Cardiomyopathy, Feline
Heart disease, Heart muscle failure

Cat Scratch Disease, Feline
Cat scratch disease or fever

Chronic Renal Failure, Canine
Kidney failure, renal insufficiency

Chronic Renal Failure, Feline
Kidney failure, renal insufficiency, renal disease

Coccidiosis, Canine and Feline
Coccidia

Corneal Ulcers, Canine and Feline
Corneal ulcer

Coronavirus Disease, Canine
Coronavirus disease, Viral inflammation of the small intestine

Cruciate Ligament Rupture, Canine
Ruptured cruciate, Ruptured ligament, Ruptured anterior cruciate ligament (ACL), Torn ACL, Torn ligament

Cushing's Disease, Canine
Cushing's disease, Cushing's syndrome

Cystitis, Canine
Bladder inflammation

Declawing, Feline
Declawing

Demodectic Mange, Canine
Red mange, follicular mange

Dental Disease, Canine
Dental disease, tooth decay, gum disease

Dental Disease, Feline
Dental disease

Diabetes Mellitus, Canine
Diabetes, diabetic

Diabetes Mellitus, Feline
Diabetes, sugar

Diabetic Ketoacidosis, Canine
DKA, ketoacidotic diabetes mellitus (KADM)

Diarrhea, Canine and Feline
Diarrhea

Dilated Cardiomyopathy, Canine
Dilated cardiomyopathy, DCM

Distemper Virus, Canine
Distemper, Hardpad disease

Distemper Virus, Feline
Feline distemper

Dominance Aggression, Canine
Aggression