Mustard
CautionMustard is not a poison with a known lethal dose, but the isothiocyanates in mustard seed irritate the mouth and stomach, and many blends carry garlic or onion powder. A lick usually means drooling and gagging; the hot dog under it is the bigger issue.
This food guide has not been reviewed by a veterinarian. It summarises general information from sources and should not be used to decide whether a food is suitable for an individual dog or to assess an emergency.
Check before feeding
Check the precautions before sharing
Risk depends on preparation, ingredients or amount. Read the precautions below; body weight alone cannot establish a safe portion.
Signs and health concerns
This list includes both observable signs and conditions identified through examination or testing. It cannot establish the cause or whether an exposure is safe.
- Drooling
- Mouth irritation
- Gagging
- Vomiting
- Diarrhoea
- Abdominal pain
- Loss of appetite
- Lethargy
More about this food
The bite in mustard comes from the seed. Mustard seeds contain glucosinolates, and when the seed is crushed and wet they convert to isothiocyanates -- the same volatile compounds that clear your sinuses. They are mucosal irritants, and a dog that licks mustard off a plate usually shows that first: heavy drooling, lip smacking, pawing at the mouth, retching. Larger amounts move on to vomiting, diarrhea and abdominal discomfort.
Mustard is not in the grape or xylitol category. There is no established lethal dose, and a dab off a ballpark hot dog is not an emergency. But "not toxic" is not "go ahead." The AKC's guidance on feeding vegetables is blunt about condiments: never add seasoning or salt, and never feed anything cooked with onions or garlic, because those are toxic to dogs. Mustard is frequently both of those things in one bottle.
Read the specific label. Honey mustard is mostly sugar. Dijon is made with white wine and some brands add garlic. Whole-grain, spicy brown, and barbecue-style mustard sauces very often list onion powder or garlic powder. Merck notes that dehydrated flakes and powders are the particularly hazardous forms of Allium, that garlic is 3-5 times more potent than onion, and that hemolysis typically appears 3-5 days after ingestion -- so a dog that ate a garlic-containing mustard in quantity can look fine the next morning and still be developing anemia. Sodium is the smaller worry here: a teaspoon of yellow mustard has roughly 55-65 mg, nowhere near Merck's salt toxicosis threshold of 2-3 g/kg of sodium chloride.
In practice the mustard is rarely what the dog swallowed. It came on a hot dog, a deli sandwich, a pretzel, or a plate of potato salad, and that package of fat and salt is what will make the dog sick. Note what was eaten and how much, and check the ingredient panel for garlic and onion. Drooling and a couple of gags usually settle within a few hours. Call your veterinarian if vomiting repeats, if there is blood in the stool, if the belly is painful, or if your dog goes quiet and flat -- and call anyway if a garlic-heavy product was eaten in quantity. The ASPCA Animal Poison Control Center is at (888) 426-4435. Do not induce vomiting at home.
Frequently asked questions
- My dog ate a hot dog with mustard on it. What now?
- The mustard will mostly cause drooling and maybe a gag or two; the hot dog's fat and sodium are the larger problem. Offer water, skip the next meal only if your vet says to, and call if vomiting repeats or the belly looks painful. Check the mustard label for garlic or onion powder.
- Is mustard actually toxic to dogs?
- It is an irritant rather than a poison with a known lethal dose. The isothiocyanates from mustard seed inflame the mouth and stomach lining, which is why vomiting and diarrhea follow bigger amounts. That is reason enough not to offer it deliberately.
- What about mustard greens or whole mustard seeds?
- Plain cooked mustard greens are a different thing from the condiment and are not a poisoning risk, though the greens are usually cooked with bacon fat, onion or garlic in American kitchens. Whole seeds in quantity irritate the gut the same way prepared mustard does.