Dog Diseases & Breed Health Conditions Dictionary
Understanding dog diseases and breed-related health conditions can help dog owners, breeders, puppy buyers, and rescue adopters recognize potential health concerns early and make informed decisions. Some dog health problems can affect any dog, while others are more common in certain breeds because of genetics, body structure, size, coat type, or inherited risk.
This dog diseases and health dictionary includes many of the common and breed-specific conditions mentioned throughout our dog breed profiles, including inherited canine disorders, orthopedic problems, eye diseases, heart conditions, skin and allergy issues, neurological diseases, digestive disorders, kidney disease, autoimmune conditions, and infectious dog diseases.
This information is provided for general education only and should never replace veterinary care. If your dog is showing signs of pain, weakness, lameness, breathing difficulty, seizures, vomiting, diarrhea, vision changes, urinary problems, skin irritation, collapse, or sudden behavior changes, contact your veterinarian promptly.
Browse Dog Diseases by Category
- Orthopedic & Joint Disorders
- Eye Diseases & Vision Disorders
- Heart & Cardiovascular Diseases
- Skin Diseases & Allergies
- Neurological Disorders
- Digestive & Gastrointestinal Disorders
- Kidney & Urinary Disorders
- Inherited & Genetic Conditions
- Infectious Dog Diseases
- Preventing Dog Diseases
Dog Diseases Listed Alphabetically
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A
Addison’s Disease (Hypoadrenocorticism): Addison’s disease occurs when the adrenal glands do not produce enough important hormones. Symptoms may include weakness, vomiting, diarrhea, weight loss, shaking, poor appetite, fatigue, or collapse.
Allergies: Dogs can be allergic to foods, fleas, pollen, grasses, dust, mold, or other environmental triggers. Symptoms can include itching, chewing the paws, recurring ear infections, runny eyes, skin rashes, and hot spots. To explore further, read our extensive information about dog allergies.
Alopecia: Alopecia means hair loss. In dogs, it may be caused by genetics, allergies, parasites, hormonal disease, immune problems, poor nutrition, or breed-related coat conditions.
Amyloidosis: Amyloidosis occurs when abnormal protein deposits build up in the body’s organs. It can affect organ function and may be inherited in some breeds.
Anal Gland Disease: Anal gland problems occur when the small scent glands near the rectum become impacted, infected, or painful. Signs may include scooting, licking under the tail, odor, swelling, or discomfort when sitting.
Anemia: Anemia means the body does not have enough healthy red blood cells. It can be caused by blood loss, immune disease, parasites, toxins, chronic illness, or inherited disorders.
Aortic Stenosis: Aortic stenosis is a heart defect that narrows the flow of blood from the heart into the aorta. It may cause a heart murmur, fainting, weakness, exercise intolerance, or sudden cardiac problems.
Arthritis: Arthritis is inflammation and degeneration of the joints. It may be related to age, injury, overuse, obesity, immune disease, hip dysplasia, elbow dysplasia, or other orthopedic conditions.
Atopic Dermatitis: Atopic dermatitis is an allergic skin disease often triggered by environmental allergens such as pollen, dust, mold, or grasses. Dogs may itch, lick, chew their paws, develop ear infections, or have recurring skin irritation.
Autoimmune Disease: Autoimmune disease refers to conditions in which the immune system mistakenly attacks the dog’s own cells or tissues. Autoimmune disease can affect the skin, blood, joints, nervous system, or internal organs.
Axonal Dystrophy: Axonal dystrophy is a rare neurological disorder that affects muscles and movement. It has been reported in young Ibizan Hound puppies, although it has not been commonly seen in the breed in many decades.
B
Bladder Infection: Bladder infections may be caused by bacteria or other infectious agents. Symptoms can include frequent urination, accidents, straining, pain, blood in the urine, or licking around the urinary opening.
Bladder/Kidney Stones: Stones can form in the bladder or kidneys from minerals in the urine. They may cause pain, blood in the urine, frequent urination, straining, or a dangerous urinary blockage.
Bleeding Disorder: Bleeding disorders affect the body’s ability to clot blood normally. Some are inherited, such as von Willebrand’s disease or hemophilia, while others may be caused by toxins, immune disease, liver disease, or illness.
Bloat (Gastric Dilatation-Volvulus/GDV): Bloat is a life-threatening emergency in which the stomach fills with gas and may twist. It is most common in large, deep-chested breeds and requires immediate veterinary care.
Bone Cancer: Bone cancer, especially osteosarcoma, is more common in large and giant dog breeds. Signs may include persistent lameness, swelling, pain, or reluctance to bear weight on a limb.
Brachycephalic Airway Syndrome: Brachycephalic airway syndrome affects short-nosed breeds such as Bulldogs, Pugs, Boston Terriers, French Bulldogs, and Shih Tzu. Dogs may snore, breathe noisily, overheat easily, or struggle with exercise and heat.
Breathing Problems: Breathing problems in dogs may be caused by allergies, infections, heart disease, lung disease, obesity, airway abnormalities, or the short-muzzled structure of brachycephalic breeds.
Bronchitis: Bronchitis is inflammation of the airways. Dogs may have a chronic cough, wheezing, gagging, or reduced stamina.
C
Cancer: Cancer is abnormal cell growth that can affect the skin, bones, blood, lymph nodes, internal organs, or other tissues. Some breeds have a higher risk for certain cancers.
Canine Epileptoid Cramping Disease (Spike’s Disease): This condition can cause episodes of staggering, trembling, exaggerated stretching, muscle contractions, abdominal discomfort, falling, or inability to rise. Dogs usually remain aware during episodes, which can make the condition look different from typical epilepsy.
Cardiomyopathy: Cardiomyopathy is a disease of the heart muscle. Dilated cardiomyopathy is especially important in some large and giant breeds and may lead to weakness, coughing, fainting, or heart failure.
Cataracts: Cataracts occur when the lens of the eye becomes cloudy. They may be inherited, age-related, caused by diabetes, or associated with injury or inflammation.
