When your dog is tired and not eating and shaking, it can be an alarming combination of symptoms that points to a potentially serious underlying issue.
While occasional fatigue or appetite changes may not be a cause for concern, when these signs appear together with shaking, it often indicates that something is wrong with your dog’s health.
We outline the common reasons why a dog is tired and not eating and shaking, when it becomes an emergency, and what steps you should take to help your furry friend recover.
Here’s Why Your Dog Is Tired and Not Eating and Shaking
A dog is tired and not eating and shaking due to various underlying health or emotional issues that affect their energy levels, appetite, and neurological or physical stability. These symptoms often occur together as a result of the body responding to stress, illness, or discomfort.
Common causes include illness or infection, pain or injury, gastrointestinal upset, poisoning or toxin exposure, stress and anxiety, hypoglycemia, medication side effects, heatstroke, and chronic conditions common in aging dogs.
Identifying the root cause quickly is important, as these signs often signal that the dog’s body is under distress and requires veterinary attention.
Dog Tired and Not Eating and Shaking: Common Causes
Illness or Infection
One of the most common reasons why a dog is tired and not eating and shaking is illness.
This can range from a minor virus to a severe systemic infection.
Infections often cause fatigue as the dog’s immune system uses energy to fight the invading pathogens.
This leaves your dog feeling weak and disinterested in food.
Shaking may occur as a result of fever, chills, or pain associated with the infection.
Common illnesses that cause these symptoms include:
Canine parvovirus
Distemper
Leptospirosis
Tick-borne diseases like Lyme disease
Infections typically cause your dog to feel drained, while inflammation and fever lead to shaking and appetite loss.
Related: Dog shaking and not eating (Causes and what to do)
Pain or Injury
Pain is another reason why a dog is tired and not eating and shaking.
Dogs experiencing internal pain (such as pancreatitis or gastrointestinal discomfort) or external injuries may become lethargic and refuse to eat.
Shaking is often a subtle sign of discomfort or pain.
In cases of musculoskeletal injuries or arthritis, especially in older dogs, fatigue may result from reduced mobility.
The effort of moving around becomes too painful, and your dog may prefer to lie down most of the time.
If the pain is intense, it may also cause them to tremble.
Signs to look for include:
Limping
Vocalizing when touched
Changes in posture
Avoiding movement or stairs
Gastrointestinal Upset
When a dog is tired and not eating and shaking, gastrointestinal issues like gastritis, intestinal blockage, or bloat may be to blame.
GI discomfort can make a dog reluctant to eat, and the effort of dealing with pain, gas buildup, or nausea can lead to trembling and fatigue.
If your dog has vomited or had diarrhea in addition to these symptoms, this could be a sign of an upset stomach.
Dogs who ingest something they shouldn’t—spoiled food, toys, foreign objects—may develop GI distress quickly.
Gastrointestinal issues may also lead to dehydration, which exacerbates tiredness and weakness.
Poisoning or Toxin Exposure
Toxins can cause acute symptoms, especially if your dog is tired and not eating and shaking within a short time frame.
Poisoning can affect the nervous system, digestive tract, or kidneys, leading to a combination of symptoms including:
Lethargy
Tremors
Vomiting
Seizures
Drooling
Common sources of poisoning include:
Chocolate
Grapes or raisins
Xylitol (found in sugar-free gum)
Human medications
Rodenticides or pesticides
Prompt treatment is crucial if poisoning is suspected. Even a small amount of some toxins can be fatal.
Stress and Anxiety
Sometimes, when a dog is tired and not eating and shaking, the root cause may be emotional rather than physical.
Dogs under stress due to changes in routine, loud noises (such as fireworks or thunderstorms), travel, or separation anxiety may develop these symptoms.
Stress causes a surge of adrenaline and cortisol, which can:
Suppress appetite
Cause shaking or trembling
Lead to restlessness or pacing, followed by exhaustion
Chronic anxiety can result in long-term fatigue as well as decreased interest in food or play.
Pay attention to your dog’s environment and recent changes that might have caused distress.
Related: Old dog not eating and shaking and lethargic (Here’s why)
Hypoglycemia
Low blood sugar levels, or hypoglycemia, especially in small breeds or puppies, may lead to episodes where a dog is tired and not eating and shaking.
If your dog hasn’t eaten in several hours or is ill, their blood sugar may drop.
Signs of hypoglycemia include:
Weakness or collapse
Shivering or tremors
Confusion or disorientation
Seizures in severe cases
This is a medical emergency and needs to be addressed quickly to avoid life-threatening complications.
Medication Side Effects
If your dog recently started a new medication and is tired and not eating and shaking, side effects may be the culprit.
Certain drugs, including painkillers, antibiotics, and anti-anxiety medications, can impact your dog’s appetite, energy levels, and neurological stability.
Some side effects to look for:
Sedation or extreme drowsiness
Gastrointestinal upset
Muscle tremors
Coordination issues
Always discuss new medications with your vet, especially if symptoms appear suddenly after beginning a treatment.
Heatstroke or Overheating
During warm weather, heat exhaustion or heatstroke can also explain why your dog is tired and not eating and shaking.
Dogs can’t sweat like humans and rely on panting to regulate their temperature.
If your dog has been exposed to high temperatures or exercised in the heat, watch for:
Heavy panting
Drooling
Shaking
Vomiting
Collapse
Heatstroke is life-threatening and requires immediate cooling and veterinary care.
Aging and Underlying Chronic Conditions
In older dogs, the combination of fatigue, appetite loss, and trembling could point to underlying chronic conditions such as:
Heart disease
Kidney failure
Liver problems
Cushing’s disease
Diabetes
When an old dog is tired and not eating and shaking, it’s often a red flag of more serious ongoing health decline.
Senior dogs are also more prone to joint pain and cognitive dysfunction, which may contribute to these symptoms.
What To Do If Your Dog Is Tired and Not Eating and Shaking
If you notice that your dog is tired and not eating and shaking, don’t panic—but do take the symptoms seriously.
Here’s what to do next:
1. Monitor closely
Watch for changes in your dog’s condition over 24–48 hours.
Keep a note of any additional symptoms such as vomiting, diarrhea, limping, or unusual behavior.
2. Check for environmental factors
Did your dog eat something they shouldn’t?
Were they exposed to high heat or a new medication?
Try to identify any recent changes or exposures.
3. Encourage hydration
Offer clean water to prevent dehydration.
If your dog refuses to drink or vomits water, seek veterinary care.
4. Offer bland food
If your dog hasn’t eaten, try a bland diet like boiled chicken and rice.
Avoid forcing food, but note whether they show interest in anything.
5. Seek veterinary help
If the symptoms persist beyond 24 hours—or worsen at any point—take your dog to the vet. Immediate attention is necessary if:
Your dog is vomiting or has diarrhea
They are completely unresponsive
There’s blood in their vomit or stool
They collapse or have seizures
They may have ingested toxins
Key Takeaway
A dog is tired and not eating and shaking for many possible reasons, ranging from emotional stress and medication side effects to serious illnesses and poisoning.
These symptoms, especially when seen together, should never be ignored.
While occasional tiredness or a missed meal might not be alarming on its own, the addition of shaking indicates discomfort or distress that warrants investigation.
Early intervention can mean the difference between a quick recovery and a prolonged or worsening condition.
Always err on the side of caution—your dog depends on you to notice the signs and get them the help they need.