Buletin Veteriner, BBVet Denpasar, Vol. XXIII, No.78, Juni 2011, Hal: ISSN: X

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1 DOG DEMOGRAPHY IN BADUNG DISTRICT THE PROVINCE OF BALI AND THEIR SIGNIFICANCE TO RABIES CONTROL * (Demografi Anjing di Kabupaten Badung Provinsi Bali Serta Signifikansinya Dalam Penanggulangan Rabies) Oleh : Anak Agung Gde Putra, I Ketut Gunata 1 and I Gde Asrama 1 Asrama 1 Disease Investigation Center Denpasar Badung District Livestock Services 1 ABSTRAK Bali merupakan salah satu provinsi di Indonesia yang sebelumnya secara historis dikenal sebagai daerah bebas rabies. Berjangkitnya rabies di Kabupaten Badung pada tahun 2008 mengharuskan untuk mempelajari ekologi anjing, dalam rangka untuk mengefektifkan program penanggulangan rabies. Studi tentang demografi anjing ini menggunakan data anjing kampung yang berhasil divaksinasi selama program vaksinasi massal dilaksanakan. Data anjing yang berhasil divaksinasi mewakili sekitar 35,5% dari estimasi populasi anjing di 62 desa di Kabupaten Badung. Vaksinasi massal rabies pertama, dimulai dalam kurun waktu satu minggu sejak kasus rabies pada anjing dikonfirmasi secara laboratorium di Semenajung Bukit, di ujung selatan Pulau Bali. Vaksinasi dilaksanakan di wilayah tertular yaitu di Semenanjung Bukit, selanjutnya bergerak ke wilayah terancam dan terakhir di daerah bebas di Kabupaten Badung. Data yang dianalisis dalam makalah ini adalah data anjing kampung yang divaksinasi pada tahap pertama vaksinasi massal yaitu dari tanggal 4 Desember 2008 sampai dengan tanggal 28 Februari Selama program vaksinasi massal rabies, sebanyak anjing kampung berhasil divaksinasi. Dari seluruh anjing yang divaksinasi, anjing umur satu tahun atau kurang ditemukan mendominasi populasi yaitu sebanyak 47%. Anjing umur 2-3 tahun sebanyak 34%, kelompok umur 4-5 tahun 11,7%, kelompok umur 6-7 tahun 3,9% dan anjing kelompok umur 8 tahun atau lebih tua sebanyak 3,3%. Tingkat kepadatan anjing kampung per km 2 bervariasi yaitu dengan rata-rata antara 129 di daerah rural (pedesaan) sampai 256 di daerah urban (perkotaan). Untuk semua kelompok umur dan di 62 desa, ditemukan bahwa populasi anjing jantan lebih banyak dari anjing betina, dengan rasio antara jantan dan betina sekitar 1:0,40. Dengan menganalisis data umur anjing 11 bulan yang populasinya sekitar 30,5% dari populasi yang diamati, ditemukan bahwa kelahiran anak anjing terjadi setiap bulan sepanjang tahun. Apabila kelahiran tersebut dikelompokkan pada perbedaan musim, jumlah kelahiran lebih banyak terjadi pada musim kemarau (Juni sampai November) yaitu sekitar 83% dibandingkan dengan pada musim hujan (Desember sampai dengan Mei) yang hanya sekitar 17%. Data ini telah menginspirasi strategi vaksinasi rabies yang harus dilaksanakan, agar tingkat kekebalan kelompok terpelihara dengan baik yaitu sekitar > 70%. Kata kunci: rabies, anjing kampung, demografi, Kabupaten Badung, Bali. ABSTRACT Historically, Bali was known as one of the province in Indonesia which is free of rabies. Since the outbreak of rabies in Badung District in 2008 it was ascertain the importance to understand the ecology of dog in order to optimise rabies control program. Data on the * This paper was presented at KIVNAS PDHI (National Indonesian Veterinary Association Scientific Meeting) in Semarang on 13 September

