Why the stew's fat matters more than oregano
Half a bowl of lamb stew for an 8 kg dog contains far more animal fat than problematic herb quantities. Oregano in cooked dishes is typically measured in fractions of a teaspoon per serving—your Shih Tzu likely ingested under 0.3 grams of the herb. The real concern with rich stews is pancreatitis risk from sudden high-fat intake, not the negligible seasoning amounts.
Cooked oregano undergoes chemical changes that make it gentler than raw herbs. Heat alters the essential oil composition, reducing the compounds that could irritate canine digestion. What remains is primarily flavor, not concentrated plant chemicals. Monitor for stew-related issues like loose stools rather than oregano-specific reactions.
Portion size relative to your dog's weight
An 8 kg dog's stomach can handle moderate amounts of seasoned foods better than tiny toy breeds. Half a bowl (assuming roughly 100–150 ml) spreads the oregano across enough food volume to prevent localized irritation. Compare this to a scenario where a dog licked pure oregano powder—the stew's bulk dilutes the herb's potential effects.
The timing of ingestion matters too: if your dog ate the stew slowly over minutes rather than gulping it, that allowed saliva to begin breaking down the food. Rapid eaters might show more digestive upset simply from the speed of consumption, unrelated to the oregano content. Either way, the herb itself isn't the primary concern here.
When to watch for digestive responses
Rich foods often cause symptoms within 4–8 hours as the stomach empties into the small intestine. Look for signs like stomach gurgling, lip-licking, or restlessness that might indicate mild discomfort. One episode of loose stools in the next 24 hours is common after dietary indiscretion but doesn't necessarily reflect oregano sensitivity.
True allergic reactions to oregano are extremely rare in dogs. More likely would be intolerance to another stew ingredient like onions or garlic (which are toxic). Since you specified oregano as the concern, rest assured that this herb alone wouldn't cause systemic reactions in the amount consumed.
Handling future seasoned-food incidents
Dogs that enjoy human foods often seek out similar smells again. To prevent repeat performances, store leftovers securely and consider offering plain cooked meats without sauces when sharing. The oregano isn't dangerous, but habitual rich food intake can lead to obesity or pancreatitis over time.
If your dog frequently scavenges seasoned foods, training a solid "leave it" command helps more than worrying about specific herbs. For one-time incidents like this stew episode, withholding food for 4–6 hours then offering a bland diet (boiled chicken + rice) can ease any minor digestive turbulence without medical intervention.
The full verdict, portion guidance and serving notes are collected on the Oregano food facts page.