Seeing your dog suffer from diarrhea can be upsetting, and understandably so. It’s messy, uncomfortable, and sometimes a sign of an underlying health issue. At Tempe Lake Veterinary Clinic & Pet Resort, this is one of the most frequent concerns we hear from pet parents: “Why does my dog have diarrhea?”
The truth is, diarrhea is a symptom with a wide range of possible causes, from simple dietary slip-ups to more serious medical conditions. While some cases resolve on their own, others require prompt veterinary attention. That’s why we’ve created this guide: to help you better understand what’s going on and when it’s time to give us a call.
Top Causes of Dog Diarrhea
1. Dietary Indiscretion (“Garbage Gut”)
Dogs are naturally curious and love to explore the world with their mouths. Eating spoiled food, garbage, table scraps, or unknown substances from the yard or sidewalk can irritate their stomach.
Signs to watch for:
- Loose or watery stool
- Mild vomiting
- Still active and eating normally
Mild cases may improve with a bland diet and rest, but worsening symptoms or signs of discomfort should be checked out.
2. Sudden Food Changes
Even high-quality food can cause digestive upset if introduced too quickly. To avoid this, always transition your dog’s food gradually over 7–10 days.
3. Parasites
Intestinal parasites like roundworms, hookworms, giardia, or coccidia are common, especially in puppies, rescue dogs, or those exposed to communal spaces like parks or daycares.
A quick fecal exam can detect most parasites, and treatment is usually straightforward. Some parasites can even be passed to humans, so don’t delay if your dog has persistent diarrhea.
4. Bacterial or Viral Infections
Infectious causes like parvovirus, distemper, salmonella, or campylobacter can trigger severe diarrhea, especially in young or unvaccinated dogs.
Look for:
- Diarrhea with vomiting
- Fever or lethargy
- Rapid decline in condition
These cases are emergencies – contact us immediately if you notice these signs.
5. Food Allergies or Intolerances
Dogs with food sensitivities may experience chronic diarrhea along with:
- Itchy skin or ears
- Chronic ear infections
- Excessive paw licking
Our team can help guide you through elimination diets or recommend prescription food options that soothe your dog’s GI tract.
6. Stress or Anxiety
Travel, boarding, moving homes, or loud noises (like fireworks) can lead to stress colitis, a temporary form of diarrhea caused by anxiety.
Common triggers include:
- New environments
- Thunderstorms
- Separation anxiety
We may recommend calming supplements or medications to help reduce anxiety and prevent recurrence.
7. Chronic Health Conditions
If diarrhea is persistent or recurring, it may be a sign of a deeper issue, such as:
- Inflammatory Bowel Disease (IBD)
- Pancreatitis
- Liver or kidney disease
- Addison’s disease
- Certain cancers
Advanced diagnostics, including bloodwork or imaging, are often needed to get to the root cause.
8. Toxin or Foreign Object Ingestion
Swallowed objects or toxins can irritate the gastrointestinal system or cause dangerous blockages.
Common culprits include:
- Toys or bones
- Grapes, chocolate, xylitol
- Marijuana or vape pens
- Sago Palm, Bufo toads
If your dog has diarrhea along with vomiting, lethargy, or signs of pain, seek emergency care.
9. Vaccine or Medication Reactions
Rarely, dogs may react to a vaccine or new medication. Watch for:
- Diarrhea and vomiting
- Swelling of the face
- Hives or itchiness
- Weakness or collapse
Let us know right away if your dog reacts after receiving a vaccine or medication.
High-Risk Cases: Puppies and Parvovirus
Puppies are particularly vulnerable to parvo and distemper, both life-threatening viral infections.
Symptoms include:
- Bloody diarrhea
- Vomiting
- Lethargy
- Fever
- Neurological signs (with distemper)
Vaccination is crucial for prevention. If you suspect your puppy may be sick, contact us immediately.
When to Call Tempe Lake Veterinary Clinic & Pet Resort
We recommend seeking veterinary care if your dog has:
- Diarrhea lasting more than 24 hours
- Blood in their stool (bright red or black)
- Vomiting along with diarrhea
- Lethargy or signs of abdominal pain
- Refusal to eat or drink
How We Diagnose Diarrhea
We use a variety of diagnostic tools to get to the bottom of your dog’s symptoms:
- Fecal parasite exams
- Giardia and parvo testing
- Comprehensive blood panels
- X-rays or ultrasound imaging
- Disease-specific testing
Treatment Options
Treatment depends on the cause but may include:
- IV fluids to treat dehydration
- Antidiarrheal and anti-nausea medications
- Deworming
- Probiotics and GI-friendly diets
- Hospitalization for severe cases
Your Dog’s Comfort Is Our Priority
At Tempe Lake Veterinary Clinic & Pet Resort, we treat every pet like family. Whether your dog has a mild digestive upset or a more complex condition, we’re here to offer compassionate, expert care. If you’re unsure whether your dog’s diarrhea is something to worry about, give us a call, we’re always happy to guide you.