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Mating System of Free-Ranging Dogs (Canis familiaris)  [PDF]
S. K. Pal
International Journal of Zoology , 2011, DOI: 10.1155/2011/314216
Abstract: Fourteen females belonging to five groups were selected for the study of mating system in free-ranging domestic dogs (Canis familiaris) All the matings occurred between August and December with a peak in late monsoon months (September to November). Both males and females differed in their degree of attractiveness to the opposite sex. The duration of courting association increased with the number of courting males in an association. The females exhibited selectivity by readily permitting some males to mate and avoiding, or even attacking others, if they attempted to mount. Frequency of mounting in courting association increased with the number of males present. There was a positive correlation between the duration of courting association and the frequency of mounting. The young adult males were more likely to copulate successfully than the old adult males. There was a negative correlation between the number of males present in an association and the number of successful copulations. In this study, six types of mating (monogamy, polygyny, promiscuity, polyandry, opportunity and rape) were recorded. Mean (±S.E.) duration of copulatory ties was 25.65 (±1.43) min. Several natural factors influencing the duration of copulatory ties were identified. 1. Introduction Mating system is the basis of any mammalian social system; and it can be defined as the ways in which different kinds of animals are associated during copulation and the factors that contribute to identification of partners, interaction, and eventually fertilization. Monogamy is the rarest form of mating system among mammals, estimated to occur in 3–5% of all mammalian taxa [1, 2]. However, it is the most common breeding system for canids [3]. This is due in part to the high demands that pups place on their parents, as for most species of canidae they are born altricial in large litters and require an extended period of training to learn to hunt and survive on their own. Also, puppies in many canid species require protection, as they face danger of intraspecific infanticide from neighboring territorial canids. Recent investigations of the mating behaviors of canidae raise doubts as to whether any canid species is genetically monogamous. For instance, the red fox (Vulpes vulpes), the swift fox (Vulpes velox), and the island fox (Urocyon littoralis), all of which were thought to have exclusive mated pair systems, were shown through genetic analysis to be polygamous [4–6]. Observational and genetic investigations have shown that extra pair mating occurs among two canid species, the Ethiopian wolf
Dogs (Canis familiaris) Evaluate Humans on the Basis of Direct Experiences Only  [PDF]
Marie Nitzschner, Alicia P. Melis, Juliane Kaminski, Michael Tomasello
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0046880
Abstract: Reputation formation is a key component in the social interactions of many animal species. An evaluation of reputation is drawn from two principal sources: direct experience of an individual and indirect experience from observing that individual interacting with a third party. In the current study we investigated whether dogs use direct and/or indirect experience to choose between two human interactants. In the first experiment, subjects had direct interaction either with a “nice” human (who played with, talked to and stroked the dog) or with an “ignoring” experimenter who ignored the dog completely. Results showed that the dogs stayed longer close to the “nice” human. In a second experiment the dogs observed a “nice” or “ignoring” human interacting with another dog. This indirect experience, however, did not lead to a preference between the two humans. These results suggest that the dogs in our study evaluated humans solely on the basis of direct experience.
Dogs (Canis familiaris), but Not Chimpanzees (Pan troglodytes), Understand Imperative Pointing  [PDF]
Katharina C. Kirchhofer, Felizitas Zimmermann, Juliane Kaminski, Michael Tomasello
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0030913
Abstract: Chimpanzees routinely follow the gaze of humans to outside targets. However, in most studies using object choice they fail to use communicative gestures (e.g. pointing) to find hidden food. Chimpanzees' failure to do this may be due to several difficulties with this paradigm. They may, for example, misinterpret the gesture as referring to the opaque cup instead of the hidden food. Or perhaps they do not understand informative communicative intentions. In contrast, dogs seem to be skilful in using human communicative cues in the context of finding food, but as of yet there is not much data showing whether they also use pointing in the context of finding non-food objects. Here we directly compare chimpanzees' (N = 20) and dogs' (N = 32) skills in using a communicative gesture directed at a visible object out of reach of the human but within reach of the subject. Pairs of objects were placed in view of and behind the subjects. The task was to retrieve the object the experimenter wanted. To indicate which one she desired, the experimenter pointed imperatively to it and directly rewarded the subject for handing over the correct one. While dogs performed well on this task, chimpanzees failed to identify the referent. Implications for great apes' and dogs' understanding of human communicative intentions are discussed.
