Shaking or tremors in dogs can be a sign of various neurological or other medical conditions. Below are 10 Medical Conditions that You Can Identify Through Tremors in Dogs:
1. Seizure Disorders (Epilepsy)
Seizure disorders is commonly referred to as epilepsy. These seizures manifest in various ways in dogs, ranging from subtle changes in behavior to dramatic, full-body convulsions. The most common types of seizures involve shaking or jerking movements, loss of consciousness, and involuntary muscle contractions.
Cornell Richard P. Riney Canine Health Center explains that, “this type of seizure is the one where a dog suddenly falls over with violent, jerking spasms affecting all four limbs, paddling, frothing at the mouth, possible loss of bladder and bowel control, and loss of consciousness.”
Seizures also lead to drooling, biting the tongue, and paddling or stiffening of the limbs. The intensity and duration of seizures vary, with some lasting only a few seconds and others continuing for several minutes.
Common symptoms of seizure include:
- Shaking and jerking movements: Involuntary muscle contractions often seen as tremors or spasms.
- Disorientation: After a seizure, dogs experience confusion, disorientation.
- Loss of consciousness: The dog may appear unresponsive and unaware of its surroundings.
- Falling or collapsing: The dog may lose balance and fall to the ground.
- Paddling of the legs: Often seen in generalized seizures.
- Rigid or stiff body posture: The dog’s body may become stiff or tense.
- Drooling or foaming at the mouth: Due to loss of control over the mouth muscles and excessive salivation.
Cause:
Idiopathic Epilepsy: Idiopathic epilepsy is the most common cause of seizures in dogs, particularly in young to middle-aged dogs.
Head Trauma: Dogs that have suffered head trauma, such as from an accident or a blow to the head, can develop seizures as a result of the injury to the brain.
Low Blood Sugar (Hypoglycemia): Hypoglycemia is a common cause of seizures, especially in small breed puppies, toy dogs, or dogs with insulin imbalances.
Liver Disease: Liver disease or liver failure can lead to hepatic encephalopathy, a condition where toxins build up in the bloodstream because the liver cannot detoxify them effectively.
2. Idiopathic Tremor Syndrome
Idiopathic tremors are a condition in which a dog experiences involuntary, rhythmic shaking or tremors in its limbs, head, or the entire body. These tremors are usually continuous or episodic. They can vary in severity, ranging from mild to more pronounced shaking.
Stephanie Phillipps has found in the research that, “All dogs presented with Idiopathic generalized tremors and most experienced concomitant neurological signs (93.3%). 22.7% were hyperthermic and 41.3% had gastrointestinal signs.”
Common symptoms of Idiopathic Tremor Syndrome include:
- Tremors and shaking: The most noticeable symptom are the involuntary shaking or rhythmic movement of the dog’s muscles. Tremors can occur in different parts of the body.
- No associated pain: In most cases, these tremors are not accompanied by signs of pain or distress. The dog may appear generally healthy apart from the shaking.
- Progression: Over time, some dogs may experience an increase in the frequency or intensity of the tremors, although this does not always occur.
- No effect on behavior: The tremors typically do not affect the dog’s behavior, alertness, or ability to perform normal activities such as eating, drinking, or walking.
Cause:
Breed predisposition: Certain dog breeds, such as the Staffordshire Bull Terrier, are more prone to developing idiopathic tremors.
Age-related factors: Idiopathic tremors are more commonly seen in middle-aged to older dog.
Genetic predisposition: There may be hereditary components that make certain dogs more susceptible.
Neurological abnormalities: While the exact pathophysiology is not fully understood, idiopathic tremors may be related to dysfunction in the central nervous system, particularly the cerebellum or other motor-control areas of the brain.
3. Canine Cognitive Dysfunction Syndrome (CDS)
Canine Cognitive Dysfunction Syndrome (CDS) is a condition similar to dementia or Alzheimer’s disease in humans. It primarily affects older dogs and is associated with a progressive decline in brain function.
