Streptococcal infections in cats: ABCD guidelines on prevention and management

Abstract

Overview: Streptococcus canis is most prevalent in cats, but recently S equi subsp zooepidemicus has been recognised as an emerging feline pathogen.

S canis infection: S canis is considered part of the commensal mucosal microflora of the oral cavity, upper respiratory tract, genital organs and perianal region in cats. The prevalence of infection is higher in cats housed in groups; and, for example, there may be a high rate of vaginal carriage in young queens in breeding catteries. A wide spectrum of clinical disease is seen, encompassing neonatal septicaemia, upper respiratory tract disease, abscesses, pneumonia, osteomyelitis, polyarthritis, urogenital infections, septicaemia, sinusitis and meningitis.

S equi subsp zooepidemicus infection: S equi subsp zooepidemicus is found in a wide range of species including cats. It was traditionally assumed that this bacterium played no role in disease of cats, but it is now considered a cause of respiratory disease with bronchopneumonia and pneumonia, as well as meningoencephalitis, often with a fatal course. Close confinement of cats, such as in shelters, appears to be a major risk factor. As horses are common carriers of this bacterium, contact with horses is a potential source of infection. Additionally, the possibility of indirect transmission needs to be considered.

Diagnosis: Streptococci can be detected by conventional culture techniques from swabs, bronchoalveolar lavage fluid or organ samples. Also real-time PCR can be used, and is more sensitive than culture.

Treatment: In suspected cases, treatment with broad-spectrum antibiotics should be initiated as soon as possible and, if appropriate, adapted to the results of culture and sensitivity tests.

Figure 1

In adult cats, S canis infection is usually opportunistic as a result of wounds, surgery, immunosuppression or viral infection. In this shelter cat, viral infection was severely complicated by secondary bacterial infection due to poor hygienic conditions. Courtesy of Tadeusz Frymus, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Poland

Figure 2

In some cats suffering from upper respiratory tract disease, S canis can be isolated from the nasal cavity. Courtesy of Tadeusz Frymus, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Poland

Figure 3

Purulent nasal discharge and cough may be early signs of S equi subsp zooepidemicus-related disease in cats. Courtesy of Tadeusz Frymus, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Poland

Figure 4

In cats succumbing to fatal S equi subsp zooepidemicus infection, the major necropsy finding is severe, acute and diffuse bronchopneumonia. Courtesy of Karolina Kozlowska, Warsaw, Poland