Australian Dog Research Articles

Meconium microbiota in naturally delivered canine puppies

BackgroundMicrobial colonization during early life has a pivotal impact on the host health, shaping immune and metabolic functions, but little is known about timing and features of this process in dogs. The objectives of this study were to characterize the first step of intestinal microbiota development in naturally delivered canine puppies and to investigate its relationship with the maternal bacterial flora, using traditional culture and molecular analyses. Sixty puppies of two breeds, Appenzeller Cattle Dog (n = 3 dams) and Lagotto Romagnolo (n = 6), housed in the same breeding kennel, were included in the study. Swabs were collected in duplicate (for culture and for molecular analysis) from the dams’ vagina and rectum at the end of parturition, from puppies’ rectum, before maternal care, and from the environment (floor of the nursery and parturition box).Results93.3% meconium samples showed bacterial growth, limited to a few colonies in 57.0% of cases. High growth was detected for Enterococcus faecalis, which was the most frequently isolated bacterium. The genus Enterococcus was one of the most represented in the dams’ rectum and vagina (88.9% and 55.6%, respectively). The genera Staphylococcus, Enterococcus, Escherichia and Proteus were also often isolated in meconium but were usually present in maternal samples as well, together with ubiquitous bacteria (Acinetobacter, Psychrobacter). In the environmental samples, just a few bacterial species were found, all with low microbial load. Additionally, bacteria of the phyla Proteobacteria, Firmicutes, and Actinobacteria were identified in meconium through molecular analysis, confirming the culture results and the early colonization of the newborn gut. Maternal, meconium and environmental samples had similar alpha diversity, while beta-diversity showed differences among families (i.e. a dam and her litter), and association indexes revealed a significant correlation between family members and between sample origin, suggesting a strong contribution of the maternal flora to the initial seeding of the canine neonatal gut and a strong individual dam imprint.ConclusionThis study showed that the meconium of vaginally delivered puppies has its own microbiota immediately after birth, and that it is shaped by the dam, which gives a specific imprint to her litter.

Computed tomography findings of nasal cryptococcosis in Australia (2008-2020): 12 dogs and 9 cats.

To describe the CT findings of Australian dogs and cats with nasal cryptococcosis over a 12-year period. 12 dogs and 9 cats diagnosed with nasal cryptococcosis from 2008 through 2020. CT findings were compared among enrolled cases from Australian veterinary referral centers. Disease severity was compared between a subset of patients with cryptococcal speciation performed (n = 6 dogs; n = 3 cats) and geographic domicile. Dogs demonstrated diffuse disease affecting numerous nasal regions and sinuses. Cats displayed more focal nasal and nasopharyngeal disease. Dogs were more likely to have a nasal mass, whereas cats were more likely to have a nasopharyngeal mass. Cribriform plate lysis was common in dogs but not observed in cats. Sinonasal osteolysis was a common feature in both species. Mandibular lymph nodes were commonly enlarged in dogs, whereas in cats, the retropharyngeal lymph nodes were more likely enlarged. There was no obvious difference in disease severity or lesion distribution in relation to the causal species of Cryptococcus, although to determine if this finding is robust, an appropriately powered prospective study is warranted. There are numerous studies describing the clinical features, treatment, and outcomes of dogs and cats with cryptococcosis. To the best of our knowledge, there is only 1 previous study describing the CT features of nasal cryptococcosis, undertaken in one part of North America. Our study describes the CT features of nasal Cryptococcus sp in an Australian canine and feline cohort, adding new pertinent observations while reinforcing reported radiological observations.

Epidemiology of Angiostrongylus vasorum and Crenosoma vulpis infection in dogs in Denmark.

