List of dog diseases

Infectious diseases

Viral infections

• Rabies is a fatal viral disease that can affect any mammal, although the close relationship of dogs with humans makes canine rabies a zoonotic concern. Vaccination of dogs for rabies is commonly required by law. Please see the article dog health for information on this disease in dogs.
• Canine parvovirus is a sometimes fatal gastrointestinal infection that mainly affects puppies. It occurs worldwide.
• Canine coronavirus is a gastrointestinal disease that is usually asymptomatic or with mild clinical signs. The signs are worse in puppies.
• Canine distemper is an often fatal infectious disease that mainly has respiratory and neurological signs.
• Canine influenza is a newly emerging infectious respiratory disease. Up to 80 percent of dogs infected will have symptoms, but the mortality rate is only 5 to 8 percent.
• Infectious canine hepatitis is a sometimes fatal infectious disease of the liver.
• Canine herpesvirus is an infectious disease that is a common cause of death in puppies less than three weeks old.
• Pseudorabies is an infectious disease that primarily affects swine, but can also cause a fatal disease in dogs with signs similar to rabies.
• Canine minute virus is an infectious disease that can cause respiratory and gastrointestinal signs in young puppies.

  Bacterial infections

• Brucellosis is a sexually transmitted bacterial disease that can cause uveitis, abortion, and orchitis in dogs.
• Leptospirosis is an infectious disease caused by a spirochaete. Symptoms include liver and kidney failure and vasculitis.
• Lyme disease* is a disease caused by Borrelia burgdorferi, a spirochaete, and spread by ticks of the genus Ixodes. Symptoms in dogs include acute arthritis, anorexia and lethargy. There is no rash as is typically seen in humans.
• Ehrlichiosis is a disease caused by Ehrlichia canis and spread by the brown dog tick, Rhipicephalus sanguineus. Signs include fever, vasculitis, and low blood counts.
• Rocky Mountain spotted fever* is a rickettsial disease that occurs in dogs and humans. It is caused by Rickettsia rickettsii and spread by ticks of the genus Dermacentor. Signs are similar to human disease, including anorexia, fever, and thrombocytopenia.
• Clostridium species can cause diarrhea in dogs. Associated species include C. perfringens and Clostridioides difficile.
• Kennel cough is an infectious respiratory disease that can be caused by one of several viruses or by Bordetella bronchiseptica. It most commonly occurs in dogs in close confinement such as in kennels.

  Fungal infections

• Blastomycosis* is a fungal disease caused by Blastomyces dermatitidis that affects both dogs and humans. Dogs are ten times more likely to be infected than humans. The disease in dogs can affect the eyes, brain, lungs, skin, or bones.
• Histoplasmosis* is a fungal disease caused by Histoplasma capsulatum that affects both dogs and humans. The disease in dogs usually affects the lungs and small intestine.
• Coccidioidomycosis* is a fungal disease caused by Coccidioides immitis or Coccidioides posadasii that affects a variety of species, including dogs. In dogs signs of primary pulmonary disease include a cough, fever, weight loss, anorexia, and lethargy. Disseminated disease occurs when the fungus has spread outside of the lungs and may include clinical signs such as lameness, pain, seizures, anterior uveitis, and localized swelling. Diagnosis of Valley Fever may include multiple tests, including serology and radiology. According to a study performed in the Tucson and Phoenix area, 28% of dogs will test positive for exposure to the fungus by two years of age, but only 6% of the dogs will be ill with clinical disease. There is an increased risk of infection associated with amount of time spent outdoors, a larger roaming space accessed by the dog, and increasing age.
• Cryptococcosis* is a fungal disease caused by Cryptococcus neoformans that affects both dogs and humans. It is a rare disease in dogs, with cats seven to ten times more likely to be infected. The disease in dogs can affect the lungs and skin, but more commonly the eye and central nervous system.
• Ringworm is a fungal skin disease that in dogs is caused by Microsporum canis, Microsporum gypseum, and Trichophyton mentagrophytes. Typical signs in dogs include hair loss and scaly skin.
• Sporotrichosis is a fungal disease caused by Sporothrix schenckii that affects both dogs and humans. It is a rare disease in dogs, with cat and horse infections predominating in veterinary medicine. The disease in dogs is usually nodular skin lesions of the head and trunk.
• Aspergillosis* is a fungal disease that in dogs is caused primarily by Aspergillus fumigatus. Infection is usually in the nasal cavity. Typical signs in dogs include sneezing, nasal discharge, bleeding from the nose, and ulcerations of the nose.
• Pythiosis is a disease caused by a water mould of the genus Pythium, P. insidiosum. It occurs primarily in dogs and horses, but can also affect humans. In dogs it affects the gastrointestinal system and lymph nodes, and rarely the skin.
• Mucormycosis is a collection of fungal and mold diseases in dogs including pythiosis, zygomycosis, and lagenidiosis that affect the gastrointestinal tract and skin.