2 number of dogs vaccinated during mass vaccination campaign was used to study dog population structure and months of puppies birth. These data represent 35.5% of dogs population estimate in all 62 villages in Badung District. The first mass rabies vaccination in Badung District undertaken within a week following laboratory confirmed rabies case in dog at Bukit peninsula on the southern tip of Bali. The vaccination started at Bukit peninsula, then followed to at risk and free areas in Badung District, respectivelly. The data used in this analyses were data of kampung dogs that were collected during the first step of mass vaccination campaign from 4 December 2008 to 28 February A total of 16,707 kampung dogs were vaccinated during the first mass rabies vaccination program where by age structure dogs age one year or less were predominantly (47%) observed folowed by age group 2-3 years (34%), 4-5 years (11.7%), 6-7 years (3.9%) and 8 years or more (3.3%), respectivelly. Dog population density per km 2 varies from 129 in rural to 256 in urban areas. For all age groups and in all 62 villages, male dog population were found higher than the female with sex ratio 1:0.40. Using data of dogs age 11 month old or younger which represented 30.5% of the population observed, it was found that puppies birth all year round. Alternativelly, when the data were grouped into seasons, it was found that number of birth were significantly higher during dry season (83%) (June-November) as compared to wet season (17%) (December-May). The data inspired that vaccination strategies should be set up according to the puppies birth pattern in order to maintain herd immunity of > 70%. Keywords: rabies, kampung dog, demography, Badung District, Bali. INTRODUCTION Kampung (indigenous) dog has been well known as part of community life in Bali, and none village is known without this animal. Dog in Bali has multi functions such as house / garden guards, as pet animal, and in the past was used for hunting. Certain colour of dog is used in cultural ceremony by balinese people and it is believe if could cure certain disease and also as a magic alarm or to avert calamity. It was estimated that majority of dogs in Bali are owned (>95%) and only a few (<5%) are un-owned (Putra and Gunata, 2009). Generally, owned dog (>70%) is kept free as a semi free-range live style and these dogs mix with un-owned dogs. As such, dog in Bali are found free roaming in public facilities, such as: on the street, around traditional markets and temples, on the beach, building, parking area and around garbage block. Some (<25%) of the dogs are kept restricted, in cage, fen house, or chained. Bali is known as previously rabies free province in Indonesia. Since the entrance of rabies virus into Bali in 2008 (Putra and Gunata, 2009; Putra etal., 2009a,b), concern has been given to study dog ecology as it is related to the epidemiology of rabies. Dog is well known as the main rabies reservoir which could maintain the virus cycle because in this animal the average ratio of transmission is one or more, or during the outbreack has basic reproductive number (Ro) more than one (Bingham, 2005). Eventhough rabies has long been recognized in Indonesia, more than 125 year (Putra, 2009), 15

3 research related with dog ecology is scarce. The only study in this field was that conducted in Flores following the outbreack of rabies in late 1997 (Hutabarat etal., 2003). This paper described dog demography in Badung District i.e population density, population structure and month of puppies birth. The information derived is expected usefull as the preliminary part to study dog ecology in Bali and perhaps also can be used to optimised the effectiveness of rabies control programs (Anonymous, 2002; Putra etal., 2008, Putra, 2010), especially vaccination program as well as to develop strategy to control dog population in Bali. MATERIAL AND METHODS 1. Data Collection Data of kampung dogs that have been vaccinated during the first mass rabies vaccination campaign wich were conducted from 4 December to 28 February 2009 in Badung District were recorded for this study. Badung District is one of the nine districts in Bali Province, which is consisted of 6 sub-districts, 62 villages. Data regarding address/village, dog owner, sex, breed and age of the dog were recorded in a special form. Age of dog was given by the owner or in a few cases was estimated by a veterinarian who member in the rabies vaccination team. To improve data accuracy on age, especially for the purpose of estimating month of puppies birth, age of juvenile and young dogs were recorded in month up to 11 month. Those adult dogs age one year or more were recorded in year. 2. Dog Population Estimate Dog population number in each village was estimated using the ratio of dog and human in which was found to be 1:8.27 according to our survey in Badung District in 2009 (unpublished data). Data on human population and the size, in, of each village (km 2 ) is derived from the Book Badung Dalam Angka Tahun 2008 published by Badung District Goverment. 3. Data Analyses Estimation on puppies birth were calculated based on their age when they were vaccinated, then trace back to find the month of birth. Only kampung dogs were included in this analyses, while those pedigree dogs which is having different ecology and relatively small population size were not included. The population of pedigree dogs in Bali were estimated around 10,000 which is 2% from kampung dogs which were estimated 450,000. RESULTS 1. Population Structure During the first mass rabies vaccination program (4 December 2008 to 28 February 2009), 16,707 kampung dogs have been vaccinated in all 62 16