Cross Modal Perception of Body Size in Domestic Dogs (Canis familiaris)  [PDF]
Anna M. Taylor,David Reby,Karen McComb
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0017069
Abstract: While the perception of size-related acoustic variation in animal vocalisations is well documented, little attention has been given to how this information might be integrated with corresponding visual information. Using a cross-modal design, we tested the ability of domestic dogs to match growls resynthesised to be typical of either a large or a small dog to size-matched models. Subjects looked at the size-matched model significantly more often and for a significantly longer duration than at the incorrect model, showing that they have the ability to relate information about body size from the acoustic domain to the appropriate visual category. Our study suggests that the perceptual and cognitive mechanisms at the basis of size assessment in mammals have a multisensory nature, and calls for further investigations of the multimodal processing of size information across animal species.
Neospora Caninum and Leishmania Infantum Co-Infection in Domestic Dogs (Canis Familiaris) in Meshkin-Shahr District, Northwestern Iran
M Sharifdini,M Mohebali,H Keshavarz,M Hosseininejad
Iranian Journal of Arthropod-Borne Diseases , 2011,
Abstract: Background: Mediterranean visceral leishmaniasis (MVL) is an infectious disease that affects both human and ani-mals. Domestic dogs (Canis familiaris) are principal reservoir hosts of MVL caused by Leishmania infantum. Dogs are definitive hosts for Neospora caninum and a risk factor for infecting intermediate hosts. The immunosuppression caused by visceral leishmaniasis (VL) can promote the occurrence of co-infections with other agents such as neosporo-sis. This study aimed to determine the frequency of co-infection of the both protozoan parasites in the en-demic areas of VL from Meshkin-Shahr District, north-west of Iran. Methods: Altogether, 171 serum samples were collected from domestic dogs of Meshkin- Shahr District by multistage cluster sampling from October 2008 to August 2009. The collected serum samples were tested for the detection of simultaneous infection of L. infantum and N. caninum using direct agglutination test (DAT) and indirect ELISA, respectively. Results: Of the 171 domestic dogs, 27 (15.8%) and 52 (30.4%) were showed antibodies against L. infantum and N. caninum, respectively. Simultaneous infections of N. caninum and L. infantum was found in 16 (9.4%) of the dogs. In VL-positive and VL-negative dogs, N. caninum infection was found in 59.3% and 25.0%, respectively. A statisti-cally significant difference was found between VL-positive and VL-negative dogs with N. caninum infection (P= 0.001). Conclusion: These findings indicate that Meshkin-Shahr District in northwestern Iran is an active focus of canine visceral leishmaniasis (CVL). Neospora caninum and L. infantum co-infection is prevalent in the area and infection by L. infantum seems to enhance susceptibility to N. caninum infection in domestic dogs.
Molecular identification of Cordylobia anthropophaga Blanchard (Diptera: Calliphoridae) larvae collected from dogs (Canis familiaris) in Jos South, Plateau State, Nigeria  [cached]
Ndudim I. Ogo,Emmanuel Onovoh,Oluyinka O. Okubanjo,Ruth C. Galindo
Onderstepoort Journal of Veterinary Research , 2012, DOI: 10.4102/ojvr.v79i1.349
Abstract: Myiasis-causing larvae were extracted from dogs attending veterinary clinics in Plateau State, Nigeria and subjected to molecular analysis involving polymerase chain reaction amplification of the 28S rRNA gene of blowflies, cloning and sequencing techniques. All larvae were confirmed as Cordylobia anthropophaga Blanchard (Diptera: Calliphoridae) after the initial morphological identification. This is the first molecular identification of any myiasis-causing fly species in Nigeria and may serve as a reliable alternative to morphological identification where samples are not well preserved or difficult to identify to species level. How to cite this article: Ogo, N.I., Onovoh, E., Okubanjo, O.O., Galindo, R.C., De la Lastra, J.P. & De la Fuente, J., 2012, ‘Molecular identification of Cordylobia anthropophaga Blanchard (Diptera: Calliphoridae) larvae collected from dogs (Canis familiaris) in Jos South, Plateau State, Nigeria’, Onderstepoort Journal of Veterinary Research 79(1), Art. #349, 4 pages. http://dx.doi.org/10.4102/ojvr.v79i1.349
Do Dogs (Canis lupus familiaris) Make Counterproductive Choices Because They Are Sensitive to Human Ostensive Cues?  [PDF]
Sarah Marshall-Pescini, Chiara Passalacqua, Maria Elena Miletto Petrazzini, Paola Valsecchi, Emanuela Prato-Previde
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0035437
Abstract: Dogs appear to be sensitive to human ostensive communicative cues in a variety of situations, however there is still a measure of controversy as to the way in which these cues influence human-dog interactions. There is evidence for instance that dogs can be led into making evaluation errors in a quantity discrimination task, for example losing their preference for a larger food quantity if a human shows a preference for a smaller one, yet there is, so far, no explanation for this phenomenon. Using a modified version of this task, in the current study we investigated whether non-social, social or communicative cues (alone or in combination) cause dogs to go against their preference for the larger food quantity. Results show that dogs' evaluation errors are indeed caused by a social bias, but, somewhat contrary to previous studies, they highlight the potent effect of stimulus enhancement (handling the target) in influencing the dogs' response. A mild influence on the dog's behaviour was found only when different ostensive cues (and no handling of the target) were used in combination, suggesting their cumulative effect. The discussion addresses possible motives for discrepancies with previous studies suggesting that both the intentionality and the directionality of the action may be important in causing dogs' social biases.
