Staphylococci are important opportunistic pathogens often found in the microflora of skin and mucosal surfaces of the upper respiratory tract of man and animals. The coagulase-positive species such as Staphylococcus aureus are capable of causing invasive (eg furuncles and bacteraemia) and non-invasive (food poisoning and toxic shock syndrome) conditions in humans. In animals, S. intermedius and S. aureus have been implicated in a variety of conditions including pyoderma in dogs, mastitis in cows and skin infections in horses with S. intermedius being responsible for more than 95% of staphylococcal infections in dogs. The emergence of antibiotic-resistant bacteria, in humans, animals and the environment, has become a cause for concern following the introduction of antimicrobial agents in clinical practice. Staphylococcal species, in particular, have developed or acquired antibiotic-resistance determinants to almost all the antimicrobial agents in clinical use today. In recent years there has been an increase in reports of the isolation of antibiotic-resistance staphylococci especially methicillin-resistant staphylococci (MRS), from cats and dogs. Cats and dogs are in close contact with humans, especially in advanced countries and therefore the possibility for transfer of antibiotic-resistant staphylococci from these animals to humans or vice versa may exist. The aims of this study were; to determine the species distribution and antibiotic sensitivity of staphylococci obtained from cats and dogs, to investigate the molecular basis of resistance and to examine the genetic relatedness of specific resistant isolates. Many studies have shown that S. intermedius and S. simulans (S. felis) are the predominante species on healthy dogs and cats, respectively, and lesions in these animals are caused by S. aureus and S. intermedius. In this study, a diverse range of coagulase-negative staphylococci was isolated from healthy animals but staphylococci from skin lesions of cats and dogs were identified mainly as S. intermedius as reported in the literature. A limited number of resistant isolates (~20%) were observed in this study and were mostly isolated from dogs. Investigations into the molecular basis of resistance to beta-lactam, macrolide and tetracycline antibiotics were carried out. The resistant isolates were analysed by polymerase chain reaction (PCR) and DNA sequencing techniques. MRS were analysed for the presence of the mecA gene and the staphylococcal cassette chromosome mec (SCCmec). The recombinase genes, cassette chromosome recombinase (ccr) on SCCmec elements were also examined. The SCCmec elements detected were as diverse as those reported in human staphylococcal strains. Comparative analysis of nucleotide and amino acid sequences of mecA and ccr gene complexes revealed that the genes are conserved among MRS of cat and dog orgin. Multilocus sequence typing (MLST) of methicillin-resistant S. aureus (MRSA) and S. epidermidis isolates showed that, the MRSA were of human origin but the S. epidermidis isolates were unique to cats and dogs. In addition, the blaZ gene which codes for ??-lactamases production, the erm genes responsible for erythromycin resistance and the tet genes which encode tetracycline resistances, were found to be identical to those observed in humans and other animal staphylococci and demonstrated similar diversity. The study has provided important information about the molecular basis of resistance in beta-lactamase producing staphylococci as well as the molecular epidemiology of MRS of cat and dog origin and identifies the risk of spread of MRS between humans and pets and vice versa. These findings should form part of a larger surveillance study on staphylococci of cat and dog origin for a better understanding of the epidemiology of antibiotic-resistance genes for improved management and control of resistant staphylococci in the community and in health care settings. / PhD Doctorate

Theory of mind, the ability to attribute mental states to oneself and others, has traditionally been investigated in humans and nonhuman primates. However, non-primate species, such as domestic dogs, may also be potential candidates for such a faculty. Domestic dogs (Canis familiaris) evolved from a social-living, wolf-like ancestor, and were the first species to be domesticated, with likely selection for sensitivity to human cues and human-like cognitive abilities. Dogs typically spend their lives in the rich social environment of human families, and thus dogs are naturally enculturated. The combination of these factors make dogs an excellent candidate for having a functional theory of mind. Yet perhaps surprisingly, prior research on theory of mind in dogs is limited, with inconclusive and contradictory results. The research described in this thesis is a systematic investigation of dogs' potential to demonstrate a functional theory of mind in their interactions with humans. Four experiments are presented, based on the Knower-Guesser paradigm (Povinelli et al., 1990), in which a knowledgeable and an ignorant human informant indicated the location of hidden food to the dog. In Experiment 1, one informant was absent (Guesser) and one present (Knower) during the food-hiding, and the dogs chose the Knower. However, when both informants were present, the dogs chose the informant that did the baiting, but this preference was less than when the Guesser was absent. In Experiments 2 and 3, a third experimenter hid the food while the informants covered their cheeks (Knower) or eyes (Guesser) with their hands, or were attentive (Knower) or inattentive (Guesser) to the food-hiding. In both cases, the dogs showed a significant preference for the Knower. In Experiment 4, the dogs showed no preference between the informants when they had equal perceptual access to the baiting, and were unsuccessful at selecting any container when the informants did not provide communicative cues. Overall, the present research provides the most definitive evidence yet that domestic dogs may be able to attribute differential states of knowledge to human observers, and thus may possess a functional theory of mind.

