**6. Acknowledgment**

50 Non-Flavivirus Encephalitis

occurs in 13% of cases (Bosnic et al. , 2010; Cianfoni et al., 2010). As highlighted in our case, *Nocardia* generally causes solitary brain lesions, but cases have also been reported of multiple abscesses, which are very rare in dogs (Smith et al., 2007; Munana, 1996; Kaplan, 1985). The disease has been reported in the brain of immunocompromised dogs and humans due to concomitant diseases (systemic lupus erythematosus or AIDS) or immunosuppressive therapy (cyclosporine, chemotherapy) (Smith et al., 2007). Brain infections can occur after penetrating trauma, due to extension of infection to adjacent structures (internal ear and dental root) or via the bloodstream (Dow et al. , 1988; Munana,

**Protothecosis** is caused by achlorophil algae of the genus *Prototheca*, including five species widely distributed in the environment, especially in organic matter. It is considered an emerging disease in humans and animals. Infection occurs primarily through skin lesions in contact with contaminated water, but the algae can colonize the skin, even the nails, the respiratory and digestive systems. In cattle the algae cause clinical and subclinical mastitis refractory to treatment, with high economic losses and potential risk to public health; systemic forms are rare (Marques et al., 2006). In dogs and cats it can present both as localized cutaneous and systemic forms (Ginel et al., 1997; Dillberger et al., 1988; Krohne, 2000); respiratory and cutaneous forms have also been reported in the goat (Macedo et al.,

Systemic protothecosis involving the eye and the CNS have been reported in dogs (Stenner et al., 2007); in our case only cerebral lesions were found. In humans the disease has low pathogenicity in immunocompetent subjects, with local indolent skin lesions, whereas in the immunocompromised it may occur as a scattered form and not infrequently associated with such other pathogens as *Candida*, *Staphylococcus aureus*, herpes simplex, and *Cryptococcus*

**Rickettsiosis** was diagnosed in only one subject in this series; the disease is caused by an obligate intracellular organism considered to be an intermediate form between a virus and a bacterium of the genus *Rickettsiae*. The disease is a tick-borne zoonosis. Many *Rickettsiae* cause diseases involving the CNS in animals and humans (Parola et al., 2005), one of the most important is *R. conorii* transmitted by the dog tick (*Rhipicephalus sanguineus*) that causes Mediterranean spotted fever in humans. In recent years, the number of cases of rickettsiosis in dogs and humans has increased significantly in Italy, in conjunction with climate change (temperature and rainfall) and environmental (human-dog contact) factors that allow for prolonged survival of the carrier. The most affected regions are Sicily, Sardinia, Latium, Liguria and Piedmont (Garavelli et al., 1990; Cocco et al., 2003; Cascio et al., 2006; Beninati et

Given the wide diffusion of the vector and the pathogen in Italy, the incidence of rickettsiosis was surprisingly low in this series, which may have been due to the fact that many cases go undiagnosed or are asymptomatic without showing neurological signs and are not recognized. Vector control is an indispensable means to prevent diseases transmitted by ticks; rickettsioses should therefore always be included in the differential diagnosis of

In our investigation, among the many neurological cases potentially attributable to infectious agents, about 27% were confirmed as a zoonosis, but there remain many cases of

cases with neurological signs, especially following an arthropod bite.

1996). Drug therapy is not always effective.

2008).

al., 2002).

**5. Conclusions** 

spp. (Lass-Florl et al. , 2007).

We thank Debora Corbellini, Caterina Lucia Florio, Paola Gazzuola, Tiziana Avanzato and Saverio Bessone for their technical assistance.

The authors declare that this study was carried out under the following Research Projects: IZSPLV 14/06; IZSPLV 13/08 ; Monitoring Project "A new strategy to deal with the TSE in Italy" funded by the Ministry of Health; Research Project "Monitoring of Streptococcus suis infections in pigs fattening farm " funded by Cassa di Risparmio di Cuneo.