  Protozoal diseases

• Giardiasis* is an intestinal infection in dogs caused by the protozoa Giardia lamblia. The most common symptom is diarrhea. The zoonotic potential of giardiasis is controversial.
• Coccidiosis can be caused by a variety of coccidian organisms in dogs, most commonly Isospora. There are usually no symptoms, but diarrhea and weight loss may occur.
• Leishmaniasis* is spread by the sandfly, and in the dog as well as human has both cutaneous and visceral forms. The dog is considered to be the reservoir for human disease in the Americas.
• Babesiosis* is spread by members of the family Ixodidae, or hard ticks. The two species of the genus Babesia that affect dogs are B. canis and B. gibsoni. Babesiosis can cause hemolytic anemia in dogs.
• Neosporosis* is caused by Neospora caninum
• Protothecosis in dogs is caused by a mutant form of green algae and is usually disseminated. Symptoms include weight loss, uveitis, retinal detachment, and anal seepage.

  Parasites

Internal parasites (endoparasites)

• Trichinosis caused by Trichinella spiralis, T. britovi.
• Echinococcosis is an infectious disease infecting dogs and sheep.
• Heartworm disease is caused by Dirofilaria immitis, which uses the mosquito as its vector. Heartworms live in the pulmonary artery and right ventricle of the heart. Heartworm disease in dogs is spread by mosquitoes that harbor the parasite Dirofilaria immitis. Signs include cough, difficulty breathing, and death.
• Gnathostomiasis is a disease from mammal feces and undercooked seafood.
• Intestinal parasites
• *Hookworms* are a common parasite of dogs. The most common is Ancylostoma caninum, followed by Uncinaria stenocephala and A. braziliense. Signs include diarrhea, vomiting, and weight loss.
• *Tapeworms* are also common and in the dog are usually Dipylidium caninum, which is spread by ingesting fleas and lice. Also common is Taenia pisiformis, spread by ingesting rabbits and rodents. Rare tapeworm infections are caused by species of the genera Echinococcus, Mesocestoides, and Spirometra. There are usually no symptoms.
• *Toxocariasis is an infection of Toxocara canis or Toxascaris leonina. Signs are usually mild, but may include diarrhea, pot-bellied appearance, poor growth, and vomiting.
• *Whipworms are parasites that live in the cecum and large intestine. The canine whipworm is Trichuris vulpis.

