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Decline in hospitalisations due to dog bite injuries in Catalonia, 1997–2008. An effect of government regulation?
  1. Joan R Villalbí1,2,
  2. Montse Cleries3,
  3. Susana Bouis1,
  4. Víctor Peracho1,
  5. Julia Duran1,
  6. Conrad Casas1,2
  1. 1Agència de Salut Pública de Barcelona, Barcelona, Spain
  2. 2CIBER ESP, Spain
  3. 3Divisió de Gestió de Registres d'Activitat, Servei Català de la Salut, Barcelona, Catalonia, Spain
  1. Correspondence to Dr Joan R Villalbí, Agència de Salut Pública de Barcelona, Pl Lesseps 1, 08023 Barcelona, Catalonia, Spain; jrvillal{at}


Objective To analyse population-based data on hospitalisation caused by dog bite injuries after changes in legal regulations on dog ownership, including breed-specific regulations.

Design Descriptive study.

Setting Hospitals in Catalonia (Spain), 1997–2008.

Subjects Persons hospitalised with injuries caused by dog bites.

Results There has been a significant decline in hospitalisation caused by injuries from dog bites from 1.80/100 000 in 1997–9 to 1.11/100 000 in 2006–8, after the enactment of stricter regulations on dog ownership in 1999 and 2002. The magnitude of this change is significant (−38%), and has been greatest in less urban settings.

Conclusions Government regulations were associated with a sizable decrease in injuries caused by dog bites in Catalonia. More evaluative studies in this field may provide criteria to focus future regulations and other preventive interventions.

  • Injury
  • dog bites
  • hospitalisation
  • epidemiology
  • government regulation
  • evaluation
  • government
  • health services
  • legislation

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Animal bites in humans are a public health problem. Over the last few years, dog bite injury episodes involving children have received high media exposure, resulting in rising public concern. As a result, regulations on dog ownership and breed-specific regulations have been adopted in many countries, sometimes with controversy.1–3 The objective of this study was to analyse existing population-based data from Catalonia (Spain) on hospitalisations caused by dog bite injuries after the adoption of legal regulations in this field. The aim was to see if the data suggest noticeable changes after their adoption.4

Materials and methods

The study is based in Catalonia, Spain (population 7.2 million). Since 1991, acute care hospitals have been reporting their activity through the CMBDAH (hospital discharge basic minimal dataset in its Catalan acronym); data in this information system include inpatient characteristics and details of each hospitalisation such as main and secondary diagnoses, currently coded with the 9th revision of the International Classification of Diseases (ICD).5 These data are compiled and analysed, statistics and reports are published periodically, and information is available for specific enquiries or studies.5 6

For this study, information was collected on all hospital discharges financed by the Catalan Health Service for the 12 years from 1997 to 2008. All cases for which dog bite was present as an external cause code (ICD-9-CM code E906.0) were included, sorted by place of residence (the city of Barcelona versus the rest of Catalonia). The Catalan Statistics Institute (IDESCAT) provided the population estimates from the municipal population counts to be used as denominators. Annual hospitalisation rates were estimated for 3-year periods with 95% CIs to enable rate comparisons.

In 1999 and 2002, regulations on dog ownership, with specific reference to potentially dangerous dogs, were approved by both the Kingdom of Spain and the government of Catalonia.4 They mandated that all dogs have to be identified, and that the dog owner is responsible for the dog's actions. The definition of potentially dangerous dogs included several breeds (in Catalonia: pit bull terrier, Staffordshire bull terrier, American Staffordshire terrier, Rottweiler, bull mastiff, Naples mastiff, Argentina mastiff, Bordeaux mastiff, Canary fighting dog, Brazilian Fila, Doberman, tosa inu, akita inu and their mixed breeds), those with certain physical traits (regarding size, weight, thorax size, muscle, head and jaws, etc), and also dogs declared dangerous by a veterinarian because of a history of aggression. Regulations mandated that a special licence is required to own such an animal (costing €48.88 for 5 years in Barcelona), which requires special insurance coverage (to cover damages up to €150 000, annual cost estimated at €70), and both a psychological aptitude certificate (estimated cost of about €40) and the absence of criminal records for the owner. They also mandated that such dogs had to be leashed and muzzled in public areas and identified with microchips or other suitable means. These regulations received extensive public attention and media coverage, and in successive years were often transposed in municipal ordinances, to ensure enforcement by local police.


