If your dog is vomiting, has diarrhea, is shaking, seems lethargic, or has stopped eating, it can be hard to know how serious it is. This guide explains what each symptom may mean, which warning signs require urgent care, and when it’s safe to monitor your dog at home.

These are among the most common reasons pet owners contact a veterinarian, and knowing the difference between a mild issue and a medical emergency can protect your dog’s health.

 

Quick Reference: Dog Symptoms and When to Get Help

Use this as a general guide. When in doubt, always contact your veterinarian.

• Vomiting once, dog acting normal → Monitor at home; call your vet if it recurs
• Vomiting repeatedly or can’t keep water down → Call vet or seek urgent care
• Diarrhea under 24 hours, dog active → Monitor; try a bland diet (boiled chicken and rice)
• Bloody diarrhea or diarrhea with vomiting → Veterinary care needed
• Shaking with other symptoms → Call vet; may indicate pain, toxin, or neurological issue
• Not eating for more than 24 hours → Consult your veterinarian
• Bloated or swollen abdomen → Emergency: seek care immediately

 

Dog Vomiting

Vomiting is one of the most common symptoms in dogs. While it often results from something minor, like eating too fast or a brief stomach upset, it can also signal a more serious underlying condition.

Common causes of vomiting in dogs

• Eating spoiled food, garbage, or a foreign object
• Sudden diet change
• Intestinal parasites
• Gastrointestinal infection or inflammation
• Pancreatitis
• Toxin or medication ingestion
• Motion sickness

 

Dogs vomiting white foam or yellow bile typically do so on an empty stomach. This can be harmless (hungry dog) or may indicate acid reflux, gastritis, or bilious vomiting syndrome.

When vomiting requires veterinary care

Contact your veterinarian if your dog:

• Vomits more than once or twice in a 24-hour period
• Cannot keep water down
• Appears lethargic, weak, or unresponsive
• Has vomiting along with diarrhea
• May have eaten a toxic substance or foreign object
• Has blood in the vomit

 

If your dog is experiencing vomiting reach out to your primary care veterinarian to make an appointment for an assessment. If symptoms are severe or continue to worsen your pet may require an urgent or emergency evaluation.

Call for Emergency Veterinary Services

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Dog Diarrhea

Diarrhea in dogs is extremely common and ranges from a minor dietary upset to a sign of serious illness. Understanding the cause helps determine the right level of care.

Common causes of diarrhea in dogs

• Dietary indiscretion (eating something unusual or spoiled)
• Sudden change in food
• Stress or anxiety
• Intestinal parasites (giardia, roundworms, hookworms)
• Bacterial or viral infections
• Inflammatory bowel disease (IBD)
• Food intolerance or allergy

 

When to call a veterinarian for dog diarrhea

Mild diarrhea lasting less than 24 hours in an otherwise healthy, active dog can often be managed at home with a bland diet. Seek veterinary care if your dog:

• Has diarrhea lasting more than 24–48 hours
• Has blood or mucus in the stool
• Is also vomiting
• Seems lethargic, weak, or dehydrated
• Is a puppy, a senior dog, or has underlying health conditions

 

Signs of dehydration include dry or tacky gums, sunken eyes, and skin that doesn’t spring back when gently pinched. Dehydrated dogs need prompt veterinary attention.

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Dog Shaking or Trembling

Occasional shaking can be normal. Dogs shiver when cold or excited, and some small breeds are prone to trembling. But shaking that comes on suddenly or is paired with other symptoms is a reason to call your vet.

Possible causes of shaking in dogs

• Pain or injury
• Fever
• Anxiety or fear
• Toxin ingestion (xylitol, chocolate, grapes, certain medications)
• Neurological conditions or seizure activity
• Distemper virus or other infections
• Hypoglycemia (low blood sugar), especially in small dogs
• Generalized weakness or illness

 

Shaking combined with vomiting, lethargy, loss of balance, or collapse may indicate a medical emergency. Do not wait to seek care if multiple symptoms appear together.

Call for Emergency Veterinary Services

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Dog Lethargy

A lethargic dog seems unusually tired, sluggish, or uninterested in activities they normally enjoy, including walks, play, food, or interaction. They may sleep more than usual or seem hard to rouse.

