doi:10.5455/vetworld.2013.388-392

Aim: A cross-sectional study was carried out from November 2011 to April 2012 to determine the prevalence and species of gastrointestinal (GI) helminth parasites in pet and stray dogs as a potential risk for human health in Bahir Dar town, northwestern Ethiopia. Materials and Methods: A total of 384 and 46 faecal samples were collected from pet and stray dogs, respectively and examined by using standard coprologic techniques. Results: The overall prevalence of GI helminth infection in pet and stray dogs was 75.26 and 84.78%, respectively. The detected parasites with their frequencies in pet dogs were Ancylostoma caninum (78.89%), Toxocara canis (39.79%), Dipylidium caninum (29.75%), Strongyloides stercoralis (29.06%), Taeniidae (23.87%) and Trichuris vulpis (7.95%). Stray dogs were found more likely to be polyparasitized and presented higher prevalence of A. caninum, T. canis, S. stercoralis, Trichuris vulpis and Taeniidae (P < 0.05) than domiciled ones. Diphyllobothrium latum was detected only in 10.25% of stray dogs. Toxocara canis and A. caninum (P < 0.05) were detected more frequently in dogs with less than 6 months of age (P < 0.05) than old age dogs. The sex or breed groups didn't significantly affect the prevalence of parasites. A significant variation was recorded (P < 0.05) between different feeding systems where higher prevalence was observed in uncontrolled feeding group (82.18%) compared to controlled feeding (32.08%). Conclusion: Different gastrointestinal parasites in pet and stray dogs were identified in the study area that can potentially infect humans and cause serious public-health problems. Thus, concerted efforts should therefore be made to educate dog owners to embrace modern dog disease control programs and measures have to be taken on stray dogs.


Introduction
by lowered resistance to infectious diseases, retarded growth, reduced work and feed efficiency and general The domestic dog (Canis familiaris) is generally ill health [7]. Uncontrolled population of stray and considered as the first domesticated mammal and has semi-domesticated dogs in close proximity to co-existed with man as a working partner and house pet increasing densities of human population in urban in all eras and culture since the days of the cave environments is a common fact in developing dwellers [1]. Dogs perform a range of cultural, social countries, in conjunction with the lack of veterinary and economic functions in society. Dogs are kept as attention and zoonotic awareness, increases the risks of pets and companions, for hunting, as guards or for disease transmission [5]. Thoughtless dog breeding commercial purposes. Some studies also suggest that raises the number of stray and free-living dogs. From keeping pets is associated with a higher level of selfthe aspect of transmission of diseases in urban and rural esteem in children [2,3].
habitats, they present a high risk factor [8]. Some The dog population in urban and suburban surveys have been conducted on the prevalence of the regions is composed of dogs that roam only with their helminth parasites of dogs in different parts of the owners and stray dogs which are ownerless [4]. In both country [9. 10]. However, there is no any information cases, the animals come in close contact with humans on the literature on the prevalence of gastrointestinal and their dwellings and act as reservoirs and helminth parasites of pet and stray dogs in Bahir dar transmitters of zoonotic diseases [5,6]. Gastrointestown, Therefore, the objectives of this study were to tinal helminths of dogs pose serious impact both on the identify and determine the prevalence of GI helminth host and human beings. They impede the successful parasites of pet and stray dogs in the town. rearing of dogs and result in losses that are manifested Gastrointestinal helminth parasites of pet and stray dogs as a potential risk for human health in Bahir Dar town, north-western Ethiopia north-western Ethiopia. The town is bordered by the analyses were performed using the "SPSS" statistical biggest lake (Tana) and river (Blue Nile) in Ethiopia. It software and 95% confidence level was used to o O determine significant difference. For simplicity, only is located between 12 29'N latitude and 37 29'E longitude. The average annual 0rainfall ranges from "P" values were quoted. 1200-1600 mm and it has mean annual temperature of The overall prevalence of parasitism was 75.26 Study animals and sample size determination: The and 84.78% in pet and stray dogs, respectively. There study animals were dogs available in Bahir dar as pet was no statistical significant different (P>0.05) (having owner) and stray (owner less) dogs. There are between pet and stray dogs ( Table-1). about 1670 pet and more 100 stray dogs in the town