Cerebellar Ataxia: Cerebellar ataxia is a neurological disorder that affects coordination and balance. Dogs may have an unsteady gait, tremors, poor coordination, or difficulty walking normally.
Ceroid Lipofuscinosis (Storage Disease): Ceroid lipofuscinosis is a hereditary storage disease that affects nerve cells. Symptoms may include behavior changes, extreme fear, vision problems, seizures, and an unsteady gait.
Cherry Eye: Cherry eye occurs when the gland of the third eyelid protrudes and appears as a red or pink swelling in the corner of the eye.
Chiari-like Malformation/Syringomyelia: Chiari-like malformation and syringomyelia are neurological conditions seen most often in some small and toy breeds. Dogs may show neck pain, sensitivity, scratching at the air, weakness, or discomfort around the head and neck.
Chondrodysplasia: Chondrodysplasia is abnormal cartilage and bone development. It may be part of normal breed structure in some short-legged breeds, but severe forms can cause skeletal problems.
Chronic Ear Infections: Chronic ear infections are common in dogs with allergies, floppy ears, heavy ear hair, narrow ear canals, or moisture trapped in the ears. Signs include head shaking, odor, discharge, redness, and scratching.
Chronic Kidney Disease: Chronic kidney disease is a gradual decline in kidney function. Dogs may drink more water, urinate more often, lose weight, vomit, have poor appetite, or appear weak.
Cleft Palate: A cleft palate is a birth defect in which the roof of the mouth does not close properly. It can make nursing difficult and may allow milk or food to enter the nasal passages.
Collapsed Trachea: A collapsed trachea occurs when the windpipe weakens and partially collapses. It is more common in small and toy breeds and may cause a honking cough, gagging, or breathing difficulty.
Collie Eye Anomaly: Collie Eye Anomaly is an inherited eye disorder that causes abnormal eye development. It can range from mild changes to vision loss or blindness in affected dogs.
Colitis: Colitis is inflammation of the colon. Dogs may have diarrhea, mucus in the stool, straining, urgency, or small frequent bowel movements.
Congenital Esophageal Achalasia (Cardiospasm, Megaesophagus, Ectasia, Dilated Esophagus): This condition involves poor movement of food through the esophagus and is often detected in young puppies. Symptoms include regurgitating food shortly after eating, poor growth, coughing, or aspiration pneumonia.
Congenital Heart Disease: Congenital heart disease means a dog is born with a heart defect. Some defects cause no obvious signs early in life, while others may cause murmurs, poor growth, weakness, fainting, or heart failure.
Copper Toxicosis/Copper Storage Disease: Copper storage disease occurs when too much copper accumulates in the liver. It can lead to liver inflammation, liver damage, and serious illness in affected breeds.
Corneal Dystrophy: Corneal dystrophy is an inherited or degenerative disorder of the clear surface of the eye. It may cause cloudy areas in the cornea and can affect vision in some dogs.
Cranial Cruciate Ligament Rupture (CCL): A cranial cruciate ligament rupture is a tear of an important ligament in the stifle joint, similar to the ACL in people. It can cause sudden lameness, pain, swelling, and arthritis.
Cranial Muscular Atrophy: Cranial muscular atrophy is a disease that affects muscles of the head and can cause weakness, difficulty chewing, or changes in facial muscle tone.
Craniomandibular Osteopathy: Craniomandibular osteopathy is a bone disease that causes excess bone growth along the jaw and skull. It can make opening and closing the mouth painful.
Cryptorchidism: Cryptorchidism occurs when one or both testicles do not descend normally. It is considered inherited and may increase the risk of testicular problems later in life.
Cushing’s Disease (Hyperadrenocorticism): Cushing’s disease occurs when the body produces too much cortisol. Signs may include increased thirst, increased urination, panting, hair loss, a pot-bellied appearance, and muscle weakness.
Cyst: A cyst is a lump filled with soft or fluid-like material. Some cysts remain small, while others may grow, rupture, become infected, or need veterinary evaluation.
Cystinuria: Cystinuria is an inherited condition that can cause cystine stones to form in the bladder or kidneys. It may lead to pain, urinary problems, or blockage.
D
Deafness: Deafness can be inherited, age-related, caused by chronic ear disease, medication reactions, infection, injury, or certain coat color patterns. One or both ears may be affected.
Degenerative Disc Disease: Degenerative disc disease affects the cushioning discs between the vertebrae. It can cause back pain, neck pain, weakness, difficulty walking, or paralysis.
Degenerative Joint Disease: Degenerative joint disease is another term often used for osteoarthritis. It causes joint pain, stiffness, reduced mobility, and gradual cartilage loss.
Degenerative Myelopathy: Degenerative myelopathy is a progressive spinal cord disease that usually begins with weakness or wobbliness in the rear legs. It is seen more often in some middle-aged and older breeds.
Demodectic Mange: Demodectic mange is caused by Demodex mites that normally live on the skin but may overgrow in some dogs. It can cause hair loss, redness, scaling, and secondary skin infections.
Dental Disease: Dental disease is one of the most common health problems in dogs. Plaque, tartar, gum inflammation, tooth loss, and oral pain can affect eating, comfort, and overall health.
Dermatitis: Dermatitis means inflammation of the skin. It may be caused by allergies, parasites, infection, irritants, autoimmune disease, or internal health problems.
Dermatomyositis: Dermatomyositis is an inherited inflammatory disease that affects the skin and muscles. It may cause skin lesions, hair loss, crusting, and muscle weakness.
Dermoid Sinus: A dermoid sinus is a tube-like or cyst-like defect along the neck or back that can become impacted with debris or infected. It is associated with certain breeds.
Diabetes Mellitus: Diabetes occurs when the body cannot properly regulate blood sugar. Signs may include increased thirst, increased urination, weight loss, increased appetite, cataracts, and weakness.
Digital Hyperkeratosis: Digital hyperkeratosis is thickening of the outer layer of the foot pads, often due to abnormal keratin production. It can cause rough, cracked, or painful pads.
Dilated Cardiomyopathy (DCM): Dilated cardiomyopathy is a heart disease in which the heart muscle becomes enlarged and weakened. It is more common in some large and giant breeds.