Common causes of lethargy in dogs

• Infection (bacterial, viral, or fungal)
• Fever
• Dehydration
• Gastrointestinal illness
• Pain from injury, dental disease, or internal conditions
• Toxin exposure
• Anemia or blood loss
• Organ dysfunction (liver, kidney, or heart disease)

 

If your dog is lethargic and not eating, or lethargic with vomiting or diarrhea, prompt veterinary evaluation is recommended. These combinations are commonly associated with gastrointestinal illness, systemic infection, or pain.

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Dog Not Eating (Loss of Appetite)

A dog refusing food, especially one that’s usually food-motivated, is one of the earliest signs that something is wrong. The medical term is anorexia, and it should not be dismissed if it lasts more than 24 hours.

Reasons dogs stop eating

• Nausea or upset stomach
• Dental pain or oral disease
• Infection or fever
• Internal pain
• Stress, anxiety, or environmental change
• Systemic illness (kidney disease, liver disease, cancer)
• Side effect of medication

 

If your dog skips one meal but otherwise seems bright and alert, you can monitor for a few hours. If your dog has not eaten for more than 24 hours, or is refusing food alongside other symptoms, contact your veterinarian.

 

Dog Bloated Stomach: Know the Warning Signs

A visibly swollen or distended abdomen may indicate gastric dilatation-volvulus (GDV), a life-threatening condition sometimes called bloat. GDV occurs when the stomach fills with gas and twists on itself, cutting off blood supply. Without treatment, it can be fatal within hours.

Emergency signs of bloat (GDV) in dogs

• Swollen, hard, or visibly distended abdomen
• Unproductive retching: attempting to vomit with nothing coming up
• Restlessness, pacing, or obvious distress
• Excessive drooling
• Rapid or labored breathing
• Weakness, collapse, or pale gums

 

GDV is most common in large, deep-chested breeds such as Great Danes, German Shepherds, Standard Poodles, and Weimaraners. It can occur in any dog.

If you suspect bloat, do not wait. Contact an emergency veterinarian immediately.

Call for Emergency Veterinary Services

 

When Multiple Symptoms Occur Together

A single mild symptom often resolves on its own. But when two or more symptoms appear at the same time, the risk of a serious underlying condition increases significantly.

Symptom combinations that require veterinary care

• Vomiting and diarrhea together
• Vomiting and lethargy
• Shaking with weakness or inability to stand
• Not eating combined with lethargy
• Any symptom combined with a bloated abdomen
• Any symptom in a puppy under 6 months or an elderly dog

Do not wait to see if symptoms improve on their own when multiple warning signs are present. Rapid deterioration is possible, especially in puppies, seniors, or small-breed dogs.

 

When to Visit a Primary Care Veterinarian

Not every symptom requires an emergency visit. A primary care veterinary appointment is appropriate when your dog:

• Vomits once but otherwise acts normal and is eating and drinking
• Has mild diarrhea that started within the last 24 hours and is otherwise active
• Shows minor changes in appetite without other symptoms
• Appears mildly uncomfortable but is stable
• Has recurring digestive issues you want evaluated

 

Primary care veterinarians can run diagnostic tests, prescribe treatment, and help you understand the root cause of your dog’s symptoms. Many issues that seem worrying are very manageable when caught early.

Find Your Nearest Primary Care Location

Find Your Nearest Urgent Care Location

 

When to Seek Emergency Veterinary Care

Go directly to an emergency veterinary clinic, or call ahead while en route, if your dog:

• Is vomiting repeatedly and cannot keep water down
• Collapses or becomes extremely weak
• Has a visibly swollen or hard abdomen
• Is trembling or shaking along with weakness or loss of coordination
• Shows signs of severe dehydration (dry gums, sunken eyes, extreme weakness)
• May have eaten a toxin, medication, or foreign object
• Has blood in vomit or stool
• Has not eaten or drunk water in more than 24 hours and seems unwell

 

Pieper Memorial Veterinary Center provides 24/7 emergency and specialty care for pets throughout Connecticut. Emergency teams are equipped to stabilize and diagnose serious conditions quickly.

Call for Emergency Veterinary Services

 

Keeping Your Dog Safe

Changes in digestion, appetite, energy level, or behavior are often the earliest signs that something is wrong. Trusting your instincts as a pet owner matters. If your dog does not seem like themselves, it’s worth a call to your vet.

If your dog develops symptoms such as vomiting, diarrhea, shaking, lethargy, loss of appetite, or abdominal bloating, acting promptly can prevent minor issues from becoming serious ones.

When in doubt, contact a veterinarian. Even a brief phone consultation can help you decide the safest next step for your pet.