Dog health conditions

Congenital heart defects are abnormalities of the heart that are present at birth. Development of the heart structures and function in the unborn puppy may be defective due to genetic predisposition, environmental factors in the womb, or infection.

Hypertrophic cardiomyopathy (HCM) is a rare form of heart disease in dogs which results in enlargement of the heart muscles. Excessive enlargement narrows the internal size of the heart chambers, reducing blood flow.

Pericarditis in dogs is inflammation of the pericardium, the thin sac that surrounds the heart.

Heartworm disease is caused by a roundworm parasite, Dirofilaria immitis. Dogs are exposed to the parasite through mosquito bites. Mosquitoes feed on an infected animal and pick up immature worms, then pass them to other animals they feed on later.

Heatstroke is a type of heat related illness, and is always a  life-threatening emergency. It is the direct result of thermal injury to the organs and systems within a dog’s body.

Hemangiosarcoma (HSA) describes an aggressive cancer of the blood vessels. The visceral form leads to tumors inside the body, as opposed to the skin (cutaneous) form which has its own unique characteristics.

Acute hemorrhagic diarrhea syndrome (AHDS) in dogs is a common condition characterized by sudden onset of bloody stools and dehydration. The mechanism behind AHDS is not fully understood, but bacterial involvement is possible, such as a toxin produced by Clostridium perfringens.

Hepatozoonosis is a tick-borne protozoal infection in dogs.

A hernia is a swelling caused by abdominal contents bulging out due to a defect in the surrounding muscles. Most hernias are either present at birth or result from injuries

Hip dysplasia occurs when the hip joint develops in an abnormally loose manner, creating chronic instability in the hip joint.

A Histiocytoma is a growth that develops on the surface of a dog's skin. Histiocytomas are benign, non-cancerous nodules, commonly known as round cell tumors.

Hives (urticaria) are an uncommon condition where dome-shaped bumps (wheals) develop on a dog’s skin. Hives are  most commonly caused by reactions to insect bites or allergies. Hives are rarely dangerous, although in severe cases swelling around the throat may impact breathing.

Hookworm disease describes infection with Ancylostoma or Uncinaria parasites. Hookworms are intestinal parasites and symptoms vary depending on the different species, age of onset, and severity of the worm burden.

A moist, inflamed, red, weepy, clearly defined spot on a dog’s skin is often referred to as a hot spot.

Hydrocephalus in dogs is the condition of too much fluid inside the head, often resulting in pressure on the brain.

Hyperlipidemia in dogs refers to the presence of excessive amounts of fat (lipids) in the blood, including triglycerides and/or cholesterol. Hyperlipidemia can be primary (inherited, idiopathic) or secondary to something else (e.g., diabetes mellitus, hypothyroidism, Cushing’s disease, kidney disease, certain medications).

Hyperparathyroidism in dogs refers to excessive release of parathyroid hormone from the parathyroid glands. Parathyroid hormone (PTH) is a major regulator of calcium levels in the bloodstream and responds to low blood calcium levels by increasing calcium release from the bones and absorption of calcium from food in the intestinal tract.

Canine hyperthyroidism results from the excessive production of thyroid hormones due to a functional thyroid gland tumor.

Hypertrophic Osteopathy is a bone disease where new bone information appears in the limbs of a young growing dog. Although the exact mechanisms of the inflammation is poorly understood, it is thought to be an immune-mediated disorder.

Hypothermia is defined as lower than normal body temperature. Normal body temperature of dogs is 101-102°F (38.3-39°C). Body temps of below 98°F (36.7°C) are considered hypothermic.

Hypothyroidism is a common clinical condition in dogs resulting from reduced production of thyroid hormones by the thyroid glands.