Disc Disease: Disc disease refers to degeneration or rupture of the discs between the vertebrae. It can cause pain, weakness, difficulty walking, or paralysis.
Distichiasis: Distichiasis occurs when extra eyelashes grow from the eyelid margin and rub against the eye. It may cause tearing, squinting, irritation, or corneal damage.
Dry Eye: Dry eye, also called keratoconjunctivitis sicca or KCS, occurs when the eyes do not produce enough tears. Dogs may have redness, thick discharge, squinting, discomfort, or corneal scarring.
Dwarfism: Dwarfism is a disorder that causes stunted or abnormal growth. It may be hereditary and can affect bone development, body proportions, and overall health.
E
Ear Infections: Ear infections can be caused by bacteria, yeast, allergies, moisture, ear mites, foreign material, or ear structure. Redness, odor, discharge, head shaking, and pain are common signs.
Ectopic Cilia: Ectopic cilia are abnormal eyelashes that grow through the eyelid and rub against the eye. They can cause pain, tearing, squinting, and corneal ulcers.
Ectropion: Ectropion occurs when the eyelid droops outward, exposing the eye to irritation, dryness, and infection.
Ehlers-Danlos Syndrome: Ehlers-Danlos syndrome is a connective tissue disorder that can cause unusually stretchy, fragile skin and joint problems.
Elbow Dysplasia: Elbow dysplasia is an inherited developmental disorder of the elbow joint. It is more common in large breeds and can cause front-leg lameness, pain, stiffness, and arthritis.
Entropion: Entropion occurs when the eyelid rolls inward, causing eyelashes or facial hair to rub against the eye. It can be painful and may require surgery.
Epilepsy: Epilepsy refers to repeated seizures over time. It may be idiopathic, inherited, or secondary to another medical condition, toxin, injury, or brain disease.
Exercise-Induced Collapse (EIC): Exercise-induced collapse is an inherited condition seen in some active breeds. Affected dogs may become weak, wobbly, or collapse after intense exercise or excitement.
Exocrine Pancreatic Insufficiency (EPI): EPI occurs when the pancreas does not produce enough digestive enzymes. Dogs may lose weight despite eating well and may have large, loose, or greasy stools.
Eyelash Disorders: Eyelash disorders include abnormal eyelashes that grow inward, from the wrong location, or toward the eyeball. These conditions may irritate the eye and damage the cornea.
Eye Infection: Eye infections may be caused by bacteria, viruses, injury, irritation, or underlying eye disease. Discharge, redness, squinting, or cloudiness should be evaluated by a veterinarian.
F
Factor VII Deficiency: Factor VII deficiency is an inherited blood-clotting disorder. Some dogs show few signs, while others may bleed excessively after surgery, injury, or trauma.
Familial Nephropathy (FN): Familial nephropathy is an inherited kidney disorder that can cause protein loss through the kidneys and may lead to kidney failure.
Fanconi Syndrome: Fanconi syndrome affects the kidney tubules and prevents proper reabsorption of nutrients. It may cause excessive drinking, excessive urination, weight loss, and metabolic problems.
Fibrocartilaginous Embolic Myelopathy (FCE): FCE occurs when cartilage-like material blocks blood flow to part of the spinal cord. It can cause sudden weakness or paralysis.
Flea Allergy Dermatitis: Flea allergy dermatitis is an allergic reaction to flea saliva. Even a few flea bites can cause severe itching, hair loss, scabs, and skin infections in sensitive dogs.
Follicular Dysplasia: Follicular dysplasia is an inherited hair follicle disorder that can cause abnormal coat texture, thinning hair, or patchy hair loss in certain breeds.
Food Allergies: Food allergies can cause itching, ear infections, skin irritation, vomiting, diarrhea, or chronic digestive upset. Diagnosis usually requires a veterinarian-guided elimination diet.
G
Gastric Dilatation-Volvulus (GDV): GDV is the medical term for bloat with twisting of the stomach. It is a life-threatening emergency most often seen in large, deep-chested breeds.
Gastritis: Gastritis is inflammation of the stomach. Dogs may vomit, refuse food, drool, act nauseated, or show signs of abdominal discomfort.
Giardia: Giardia is a microscopic protozoan parasite that causes an intestinal infection called giardiasis. Explore our detailed Giardia information page.
Glaucoma: Glaucoma occurs when pressure inside the eye becomes too high. It is painful and can lead to blindness if not treated quickly.
Globoid Cell Leukodystrophy (GCL/Krabbe Disease): Globoid cell leukodystrophy is an inherited neurological disease that affects the brain and spinal cord. It can cause weakness, tremors, coordination problems, and progressive decline.
Granulomatous Meningoencephalitis (GME): GME is an inflammatory disease of the brain and spinal cord. Signs may include seizures, weakness, vision problems, behavior changes, or balance issues.
H
Hashimoto’s Disease: Hashimoto’s disease is an immune-mediated thyroid disorder. In dogs, thyroid problems are more commonly discussed as hypothyroidism.
Heart Arrhythmia: A heart arrhythmia is an abnormal heart rhythm. It may occur occasionally or be associated with heart disease, weakness, fainting, or exercise intolerance.
Heart Disease: Heart disease in dogs can affect the heart valves, heart muscle, rhythm, or blood flow. Signs may include coughing, fatigue, fainting, exercise intolerance, or trouble breathing.
Heart Murmur: A heart murmur is an abnormal sound heard during a veterinary exam. Some murmurs are mild, while others may indicate heart valve disease, congenital heart defects, or other cardiac problems.
Hemangiosarcoma: Hemangiosarcoma is an aggressive cancer that often affects the spleen, heart, liver, or blood vessels. It is more common in some large breeds and may cause sudden weakness or collapse.
Hemolytic Anemia: Hemolytic anemia occurs when red blood cells are destroyed faster than the body can replace them. Causes may include immune disease, toxins, infections, parasites, or inherited conditions.
Hemophilia: Hemophilia is an inherited bleeding disorder caused by a deficiency in clotting factors. Dogs may bruise easily or bleed excessively after injury, surgery, or trauma.