Sonja Prpar Mihevc and Gregor Majdič found in their research that, “Most common symptoms include disorientation, anxiousness, dogs get easily scared, do not recognize their owner, become aggressive or apathetic, have difficulty controlling the secretion of body fluids, change circadian rhythms and others.”
CDS can result in various behavioral changes, including tremors, disorientation, confusion, and difficulty with coordination. As a result, affected dogs experience challenges in recognizing familiar people, navigating their environment, and performing basic tasks.
Common symptoms of CDS include:
- Shaking and Tremors: affected dogs may exhibit tremors, particularly in their limbs, head, or body.
- Disorientation: Dogs with CDS seem confused or lost, even in familiar surroundings.
- Changes in Behavior: CDS results in significant changes in a dog’s usual behavior. These changes include increased anxiety, irritability, or vocalization.
- Disrupted Sleep Patterns: Dogs with CDS experience altered sleep-wake cycles, leading to restlessness during the night.
- Reduced Activity or Stiffness: Dogs with CDS show reduced interest in activities they once enjoyed, such as walks, playing, or engaging with toys
Cause:
Brain aging: As dogs grow older, their brains experience degenerative changes, including the accumulation of amyloid plaques (similar to those found in human Alzheimer’s disease) and the shrinkage of brain tissues. This can impair memory, learning, and decision-making abilities.
Neurochemical imbalances: The declines of brain’s production of certain neurotransmitters (such as dopamine and serotonin) negatively affect mood, behavior, and cognitive function.
Reduced blood flow to the brain: Decreased circulation in the affects their ability to process information efficiently and maintain coordination.
4. Brain Tumors or Lesions
Tumors or lesions in the brain can significantly disrupt normal neurological function in dogs. These abnormal growths can be either benign or malignant (cancerous). They damage surrounding brain tissues and interfere with essential functions like motor control, balance, and coordination.
SouthEast Veterinary Neurology explains that, “A tumor is an uncontrolled growth of cells within tissue. These abnormal cells create masses that destroy healthy tissue. Therefore, a tumor in the brain will cause brain damage, resulting in serious neurological symptoms.”
Common symptoms of Brain Tumors include:
- Shaking and Tremors: Dogs with brain tumors exhibit tremors or shaking as a result of interference with the brain’s motor control centers.
- Seizures: Brain tumors disrupt the brain’s electrical activity, leading to seizures.
- Difficulty Walking: Tumors in areas of the brain responsible for movement and coordination (like the cerebellum) can cause ataxia (lack of coordination) or unsteady, wobbly walking.
- Vomiting: Increased pressure on the brain due to a growing tumor can lead to vomiting.
- Changes in Behavior: These include aggression, irritability, withdrawal, confusion, and anxiety.
Cause:
Primary Brain Tumors: These tumors originate within the brain itself. Primary brain tumors in dogs are either gliomas or meningiomas.
Secondary Brain Tumors: These are tumors that have spread (metastasized) to the brain from other parts of the body, such as the lungs, mammary glands, or skin. Metastatic tumors can cause more severe symptoms due to their rapid growth.
Benign Growths or Lesions: Not all brain tumors are cancerous. Some are benign lesions. But the can cause significant problems by pressing on important brain structures and affecting their function.
Breed: Certain breeds are more predisposed to developing brain tumors, including Boxers, Bulldogs, Doberman Pinschers, and Golden Retrievers.
5. Vestibular Disease
Vestibular disease refers to a condition affecting the inner ear and the balance centers in the brain. This disease leads to disorientation, shaking, and difficulty maintaining balance. This is sometimes called “canine idiopathic vestibular syndrome”.
Common symptoms of Vestibular Disease include:
- Shaking and Tremors: One of the hallmark symptoms of vestibular disease is tremors or shaking. These tremors are generally associated with the disorientation.
- Loss of Balance: Dogs with vestibular disease typically experience loss of balance, making them appear dizzy or unstable when standing or walking. They may lean to one side or fall over.
- Head Tilting: A head tilt is a classic sign of vestibular disease. This occurs because the brain is receiving incorrect signals from the inner ear about the dog’s spatial orientation, causing the head to tilt to one side.