Inquiry of cases of myiasis by Dermatobia hominis in dogs (Canis familiaris) of the Northern and Western zones of Rio de Janeiro city in 2000
Cramer-Ribeiro, Bianca Chiganer;Sanavria, Argemiro;Monteiro, Heloísa Helena Magalh?es Soares;Oliveira, Marcelo Queiroz de;Souza, Fábio Silva de;
Brazilian Journal of Veterinary Research and Animal Science , 2003, DOI: 10.1590/S1413-95962003000100002
Abstract: an inquiry about cases of myiasis by dermatobia hominis larvae on dogs presented to 190 veterinary establishments of the northern and western zones of rio de janeiro city in 2000 was performed. cases were presented to 37 of 108 establishments in the northern zone and to 55 of 82 in the western zone of the city. presence of rural or forest areas and coexistence of dogs and farm animals created an adequate ambient to flies proliferation, including the vector flies of dermatobia hominis eggs. adult, pure breed, short and dark-haired dogs were most infested. males were most infested in the northern zone, while in the western zone no predilection for sex was noticed. dogs kept in small farms and house yards, as adult and large breed dogs (usually for house guard), were most affected. dorsal and lumbar regions, which are easily accessible to flies, were most infested body regions. prevention programs against myiasis should be intensified during months of highest incidence, although sometimes it is not possible, because many clinicians reported that no month presented higher incidence than another or they did not know to answer this question. clinicians should warn pet owners that it is necessary to correct handling and to maintain hygiene of the place where the dogs are kept, in order to avoid the existence of flies. more studies are necessary in order to identify other predisposing causes to myiasis and avoid this disease.
Inquiry of cases of myiasis by Cochliomyia hominivorax in dogs (Canis familiaris) of the Northern and Western zones of Rio de Janeiro city in 2000
Cramer-Ribeiro, Bianca Chiganer;Sanavria, Argemiro;Monteiro, Heloísa Helena Magalh?es Soares;Oliveira, Marcelo Queiroz de;Souza, Fábio Silva de;
Brazilian Journal of Veterinary Research and Animal Science , 2003, DOI: 10.1590/S1413-95962003000100001
Abstract: an inquiry about cases of myiasis by c. hominivorax larvae on dogs presented to 190 veterinary establishments of rio de janeiro city in 2000 was performed to contribute to the comprehension of epidemiological features of this myiasis. cases of screwworm infestation were observed in 184 veterinary establishments: in 104 among 108 establishments of the northern zone, and in 80 of 82 establishments of the western zone of the city. most infested dogs were adult, pure breed, long and dark-haired, living in houses, while no preference for sex was observed. ears were most infested, and the main cause of lesions that led to myiasis was otitis. screwworm infestation is a very frequent disease on dogs, and prevention programs should be developed, specially during hot weather months (december and january), when incidence was higher. most infested dogs are the ones that need more care, and prevention of all possible causes of myiasis will help its avoidance. dirt and lack of hygiene are also causes of screwworm infestation and must be avoided, as other myiasis causes. pet owners negligence is a contributing factor to the appearance of screwworm infestation on dogs, and pet owners should receive orientation from veterinary clinicians. additional studies about screwworm infestation on dogs should be performed, in order to identify more predisposing factors to be used in prevention programs.
Use of fresh autogenous vaginal tunic in the experimental lamellar keratoplasty in dogs (Canis familiaris, LINNAEUS, 1758)
GALERA, Paula Diniz;LAUS, José Luiz;FERREIRA, Affonso Luiz;
Brazilian Journal of Veterinary Research and Animal Science , 2000, DOI: 10.1590/S1413-95962000000600010
Abstract: autogenous vaginal tunics have been researched in lamellar keratoplasty in dogs using fresh autogenous grafts in the repair of superficial keratectomies. fourteen dogs have been used for the evaluation at the early, intermediary and late postoperative periods. photophobia, blepharospasm, ocular discharge, edema, neovascularization and pigmentation have been observed. the results have showed that the original procedure is useful for the repair of corneas after superficial keratectomies.
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