Hereditary Nephritis (HN): Hereditary nephritis is an inherited kidney disease that can lead to kidney failure. Signs may include increased thirst, increased urination, weight loss, or poor growth.
Hernia (Umbilical): An umbilical hernia occurs when the opening where the umbilical cord attached does not close properly. Tissue or organs may protrude through the opening.
Hip Dysplasia: Hip dysplasia is abnormal development of the hip joint. It is common in many medium, large, and giant breeds and can lead to pain, lameness, arthritis, and reduced mobility.
Hot Spots: Hot spots are moist, inflamed, painful skin lesions that can develop quickly. They are often linked to allergies, fleas, moisture, licking, or underlying skin irritation.
Hyperthyroidism: Hyperthyroidism means the thyroid gland produces too much thyroid hormone. It is uncommon in dogs but can occur, often in association with thyroid tumors.
Hypertrophic Osteodystrophy (HOD): HOD is a painful bone disease seen in growing large-breed puppies. It may cause fever, swelling, lameness, and reluctance to move.
Hypoglycemia: Hypoglycemia means low blood sugar. It is especially concerning in tiny puppies, toy breeds, diabetic dogs receiving insulin, or dogs with certain metabolic problems.
Hypomyelinogenesis: Hypomyelinogenesis is defective formation of myelin in the spinal cord, brain, or nerves. Puppies may show tremors, weakness, or abnormal movement.
Hypothyroidism: Hypothyroidism occurs when the thyroid gland does not produce enough thyroid hormone. Signs may include weight gain, low energy, hair loss, skin infections, cold intolerance, and sluggishness.
I
Immune Disorders: Immune disorders include a wide variety of diseases caused by an immune system that is overactive, underactive, or attacking the dog’s own tissues.
Immune-Mediated Hemolytic Anemia (IMHA): IMHA occurs when the immune system destroys red blood cells. Dogs may become weak, pale, jaundiced, or collapse.
Immune-Mediated Thrombocytopenia (ITP): ITP occurs when the immune system destroys platelets needed for blood clotting. Dogs may bruise, bleed from the nose or gums, or develop tiny red spots on the skin.
Immune Mediated SLE: See Systemic Lupus Erythematosus.
Immunoproliferative Small Intestine Disease (IPSID): IPSID affects the small intestine and interferes with nutrient absorption. It can cause chronic diarrhea, weight loss, and poor condition.
Inflammatory Bowel Disease (IBD): IBD is chronic inflammation of the digestive tract. Dogs may have vomiting, diarrhea, weight loss, gas, poor appetite, or recurring stomach upset.
Intervertebral Disc Disease (IVDD): IVDD affects the cushioning discs between the vertebrae of the spine. It can cause back pain, weakness, difficulty walking, or paralysis.
J
Joint Disease: Joint disease is a broad term that includes arthritis, dysplasia, ligament injuries, developmental disorders, and degenerative orthopedic problems. Dogs may limp, move stiffly, avoid stairs, or become less active.
Juvenile Cataracts: Juvenile cataracts are cataracts that develop in young dogs. They may be inherited in some breeds and can affect vision early in life.
K
Keratitis: Keratitis is inflammation of the cornea. It may cause redness, cloudiness, pain, tearing, or ulcers and should be evaluated promptly.
Keratoconjunctivitis Sicca (KCS/Dry Eye): KCS, commonly called dry eye, occurs when the eyes do not produce enough tears. It can cause redness, thick discharge, discomfort, and corneal damage.
Kidney Disease: Kidney disease may be inherited, age-related, infectious, toxic, or linked to other medical conditions. Signs can include increased thirst, increased urination, vomiting, weight loss, and poor appetite.
Kidney Stones: See Bladder/Kidney Stones.
L
Laryngeal Paralysis: Laryngeal paralysis occurs when the muscles that open the airway do not work properly. Dogs may have noisy breathing, voice changes, coughing, gagging, exercise intolerance, or breathing distress.
Legg-Calve Perthes Disease: Legg-Calve Perthes disease affects the hip joint, usually in small breeds. It causes degeneration of the femoral head and may lead to pain, limping, and muscle loss.
Lens Luxation: Lens luxation occurs when the lens inside the eye shifts out of place. It can be painful and may lead to glaucoma or vision loss.
Liver Disease: Liver disease can have many causes, including genetics, toxins, infection, inflammation, cancer, or age-related changes. Signs may include vomiting, poor appetite, jaundice, weight loss, or behavior changes.
Liver Shunt/Portosystemic Shunt: A liver shunt is an abnormal blood vessel that allows blood to bypass the liver. Dogs may show poor growth, vomiting, drooling, seizures, behavior changes, or urinary problems.
Lupoid Dermatosis: Lupoid dermatosis is an inflammatory skin disease that may be related to immune system dysfunction. It can cause scaling, itching, crusting, and skin irritation.
Luxating Patella (Slipped Stifles): Luxating patella means the kneecap slips out of its normal groove. It is common in small breeds but can affect larger dogs, causing skipping, limping, stiffness, or arthritis.
Lymphoma/Lymphosarcoma: Lymphoma is cancer of the lymphatic system. Dogs may develop enlarged lymph nodes, weight loss, lethargy, reduced appetite, vomiting, diarrhea, or other signs depending on the organs involved.
M
Malassezia Dermatitis: Malassezia dermatitis is a yeast-related skin condition. Dogs may have greasy skin, odor, itching, redness, thickened skin, or recurring ear infections.
Mammary Tumor: Mammary tumors occur in the mammary glands of female dogs. They may be benign or malignant and should be checked by a veterinarian.
Mast Cell Tumors: Mast cell tumors are common skin tumors in dogs. They can vary from mild to aggressive, so any new lump or bump should be examined by a veterinarian.
MDR1 Drug Sensitivity: MDR1 drug sensitivity is an inherited mutation that affects how some dogs process certain medications. It is most often associated with herding breeds and can cause serious drug reactions.
Megaesophagus: Megaesophagus occurs when the esophagus becomes enlarged and does not move food normally into the stomach. Dogs may regurgitate food, lose weight, or develop aspiration pneumonia.