This retrospective study aimed to evaluate the risk factors (age and breed group) associated with Angiostrongylus vasorum and Crenosoma vulpis infection in dogs. Faecal examinations obtained in dogs from January 2016 to December 2021 as part of routine clinical practice at two veterinary clinics in the Odsherred region of Zealand, Denmark, were included in this study. Faecal samples were analysed using the Baermann technique for nematode detection. Samples were collected from two clinics located in Northwestern Zealand, Denmark. Multinomial regression analysis, quasi-Poisson models and a generalised additive model for linearity were used to analyse the data. A total of 2,013 faecal samples were included in the study. Age was a significant risk factor for a positive Baermann, with a negative linear relationship observed (A. vasorum odds ratio: 0.80, 95% confidence interval: 0.70 to 0.91, C. vulpis odds ratio: 0.95, 95% confidence interval: 0.91 to 0.99, both nematodes: odds ratio: 0.87, 95% confidence interval: 0.77 to 0.99). Breed group analysis considering retrievers and flushing and water dog as reference group, demonstrated that sheep- and cattle dogs had a reduced risk of C. vulpis infection (odds ratio: 0.49, 95% confidence interval: 0.24 to 0.97), whereas dachshunds had an increased risk of A. vasorum infection (odds ratio: 3.28, 95% confidence interval: 1.14 to 9.47). Variations in the number of nematodes was found, with companion and toy dogs exhibiting higher numbers of C. vulpis (incidence rate ratio: 21.40, 95% confidence interval: 2.88 to 159) and sheep- and cattle dogs displaying higher numbers of A. vasorum (incidence rate ratio: 30.20, 95% confidence interval: 7.33 to 125). The prevalence rates of C. vulpis and A. vasorum were estimated at 14.50% (95% confidence interval: 13 to 16.10) and 3.40% (95% confidence interval: 2.70 to 4.30), respectively. There are significantrisk factors for nematode infection in dogs that can be considered for proper preventive care of this condition.

Prevalence of Cadmium and Lead Residues in Fried Meat (Suya) Sold in Kaduna Metropolis, Kaduna State, Nigeria

Study’s Novelty/Excerpt This study is novel as it provides the first comprehensive analysis of cadmium (Cd) and lead (Pb) contamination in various types of suya meat in Kaduna, Nigeria, using Atomic Absorption Spectrophotometry. Unlike previous research, this study uniquely examines multiple animal sources and local government areas, offering a detailed comparison of contamination levels across species and regions. Additionally, the findings highlight the widespread public health risk due to Cd and Pb levels exceeding international safety standards, emphasizing the urgent need for regulatory measures to mitigate environmental pollution and protect public health. Full Abstract Heavy metals are of public health concern worldwide due to their damaging effects on human and animal health. The study was aimed at analyzing the presence of cadmium (Cd) and lead (Pb) residues in suya meats; cattle meat (beef), sheep meat (mutton), goat meat (chevon), fowl meat (chicken) and dog meat sold in the Kaduna metropolis, Kaduna State. A descriptive-quantitative research design was used, with fifty samples collected from four Local Government Areas (Chikun, Igabi, Kaduna North and Kaduna South). Atomic Absorption Spectrophotometery was used to analyze and quantify the presence of these heavy metals. Microsoft Excel (Version 2019) and one-way ANOVA are the statistical tools used for result analysis and Cd and Pb were found to be present in all the suya samples analyzed. The results showed statistical significance (p<0.05) between the overall mean concentration of Cd (0.049 mg/kg) and Pb (0.44 mg/kg) in the samples. Even though the mean concentration of Cd in suya samples varied with regards to which the animal originates viz: cattle (0.033 mg/kg), sheep (0.058 mg/kg), goat (0.048 mg/kg), dog (0.04 mg/kg) and chicken (0.078 mg/kg); likewise that of Pb: cattle (0.47 mg/kg), sheep (0.41 mg/kg), goat (0.41 mg/kg), dog (0.39 mg/kg) and chicken (0.51 mg/kg); the animal species from which the meat used in making the suya had no statistically significant influence on the heavy metal content of the meat (p˃0.05). The mean concentration of Cd and Pb obtained within the study areas, in mg/kg were: Chikun (0.046 and 0.43), Igabi (0.044 and 0.43), Kaduna North (0.054 mg/kg) and (0.49 mg/kg), Kaduna South (0.053 mg/kg) and (0.41 mg/kg) respectively. The mean concentration of cadmium and lead in the suya samples was above the permissible limits set by EC and FAO limits of 0.01ug/g lead and 0.003ug/g for cadmium (FAO, 1983), indicating the general contamination of suya meats by heavy metals. The study recommends public measures to minimize environmental pollution and bioaccumulation of Cd and Pb to prevent related ailments and mortality; enforcing regulations governing industrial activities and waste disposal to protect the public from heavy metals pollution.

