Canine parvovirus [ In Viral Infections ]
Canine parvovirus is a sometimes fatal gastrointestinal infection that mainly affects puppies. It occurs worldwide.

Canine transmissible venereal tumor [ In Cancers ]
Canine transmissible venereal tumor is a tumor of the genitals. It is spread by sexual contact.

Cataracts [ In Eyes ]
Cataracts are an opacity in the lens of the eye. Most cataracts in dogs are caused by a genetic predisposition, but diabetes mellitus is also a common cause. The only effective treatment is surgical removal.

Cauda equina syndrome [ In Nervous System ]
Cauda equina syndrome, also known as degenerative lumbosacral stenosis, in dogs is a compression of the cauda equina by a narrowing of the lumbosacral vertebral canal. It is most commonly seen in German Shepherd Dogs. Signs include pain, weakness, and rear limb muscle atrophy.

Cerebellar abiotrophy [ In Nervous System ]
Cerebellar abiotrophy is caused by the death of Purkinje cells in the cerebellum. It results in progressive ataxia beginning at a young age. It is most commonly seen in Kerry Blue Terriers and Gordon Setters.

Cerebellar hypoplasia [ In Nervous System ]
Cerebellar hypoplasia is an incomplete development of the cerebellum. The most common cause in dogs is an in utero infection with canine herpesvirus.  It is also seen associated with lissencephaly in Wire-haired Fox Terriers and Irish Setters, and as a separate condition in Chow Chows.

Chalazion [ In Eyes ]
Chalazion is a granuloma that forms in the eyelid due to blocked secretions from the Meibomian gland. Inflammation of the eyelid may result.

Cherry eye [ In Eyes ]
Cherry eye is the term used to refer to canine nictitans gland prolapse, a common eye condition in various dog breeds where the gland of the third eyelid prolapses and becomes visible.

Cheyletiellosis [ In Parasites ]
Cheyletiellosis is a mild pruritic skin disease in dogs caused by Cheyletiella yasguri. Humans can be transiently infected.

Chiggers [ In Parasites ]
Chiggers, also known as harvest mites, can cause itching, redness and crusting in dogs.

Chocolate [ In Poisons and Overdoses ]
Chocolate is a common cause of poisoning in dogs. The toxic principles in chocolate are theobromine and caffeine. Baker's chocolate is the most dangerous form since it contains higher concentrations of these drugs, followed by semi-sweet, dark, and then milk chocolate. Signs include vomiting, diarrhea, tremors, difficulty walking, seizures, and heart problems.

Cleft lip and palate [ In Miscellaneous ]
Cleft lip and palate is occasionally seen in dogs. Difficulty with nursing is the most common problem associated with clefts, but aspiration pneumonia may be seen with a cleft palate.

Clostridium [ In Bacterial Infections ]
Clostridium species are a potential cause of diarrhea in dogs. Associated species include C. perfringens and C. difficile.

Coccidioidomycosis [ In Fungal Infections ]
Coccidioidomycosis is a fungal disease caused by Coccidioides immitis that affects both dogs and humans. In dogs signs include coughing, fever, lethargy, and anorexia. Many cases include lameness due to bome lesions.

Coccidiosis [ In Protozoal Infections ]
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.