Doctor of Philosophy / Pup mortality is reported to be a significant problem in the dog. The purpose of this thesis was to identify the extent and causes of the mortality and the risk factors. Mortality was classified according to the clinical condition of the pup at birth and the pathological investigation was designed to investigate the validity of this classification. Total pup mortality, excluding elective euthanasia for show reasons, was 18.5%. Perinatal mortality, that is, stillbirths and deaths that occurred in the first week, accounted for 90.9% of these losses. Each breed surveyed exhibited a specific mortality pattern and the results of one breed could not be used to anticipate the outcome in another breed. As a consequence of this, there was a marked difference in the predictor variables, or risk factors, identified for each breed. Birth weight and inter-pup whelping intervals were the most consistent variables that increased the odds of a pup dying. The principal cause of pup mortality was attributed to foetal asphyxia, that is, apparently normal pups subjected to excessive hypoxia during the birth process and they were either still born or born in a distressed condition and subsequently died. Death attributed to foetal asphyxia accounted for 7.8% of all pups born and 42.5% of the total mortality. The majority of these pups (82.2%) died during whelping or in the first 24 hours after birth. The death of just over half of these pups could be directly attributed to dystocia. The remaining pups were compromised during what appeared to be a normal whelping. Neonatal atelectasis, pulmonary congestion, inhalation of amniotic fluid and meconium, leptomeningeal and generalised systemic congestion were the principal pathological findings in these pups. Average birth weights, inter-pup whelping intervals, parity, pup presentation and litter position were all significant predictors of mortality due to foetal asphyxia. The abnormal pup was defined as a pup at birth that was mummified, had died prior to birth, was small for date or had gross congenital defects present. These accounted for the death of 4.9% of all pups born and 26.3% of all losses. The only significant predictors of mortality due to the birth of an abnormal pup were the inter-pup interval and birth weight. Since the abnormality occurred in utero and was not related to the birth process this result had no bearing on the outcome. The death of live born, apparently normal pups, in the neonatal period accounted for 5.7% of all pups born and 31.2% of the total mortality. Over half these losses were attributed to fading puppy syndrome. The remainder were due to mismothering / mismanagement and other miscellaneous causes. The majority of fading pups examined were not normal at birth. Growth retardation and the consequent increased susceptibility to foetal hypoxia, lung pathology indicative of foetal asphyxia and intrauterine and/or very early neonatal infections were the principal causes of mortality attributed to fading puppy syndrome identified in this study. The canine perinate is totally dependent on the bitch both in the uterus and in the immediate post partum period. The investigation of pup mortality can not be divorced from the assessment of maternal health, the influence of the whelping process and the post whelping care of the immature pups by the bitch. These factors must be correlated with gross and histological changes identified in dead pups to determine the sequence of events that contributed to the death of the whelp.

Doctor of Philosophy / Pup mortality is reported to be a significant problem in the dog. The purpose of this thesis was to identify the extent and causes of the mortality and the risk factors. Mortality was classified according to the clinical condition of the pup at birth and the pathological investigation was designed to investigate the validity of this classification. Total pup mortality, excluding elective euthanasia for show reasons, was 18.5%. Perinatal mortality, that is, stillbirths and deaths that occurred in the first week, accounted for 90.9% of these losses. Each breed surveyed exhibited a specific mortality pattern and the results of one breed could not be used to anticipate the outcome in another breed. As a consequence of this, there was a marked difference in the predictor variables, or risk factors, identified for each breed. Birth weight and inter-pup whelping intervals were the most consistent variables that increased the odds of a pup dying. The principal cause of pup mortality was attributed to foetal asphyxia, that is, apparently normal pups subjected to excessive hypoxia during the birth process and they were either still born or born in a distressed condition and subsequently died. Death attributed to foetal asphyxia accounted for 7.8% of all pups born and 42.5% of the total mortality. The majority of these pups (82.2%) died during whelping or in the first 24 hours after birth. The death of just over half of these pups could be directly attributed to dystocia. The remaining pups were compromised during what appeared to be a normal whelping. Neonatal atelectasis, pulmonary congestion, inhalation of amniotic fluid and meconium, leptomeningeal and generalised systemic congestion were the principal pathological findings in these pups. Average birth weights, inter-pup whelping intervals, parity, pup presentation and litter position were all significant predictors of mortality due to foetal asphyxia. The abnormal pup was defined as a pup at birth that was mummified, had died prior to birth, was small for date or had gross congenital defects present. These accounted for the death of 4.9% of all pups born and 26.3% of all losses. The only significant predictors of mortality due to the birth of an abnormal pup were the inter-pup interval and birth weight. Since the abnormality occurred in utero and was not related to the birth process this result had no bearing on the outcome. The death of live born, apparently normal pups, in the neonatal period accounted for 5.7% of all pups born and 31.2% of the total mortality. Over half these losses were attributed to fading puppy syndrome. The remainder were due to mismothering / mismanagement and other miscellaneous causes. The majority of fading pups examined were not normal at birth. Growth retardation and the consequent increased susceptibility to foetal hypoxia, lung pathology indicative of foetal asphyxia and intrauterine and/or very early neonatal infections were the principal causes of mortality attributed to fading puppy syndrome identified in this study. The canine perinate is totally dependent on the bitch both in the uterus and in the immediate post partum period. The investigation of pup mortality can not be divorced from the assessment of maternal health, the influence of the whelping process and the post whelping care of the immature pups by the bitch. These factors must be correlated with gross and histological changes identified in dead pups to determine the sequence of events that contributed to the death of the whelp.

Thesis (M.D.S.)--University of Adelaide, 1982. / Some ill. mounted. Includes bibliographical references (v. 2. leaves 173-203).

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2002. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 4 uppsatser.