Dog Diseases Database
Every hereditary and common canine condition — with tests, affected body regions, and the breeds where each shows up most.
Filters
- SevereGeneral / metabolicUnknown
Hemophagocytic syndrome(HLH)
Hemophagocytic syndrome is a severe disorder of the immune system where the body's defense cells abnormally activate and begin destroying its own healthy blood cells, including red blood cells, white blood cells, and platelets. This destructive process primarily occurs in the spleen, bone marrow, and liver, leading to a critical shortage of vital blood components.
View details - SevereHead / nervous systemAutosomal recessive
Hereditary sensory and autonomic neuropathy, SCN9A-related(HSAN)
This is a severe, inherited nervous system disorder caused by a genetic mutation in the SCN9A gene. It disrupts the normal function of sensory nerves, which are the pathways responsible for transmitting signals like pain and temperature to the brain. Without these signals, affected dogs cannot feel pain or heat, leaving them unable to protect themselves from injury.
Tested via: DNA testView details - ModerateGeneral / metabolicUnknown
Heterotopic ossification
Heterotopic ossification is a condition where true bone tissue abnormally develops inside soft tissues like muscles, tendons, or ligaments where it does not belong. This misplaced bone growth occurs within the musculoskeletal system, typically triggered by trauma, surgery, or deep tissue injury. Over time, these hard deposits can restrict the normal movement of the surrounding joints and muscles.
Tested via: RadiographView details - ModerateGeneral / metabolicComplex
Hiatal hernia
A hiatal hernia is a physical defect in the diaphragm, which is the muscular barrier separating the chest cavity from the abdomen. This opening allows the upper portion of the stomach to slide forward into the chest, disrupting the normal passage of food and causing acid reflux.
Tested via: RadiographView details - MildGeneral / metabolicAutosomal recessive
High-activity sodium-potassium-ATPase
This genetic condition affects the red blood cells by causing overactivity in the sodium-potassium pump, which is the mechanism that regulates salt and water balance within the cells. This imbalance can cause the red blood cells to become misshapen into cup-like forms called stomatocytes, which can shorten their lifespan. It is typically identified through routine blood tests that show these abnormal cells and altered electrolyte levels.
Tested via: Clinical examView details - SevereGeneral / metabolicUnknown
Hodgkin's lymphoma
Hodgkin's-like lymphoma is an extremely rare type of cancer affecting the lymphatic system, which is a key part of the dog's immune network. In this condition, abnormal white blood cells multiply uncontrollably and accumulate within the lymph nodes, disrupting their normal function. Over time, this malignant change spreads through the entire lymphatic system of the body.
View details - MildHead / nervous systemUnknown
Horner syndrome
Horner's syndrome is a neurological condition resulting from a disruption in the sympathetic nervous system, which controls involuntary functions like pupil dilation and facial muscle tone. It is not a disease itself, but rather a collection of symptoms that can be triggered by middle ear infections, neck trauma, or tumors along the nerve pathway. In many cases, the condition is classified as idiopathic, meaning no clear underlying cause can be identified.
View details - SevereHead / nervous systemUnknown
Hydranencephaly
Hydranencephaly is a severe brain malformation affecting the central nervous system where the cerebral hemispheres, which are the main parts of the brain responsible for thought and movement, fail to develop. Instead of normal brain tissue, the space inside the skull is filled with cerebrospinal fluid. This is a congenital condition, meaning the puppy is born with the defect.
Tested via: Clinical examView details - HighHead / nervous systemComplex
Hydromyelia
Hydromyelia is an abnormal widening of the central canal within the spinal cord, which is the fluid-filled tube running through the center of the spine. This occurs when cerebrospinal fluid, the protective liquid surrounding the brain and spinal cord, builds up and puts pressure on the surrounding nerve tissue. Over time, this pressure can cause progressive damage to the nervous system.
Tested via: Clinical examView details - SevereGeneral / metabolicUnknown
Hydrops fetalis
Hydrops fetalis is a severe developmental condition where abnormal amounts of fluid build up within a puppy's tissues and body cavities before birth. This widespread fluid accumulation affects multiple organ systems, preventing normal development in the womb. Because the fluid cannot drain properly, the whole body becomes extremely swollen.
View details - HighGeneral / metabolicComplex
Hyperbilirubinemia
Hyperbilirubinemia is a metabolic condition characterized by an excess of bilirubin, a yellow pigment formed during the normal breakdown of red blood cells, in the bloodstream. This buildup typically points to an underlying issue with the liver, gallbladder, or bile ducts, which normally process and excrete this pigment. Because it is a generic metabolic phenotype with complex inheritance, it can stem from various genetic or environmental causes affecting these organ systems.
Tested via: Clinical examView details - ModerateGeneral / metabolicAutosomal recessive
Hyperbiliverdinaemia
This is a rare metabolic condition affecting the liver's enzyme system, caused by an inherited genetic deletion in the BLVRA gene. Without this functioning gene, the body cannot properly convert biliverdin, a green pigment produced during the normal breakdown of red blood cells. This leads to an abnormal buildup of the green pigment in the blood, a state known as hyperbiliverdinaemia.
View details - SevereHead / nervous systemAutosomal recessive
Hyperekplexia (Startle disease), SLC6A5-related(SD)
This is an inherited neurological disorder affecting the spinal cord and brainstem, caused by a genetic mutation in the SLC6A5 gene. This mutation disrupts the transport of glycine, a chemical messenger that normally helps quiet down nerve signals. Without proper glycine function, the nervous system cannot properly switch off signals, leading to uncontrolled over-excitation of the muscles.