Microphthalmia: Microphthalmia is an eye disorder in which one or both eyes are abnormally small or incompletely developed at birth.
Mitral Valve Disease: Mitral valve disease affects the valve that regulates blood flow in the heart. It is common in older small dogs and may cause a heart murmur, coughing, fatigue, or congestive heart failure.
Muscular Dystrophy: Muscular dystrophy is an inherited muscle disease that causes weakness and muscle wasting. It may affect movement, swallowing, and overall strength.
Myotonia Congenita: Myotonia congenita is a muscle disorder that can cause stiffness, difficulty getting up, an abnormal gait, and trouble swallowing.
N
Nasal Disease: Nasal disease may be caused by allergies, infections, foreign bodies, dental disease, tumors, or immune conditions. Signs include sneezing, nasal discharge, nosebleeds, or noisy breathing.
Neurological Disorders: Neurological disorders affect the brain, spinal cord, nerves, or muscles. Signs may include seizures, tremors, weakness, balance problems, paralysis, behavior changes, or abnormal movement.
Nictitating Membrane Eversion: The nictitating membrane is the third eyelid in dogs. If it folds or everts due to weakness or injury, it can irritate the eye and cause discomfort.
O
Obesity: Obesity is one of the most common health problems in dogs. Extra weight can worsen arthritis, breathing problems, diabetes risk, heart strain, orthopedic disease, and overall quality of life.
Ocular Melanosis/Pigment Dispersion Syndrome: This eye condition involves pigment buildup that can interfere with fluid drainage in the eye. Increased eye pressure and glaucoma may result.
Open Fontanel: An open fontanel occurs when the soft spot where the skull bones meet does not close properly. It is seen more often in some toy breeds.
Osteoarthritis: Osteoarthritis is chronic degeneration of joint cartilage. It causes pain, stiffness, inflammation, reduced mobility, and is common in senior dogs and dogs with orthopedic disease.
Osteochondritis Dissecans (OCD): OCD is a developmental joint disease often seen in young large-breed dogs. Abnormal cartilage development leads to pain, lameness, and joint inflammation.
Osteochondrosis: Osteochondrosis is abnormal cartilage and bone development in growing dogs. It can contribute to osteochondritis dissecans and joint problems.
Osteosarcoma: Osteosarcoma is an aggressive bone cancer most often seen in large and giant breeds. Signs may include persistent limping, swelling, and pain in the affected limb.
P
Pancreatitis: Pancreatitis is inflammation of the pancreas. Dogs may vomit, have abdominal pain, refuse food, act lethargic, or develop diarrhea.
Panosteitis: Panosteitis is a painful bone condition that occurs in puppies and young dogs, especially large breeds. It often causes shifting leg lameness and usually resolves with time.
Paronychia: Paronychia is inflammation or infection of the skin around the toenails. It may cause swelling, pain, licking, discharge, or nail problems.
PBGV Juvenile Pain Syndrome: PBGV juvenile pain syndrome is a painful inflammatory condition reported in Petit Basset Griffon Vendéen puppies. It may cause neck or spinal stiffness, fever, and pain.
Patent Ductus Arteriosus (PDA): PDA is a congenital heart defect in which a fetal blood vessel fails to close after birth. It may cause a heart murmur, poor growth, weakness, or heart failure.
Perianal Fistulas: Perianal fistulas are painful draining sores around the anus. They are seen more often in certain breeds and may cause licking, odor, discomfort, or difficulty passing stool.
Periodontal Disease: Periodontal disease is infection and inflammation around the teeth and gums. It can cause bad breath, tooth loss, oral pain, and bacteria that may affect overall health.
Persistent Hyperplastic Primary Vitreous (PHPV): PHPV is an eye disorder that affects fetal eye development and can cause deposits or abnormalities behind the lens.
Persistent Pupillary Membrane (PPM): PPM occurs when fetal eye tissue does not fully disappear after birth. Many cases are mild, but some may affect vision depending on severity and location.
Persistent Right Aortic Arch: Persistent right aortic arch is a congenital blood vessel abnormality that constricts the esophagus. It can cause regurgitation and often requires surgery.
Phosphofructokinase (PFK) Deficiency: PFK deficiency is an inherited enzyme disorder that affects energy production in red blood cells and muscles. Signs may include weakness, muscle cramps, dark urine, and anemia.
Pigmentary Keratitis: Pigmentary keratitis occurs when dark pigment spreads across the cornea. It may interfere with vision and is often associated with chronic irritation or certain facial structures.
Portosystemic Shunt: See Liver Shunt.
Progressive Neuronal Abiotrophy: Progressive neuronal abiotrophy is a neurological disease of young dogs that affects nerve cells and can severely impair coordination and movement.
Progressive Retinal Atrophy (PRA): PRA is an inherited eye disease that gradually damages the retina. It often begins with night blindness and may progress to complete blindness.
Protein-Losing Enteropathy (PLE) and Protein-Losing Nephropathy (PLN): PLE involves protein loss through the gastrointestinal tract, while PLN involves protein loss through the kidneys. Signs may include diarrhea, weight loss, fluid buildup, and poor condition.
Pulmonary Fibrosis: Pulmonary fibrosis causes scarring of lung tissue and difficulty breathing. A dry cough and reduced exercise tolerance may be present.
Pulmonic Stenosis: Pulmonic stenosis is a congenital heart defect that narrows blood flow from the heart to the lungs. It may cause a murmur, fainting, weakness, or exercise intolerance.
Pyometra: Pyometra is a serious infection of the uterus in unspayed female dogs. Signs may include lethargy, fever, vomiting, increased thirst, poor appetite, or vaginal discharge.
Pyruvate Kinase Deficiency: Pyruvate kinase deficiency is an inherited red blood cell disorder that causes anemia. Signs may include weakness, pale gums, poor stamina, or enlarged organs.
R
Renal Dysplasia: Renal dysplasia is abnormal kidney development present from birth. It can lead to kidney dysfunction or kidney failure.