- Uncoordinated Movements: The lack of coordination, or ataxia, is another significant symptom. Affected dogs shows difficulty with tasks that require balance, like climbing stairs, jumping, or navigating through doorways.
- Nausea and Vomiting: Due to the disorientation and imbalance, dogs may experience nausea, which can lead to vomiting. This is particularly common in the acute phase of the disease.
Cause:
Idiopathic: The exact cause of vestibular disease remains unknown. It typically has no known trigger, and the condition may resolve on its own over time.
Ear Infections: Middle or inner ear infections (otitis media or otitis interna) are another common cause of vestibular disease. Infections in the ear can spread to the vestibular apparatus, which is responsible for balance, leading to symptoms similar to those of idiopathic vestibular disease.
Neurological Conditions: Vestibular disease can also be secondary to other neurological conditions, such as brain tumors, stroke, or trauma to the head or neck. These issues directly affect the vestibular system which leads to dizziness and imbalance.
6. Hypoglycemia (Low Blood Sugar)
Hypoglycemia, or low blood sugar, is a condition where a dog’s blood glucose levels fall below normal levels. While it can affect dogs of any size or age, it is especially common in small breed dogs and puppies. Additionally, dogs with diabetes mellitus or those undergoing insulin therapy are also at risk.
Common symptoms of Hypoglycemia include:
- Shaking and Tremors: Shaking occurs because the brain and muscles are not getting enough glucose to function properly.
- Lethargy: A dog appears extremely lethargic or weak.
- Weakness: Difficulty walking or standing, weak and unsteady on their feet due to the lack of energy.
- Confusion: Dogs show signs of confusion, appearing disoriented or “out of it.”
- Severe Symptoms: In more severe cases, hypoglycemia can lead to:
- Seizures: When the brain is deprived of glucose for an extended period, it can cause seizures. This is a medical emergency and requires immediate intervention.
- Loss of Consciousness: If blood sugar levels drop very low, the dog collapse, become unresponsive, or even fall into a coma. This is a life-threatening situation and requires urgent veterinary care.
Cause:
Olutunbi Idowu and Kathryn Heading included the reasons behind hypoglycemia in dogs. They cited the information in their research named “Hypoglycemia in dogs: Causes, management, and diagnosis.”
Physiological causes of hypoglycemia
Extreme exercise
Neonatal/juvenile or toy breed juvenile
Malnutrition/starvation
Drug and toxin associated causes such as iatrogenic insulin overdose, xylitol toxicity, oral hypoglycemic agents (usually sulfonylureas), beta blockers
Pathological causes of hypoglycemia
Severe hepatic disease such as hepatitis, cirrhosis, neoplasia, amyloidosis, hepatotoxins
Congenital portosystemic shunt
Hypoadrenocorticism
Hypopituitarism
Extra-pancreatic tumors (e.g., hepatocellular carcinoma, hepatoma, leiomyosarcoma, leiomyoma)
Other causes are: –
Insufficient Glucose Intake: It can happen if a dog skips a meal or isn’t eating enough.
Small Breed Dogs: Smaller breeds tend to have faster metabolisms and higher energy requirements. This is why hypoglycemia is commonly seen in toy breeds such as Chihuahuas, Yorkshire Terriers, and Pomeranians.
Puppies: Puppies have a higher risk of hypoglycemia due to their smaller size, higher metabolic rate, and lower glycogen stores. They may not be able to regulate their blood sugar as efficiently as adult dogs.
Diabetes and Insulin Imbalances: Dogs with diabetes mellitus who are on insulin therapy are at an increased risk of hypoglycemia, especially if too much insulin is given, if meals are skipped, or if exercise is excessive. This condition is referred to as insulin-induced hypoglycemia.
Liver Disease or Dysfunction: The liver plays a crucial role in regulating blood sugar levels by storing and releasing glucose as needed. Liver conditions, such as liver disease, hypoadrenocorticism (Addison’s disease), or portosystemic shunts, can impair the liver’s ability to maintain normal blood sugar levels, leading to hypoglycemia.