Early Uses by Ancient Hawaiians, and Environmental, Geographical, and Ecological History, of Haleakalā Crater, East Maui

This research assesses the environmental uses of Haleakalā Crater, and adjoining east Maui areas, by native Hawaiians during recent centuries, and evaluates the modern utilization of this volcanic depression. The study methods examine, and focus on, numerous historical and modern accounts and reports. Three historical periods were identified as follows: (1). A phase, from the ~1400s until contact with foreigners in 1778, characterized by the development of settlements, population expansion, the intensification of traditional agriculture, and the political consolidation of Maui. The construction of the Kiha-a-Pi‘i-lani trail across the crater enhanced travel between distant island areas. (2). Following the collapse of Maui’s human populations during the late 1700s, and until the 20th century, came a period distinguished by scientific exploration of the crater, and intentional or accidental introductions of animals, including goats, horses, cattle, and wild dogs. (3). After Haleakalā became a National Park in 1916, efforts to eradicate introduced animals and to encourage the reproduction of silverswords and other plants were initiated. Unfortunately, in retrospect, construction of a modern paved road, improvement of hiking trails, and building of facilities allowed swift access to the Park and substantially increased tourist numbers, up to ~2 million yearly visitors. Faced with such crowds, the long-term planning of Park resources appears to be a formidable task.

Copper hepatopathies in Australian dogs.

To evaluate hepatopathies in Australian dogs according to the World Small Animal Veterinary Association (WSAVA) guidelines. Specifically, to describe the prevalence and survival of dogs with copper-associated hepatopathy. Medical records from the Small Animal Specialist Hospital were reviewed to identify dogs with liver disease and liver biopsy between November 2008 and November 2021. Liver histopathology reports were reviewed with a board-certified veterinary pathologist and classified according to the WSAVA guidelines. Histopathology reports and clinical records were reviewed to ascertain the most important histological process for statistical analysis. Copper-associated hepatopathy was defined as (i) histological evidence of copper accumulation in centrilobular areas (Zone 3) associated with hepatocyte necrosis, inflammation with copper-laden macrophages and chronic hepatitis (ii) histochemical copper staining showing hepatocyte copper accumulation in the centrilobular areas and iii) hepatic copper measurement with concentrations greater than 600 μg/g dry weight of liver. Dogs with primary inflammatory parenchymal disease included dogs with copper-associated hepatopathy, idiopathic chronic hepatitis, non-specific reactive hepatitis, chronic bacterial hepatitis and immune-mediated chronic hepatitis. Descriptive statistics were performed for all dogs. Age, weight and clinicopathologic data were compared between dogs with copper-associated hepatopathy and dogs with other causes of chronic primary inflammatory parenchymal liver disease (Kruskal-Wallis test). Survival times were calculated and compared (Kaplan-Meier curves and log rank test) between dogs with copper-associated hepatopathy and dogs with other chronic primary inflammatory parenchymal liver diseases. Breed was evaluated to determine the breed most commonly affected with copper-associated hepatopathy and identify any breed in which this disease has not previously been described. Sixty-seven (43 female, 24 male) dogs with a median age of 7.8 years (quartile [Q] Q1-Q3 4.5-9.6 years) were included. Thirteen dogs had copper-associated hepatopathy, eight dogs had idiopathic chronic hepatitis, eight dogs had non-specific reactive hepatitis, seven dogs had disorders associated with portal hypertension, five dogs had chronic bacterial hepatitis and four dogs had immune-mediated chronic hepatitis. Compared with dogs with other causes of chronic primary inflammatory parenchymal liver disease, dogs with copper-associated hepatopathy tended to be younger (6.73 vs. 8.01 years, P = 0.057) and heavier (19.8 vs. 9.6 kg, P = 0.052) than dogs with other causes of primary chronic inflammatory parenchymal diseases. There was no statistically significant difference when ALT (P = 0.30), ALP (P = 0.18) and total bilirubin (P = 0.13) were compared between the two groups. The median survival time for all dogs after liver biopsy was 2010 days (CI 1321 days - not reached). There was no significant difference in survival between dogs with copper-associated hepatopathy and dogs with other causes of chronic primary inflammatory parenchymal liver disease (P = 0.5). Copper-associated hepatopathy was common among Australian dogs with chronic hepatopathies, occurring in younger and heavier dogs than other causes of primary inflammatory parenchymal liver disease. Clinical pathology is not useful for differentiating between copper-associated hepatopathy and other causes of chronic primary inflammatory parenchymal liver disease. When copper-associated hepatopathy is treated, the prognosis can be good. This is the first report of copper-associated hepatopathy in Australian Cavalier King Charles Spaniels.