  External parasites (ectoparasites)

• Fleas* cause itching and hair loss. The most common flea in dogs is the cat flea, Ctenocephalides felis, followed by the dog flea, C. canis.
• Ticks* are an external parasite of the dog and can spread diseases such as Lyme disease, Rocky Mountain spotted fever, babesiosis, and ehrlichiosis. They can also cause a neurological disorder known as tick paralysis.
• Mites
• * Ear mites are microscopic members of the species Otodectes cynotis. Symptoms include itching, inflammation, and black debris in the ear.
• * Cheyletiellosis is a mild pruritic skin disease caused by Cheyletiella yasguri. Humans can be transiently infected.
• * Chiggers*, also known as harvest mites, can cause itching, redness and crusting of the skin.
• * Demodicosis, also known as demodectic mange, is caused by Demodex canis mites which live in small numbers in sebaceous glands and hair follicles. These mites can cause inflammation and hair loss, and may also lead to secondary bacterial infections such as fever, lethargy, and enlarged lymph nodes.
• * Sarcoptic mange is caused by Sarcoptes scabiei canis. Signs include intense itching and scaling, and is contagious to humans.

  Diseases and disorders by system

Skeletal and muscular disorders

• Osteoarthritis*, also known as degenerative arthritis, is a common condition in dogs characterized by progressive deterioration of articular cartilage in the joints of the limbs. It can cause a great deal of pain and lameness. Treatment options include medications such as NSAIDs, corticosteroids, and joint fluid modifiers such as glycosaminoglycans. Other treatments include surgery, massage, warm compresses, chiropractic, and acupuncture.
• Hip dysplasia is an inherited disease in dogs that is characterized by abnormal development of the acetabulum and head of the femur. It is more common in large breeds.
• Elbow dysplasia is a condition found more commonly in large breeds. It incorporates several different hereditary conditions of the elbow, including osteochondritis of the medial condyle of the humerus, fragmentation of the medial coronoid process of the ulna, and ununited anconeal process of the ulna.
• Luxating patella is a medial or lateral displacement of the patella, or kneecap. It is strongly suspected to be inherited, but can also result from trauma. It is more common in smaller breeds of dogs
• Osteochondritis dissecans is separation of immature articular cartilage from underlying bone. It is caused by osteochondrosis, which is characterized by abnormal endochondral ossification of epiphyseal cartilage. It is most commonly seen in the stifle, elbow, shoulder, and hock.
• Panosteitis is a common disease of unknown cause that causes pain and a shifting leg lameness in medium and large breed dogs. It affects the long bones of the hind and forelimbs.
• Legg–Calvé–Perthes syndrome, also known as Perthes disease or avascular necrosis of the femoral head, is characterized by a deformity of the head of the femur and hip pain. It occurs in small-breed puppies.
• Back pain* in dogs, particularly in long-backed breeds, such as Basset Hounds and Dachshunds, is usually caused by intervertebral disk disease. It is caused by degeneration and protrusion of the disk and compression of the spinal cord. It occurs most commonly in the cervical and thoracolumbar regions. Signs include back pain, hind limb weakness, and paralysis.
• Congenital vertebral anomalies, including butterfly, block, and transitional vertebrae, and hemivertebrae, are a collection of malformations of the spine in animals. Most are not clinically significant, but they can cause compression of the spinal cord by deforming the vertebral canal or causing instability.
• Craniomandibular osteopathy is a hereditary disease in West Highland White Terriers and also occurs in other terrier breeds. It is a developmental disease in puppies causing extensive bony changes in the mandible and skull. Signs include pain upon opening the mouth.
• Hypertrophic osteopathy is a bone disease secondary to disease in the lungs. It is characterized by new bone formation on the outside of the long bones.
• Hypertrophic osteodystrophy is a bone disease in rapidly growing large breed dogs. Signs include swelling of the metaphysis, pain, depression, loss of appetite, and fever. The disease is usually bilateral in the limb bones.
• Spondylosis*, known as spondylosis deformans in dogs, is growth of osteophytes on the ventral and lateral surfaces of the vertebral bodies. It is usually an incidental finding on radiographs and rarely causes symptoms.
• Masticatory muscle myositis is an inflammatory disease in dogs affecting the muscles of the jaw. Signs include swelling of the jaw muscles and pain on opening the mouth. In chronic MMM there is atrophy of the jaw muscles, and scarring of the masticatory muscles due to fibrosis may result in inability to open the mouth.