4 villages in Badung District. The number of kampung dog vaccinated during this first step of vaccination program represented about 35.5% (16,707/47,010) of dog population estimate in Badung District. Of those vaccinated dogs (Table 1), 47% (7,837/16,707) age one year or less. The age group of 2-3 year was 34%, age group 4-5 year 11.7%, age group 6-7 year 3.9% and age group 8 year or older were found 3.3%. Majority (81%) of kampung dogs observed were 3 year old or younger. The youngest dog observed was age 1 month old while the oldest was 20 year old two dogs and both are male. The mean age of those 16,707 dogs is 2 year and 2 month, with 95% confidence interval are 2 year and 2 month up to 2 year and 3 month. Mean age of male dogs are 2 year and 2 month with 95% confidence interval are 2 year and 2 month up to 2 year and 3 month. Meanwhile, those female dogs having mean age 2 year and 1 month with 95% confidence interval are 2 year up to 2 year and 2 month (Table 2). 2. Sex Ratio As shown in Table 1, male dogs were predominantly observed in all age group with male to female ratio varied from 1:0.20 to 1:0.60 and mean for all age groups is 1:40. The predominant of male dogs were also observed in all 62 villages in Badung District, either in urban, peri urben or rural villages. In urban areas the mean ratio of male to female is 0.48 where in peri urban is 0.43 slightly lower, and the lowest ratio is 0.34 found in rural villages (Table 3). 3. Dog Population Density The highest mean of dog population density was found in urban areas which is 256 per km 2 while in peri-urban and rural villages are 184 and 129 per km 2, respectivelly (Table 3). 4. Month of Puppies Birth As shown in Table 4, of those 5,092 dogs age 11 month or younger it was found that puppies birth all year round. However, about 19% (969/5,092) of puppies was borne in September. If puppies birth is grouped according to season in Bali it was found that 83% borned during dry season (June-November) where as 17% during wet season (December-May) (Table 5). 17

5 Table 1 Age structure of kampung dog in Badung District, Bali. Age Num ber of male Number of female Total male and female Proportion of age in population (%) 1 month month month month month month month month month month month year year year year year year year year year year Total: 11,922 4,785 16, Cummu lative frequency (%) Male female Ratio 1 : : : : : : : : : : : : : : : : : : : : : : 0.40 Parameter Table 2 Age of kampung dogs observed in Badung District, Bali Number of dogs observed Mean + Standar deviation (in month) All population 17, month 20 Male population 11, month 20 year Female 4, month 18 population year Range 95% Confidence interval (in month) year

6 Table 3 Demography of kampung dog in urban, peri-urban and rural villages in BadungDistrict, Bali. Parameters Urban (6 villages) Peri Urban (22 villages) Rural (34 villages) Mean + SD Range 95% Confidence interval Mean + SD Range 95% Confidence interval Mean + SD Range 95% Confidence interval Size km Human population Dog population estimate Human density km -2 Dog density km -2 Male to female dogs ratio Male dogs vaccinated Female dogs vaccinated All dogs vaccinated Percentage of all dogs vaccinated to population estimate ,

7 Table 4 Month of kampung dogs birth in Badung District, Bali Month Number of puppies borned Proportion January % February % March % April % Mai % June % July % August % September % October % November % December % Total: 5, % Table 5 Month of kampung dogs birth in Badung District, Bali. Data presented according to season. Season Number of puppies borned Proportion Wet (December-May) % Dry (June-November) 4, % Jumlah: 5, % DISCUSSION The data analysed and presented in this paper represented 35.5% from dogs population estimate in Badung District, and was derived from the first mass vaccination program. Before the outbreak of rabies in Bali, there was none government institutions having a task to deal with this animal and consequently their population is not known. Temadja (1984) assumed that the ratio of human and dog in Bali was 1:5, and this was not based on a research finding. There was no research work have been published related with dog ecology or demography in Bali. A preliminary survey conducted in 2009 in Badung District (unpublished data) found that human dog ratio was 1:8.27, 20 this data was then used to estimate dog population in this study. Eventhough, the dog data were derived following rabies mass vaccination program, because the number observed is more than one third to dog population estimate, it was then expected that dog characteristicts described in this paper represent not far from the real situation. Kampung dog in Bali have been domesticated years and may similar to those reported in Flores. Although as domesticated animal, they still having some wild characteristics as she is able to survive with very limitted dependency to the owner (Hutabarat etal., 2003). They can

