Dog with toxic shock-like syndrome from mixed bacterial infection

Abstract

Toxic shock syndrome (TSS) is a serious, often fatal disease, rarely occurring in dogs via infection with Staphylococcus and Streptococcus. The development of TSS is mainly dependent on the presence of bacterial toxins recognized to be potent superantigens causing the release of massive amounts of host inflammatory cytokines, notably TNF-α, progressing to high fever, hypotension, haemoconcentration, thrombosis and neutrophil and endothelial activation with multiple organ failure. Rarely, TSS is associated with erythematous and exfoliative dermatitis progressing to ulceration with extremely extensive dermo-epidermal detachment, which is often very painful. Like in humans, very little is known about the transmission and prevention of this condition. In our paper, a case of TSS-like caused by a mixed bacterial infection with Staphylococcus aureus, Streptococcus halichoeri and Dermatophilus spp. has been described in an 11 year-old, cross-breed male dog, most probably following injury due to biting and fighting. Lesions consisted of severe and diffuse ulceration on the dorsum, and bacterial culture/cytology led to the isolation and identification of Gram-positive staphylococci and streptococci associated with an intense neutrophil reaction. Dermatophilus spp. was presumed morphologically based on cytological preps, not by culture or molecular analysis. PCR demonstrated the presence of the nuc thermonucleaze gene (for S. aureus confirmation) together with the genes encoding enterotoxin H (seh), protein A (spa), toxic shock syndrome toxin TSST-1 (tst) and methicillin resistance (mecC); the exfoliative toxins (eta, etb) were detected. Clinical signs, cytology, bacterial culture and the response to systemic antibiotic therapy were compatible with a TSS-like diagnosis. The patient has completely recovered after 1 year of treatment.