than the one you started with.
The words all of a sudden matter
If this genuinely appeared out of nowhere, say those words to your vet. Sudden behaviour change warrants a veterinary examination, particularly alongside a change in appetite, weight or stools.
Safety note
Book a veterinary appointment if this started suddenly, or if it comes with weight loss, diarrhoea, vomiting or a change in your dog's stools. Sudden behaviour change warrants a veterinary examination. Call sooner if your dog has eaten the faeces of an animal you do not know and then becomes unwell.
Today's version, in one line: pick up the garden tonight, go out with your dog tomorrow, and do 6 leave-it reps indoors.