Feline infectious peritonitis is a viral infectious disease caused by a mutated strain of feline coronavirus. The disease is more common in group held-cats like those from the kennels or the shelters. The frequency is higher among kittens and young cats. The virulence and infectious dose depend on the virus biotype and serotype. Once the feline infectious peritonitis has become clinically overt the mortality rate is extremely high. The primary sources of infection are sick cats and carriers and the secondary sources of infection are contaminated objects. The disease is spread mainly horizontally, by indirect contact. The faecal-oral route of transmission is the most common way of transmission because the faeces contains a high amount of feline coronavirus. The incubation period can last between two days and a couple of months. Two different forms of the disease have been distinguished: the wet and the dry form. The wet form is characterized by the accumulation of fluid in the body cavities and the dry form with granulomatous lesions. Most often, a firm differentiation cannot be made between these two forms of the disease and that is furthermore confirmed by the pathoanatomical and patohistological findings. Diagnosing the disease during life is often complicated and difficult to carry out. A reliable diagnosis is established by the visualization of the virus in the samples of the tissue by immunohistochemistry. Considering the invasiveness of the method and often the poor health of the cat, immunohistochemistry is usually performed post mortem. The impossibility of establishing a reliable diagnosis of the disease ante mortem, the lack of definitive diagnostic tests and a high mortality rate have caused reluctance among veterinarians to make a definitive diagnosis even in obvious cases. Furthermore, considering lack of etiological therapy and the poor prognosis of the disease, most cats are euthanized. More recent research on antiviral drugs, among which, primarily nucleoside analogues, has shown promising results in treating feline infectious peritonitis. To date, several studies have been conducted that have shown the high efficiency of the treatment of feline infectious peritonitis with nucleoside analogue GS 441524. The research has proven its efficiency in treating both forms of the disease while at the same time the drug did not show toxicity. The problem lies in the fact that the nucleotide analogue GS 441524, sold under the factory name Remdesivir, made by company Gilead Sciences is currently licenced only for use in the treatment of humans. Unavailability of the drug for veterinary use, 41 difficulty in making a reliable diagnosis ante mortem and insufficient awareness of veterinary practitioners of advances in feline infectious peritonitis treatment have led to a halting in the progress of the treatment of the disease.