Figure 1 shows the number of hospitalisations for the 12 years studied, broken down by setting (Barcelona and the rest of Catalonia), including estimated 3-year moving averages. Although the relatively small numbers show some intrinsic variation from year to year, there is a noticeable decline during this period, mostly outside the city of Barcelona. Table 1 shows dog bite hospitalisation rates per 100 000 population with their 95% CI for the years studied. Hospitalisation rates are lower in the urban setting of the city, and higher in the rest of Catalonia. There is a decline in Barcelona until 2003–5 compared with 1997–9, and then the rates are stable. In the rest of Catalonia, the rates decline over the whole study period. Comparing the rates in the last period with the initial rates, they are 22% lower in Barcelona and 38% lower for Catalonia. This change is not statistically significant for the city, but for the rest of Catalonia and Catalonia as a whole, the CI for the rates in the last period do not overlap with those for the initial period.

Figure 1

Number of hospital admissions due to dog bite injuries by year and setting. Catalonia, 1997–2008.

Table 1

Annual hospitalisation rates for injury due to dog bite, by 4-year period and setting. Catalonia, 1997–2008


This study shows a significant decline in hospitalisation due to injuries caused by dog bites from 1997 to 2008, after the enactment of stricter regulations on dog ownership in 1999 and 2002. The magnitude of this change is significant, and seems to have been greatest in the less urban settings, where other studies have documented a higher risk of dog bite injuries.7 8 Its effect seems to have been cumulative and not concentrated at a single time point. This is reasonable, as licensing requirements and dog bite reporting result in increasing pressure on dog owners, and media reports about regulations and their effective implementation influence public perceptions about responsible dog ownership. Each municipality has autonomy on how to manage the issue, but some information from Barcelona may illustrate this. In 2006 the owner of a pit bull terrier abandoned in a public park was identified and fined €5770 by the city public health services, with wide media coverage; over the last few years there have been around 60 annual police reports involving aggression episodes by dogs in the city (mostly for minor injuries), which generated follow-up work by the public health services with dog owners, ensuring that they have complied with all legal requirements and punishing violations; the number of city fines related to dog ownership was 1400–1700/year for minor offences (up to €600, many related to unleashed dogs in public areas) and about 50/year for serious offences; the number of potentially dangerous dogs licensed in the city was 880 in 2008. The current low demand for breeds considered potentially dangerous has led to their practical disappearance from pet shops.

During this period, no major changes occurred in the distribution or financing of hospital care services nor in the CMBDAH information system. The study is based on hospital inpatients, which are likely to have had severe injuries. Responsible ownership and proper education have been advocated as appropriate prevention strategies, but the empirical evidence on the efficacy of these options is rather disappointing.9 Government regulation is in itself an educational strategy, as it conveys a solid message on enforced responsibility, even if breed-specific regulation is controversial.1 2 A decrease in injuries has also been documented recently in other settings in North America and Europe.3 8 10 It is hard to attribute these declines to a specific intervention, but increasing legal requirements may well play a role.

Population-based studies in Spain from other settings around the same period estimated incidence rates of bites at 48–100 cases/100 000 persons.7 11 Of course, most dog bites do not require hospitalisation: our estimated hospitalisation rates range from one to two cases per 100 000 persons, tend to decrease, and are lower in the most urban setting (the city of Barcelona). As is often the case in policy evaluations, the influence of other factors cannot be ruled out.12 More evaluation studies in this field (both with comparable data in other populations or using information from other sources) would be useful, to provide criteria to focus future regulations and other preventive interventions.


After the adoption of new and stricter government regulations in Catalonia, there was a decrease in severe injuries caused by dog bites. Although the contribution of other factors to this decline cannot be ruled out, these results suggest that a regulatory approach may help in reducing serious dog bite injuries.

What is already known on this subject

  • Dog bite injuries involving children cause increasing public concern.

  • Many countries have adopted regulations on dog ownership and breed-specific regulations, sometimes with controversy.

What this study adds

  • The adoption of stricter government regulations on dog ownership in Catalonia was followed by a decrease in hospitalisations due to injuries caused by dog bites.

  • The magnitude of the decrease is lower in urban settings, and seems to be cumulative.

  • The results suggest that a regulatory approach may help in reducing serious dog bite injuries.


This work benefited from partial funding from the CIBERESP to the ASPB to support evaluative research in public health.



  • Funding Funded by in-house resources, and partial support from the CIBER ESP.

  • Competing interests None.

  • Provenance and peer review Not commissioned; externally peer reviewed.