Retinal Dysplasia/Retinal Folds: Retinal dysplasia is abnormal development of the retina. It may range from mild retinal folds to more serious vision problems or blindness.
Ringworm: Ringworm is a contagious fungal skin infection, not a worm. It may cause circular patches of hair loss, scaling, crusting, and skin irritation.
S
Sebaceous Adenitis (SA): Sebaceous adenitis is an inflammatory disease of the oil glands in the skin. It can cause dry, scaly skin, hair loss, dull coat, and secondary infections.
Seborrhea: Seborrhea causes abnormal scaling, dandruff, greasiness, odor, or thickened skin. It may be inherited or secondary to allergies, parasites, hormonal disease, or infection.
Seizures: Seizures are episodes of abnormal electrical activity in the brain. They may be caused by epilepsy, toxins, metabolic disease, brain disease, or unknown causes.
Skin Fold Dermatitis: Skin fold dermatitis occurs when moisture, heat, and friction irritate skin folds. It is common in wrinkled breeds and may cause redness, odor, itching, and infection.
Slipped Disc: Slipped disc is a common term for intervertebral disc disease. It can cause back pain, neck pain, weakness, difficulty walking, or paralysis.
Stenotic Nares: Stenotic nares are narrowed nostrils, often seen in brachycephalic breeds. Dogs may breathe noisily, snore, tire easily, or struggle in heat.
Storage Disease: See Ceroid Lipofuscinosis. Storage diseases are inherited metabolic disorders in which substances accumulate in cells and interfere with normal function.
Subaortic Stenosis/Subvalvular Stenosis: Subaortic stenosis is a congenital heart defect that partially obstructs blood flow from the heart. It may cause a heart murmur, fainting, exercise intolerance, or sudden cardiac problems.
Systemic Lupus Erythematosus (SLE): SLE is an autoimmune connective tissue disease that can affect multiple organs, including the skin, joints, kidneys, blood, and nervous system.
T
Tail Fold Dermatitis: Tail fold dermatitis affects dogs with tight or deep skin folds around the tail. Moisture and bacteria can cause odor, redness, discomfort, and infection.
Tear Staining: Tear staining is discoloration under the eyes. It may be related to facial structure, blocked tear ducts, allergies, eye irritation, or chronic tearing.
Tetralogy of Fallot: Tetralogy of Fallot is a congenital heart condition involving four specific heart defects. It can cause weakness, exercise intolerance, bluish gums, or poor growth.
Thyroid Disease: Thyroid disease in dogs most often refers to hypothyroidism, although hyperthyroidism can occur. Thyroid problems can affect energy, weight, skin, coat, and metabolism.
Tracheal Collapse: Tracheal collapse is weakening of the windpipe that can cause coughing, gagging, or breathing difficulty. It is most common in small and toy breeds.
Trichiasis: Trichiasis occurs when eyelashes or facial hairs grow toward the eyeball, causing irritation, tearing, pain, or corneal injury.
U
Uric Acid Syndrome: Uric acid syndrome involves abnormal uric acid excretion and can contribute to urinary stones. It may also cause a bronze discoloration of the skin in some dogs.
Urolithiasis: Urolithiasis means stones in the urinary tract. Bladder or kidney stones can cause straining, frequent urination, blood in the urine, discomfort, or urinary blockage.
Urinary Incontinence: Urinary incontinence is involuntary urine leakage. It may be related to age, hormones, anatomy, urinary tract disease, spinal problems, or other medical conditions.
Uveitis: Uveitis is inflammation inside the eye. It can cause redness, squinting, cloudiness, pain, tearing, or vision problems and should be evaluated promptly.
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Valve Disease: Valve disease affects how blood flows through the heart. Mitral valve disease is especially common in older small dogs and may eventually lead to coughing, fatigue, or heart failure.
Vestibular Disease: Vestibular disease affects balance and coordination. Dogs may suddenly tilt their head, circle, stumble, fall, or have rapid eye movements.
Von Willebrand’s Disease: Von Willebrand’s disease is an inherited bleeding disorder caused by a deficiency or abnormality of a clotting protein. Dogs may bleed excessively after injury, surgery, or dental work.
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White Shaker Dog Syndrome: White shaker dog syndrome causes tremors, often in young small-breed dogs. Despite the name, it can affect dogs of different coat colors.
Wobbler Syndrome: Wobbler syndrome is a disease of the neck vertebrae and spinal cord. It is more common in some large and giant breeds and may cause an unsteady gait, weakness, neck pain, or coordination problems.
Orthopedic & Joint Disorders in Dogs
Orthopedic and joint disorders are among the most common breed-related health conditions in dogs. Large and giant breeds are often associated with hip dysplasia, elbow dysplasia, osteoarthritis, panosteitis, osteochondritis dissecans, cruciate ligament injuries, and wobbler syndrome. Smaller breeds may be more prone to luxating patella, Legg-Calve Perthes disease, and certain spinal problems.
Signs of orthopedic disease may include limping, stiffness, difficulty rising, reluctance to jump, trouble using stairs, weakness in the rear legs, reduced activity, or pain after exercise. Some orthopedic conditions are inherited, while others are influenced by growth rate, weight, nutrition, injury, and age.
Eye Diseases & Vision Disorders in Dogs
Canine eye diseases may be inherited, developmental, age-related, or caused by injury, inflammation, infection, or other medical conditions. Breed-related eye conditions include cataracts, juvenile cataracts, progressive retinal atrophy, glaucoma, Collie Eye Anomaly, retinal dysplasia, entropion, ectropion, distichiasis, dry eye, lens luxation, corneal dystrophy, and persistent pupillary membranes.
Dog owners should watch for squinting, redness, cloudy eyes, eye discharge, pawing at the face, bumping into objects, night blindness, or sudden vision changes. Many inherited eye diseases are important considerations for responsible breeders and breed health screening.
Heart & Cardiovascular Diseases in Dogs
Heart disease in dogs can involve the heart valves, heart muscle, heart rhythm, or congenital defects present from birth. Breed-related heart conditions may include mitral valve disease, dilated cardiomyopathy, pulmonic stenosis, subaortic stenosis, patent ductus arteriosus, aortic stenosis, arrhythmias, and heart murmurs.