7. Canine Distemper
Canine distemper affects multiple organ systems in the body, including the nervous system, respiratory system, and gastrointestinal system. It is a highly contagious disease caused by the canine distemper virus (CDV), which is closely related to the measles virus in humans. Distemper primarily affects unvaccinated dogs, though vaccinated dogs may still be at risk if their immune protection wanes over time. The virus is transmitted through respiratory droplets or direct contact with infected animals.
Common symptoms of Canine Distemper include:
- Tremors and Shaking: These are often seen as a result of the virus’s impact on the central nervous system.
- Seizures: These can range from mild muscle spasms to full-blown seizures and can be a sign of significant brain involvement.
- Coughing and Respiratory Symptoms: The distemper virus affects the respiratory system, leading to symptoms like a persistent cough, nasal discharge, and watery eyes.
- Eye and Nasal Discharge: Dogs with distemper have clear or thick yellow discharge from the eyes and nose. This is one of the early signs of the infection.
- Gastrointestinal Issues: Distemper can cause significant gastrointestinal distress, including vomiting, diarrhea, and loss of appetite. This can lead to dehydration, which can worsen the dog’s condition.
Cause:
Canine Distemper Virus (CDV): The cause of distemper is the canine distemper virus. It spreads through the air via respiratory droplets. It can also spread through contact with contaminated surfaces, feces, or urine.
Unvaccinated Dogs: Distemper primarily affects unvaccinated dogs.
Susceptible Populations: Puppies between 3-6 months of age are particularly vulnerable. The immunity system in their body isn’t matured enough to fight the disease.
Environmental Spread: The virus can survive for a period in the environment, making it possible for dogs to contract distemper through exposure to infected animals or contaminated areas.
8. Myasthenia Gravis
Myasthenia Gravis (MG) is an autoimmune disorder that affects the neuromuscular junction — the area where the nerves communicate with the muscles. In this condition, the dog’s immune system mistakenly attacks the acetylcholine receptors at the neuromuscular junction.
These receptors are essential for transmitting nerve impulses that tell muscles to contract. When these receptors are impaired, muscle weakness and tremors occur. Affected dogs show difficulty with normal motor activities such as walking, swallowing, or breathing.
Common symptoms of Myasthenia Gravis include:
- Tremors: Muscle tremors are present in limbs or other muscle groups affected by weakness. These tremors result from disrupted communication between nerves and muscles.
- Weakness: A hallmark of Myasthenia Gravis is muscle weakness, which can be generalized (affecting the entire body) or localized to specific muscle groups.
- Difficulty Swallowing (Dysphagia): Affected dogs choke on food or water, or drool excessively. This can lead to nutritional problems, aspiration pneumonia, and a decrease in overall health.
- Lethargy: Dogs with MG may exhibit significant lethargy due to muscle weakness and fatigue.
- Regurgitation: In more severe cases, especially when the disorder affects the muscles involved in digestion, dogs may regurgitate food due to the inability to swallow properly, which can lead to aspiration pneumonia (food entering the lungs).
Cause:
Autoimmune Response: When the receptors are damaged or blocked, the muscle cannot respond appropriately to nerve signals, leading to muscle weakness and fatigue.
Acetylcholine Receptor Antibodies: In Myasthenia Gravis, the immune system produces antibodies that target the acetylcholine receptors, preventing the muscles from receiving nerve signals properly. The result is impaired muscle function, weakness, and tremors.
9. Toxicity or Poisoning
Toxicity or poisoning occurs when a dog ingests or is exposed to harmful substances. The body’s response to toxic agents often involves disruptions to various physiological systems, including the nervous system, leading to muscle tremors, seizures, and other signs of distress. Common sources of poisoning in dogs include chocolate, pesticides, antifreeze, human medications, and other chemicals.
Common symptoms of Toxicity include:
- Tremors and Shaking: One of the common signs of poisoning in dogs is muscle tremors.
- Vomiting and Diarrhea: Gastrointestinal distress is a common response to ingestion of toxins. Dogs may vomit, have diarrhea, or both. This is often the body’s way of attempting to rid itself of the toxic substance.
