Dog Has Bad Gas and Not Eating: Should You Be Worried?

Dog Has Bad Gas and Not Eating: Common Causes 

1. Dietary Indiscretion 

Dogs are naturally curious eaters. If your dog got into the trash, snuck table scraps, or chewed on something unusual during a walk, it could trigger dietary indiscretion—a fancy term for eating the wrong thing.

This often causes:

• Bad-smelling gas due to fermentation of unfamiliar food in the gut

• Nausea or vomiting

• Temporary refusal to eat

• Diarrhea or soft stool

Common culprits include fatty foods, spoiled leftovers, dairy, or high-fiber scraps. The smell can be overpowering, and your dog may skip meals for a day or more while their system tries to recover.

2. Sudden Change in Diet

Switching your dog’s food too quickly can throw off the balance of gut bacteria, leading to gas and digestive upset. Even high-quality foods may cause issues if introduced abruptly.

Symptoms include:

• Loud stomach gurgling (borborygmi)

• Sulfur-like flatulence

• Decreased appetite or food refusal

• Soft or loose stool

Transitioning to a new food should take 7–10 days. Skipping this step may lead to a “food strike” or excessive gas as your dog’s system adjusts.

Related: Dog vomiting and not eating (Causes and when to worry)

3. Food Intolerances or Allergies

Some dogs develop food sensitivities, especially to proteins like chicken, beef, or grains such as corn or wheat. These sensitivities can cause:

• Chronic gas or bloating

• Skin irritation or ear infections

• Diarrhea or mucus in the stool

• Appetite loss due to ongoing stomach discomfort

The bad gas may persist even with a regular diet if the food contains something your dog is sensitive to.

Hypoallergenic diets or elimination trials can help isolate the trigger.

4. Pancreatitis

Pancreatitis—inflammation of the pancreas—is a painful and potentially serious condition often triggered by fatty foods or systemic illness. It leads to:

• Loss of appetite

• Vomiting and abdominal pain

• Gas or bloating

• Lethargy and dehydration

Dogs with pancreatitis may lie in a “prayer position” (front legs stretched forward, hips up) to relieve pain.

Flatulence may be a secondary symptom due to poor digestion or fermentation of food in the gut.

This condition can be life-threatening and needs prompt veterinary care.

Related: Dog diarrhea and not eating (Causes and when to worry) 

5. Intestinal Parasites

Parasites like giardia, whipworms, and hookworms can disrupt digestion and lead to foul-smelling gas. Dogs may contract parasites through contaminated water, soil, or feces.

Other signs include:

• Intermittent diarrhea or mucus in the stool

• Bloated belly or “pot-bellied” appearance

• Sudden loss of appetite

• Dull coat and weight loss

Gas caused by parasites is typically sulfuric or rotten-smelling. Puppies and dogs not on parasite prevention are most at risk.

6. Small Intestinal Bacterial Overgrowth (SIBO)

An imbalance of bacteria in the small intestine can result in excessive fermentation, producing bad gas, bloating, and food aversion. Dogs with SIBO may show:

• Gurgling stomach

• Excess flatulence

• Intermittent appetite

• Loose stools or diarrhea

SIBO can result from other conditions like IBD or food sensitivities. Probiotic therapy and dietary changes are often part of treatment.

7. Inflammatory Bowel Disease (IBD)

IBD causes chronic inflammation in the gastrointestinal tract, leading to poor nutrient absorption and frequent GI upset. Dogs with IBD often show:

• Bad-smelling gas and bloating

• Reluctance to eat

• Vomiting or diarrhea (sometimes with mucus)

• Weight loss or poor coat condition

Because the gut lining is inflamed, even normal food can irritate the system. IBD is often diagnosed through biopsy and treated with prescription diets, steroids, or immunosuppressants.

• Related: Dog back legs weak and not eating (What it means)

8. Kidney or Liver Disease

Less commonly, a systemic illness like kidney or liver disease can lead to foul-smelling breath and gas due to the body’s inability to eliminate toxins properly. In these cases, you may notice:

• Ammonia or metallic odor

• Nausea and vomiting

• Appetite loss or refusal to eat

• Weakness or lethargy

Blood tests are needed to confirm kidney or liver involvement. These cases are often more serious and require long-term management.

What to Do If Your Dog Has Bad Gas and Isn’t Eating

If your dog is stable and not showing signs of distress:

• Withhold food for 12 hours, then offer bland food like boiled chicken and rice

• Avoid high-fat or unfamiliar treats, which may worsen symptoms

• Encourage hydration with water or low-sodium broth

• Give a dog-safe probiotic if your vet approves

• Walk your dog gently to stimulate digestion and relieve trapped gas

Do not give over-the-counter gas medications unless advised by your vet.

When to Call or Visit Your Vet

Seek veterinary attention if your dog:

• Refuses food for more than 24 hours

• Has persistent vomiting or diarrhea

• Shows signs of pain, panting, or restlessness

• Has a distended or hard belly

• Acts lethargic, shaky, or collapses

Your vet may conduct a fecal test, abdominal X-rays, or blood work to determine the cause. If pancreatitis or an obstruction is suspected, early intervention is critical.

• Read more: Dog not eating and smells bad (Here’s why)

Key Takeaway

When your dog has bad gas and isn’t eating, don’t assume it’s just a passing issue.

While occasional flatulence is normal, persistent foul-smelling gas paired with appetite loss often signals a deeper problem—ranging from a minor dietary upset to a more serious condition like pancreatitis or IBD.

Keep a close eye on your dog’s symptoms, offer gentle care, and reach out to your vet if things don’t improve quickly.

With the right support, your dog can get back to feeling comfortable and enjoying meals again soon.