Possible signs of heart disease include coughing, fatigue, fainting, weakness, exercise intolerance, rapid breathing, or difficulty breathing. Some dogs show no obvious signs early in the disease, which is why veterinary exams and breed-appropriate cardiac screening can be important.
Skin Diseases & Allergies in Dogs
Skin disease is one of the most common reasons dogs visit the veterinarian. Allergies, parasites, yeast, bacterial infections, hormonal disorders, autoimmune disease, and inherited skin conditions can all affect the skin and coat. Common conditions include atopic dermatitis, food allergies, flea allergy dermatitis, Malassezia dermatitis, hot spots, skin fold dermatitis, sebaceous adenitis, seborrhea, demodectic mange, and alopecia.
Signs may include itching, chewing, licking, hair loss, redness, odor, dandruff, ear infections, sores, scabs, or thickened skin. Because many skin problems look similar, proper diagnosis is important before choosing treatment.
Neurological Disorders in Dogs
Neurological disorders affect the brain, spinal cord, nerves, or muscles. Breed-related neurological conditions may include epilepsy, degenerative myelopathy, intervertebral disc disease, cerebellar ataxia, vestibular disease, wobbler syndrome, Chiari-like malformation, syringomyelia, white shaker dog syndrome, and inherited storage diseases.
Warning signs may include seizures, tremors, weakness, balance problems, stumbling, paralysis, head tilt, abnormal gait, behavior changes, or sudden collapse. Neurological symptoms should always be taken seriously and discussed with a veterinarian.
Digestive & Gastrointestinal Disorders in Dogs
Digestive disorders can affect a dog’s stomach, intestines, pancreas, liver, or esophagus. Common conditions include inflammatory bowel disease, colitis, pancreatitis, gastritis, exocrine pancreatic insufficiency, megaesophagus, protein-losing enteropathy, liver shunts, and bloat.
Signs of digestive disease may include vomiting, diarrhea, weight loss, gas, poor appetite, regurgitation, abdominal pain, loose stools, or failure to thrive. Some gastrointestinal conditions are inherited or breed-associated, while others may be related to diet, infection, inflammation, parasites, or other illness.
Kidney & Urinary Disorders in Dogs
Kidney and urinary disorders can include kidney disease, bladder infections, bladder stones, kidney stones, cystinuria, renal dysplasia, familial nephropathy, hereditary nephritis, Fanconi syndrome, protein-losing nephropathy, urinary incontinence, and urolithiasis.
Symptoms may include increased thirst, increased urination, accidents in the house, blood in the urine, straining, poor appetite, vomiting, weight loss, or weakness. Some urinary and kidney conditions are inherited and may be important for breed health testing.
Inherited & Genetic Conditions in Dogs
Inherited canine disorders are health conditions passed through genetics. These may affect the joints, eyes, heart, skin, blood, nervous system, kidneys, liver, or metabolism. Responsible breeders often use breed-specific health testing to help reduce the risk of inherited disease in future generations.
Examples of inherited or breed-associated conditions include hip dysplasia, elbow dysplasia, progressive retinal atrophy, Collie Eye Anomaly, von Willebrand’s disease, degenerative myelopathy, MDR1 drug sensitivity, copper storage disease, Fanconi syndrome, pyruvate kinase deficiency, phosphofructokinase deficiency, exercise-induced collapse, and many breed-specific eye, heart, and orthopedic conditions.
Genetic risk does not mean every dog of a breed will develop a disease. It does mean owners, breeders, and puppy buyers should understand which conditions are more common in a breed and what health screening may be recommended.
Common Infectious Dog Diseases
Infectious dog diseases are caused by viruses, bacteria, fungi, or parasites. These diseases may be spread through direct contact with infected animals, contaminated environments, insects, wildlife, feces, respiratory droplets, or shared spaces where dogs gather.
Parvovirus
Parvovirus is a highly contagious viral infection that primarily affects puppies and unvaccinated dogs. It attacks the gastrointestinal tract and can cause severe vomiting, bloody diarrhea, dehydration, shock, and death.
Canine Distemper
Canine distemper is a serious viral disease that can affect the respiratory, gastrointestinal, and nervous systems. Symptoms may include fever, coughing, nasal discharge, vomiting, diarrhea, seizures, and neurological damage. Vaccination is the best prevention.
Kennel Cough
Kennel cough, or canine infectious respiratory disease complex, is a contagious respiratory illness that can cause coughing, sneezing, nasal discharge, and throat irritation. It is often spread where dogs are in close contact, such as boarding kennels, grooming salons, shelters, and dog parks.
Rabies
Rabies is a fatal viral disease that affects the nervous system and can spread to people and other animals. Rabies vaccination is required by law in many areas and is one of the most important vaccines for dogs.
Leptospirosis
Leptospirosis is a bacterial disease that can affect the kidneys and liver. Dogs may be exposed through contaminated water, soil, wildlife urine, or infected animals. It can also pose a risk to people.
Lyme Disease
Lyme disease is a tick-borne illness that can cause fever, lameness, swollen joints, lethargy, and kidney complications in some dogs. Tick prevention is an important part of reducing risk.
Giardia
Giardia is an intestinal parasite that can cause diarrhea, soft stools, gas, and poor condition. Dogs may be exposed through contaminated water, feces, soil, or shared environments. Read more on our Giardia in dogs page.
Common Non-Infectious Dog Diseases
Not all dog diseases are infectious. Many health problems in dogs are caused by genetics, aging, immune system problems, injury, body structure, obesity, hormonal disease, poor dental care, or breed predisposition.
Hip Dysplasia
Hip dysplasia is a genetic and developmental orthopedic condition in which the hip joint does not form properly. It is especially common in many medium, large, and giant dog breeds. If your dog is showing signs of stiffness, limping, back pain, hip pain, or rear leg weakness, read our complete guide to Back Pain, Hip Pain, and Rear Leg Weakness in Dogs.
