My dog is suffering from vomiting and diarrhea! What are the causes, what is the diagnosis, how can I treat it at home, and when should I take him to the vet?

Part 1: Potential Causes of Vomiting and Diarrhea

The causes can be broadly categorized. Identifying the potential cause can help you communicate more effectively with your vet.

A) Dietary Indiscretion or Digestive Upset (Very Common):

Dietary Indiscretion: This is the “garbage gut” or “dietary scavenging.” Eating something they shouldn’t have, such as spoiled food, garbage, table scraps, or getting into the cat’s food.
Sudden Diet Change: Abruptly switching your dog’s food without a gradual transition.
Food Intolerance or Allergy: An adverse reaction to a specific ingredient in their food.

B) Infectious Causes:

Bacterial Infections: Salmonella, E. coli, Campylobacter.
Viral Infections: Parvovirus (especially in unvaccinated puppies), Distemper, Coronavirus.
Parasites: Intestinal worms (roundworms, hookworms), Giardia, Coccidia.

C) Ingestion of Toxins or Foreign Objects:

Toxins: Human medications, toxic plants (lilies, sago palm), antifreeze, pesticides, chocolate, xylitol (a sweetener).
Foreign Bodies: Swallowing non-food items like toys, socks, rocks, or bones that can cause a physical blockage.

D) Underlying Medical Conditions:

Pancreatitis: Inflammation of the pancreas, often triggered by a high-fat meal.
Kidney Disease: The buildup of toxins in the blood can cause gastrointestinal upset.
Liver Disease: The liver’s inability to filter toxins can lead to vomiting and diarrhea.
Inflammatory Bowel Disease (IBD): A chronic condition involving infiltration of inflammatory cells into the intestinal wall.
Certain Cancers: Especially those affecting the gastrointestinal tract.
Stress or Anxiety: Can lead to a condition sometimes called “stress colitis.”

Part 2: The Diagnostic Process (What Your Vet Will Do)

If you take your dog to the vet, the diagnosis will be a process of gathering clues. Be prepared to answer these questions:

History: What is the timeline? How many times has he vomited/had diarrhea? What does the vomit/diarrhea look like (color, consistency, presence of blood or mucus)?
Description of Vomit/Diarrhea:
- Vomit: Yellow/green (bile), undigested food, brown coffee-ground material (digested blood), frothy.
- Diarrhea: Watery, cow-pie consistency, contains blood (hematochezia – red, or melena – black/tarry), mucus.
Your Dog’s Behavior: Is he lethargic, depressed, or still bright and alert? Is he still drinking water? Has he eaten anything unusual? Any recent access to toxins?
Physical Examination: Your vet will check your dog’s weight, temperature, hydration status (skin tenting, gum moisture), abdominal palpation (for pain or foreign objects), gum color, and heart rate.

Based on the history and exam, your vet may recommend diagnostic tests, which could include:

Fecal Exam: To check for parasites.
Bloodwork (CBC/Chemistry): To assess organ function, hydration, and check for infection or inflammation.
Urinalysis: To help evaluate kidney function and hydration.
X-rays (Radiographs): To look for foreign objects or blockages.
Abdominal Ultrasound: For a more detailed look at the gastrointestinal organs.

Part 3: Home Care (For MILD Cases Only)

Only attempt home care if your dog is:

An adult (not a puppy or senior).
Otherwise bright, alert, and responsive.
Still drinking water.
Has no other serious symptoms listed in “Part 4.”

Step 1: Withhold Food (Gut Rest)

Withhold all food for 12-24 hours. Do not withhold food for puppies, small breed dogs, or for more than 12 hours without consulting your vet, as they are prone to low blood sugar.

Step 2: Encourage Small Amounts of Water

Dehydration is the biggest immediate risk. Offer small amounts of fresh, clean water frequently. You can also offer ice cubes to lick.
If your dog vomits after drinking water, wait an hour and try again with even smaller amounts (a few teaspoons at a time for a medium-sized dog).

Step 3: Introduce a Bland Diet

After the 12-24 hour fasting period, if the vomiting has stopped, you can introduce a bland diet.
Common options: Boiled, skinless, boneless chicken breast or lean ground beef mixed with plain, boiled white rice or plain pumpkin (not pie filling). The ratio should be about 1:3 (meat to rice/pumpkin).
Feeding: Offer a small amount (e.g., a few tablespoons for a medium dog). If he keeps it down for 2-4 hours, offer another small meal. Feed small, frequent meals for the next few days.

Step 4: Gradual Transition Back to Regular Food

After 2-3 days of a bland diet with no vomiting or diarrhea, you can gradually start mixing his regular food back in over 2-3 days.

What to Avoid:

Do not give any human anti-vomiting or anti-diarrhea medications unless specifically instructed by your veterinarian. Many are toxic to dogs.

Part 4: When to Take Your Dog to the Vet IMMEDIATELY (Red Flags)

This is the most critical part. Contact your veterinarian or an emergency clinic immediately if you notice any of the following:

Vomiting or Diarrhea that is Continuous or Severe: Multiple episodes in an hour, or persistent for more than 24 hours in a mild case.
Blood in Vomit or Diarrhea: This is always a reason to call the vet. Fresh red blood or a dark, coffee-ground appearance in vomit, and red or black, tarry stools are serious.
Suspicion of Ingesting a Toxin or Foreign Object: If you even suspect your dog ate something toxic (chocolate, medication, a plant) or a foreign object (toy, sock), do not wait for symptoms.
Lethargy, Depression, or Weakness: If your dog is unusually tired, weak, or unresponsive.
Signs of Pain: Whining, trembling, a hunched back, or a tense abdomen.
Distended or Bloated Abdomen: This can be a sign of the life-threatening condition GDV (bloat), especially in large, deep-chested breeds.
Pale or White Gums: This can indicate shock or internal bleeding.
Inability to Keep Water Down: If your dog vomits immediately after drinking water, he will become dehydrated quickly.
A Pre-existing Medical Condition: If your dog has diabetes, kidney disease, is very young, or is a senior.
No Improvement: If home care for 24 hours does not lead to any improvement.

Summary and Final Recommendation

Vomiting and diarrhea are signs, not a disease themselves. While many cases are self-limiting and resolve with simple home care, they can rapidly escalate into a life-threatening situation due to dehydration and electrolyte imbalances.

My professional advice is to closely monitor your dog using the guidelines above. When in doubt, it is always safer and more prudent to have your dog evaluated by a veterinarian. It is far better to have a simple problem checked out than to wait until a minor issue becomes a major crisis.

I hope your dog feels better soon. Please do not hesitate to seek professional care.

Disclaimer:

This information is for educational purposes and is not a substitute for professional veterinary medical advice, diagnosis, or treatment. If your dog is severely ill or you are unsure, always err on the side of caution and contact your veterinarian immediately.