8 survive and with relatively good reproductive performances under relatively limmited food sources that provided by the owner. To fullfill their need for food, kampung dogs will find with their own ways out side of owner s home. As such, in Bali is not difficult to see a number of dogs marking around on public facilities, and also as part of it s roaming behavior, i.e. on the streets, around garbage block, traditional markets, on the beach, parking areas, around the temples and others. With these behaviors it is known now is not easy to control rabies properly because the virus cycle is maintained in this population (Putra etal., 2009b). It is assumed that the home range of kampung dog in Bali just around the owner s preperty or as far as around the village within the radius of 2-5 km 2. Not like feral dog, the dingo in Australia, which is having home range up to km 2 (Mitchell and Balogh, 2007). As presented in the results section, about 47% of dog observed consist of dog age one year or less, this may indicate a high birth rate. As puppies borned all year round suggest that mating also accurred all month throughout the year. However, there is also a clear two peaks of birth, during wet (83%) and dry (17%) seasons. Considering the pregnancy periods of kampung dog is about two months, the available data indicate that there is a long breeding season which starts from March to September. Locally, it is well known by the balinese that during sasih kesange (balinese calender, or March) is the begining of dog breeding season. The mean age of all dogs observed which is 26 months with 95% confidence interval of 26 months and 27 months, suggest that there are also a high death rate in kampung dog population, and perhaps their life expectancy may around 3 years as reported elsewhere for the relatively the same kind of dog (Kitala etal., 2001). As reported elsewhere, in a dog population there is a high birth rate with a high death rate too to reach 3 years of age, and if the environmental conditions support, the population could reach three fold within a year (Wandeler etal., 1988; Butler and Bingham, 2000; Kitala etal., 2001). Rapid turn over population will influence rabies control strategies, especially vaccination program. Accordingly, further studies for kampung dog in Bali, such like birth rate, mortality rate, litter size, life expectancy and their interaction into the environment warrant to be carry out. The sex ratio observed in this study, either based on age groups or geographical approaches, suggested that balinese people has a strong preference to the male dog. It may be considered by the balinese that male dog is much stronger than female as home/garden guards, and the female causing nuisance during breeding season. Balinese people generally not kill their dog, ussually unexpected female juvenile, age around 2 months, is through away by the owner on the streets, around rice field/garden or on other places. This juvenile animal may then taken by someone and some of them may survive then becoming unowned dog. The population of unowned 21