What do Australians do with their dog poo? A survey of dog-owning household practices and attitudes

ABSTRACT Australian dog owners are seeking sustainable alternatives to dog faecal collection and disposal, such as compostable waste bags and home composting. Little is known about dog owners’ attitudes towards composting dog faeces or how they manage dog faeces within private households. Australian dog owners’ (N = 1054) were surveyed to investigate household demographics, how they collect and dispose of dog faeces, their home composting practices, and their attitudes, experiences, and concerns regarding home composting dog faeces. Within households, most dog faeces were collected using tools such as shovels and scoops more than single use bags. General waste bins were the most common home disposal location followed by organic waste bins, home compost and burial. Few participants included compostable plastic dog waste bags in home compost. Most composted dog faeces were applied to non-edible plants within gardens. Over half of dog owners viewed home composting as a potentially effective disposal method and many wanted to home compost dog faeces but were not yet doing so. Reported challenges included a lack of reliable compost information, hygiene concerns and uncertainty how canine de-worming treatments affect compost. Findings are important for conducting future research that reflects current practices and address dog owners’ main concerns and challenges.

Brain magnetic resonance imaging and computed tomography findings in cats and dogs with central nervous system cryptococcosis in Australia: 23 cases (2009-2020).

To describe the imaging findings in Australian cats and dogs with CNS cryptococcosis. 23 cases (10 cats; 13 dogs) with CNS cryptococcosis and brain MRI or CT studies available to review. Retrospective, multi-institutional case series. Brain MRI or CT studies were reviewed by a board-certified radiologist. Imaging findings were described and the differences between cats and dogs explored. Morphologic features were consistent with extra-axial lesions in all (n = 13) dogs and either intra-axial (5/10) or extra-axial (4/10) lesions in cats, with 1 cat having no detectable lesions in low-field brain MRI scans. Meningeal abnormalities were most common, followed by forebrain and cerebellar lesions. Intracranial MRI lesions were typically T2 hyperintense and T1 hypo- to isointense. Four cases had T2 hypointense lesions affecting the brain, sinonasal cavity, or regional lymph nodes. Intracranial CT lesions were mostly soft tissue attenuating. Contrast enhancement was present in all cases with contrast series available, with ring enhancement shown only in cats. Osteolysis was more common in dogs than cats, particularly affecting the cribriform plate. All 13 dogs and many (6/10) cats had at least 1 lesion affecting sinonasal or contiguous tissues, and locoregional lymphadenomegaly was common (7/10 cats; 11/13 dogs). Imaging lesions in cryptococcal meningoencephalitis were extra-axial in dogs but could be intra-axial or extra-axial in cats. Careful examination for extracranial lesions (sinonasal, retrobulbar, facial soft tissue, tympanic bullae, or locoregional lymph nodes) is important to provide alternative safe biopsy sites. T2 hypointense lesions, while rare, should prompt consideration of cryptococcosis.

Case report: Nonsimultaneous bilateral triceps tendon rupture and surgical repair in a healthy dog

A 7-year-old female spayed Australian shepherd dog was presented for an acute onset of inability to stand. On physical examination, the dog was unable to support weight on the thoracic limbs. On neurological examination, the thoracic limbs had absent hopping and paw placement and reduced withdrawal reflexes bilaterally. The remainder of the neurological examination was normal. The anatomic lesion localized to the C6-T2 spinal nerve roots, spinal nerves, or the named nerves of the thoracic limb, bilaterally. A lesion affecting the ventral gray column of the C6 through T2 spinal cord segments was considered less likely. In an effort to exclude an orthopedic disorder from consideration, radiographs of the shoulders, elbows, and manus were normal. Magnetic resonance imaging of the cervical and cranial thoracic vertebral column was normal. Analysis of synovial fluid from the carpi, elbows, and shoulders were normal. Ultrasonography of the triceps muscle and tendon of insertion revealed bilateral, acute-subacute tears of the tendon at insertion of the triceps muscles, bilaterally. Magnetic resonance imaging of both elbows revealed complete avulsion of the triceps tendons bilaterally. Surgical repair of both tendons was performed using the Arthrex FiberLoop system combined with autologous conditioned plasma soaked in a collagen sponge. Postoperatively, external coaptation was provided using Spica splints for 6 weeks followed by the use of soft padded orthotic braces for an additional 6 weeks. Concurrently, a front support wheelchair was used for 10 weeks postoperative. By 10 weeks postoperative, the dog was able to ambulate without support. To the authors’ knowledge, this is the first report of bilateral triceps tendon avulsion in a dog. Tendon avulsion occurred without a known history of trauma or predisposing metabolic abnormalities. Magnetic resonance imaging provided excellent anatomical detail that aided in surgical repair.