Tested via: DNA testView details - SevereGeneral / metabolicUnknown
Hypereosinophilic syndrome(HES)
Hypereosinophilic syndrome is a rare disorder where the bone marrow produces an excessive number of eosinophils, which are a specialized type of white blood cell. These extra cells build up in various organs, most commonly the digestive tract, liver, and spleen. This accumulation leads to severe inflammation and progressive damage to the affected organ systems.
View details - HighGeneral / metabolicComplex
Hypergammaglobulinemia
Hypergammaglobulinaemia is an abnormal buildup of immunoglobulins, which are infection-fighting proteins (antibodies) in the blood's immune system. This condition is typically triggered by underlying chronic inflammation, infections, or bone marrow cancers. Veterinarians use a specialized blood test called serum protein electrophoresis (SPEP) to confirm the diagnosis and determine if the protein increase is uniform or diverse.
Tested via: Clinical examView details - ModerateHeartComplex
Hyperhomocysteinemia(HHcy)
This is a metabolic disorder where the body is unable to properly break down an amino acid called homocysteine, leading to its accumulation in the bloodstream. This buildup can damage the lining of the blood vessels and significantly increase the risk of blood clots. It primarily affects the cardiovascular and circulatory systems.
Tested via: Clinical examView details - SevereGeneral / metabolicUnknown
Hyperinsulinemic hypoglycemia
This is a metabolic disorder of the pancreas, where the organ uncontrollably secretes excessive amounts of insulin. Insulin is a hormone that regulates blood sugar; too much of it causes blood glucose levels to drop dangerously low, depriving the brain and muscles of energy.
Tested via: Clinical examView details - ModerateGeneral / metabolicComplex
Hyperkinesis
Hyperkinesis is a neurological disorder affecting the brain and nervous system, where a dog exhibits pathological, extreme overactivity and an inability to calm down. It is caused by a chemical imbalance of neurotransmitters, which are the chemical messengers that transmit signals in the brain. This imbalance prevents the brain from properly regulating activity levels and impulse control.
View details - HighGeneral / metabolicAutosomal recessive
Hyperlipidaemia/atherosclerosis, APOE-related
This condition is a genetic disorder of the metabolic and cardiovascular systems where a defect in the apolipoprotein E (APOE) protein prevents the normal clearance of fats from the blood. This results in severely elevated cholesterol levels, which can lead to fatty deposits in the blood vessels, a process known as atherosclerosis. Currently, this genetic defect is only known as an engineered research model, with no naturally occurring cases reported in domestic dogs.
View details - MildGeneral / metabolicUnknown
Hyperphosphatasaemia(BFH)
This condition is a harmless elevation of an enzyme called alkaline phosphatase in the dog's blood. This enzyme is normally associated with the liver and bones, but in this case, the high levels occur without any underlying disease in these organs. It is considered a benign metabolic variation rather than an active illness.
View details - HighHeartComplex
Hypertension(SHT)
Hypertension is a condition where a dog experiences chronically high blood pressure in their arteries, which are the blood vessels carrying oxygen-rich blood from the heart to the rest of the body. This constant pressure puts excessive strain on the cardiovascular system and can gradually damage vital organs, particularly the kidneys, eyes, and brain.
Tested via: Clinical examView details - MildSkin & coatUnknown
Hypertrichosis
Hypertrichosis is an uncommon skin and coat condition characterized by excessive and abnormal hair growth. This abnormal growth can affect the dog's entire body or be localized to specific areas. The exact underlying genetic cause and inheritance pattern for this condition are currently unknown.
View details - SevereHeartComplex
Hypertrophic cardiomyopathy(HCM)
Hypertrophic cardiomyopathy is a severe heart disease where the muscle walls of the heart's main pumping chamber, the left ventricle, become abnormally thick. This thickening makes the chamber stiff and reduces its volume, meaning the heart cannot fill with or pump blood efficiently. Over time, this strain on the cardiovascular system can lead to congestive heart failure.
Tested via: Cardiac examView details - SevereHead / nervous systemAutosomal recessive
Hypertrophic neuropathy(HN)
Hypertrophic neuropathy, also known as Canine Inherited Demyelinative Neuropathy (CIDN), is an inherited disorder of the peripheral nervous system. In affected dogs, the protective myelin sheath surrounding the nerves abnormally thickens, which disrupts the electrical signals traveling between the brain and the muscles. This disruption leads to progressive weakness and muscle wasting.
Tested via: DNA testView details - HighGeneral / metabolicComplex
Hypertrophic Osteodystrophy(HOD)
Hypertrophic Osteodystrophy is an inflammatory bone disease that affects the growth plates in the long bones of fast-growing, large-breed dogs. It disrupts the normal blood flow to these growth plates, leading to painful swelling and abnormal bone development in the limbs.
View details
Frequently asked questions
What is the HonestDog dog diseases database?
Our database brings together hereditary and common canine conditions with symptoms, inheritance patterns, testing methods, and the breeds where each matters most.
How do I find the right test for a condition?
Search by disease name, abbreviation or symptom, then filter by test type, body region or severity. Each detail page lists recommended tests and affected breeds.
Why do health tests matter for breeders?
Health tests help catch hereditary conditions early and support responsible breeding. Many breed clubs require or recommend specific tests as part of their screening.
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