Mustard is a common condiment on burgers, hot dogs, and sandwiches. Its bold flavour—tangy, spicy, or mildly sweet—makes it popular in many households. However, mustard is unsafe for dogs.
This article covers why mustard harms dogs, symptoms to watch for, and safe ways to add flavor to your dog’s meals.
Can Dogs Have Mustard?
No, dogs should not eat mustard. Mustard seeds are toxic to dogs. Even a small lick can upset your dog’s stomach; larger amounts may cause serious health issues. Keep mustard and related products out of reach of your dog.
Why Is Mustard Unsafe for Dogs?
Mustard is unsuitable for dogs primarily due to compounds naturally present in mustard seeds. According to holistic veterinarian Kathryn Dench, these seeds contain glucosinolates—plant chemicals that can be harmful to dogs when ingested.
Glucosinolates break down into isothiocyanates in the body. These compounds irritate the gut and may cause:
Mustard seeds also contain goitrogens, which may interfere with normal thyroid function if consumed in larger quantities or over time. This can affect your dog’s hormonal balance and overall well-being.
Because of these risks, it’s safest to completely avoid feeding mustard or foods containing mustard to your dog.
Are All Types of Mustard Dangerous for Dogs?
Yes. All varieties of mustard are unsafe for dogs, including:
- Yellow mustard
- Dijon mustard
- English mustard
- Ground mustard
- Wholegrain mustard
- Honey mustard
In addition to mustard seeds, many of these products contain ingredients unsuitable for dogs, including sugar, vinegar, salt, and spices.
Signs of Mustard Toxicity in Dogs
If your dog has ingested mustard, watch closely for the following symptoms:
- Vomiting
- Diarrhea
- Excessive drooling
- Reduced appetite
- Signs of abdominal discomfort or pain
If you notice any of these symptoms, contact your vet promptly for advice.
Are Other Condiments Safe for Dogs?
Mustard is a clear no for dogs, but what about other popular condiments?
Most commercial ketchup brands contain added sugar, salt, and seasonings like onion or garlic powder, which can be harmful to dogs. Mayonnaise is not toxic, but it is high in fat and may cause digestive upset or contribute to weight gain, especially in dogs with sensitive stomachs.
Avoid sharing human condiments with your dog.
Dog-Safe Ways to Add Flavor to Meals
Dogs can enjoy tasty meals with pet-safe options, such as:
- Homemade dog-safe gravy
- Plain pumpkin purée
- Unsalted bone broth
- Commercial food toppers and mix-ins designed specifically for dogs
These alternatives add flavor and nutrition without risking your dog’s health.
Key Takeaway
Mustard seeds can harm dogs. Watch for digestive symptoms if your dog eats mustard, and contact your veterinarian if any signs appear or worsen.
