Common Dog Illnesses and Symptoms

Dogs may be affected by a number of illnesses; these may be caused by viruses, bacteria, chemicals or by hereditary factors. Knowing about some of the most common dog illnesses is important for any dog owner.

Canine Distemper

The canine distemper is a common illness in dogs and may occur in puppies that haven’t received vaccines. The distemper is caused by a virus and will cause symptoms such as lack of appetite, shaking, panting and fever. In advanced cases, the brain will be inflamed and this may lead to death.


The parvovirus is a severe infection caused by a virus and is more common in puppies. Symptoms of this infection include internal hemorrhaging, vomiting, diarrhea, lack of appetite, dehydration and weight loss. The disease may be fatal. 

Kennel Cough

The kennel cough, also called tracheobronchitis, canine infectious tracheobronchitis, Bordetellosis or Bordetella is a respiratory infection that is highly contagious. The infection will be signaled by dry coughing and lack of appetite.

Infectious Hepatitis

The infectious hepatitis is caused by a virus and will cause jaundice, intestinal bleeding and liver damage. Some dogs may not display any symptoms. The condition may become severe and may even cause inflammation of the brain.


Poisoning may occur due to the ingestion of different ingredients that are toxic for the dog. The ingestion of rat poison, garlic, chocolate, alcohol or toxic plants may cause symptoms such as vomiting, diarrhea, excessive salivation, shaking, seizures and sudden collapse.

Heart Problems

Heart problems may be inherited, but may also be linked to an excess of weight and old age. Heart problems may cause panting, exercise intolerance and sudden collapse.

Thyroid Problems

Thyroid problems may occur in dogs due to a dysfunctional thyroid gland. The real cause of these problems hasn’t been established yet.

Thyroid problems may be of 2 types: hypothyroidism (causing symptoms such as dry, flaky skin, coarse coat) or hyperthyroidism (causing oily skin and coat, weight loss).


Dermatitis is a very common condition in dogs and may be caused by different irritants. The symptoms will include red, swollen skin, hair loss and secondary bacterial or fungal infections.


Allergies may be of several types, depending on the causes of the allergies: food, inhalant, contact or allergies caused by parasites.

The symptoms range from skin itchiness, rashes, excessive scratching and chewing of affected areas to wheezing, sneezing, vomiting or diarrhea.

Heat Stroke

The heat stroke may be caused by prolonged exposure to heat. The symptoms of a heat stroke include vomiting, excessive salivation, fainting, breathing problems, seizures and even coma.

Hip Dysplasia

Hip dysplasia may be caused by old age or may be an inherited condition. The dog will display symptoms such as stiffness, hesitation to perform certain movements, lethargy and depression.


Arthritis or joint pain affects senior and obese dogs. The condition will cause a lot of pain and the dog will avoid jumping or running, spend more time sleeping and may even cry due to pain, especially when moving the affected joints.