- Lethargy: Affected dogs are weak, lethargic, or uncoordinated due to the impact of the toxin on their nervous system and general health.
- Drooling: Excessive salivation (drooling) is another symptom of poisoning. This may result from nausea, difficulty swallowing, or a direct effect of the poison on the salivary glands.
Cause:
Chocolate: Chocolate contains theobromine, a stimulant that is toxic to dogs. The toxic dose varies depending on the type of chocolate, the size of the dog, and the amount ingested. Dark chocolate and baking chocolate contain higher concentrations of theobromine, making them particularly dangerous. Symptoms of chocolate poisoning include tremors, vomiting, diarrhea, hyperactivity, and in severe cases, seizures and heart arrhythmias.
Pesticides: Some pesticides, especially those containing organophosphates or carbamates, can interfere with the nervous system and cause tremors, drooling, and gastrointestinal distress. These chemicals may be ingested through contaminated food, water, or by licking paws after walking on treated surfaces.
Antifreeze (Ethylene Glycol): Antifreeze is extremely toxic to dogs and can cause severe damage to the kidneys and central nervous system.
Human Medications: Many human medications, including acetaminophen (Tylenol), ibuprofen, antidepressants, and benzodiazepines, are toxic to dogs. These substances affect the liver, kidneys, gastrointestinal system, and nervous system.
Other Toxic Substances: There are many other household items and substances that can be toxic to dogs, including grapes and raisins, xylitol, fertilizers, paint, and certain.
10. Hypothyroidism
Hypothyroidism is a condition where the thyroid gland, located in the neck, fails to produce enough thyroid hormones, primarily thyroxine (T4) and triiodothyronine (T3). These hormones are essential for regulating metabolism, growth, and energy production in the body.
Common symptoms of Hypothyroidism include:
- Shaking or Tremors: These tremors result from metabolic disturbances caused by the lack of thyroid hormone.
- Weight Gain: A hallmark sign of hypothyroidism is unexplained weight gain, despite a normal or decreased appetite. This occurs because the slowed metabolism due to insufficient thyroid hormones causes the dog to burn calories more slowly.
- Lethargy: Affected dogs exhibit lethargy or fatigue, showing less interest in play or exercise. They are sluggish and spend more time sleeping.
- Dry Skin and Coat Problems: Dogs with hypothyroidism frequently develop dry, flaky skin (known as seborrhea) and hair thinning or hair loss.
- Increased Cholesterol Levels: Hypothyroidism causes changes in the dog’s lipid profile, leading to elevated cholesterol levels and sometimes the development of atherosclerosis (hardening of the arteries).
Cause:
Primary Hypothyroidism: This is the most common form of hypothyroidism in dogs and is caused by autoimmune thyroiditis, where the dog’s immune system attacks the thyroid gland, leading to inflammation and destruction of the gland’s tissue. Over time, this damages the thyroid, and impairs its ability to produce thyroid hormones.
Idiopathic Thyroid Gland Atrophy: In some dogs, the cause of hypothyroidism is unknown and may be due to degeneration or atrophy of the thyroid gland itself. This leads to a gradual decrease in hormone production.
Iatrogenic Causes: In some cases, hypothyroidism can develop as a result of treatment for hyperthyroidism (excess thyroid hormone) or from radiation therapy. Overcorrection during treatment or damage to the thyroid gland may result in hypothyroidism.
Reference:
- Managing seizures. Cornell Richard P. Riney Canine Health Center.
- Stephanie Phillipps, Steven DeDecker, Rodrigo Gutierrez-Quintana, Emili Alcoverro, Sergio A Gomes, Rita Goncalves. Idiopathic generalised tremor syndrome in dogs. National Library of Medicine.
- Sonja Prpar Mihevc and Gregor Majdič. Canine Cognitive Dysfunction and Alzheimer’s Disease – Two Facets of the Same Disease? PubMed Central.
- 10 Common Brain Tumor Symptoms in Dogs. SouthEast Veterinary Neurology.
- Olutunbi Idowu and Kathryn Heading. Hypoglycemia in dogs: Causes, management, and diagnosis. National Library of Medicine.