Heart Disease
Heart disease in dogs may be inherited, age-related, congenital, or associated with other health problems. Symptoms can include coughing, fatigue, fainting, breathing difficulty, reduced exercise tolerance, or fluid buildup.
Diabetes
Diabetes in dogs occurs when the body cannot properly regulate blood sugar. It is more common in middle-aged and older dogs and can cause increased thirst, frequent urination, weight loss, cataracts, and weakness.
Allergies
Dog allergies may be caused by food, fleas, pollen, grasses, dust, mold, or environmental triggers. Allergies are one of the most common causes of itching, ear infections, skin irritation, and chronic licking. Read our extensive information about causes, care, and treatment of dog allergies.
Preventing Dog Diseases
While some dog diseases are genetic or cannot be fully prevented, many health problems can be reduced, detected early, or managed more successfully with good preventative care. Regular veterinary visits, vaccinations, parasite prevention, dental care, proper nutrition, exercise, and breed-appropriate health screening all help protect a dog’s long-term health.
Vaccinations
Vaccinations are one of the most effective ways to prevent serious infectious dog diseases such as parvovirus, distemper, rabies, and some respiratory infections. Puppies usually receive a series of vaccines beginning at a young age, followed by boosters as recommended by a veterinarian. For more information on vaccine timing, see the AVMA Vaccination Schedule.
Regular Vet Visits
Routine veterinary exams help detect early signs of disease before symptoms become severe. Your veterinarian can check your dog’s heart, teeth, joints, skin, eyes, ears, weight, and overall condition, as well as recommend bloodwork, parasite testing, dental care, or breed-specific screening when appropriate.
Proper Nutrition and Weight Management
A balanced diet and healthy weight are important for preventing obesity and reducing stress on the joints, heart, and organs. Maintaining a lean body condition can help dogs with arthritis, hip dysplasia, diabetes risk, breathing problems, and mobility issues.
Flea, Tick, and Parasite Prevention
Parasites can cause itching, anemia, intestinal disease, skin infections, and tick-borne illnesses such as Lyme disease, Ehrlichiosis, and Rocky Mountain spotted fever. Speak with your veterinarian about flea, tick, heartworm, and intestinal parasite prevention based on your dog’s lifestyle and location. Our Fleas in Dogs page, Ticks in Dogs page, and Internal and External Parasites page provide more information.
Dental Care
Dental disease can cause pain, infection, bad breath, tooth loss, and health complications beyond the mouth. Regular dental care, veterinary dental exams, and appropriate chewing or brushing routines can help protect your dog’s teeth and gums.
Mental and Physical Exercise
Regular exercise and mental stimulation support a dog’s physical and emotional health. Daily walks, playtime, training, scent games, and enrichment can help prevent obesity, reduce stress, support joint health, and improve behavior.
Understanding Breed-Specific Dog Diseases
Many dog diseases and health conditions are more common in certain breeds because of genetics, body structure, size, coat type, or inherited traits. Large and giant dog breeds are often more likely to be discussed with orthopedic disorders such as hip dysplasia, elbow dysplasia, arthritis, osteochondritis dissecans, panosteitis, and bloat. Small and toy breeds may be more often associated with luxating patella, collapsing trachea, dental disease, Legg-Calve Perthes disease, and mitral valve disease.
Some breeds are predisposed to inherited eye diseases such as progressive retinal atrophy, cataracts, glaucoma, Collie Eye Anomaly, entropion, ectropion, lens luxation, and retinal dysplasia. Others may be more likely to develop heart disease, thyroid disorders, autoimmune disease, allergies, epilepsy, neurological disorders, kidney disease, liver disease, or breed-specific genetic conditions.
Understanding common breed-related health problems can help dog owners recognize symptoms earlier, choose responsible breeders who perform health testing, and provide better long-term care. A breed predisposition does not mean every dog of that breed will develop a condition, but it does help owners know what to watch for and what questions to ask.
Responsible breeders often use health screening for inherited canine diseases such as hip dysplasia, elbow dysplasia, eye disease, cardiac disease, thyroid disease, patellar luxation, and DNA-based genetic disorders. Puppy buyers can ask breeders which health tests are recommended for the breed, whether the parents were screened, and whether results are available through recognized canine health databases.
Rescue dogs may not always come with a complete health history, but a veterinary exam, good nutrition, parasite prevention, dental care, safe exercise, and early attention to symptoms can make a major difference. Whether a dog is purebred, mixed breed, adopted, or purchased from a breeder, learning about canine health conditions helps owners provide better care throughout the dog’s life.
Seeking Help for Dog Diseases
If you suspect your dog may have a health problem or has been diagnosed with a disease, contact your veterinarian. Online information can help you understand possible symptoms and questions to ask, but only a veterinarian can diagnose your dog and recommend the right treatment plan.
Seek veterinary help promptly if your dog has difficulty breathing, repeated vomiting, severe diarrhea, collapse, seizures, pale gums, bloated abdomen, sudden lameness, inability to walk, eye pain, urinary blockage, uncontrolled bleeding, or signs of extreme pain.
Quality of Life, Hospice Care & End-of-Life Support for Dogs
Caring for an aging or declining dog can bring difficult questions, emotional decisions, and concerns about comfort and quality of life. Our detailed guide on when it may be time to euthanize a dog offers compassionate information on hospice care, veterinary guidance, caregiver support, grief, and how to recognize when euthanasia may become the kindest option.
Helping Dogs Live Longer, Healthier Lives
Learning about dog diseases, inherited canine disorders, and breed-specific health conditions can help owners make better choices about prevention, early detection, and long-term care. While some diseases are genetic or unavoidable, many common dog health problems can be managed more successfully when they are recognized early.
Regular veterinary visits, vaccinations, parasite prevention, dental care, good nutrition, healthy weight management, exercise, grooming, and breed-appropriate health screening all play an important role in keeping dogs healthy. By staying informed and paying attention to changes in your dog’s behavior, movement, appetite, skin, eyes, breathing, and energy level, you can help your dog live a more comfortable and healthy life.
For more breed-specific health information, visit our individual dog breed pages, where we discuss each breed’s temperament, grooming needs, exercise requirements, training style, and common health concerns.