VetmemoDdx is a differential diagnosis application in small animal veterinary medicine (canine medicine and feline medicine). It is intended for veterinarians and vet students. VetmemoDdx provides very quick access to the differential diagnosis corresponding to a clinical sign or a laboratory finding observed in a dog or cat. More than 300 clinical signs and laboratory findings have been listed, each of which is associated with a complete differential diagnosis, listing the common and less commom causes that can produce this clinical sign or laboratory result. These lists of differential diagnoses have been drawn up from the most recent editions of gold-standard literature in small animal veterinary medicine and articles from recognized scientific journals. The differential diagnoses are regularly updated. A feature also makes it possible to combine several clinical signs and/or laboratory results, the application will then display a reduced differential diagnosis corresponding to the causes these clinical signs and/or laboratory results have in common. In order to facilitate research, the clinical signs reported by the animal's guardian or observed by the veterinarian are grouped into categories: general signs, cardio-respiratory signs, gastrointestinal signs, neurological signs, orthopedic signs (premium version), uro-genital signs (premium version), ophthalmological signs (premium version), dermatological signs (premium version). Similarly, laboratory results are also grouped by categories: urinalysis, hematology (premium version), biochemistry (premium version), endocrinology (premium version), electrolytes and blood gases (premium version). Laboratory analysis reference values are also provided. It is also possible for the user to directly search for the clinical sign or the laboratory result of interest using a search bar. When the user selects a clinical sign or a laboratory result, he obtains a definition of it as well as the corresponding differential diagnosis (frequent causes and rarer causes). In the premium version, the user can also combine several clinical signs and/or laboratory results (between 2 and 5). The application will then display a reduced differential diagnosis corresponding to the common causes of these clinical signs and/or laboratory results.