Materials and Methods
The detected parasites with their frequencies in [12]. The total number of pet dog required for sampling pet dogs were Ancylostoma caninum (78.89%), Toxocara was calculated based on the formula given by canis (39.79%), Dipylidium caninum (29.75%), Thrusfield [13]. Since, there was no information about Strongyloides stercoralis (29.06%), Taeniidae the prevalence of the parasites in the area, 50% (23.87%) and Trichuris vulpis (7.95%). Stray dogs expected prevalence was taken to calculate the sample were found more likely to be polyparasitized and size with 5% absolute precision. So the calculated presented higher prevalence of A. caninum, T. canis, S. sample size was 384 for pet dogs but only 46 stray dogs stercoralis, Trichuris vulpis and Taeniidae (P<0.05) were sampled without any calculation. Dogs of all age than domiciled ones. Diphyllobothrium latum was group and both sexes were randomly selected. Pet dogs detected only in 10.25% of stray dogs (Table-2). were categorized as pups (< 6 months of age), juvenile Concurrent infection with two or more helminth (6 months to 1 year of age) and adult dogs (> 1 years of parasites was common in 73.7% of the infected pet age) [13].
dogs. Sample collection: A total of 384 faecal samples were Out of 254 male and 130 female pet dogs, 74.80 collected directly from the rectum of each pet dog with and 76.15% were infected with gastrointestinal the help of finger and 46 faecal samples were collected helminth parasites, respectively. However, there was from the ground immediately after voiding by stray no significant difference (P>0.05) in the prevalence of dogs using plastic gloves, stored in refrigerator and gastrointestinal helminth infections between male and processed within 2-3 hours of collection at Bahir dar female dogs. Likewise, there was no significant Regional animal disease diagnosis and investigation differences (P>0.05) in the prevalence of parasitic center. The samples were processed using direct smear, infection between local (76.70%), exotic (73.80%) and sedimentation and salt floatation technique as crossbred (76.19%) pet dogs (Table 3). No significant described by Urquhart et al. [14]. Identification of difference (P>0.05) in the prevalence of helminth characteristic parasite eggs was made according to the infection was observed among age groups of pet dogs. morphological characteristics and key as outlined by The highest prevalence (P<0.05) was recorded in Soulsby [7]. young dogs (83.04%) followed by puppies (77.11%) and adults (69.84%). Regarding the feeding systems, Statistical analysis: Raw data were entered into a the prevalence of helminth parasites in uncontrolled Microsoft Excel spreadsheet and descriptive statistics fed dogs was 82.18% whereas 32.08% in controlled were used to summarise the data. The prevalence was feeding (32.08%) with a significant variation (P< 0.05) calculated for all data as the number of infected between them (Table-3). individuals divided by the number of individuals Table-4 shows the distribution of gastrointestinal examined and multiplied by 100 to express in percentage.
helminth parasites of pet dogs in Bahir dar town. Chi square was used to assess the association of risk Toxocara canis and A. caninum were detected more factors on the prevalence of parasites. All statistical  North-East Gabon and Katagiri and Oliveira-Sequira Higher prevalence than the result of this study was [17] in Brazil. This difference may be associated with reported by Davoust et al. [21] in north-east Gabon geographic location of the area, a high level awareness about dog parasites and socioeconomic status of pet (94.1%), Umar [22] in Kaduna State, Nigeria (93.8%) owners for hygiene and make use of the available and Lavallen et al. [23] in Argentina (89.13%). The veterinary cares for their animals [26]. difference in the frequency of the helminth parasite The overall and specific parasites prevalence infections between places or countries is possibly due recorded in the current study are strongly associated to the differences in climatic factors required for the with age. The overall prevalence of helminth parasites biology of the parasites, veterinary facilities and public was significantly higher in young dogs (< 1 year-old) awareness to take care of the dogs. During the survey, it than adult. This is partially due to parasite specific was noted that a large number of dogs scavenge at immunity usually acquired with age or probably as abattoirs and at butcher shops which frequently fed on consequence of single or repeated exposures [27]. thrown offal that are not in good hygienic condition. It The result obtained in this study revealed that the is also common to find animal cadaver thrown into difference in prevalence of gastrointestinal helminth street where dogs communally feed on, which could be parasite in male and female pet dogs was not a suitable for transmission of the parasites. statistically significant. This agrees with reports of Concurrent infection with two or more different Yacob [15] and Degefu et al. [10] conducted in Debre species of helminths was more common than infection Zeit and Jimma (Ethiopia), respectively. In contrast, a by Swai et al. [29] in Tanzania. This indicates that all study in Nigeria indicated that female dogs were more categories have equal chance of acquiring the infection likely to contract intestinal nematodes than male dogs if they are exposed to infected materials. [21].
The current study showed that feeding manage-In this study, concurrent infection with two or ment had a significant influence in the prevalence of more helminth parasites is common in 73.7% of the gastrointestinal helminth infections. Dogs which infected pet dogs. Similar observations have been receive a great care by their owners had lower reported by Degefu et al. [10] and Endrias et al. [9].
incidence of intestinal helminths than dogs lacking The overall prevalence of T. canis (39.79%) such privileges [30]. recorded in the current study is higher than the previous In all cases, the overall and specific parasites reports of Yacob et al. [15] and Endrias et al. [9] and prevalence recorded in stray dogs in the present study Degefu et al. [10] with a reported prevalence of 21, was similar but with different levels with household 17.1 and 25.8 % in Debre Zeit, Ambo and Jimma, dogs. The only difference was the presence of respectively. In addition, the prevalence of Toxocara Diphylobothrium latum in stray dogs. This could be infection reported here was higher than the earlier due to the free roaming character of stray dogs which reports from Netherland [2]. The present study leads them to be exposed to fish offal infected with revealed that the prevalence of T. canis was higher in infective stage of the adult parasite. puppies (54.2%) than adults (18.5%). Puppies are at

Conclusion higher risk of infection due to transplacental and
This study showed the gastrointestinal helminth transmammary transmission and parasite-specific parasites in pet and stray dogs in the study area were immunity is usually acquired with age, probably as a highly prevalent. In addition, the species of helminth consequence of single or repeated exposures [14].
parasites recorded in the present work have potential Tricuris vulpis had the least prevalence (7.95%) zoonotic importance. A combination of routinely among other gastrointestinal helminth species. This screening faecal samples for parasites, strategic result agrees with previous reports of Garedaghi and anthelmintics regimes and improved pet owner Mashaei [25] in Tabriz, Iran with prevalence of education is recommended for the control of 86.06%. Less prevalence was reported Degefu et al. gastrointestinal parasites in pet dogs including control [10] in Jimma, Ethiopia, with prevalence of 4.7%.
of stray dog population in the study area. Higher prevalence studies were found by Katagiri and Oliveira-Sequira [17] in Brazil (7.1%), Davoust et al.