during october 2004september 2006 , the sentinel surveillance system was implemented in 61 veterinary clinics ( 30 during the first year and another 31 during the second year ) located in 34 districts of santiago ( population 5.4 million ) . pet population estimates ( 1,117,192 dogs ; 518,613 cats ) were derived from a study conducted previously in santiago ( 4 ) and corresponded to a rate of 1 sentinel centers per 27,000 pets . sentinel centers were asked to participate on a voluntary basis and were grouped similarly to the human health services , following geographic criteria . of the 12 notifiable infectious diseases in the surveillance system , 5 were nonzoonotic ( distemper , canine infectious tracheobronchitis , feline respiratory complex disease , feline leukemia , and hemorrhagic gastroenteritis ) , and 7 were zoonotic ( giardiasis , brucellosis , leptospirosis , rabies , ehrlichiosis , scabies , and tinea infection ) . laboratory confirmation was required for diagnosis of giardiasis , brucellosis , leptospirosis , and rabies . they were trained in operative definitions and procedures , which included submitting a weekly report of the total number of cases seen . participation in the study was voluntary ; no funding or incentives were offered . during the 2-year period , 8,167 cases were reported : 6,974 ( 85.4% ) in dogs and 1,193 ( 14.6% ) in cats . of these dogs and cats , also , 4,524 ( 64.9% ) dogs and 503 ( 42.2% ) cats were < 1 year of age . data submitted during the first year of surveillance accounted for 67.5% of canine and 66.7% of feline diseases notifications . a negative correlation was found between the average number of notifications per sentinel center ( anc ) and time ( 8 trimesters ) for dogs (  0.95 , p<0.01 ) and cats (  0.93 , p<0.01 ) . a positive correlation , although not statistically significant , was found between the average poverty rate of the districts located in each health service ( 5 ) and the anc for dogs (  + 0.77 , p = 0.07 ) and cats (  + 0.43 , p = 0.40 ) ( table 1 ) . * first year of pilot surveillance system  average poverty rate of the districts belonging to each health service . during the 2-year surveillance period , 4 canine diseases ( hemorrhagic gastroenteritis , distemper , scabies , and infectious tracheobronchitis ) accounted for 90.1% of notifications , and 3 feline diseases ( respiratory disease complex , feline leukemia , and tinea ) accounted for 98.4% of notifications ( table 2 ) . for each disease , anc during the first year of surveillance was calculated for centers located in south  east health service ( sehs ) , which had the highest poverty rate of its districts , and east health service ( ehs ) , which had the lowest . for canine diseases , the ratios of anc for sehs / anc for ehs were 3.5 ( scabies ) , 2.5 ( distemper ) , 2.2 ( hemorrhagic gastroenteritis ) , and 1.8 ( infectious tracheobronchitis ) ; for feline diseases , these ratios were 1.2 ( respiratory disease complex ) , 1.1 ( feline leukemia ) , and 0.7 ( tinea ) . * all health services , first and second year of surveillance . for each of the 7 diseases , we calculated the following ratio : total no . notifications for the whole surveillance period for all sentinel centers for pets < 1 year of age / total no . notifications for the whole surveillance period for all sentinel centers for pets > 1 year of age . diseases most commonly occurring in pets < 1 year of age were hemorrhagic gastroenteritis ( 10.9 ) and distemper ( 3.1 ) ; on the contrary , diseases whose ratio favors pets > 1 year of age were feline leukemia ( 0.17 ) and infectious tracheobronchitis ( 0.43 ) . scabies in dogs , feline respiratory disease complex , and tinea in cats had ratios of 1.00 ( 1.07 , 0.96 , and 0.92 , respectively ) . this pilot surveillance system indicated that overall notifications predominated for pets with 3 characteristics : canine , male , and age < 1 year . these characteristics partially reflect the species and sex distribution of pets in the city , as shown by a household survey of 2,100 homes in 7 districts of santiago during 2001 , which showed that 55.7% of household pets were dogs ( 62.3% males , 16.0% < 1 year of age ) , and 23.5% were cats ( 57.9% males , 15.0% < 1 year of age ) ( m.a . however , according to our data , the predominance of notifications for animals < 1 year of age seems to represent a higher risk associated with being < 1 year of age . the finding that 4 canine and 3 feline diseases were most frequently reported may be useful in many settings , such as disease control prioritization and identification of topics of interest for investigation . from a human health perspective , 1 canine disease ( scabies ) was zoonotic and 2 others ( hemorrhagic gastroenteritis and infectious tracheobronchitis ) included zoonotic agents in their list of possible etiologies ; thus , the information provided by the surveillance system is useful for human physicians and policy makers . this finding is especially relevant because certain pet diseases may occur on a socioeconomic gradient , affecting a greater proportion of persons in the lowest socioeconomic districts . this socioeconomic gradient could have been underestimated in our study because pet owners in chile must pay for the healthcare of their pets , and the likelihood of diagnostic tests being performed for diseases requiring laboratory confirmation is low , especially in the poorest areas of the city . we also did not account for the overall number of veterinary clinics that exist in each district , making estimation of disease notification rates among districts or health services , impossible . the finding that the most prevalent diseases were preventable by vaccination ( e.g. , distemper ) raises questions about the coverage and quality of vaccinations among pets in santiago . the validity of this pilot surveillance system is limited because the overall anc showed a declining trend during the 2 years of surveillance . this trend probably does not represent reduced incidence of infectious diseases among pets in santiago ; on the contrary , it may illustrate the difficulty of maintaining a private surveillance system based on professional motivation , a key element for ensuring the sustainability of such a system over time . this pilot surveillance system may motivate other investigations regarding zoonotic infections of pets in chile . the resulting information would provide the data needed to calculate disease incidence rates and establish unbiased comparisons , which can be used to further the goal of improved pet and human health .
pet diseases may pose risks to human health but are rarely included in surveillance systems . 
 a pilot surveillance system of pet infectious diseases in santiago , chile , found that 4 canine and 3 feline diseases accounted for 90.1% and 98.4% of notifications , respectively . 
 data also suggested association between poverty and pet diseases .