Significant unmet needs within veterinary care, including a lack of drugs for senior animals, underdeveloped research in areas such as veterinary oncology, and a scarcity of novel drugs, diagnostic aids, treatment monitoring, and vaccines, are driving veterinarians to treat animals such as dogs, cats and horses by prescribing drugs intended for human use, according to business intelligence provider GBI Research.

The company's latest report states that the most significant drivers of Extralabel Drug Use (ELDU) in animals are financial.

Unlike the human drugs market, veterinary clinics are involved not only in diagnosis and treatment, but also have the right to dispense pet medications.

Consumers cannot purchase the prescribed medications from a pharmacy of their choice, where there would be access to low-priced generic drugs, and human treatments may be a viable alternative.

Ms Deekshita Allavarapu, Analyst for GBI Research, says: "A blockbuster drug in human health generates revenues in excess of $1 billion, whereas the animal health market's highest selling drugs achieve $50-100 million, with around 85% of animal sales reaching less than $1 million. In this way, many manufacturers of veterinary drugs are looking for products already licensed for human use to fill their pipelines."

Despite these drivers, there are safety, legal, ethical, and health issues associated with ELDU in animals.

For instance, prescribing a human drug for veterinary use has its own risks. Mammalian species share many basic similarities in terms of responses to drugs, but there are differences seen at the cellular level, meaning responses may differ.

Another possibility might be that a human drug is prescribed despite the presence of a veterinary-approved alternative due to affordability issues, meaning a veterinarian could face legal issues.

Ms Allavarapu concludes: "Despite such problems, the intersection between human and veterinary medicine is a very important and emerging area that GBI Research believes will receive more focus in the years to come. For example, specially designed clinical trials are currently being run in which pets can be enrolled alongside human patients."