9 dogs is estimated not more than 5% in population, varies among villages and may depend on the availability of food and environmental conditions. Culturally, there has been well known that balinese people has a strong relationship with dog since years. The present study confirm that dog is own widely in the community, found in all 62 villages in Badung District with a high density per km 2, perhaps the highest density in Indonesia. It is no doubt that high density rate and widely distributed with a semi freerange live style of dogs will increase contact rate each other, and finally play important role in maintaining rabies virus life cycle as facing now in Bali (Putra etal., 2009b). Compare to other published literatures, the population density of kampung dogs per km 2 in Badung District is quite high. The population density of dogs in Machakos District ( per km 2 ) Kenya (Kitala et al., 2001, 2002), in Serengeti (9,4 per km 2 ) and Ngorongoro Districts (1,4 per km 2 ) Tanzania (Hampson et al., 2009), in Zimbabwe (21 per km 2, Butler and Bingham, 2000), in Mexico ( per km 2, Eng et al., 1993) is smaller than that what found in Badung District, Bali, and may be similar to those found in Sri Langka (Wandeler et al., 1988). In urban areas in Badung District, the mean dog population density is 257 per km 2 and is significantly higher if compare to those in peri-urban (mean 185 per km 2 ) and rural (mean 129 per km 2 ) villages. This different may be related with socio economical differences in the community and environmental conditions which could support the survival of the semi free-range live style of kampung dogs. It s seems understandable, when both dogs and human with high density and close realationship each other, then if zoonotic fatal disease i.e. rabies entering the community, unxiety or panic in the community could not be avoided as shown now in Bali by a very high use of post-exposure treatment (Putra etal., 2010). It is estimated that 70% or more of kampung dogs is semi free-range live style and 25% or less are properly care (inside fen house, cage or chained), and may be having a similar dog-keeping practices to those reported in Madagascar (Ratsitorahina etal., 2009) or in Kenya (Kitala etal., 2001). Majority of kampung dogs are not easy to handle and have been found difficult to give parenteral injection of rabies vaccine. Those 35.5% vaccinated dogs should be interpreted as dogs that are easy to handle and brought into the vaccination post. It is estimated that only 10% of semi free-ranging dogs were vaccinated and the rest 60% remain unvaccinated, then is found maintaining rabies cycle. This condition was found difficult to achieve 70% rabies vaccination coverage in order to break down rabies cycles as have been stated in the control program (Putra 2009; Putra etal., 2009a,b,c). Culling of this semi free-range dogs, if not done selectivelly and targeted, have been found encourage the spread of the rabies virus, because owner will hide and move their animal to other places as been experienced in Flores (Putra, 1998). Accordingly, the use of long lasting immunity rabies vaccine is highly 22

10 recommended and the possible use of oral vaccine should be riviewed (Putra, 2009), along with to keep training personels with expertise to catch this free-range type of dogs. Of those described above, it is concluded that further study on dog ecology should be carried out in more details as it is related with the epidemiology of rabies and also in order to improve effectiveness of rabies control measures. Difficulties in handling kampung dogs for parenteral injection and assuming that the life expectancy of kampung dogs is about 3 years, it is suggested that the use of rabies vaccine which could induce long lasting duration of immunity is one of the best choice (Anonymous, 2000; Bowen-Davis and Lowings, 2000; Putra, 2009). Understanding the month of puppies birth, it is suggested that at least two vaccination programs could be carried out, first before the breeding season (January/February) and secondly for the new born puppies in October, with this it is expected that the herd immunity could be maintained at a high level. ACKNOWLEDGEMENTS The authors wish to thank all about 250 personels as Vaccinator Team who came from many institutions, namely: Bali Provincial Livestock Services, Badung District Livestock Services, Disease Investigation Center Region VI Denpasar, Denpasar Agricultural Quarantine Agency, Faculty of Veterinary Medicine of Udayana State University, Government of Australia through ACIAR Project AH and some Non Government Organizations. The Team recorded all dog data during first rabies vaccination program in Badung District, to whom is highly appreciated. REFFERENCES Anonymous (2000) Compendium of Animal Rabies Prevention and Control, National Association of State Public Health Veterinarians, USA. Journal of American Veterinary Medicine Association, 216 (3): Anonymous (2002) Kesiagaan Darurat Veteriner Indonesia: Penyakit Rabies. Direktorat Jenderal Peternakan, Departemen Pertanian. Anonymous (2008) Badung Dalam Angka Tahun Bingham J (2005) Canine rabies ecology in southern Africa. Emerging Infectious Disease 11: Bowen-Davies J and Lowings, P (2000) Current perspectives on rabies.1. The biology of rabies and rabies-related viruses. In practice, March 2000, Butler JRA and Bingham J (2000) Demography and dog-human relationships of the dog poulation in Zimbabwean communal lands. Veterinary Record, 147: Eng TR, Fishbein DB, Talamante HE, Hall DB, Chavez GF, et al. (1993) Urban epizootic of rabies in Mexico - Epidemiology and impact of animal bite injuries. Bull WHO, 71: Hampson K, Dushoff J, Cleaveland S, Haydon DT, Kaare M, Packer C and Dobson A (2009) Transmission Dynamics and Prospects for the Elimination of Canine Rabies. PLoS Biol 7(3): e doi: /journal.pbio Hutabarat T, Geong M, Newsome A, Ruben A and Cutter S (2003) Rabies and dog ecology in Flores. Urban Animal Management Conference Proceedings, Australian Veterinary Association,

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