Intra-articular Fibrolipoma of the Stifle in a Dog.

A 12 yr old male castrated miniature Australian shepherd dog presented for surgical consultation of historical bilateral medial patellar luxations with a 3 mo history of an acute onset of a left pelvic limb lameness. Physical examination confirmed medial patellar luxations and a mass effect of the left stifle medially. Radiographs showed medial distension of the joint capsule by a soft tissue opacity. Fine-needle aspirate of the left stifle revealed a mesenchymal cell population. Left medial parapatellar stifle arthrotomy found a fatty mass, which was excised at its base. A benign fibrolipoma was diagnosed on histopathology, and the excision was expected to be curative. The owners reported immediate improvement of perceived comfort postoperatively. At 2 and 24 wk, the dog returned to a normal level of function. Lipomas of the stifle, although rare, should be considered as a differential for intra-articular masses causing lameness.

Exploring multiplex qPCR as a diagnostic tool for detecting microfilarial DNA in dogs infected with Dirofilaria immitis: A comparative analysis with the modified Knott’s test

Current recommendations to diagnose cardiopulmonary dirofilariosis in dogs caused by Dirofilaria immitis involves tandem antigen and circulating microfilariae tests. The modified Knott’s test is an important tool in heartworm diagnosis, allowing identification of circulating microfilariae. However, the subjective nature of the modified Knott’s test affects its accuracy and diagnostic laboratories usually do not provide a quantitative outcome. Quantitative enumeration of microfilariae enables clinicians to track treatment progress and acts as a proxy for detecting emerging macrocyclic lactone resistance. There is a need for better diagnostic tools suitable for routine use to efficiently and accurately quantify the presence of D. immitis microfilaremia. The aim of this study was to determine whether the quantitative modified Knott's test can be substituted by multiplex quantitative polymerase chain reaction (qPCR) targeting D. immitis and associated Wolbachia endosymbiont DNA in canine blood samples. To do this, genomic DNA samples (n = 161) from Australian dogs, collected as part of a previous 2021 study, were assessed in a TaqMan qPCR targeting DNA of D. immitis, Wolbachia sp. and Canis lupus familiaris. Of the 161 genomic DNA samples, eight were considered positive for D. immitis microfilariae. The qPCR assay demonstrated good efficiency (E = 90 to 110%, R2 > 0.94). Considering the performance and efficient use of bench time, this TaqMan qPCR assay is a suitable alternative to the modified Knott’s test for quantitative enumeration of microfilariae (Cohen’s kappa coefficient [κ]: κ = 1 using D. immitis qPCR marker, κ = 0.93 using Wolbachia qPCR marker). The qPCR data demonstrated a comparable result to that of the quantitative modified Knott’s test in a 2022 survey of D. immitis in Australian dogs (n = 23) before and after macrocyclic lactone (ML) administration. Improving the detection and diagnosis of canine heartworm infections will assist veterinarians in better managing and controlling disease outcomes and will be valuable for tracking the spread of ML resistance in Australia.

CHARAKTERYSTYKA GENU MC1R JAKO LOCUS E WPŁYWAJĄCEGO NA UMASZCZENIE PSÓW

The color of dogs is the result of various genes that control the pigmentation of the coat mainly. There are many genes that influence the color, pattern and distribution of fur in dogs, one of which is the gene encoding the melanocortin 1 receptor (MC1R), also known as the E locus. The melanocortin 1 receptor (MC1R) is a protein that plays a key role in the regulation of skin, hair and eye pigmentation in animals. This receptor is responsible for the processing of peptide hormones that control the production of melanin, which is the pigment of the skin and fur. Mutations within this gene can affect the color of animals, including dogs. The main alleles identified and described for the E lo- cus are: E (wild type), EM (melanistic mask) and e (recessive red); they are widespread in various dog breeds, indicating that they existed at an early stage in the formation of individual breed groups. The other identified alleles are less common and are: EG (grizzle/domino), e2 (only among Australian Cattle Dogs and their crossbreds) and e3 (only among Siberian Huskies and their crossbreds), eA (ancient red) allele and the allele EH (only among English Cocker Spaniels and American Cocker Spaniels). Of course, it’s important to remember that dog color is a complex genetic phenomenon that can be controlled by many different genes working together, and that the variety of coat colors in different dog breeds results from a combination of these genes.

Incidence and risk factors of heat-related illness in dogs from New South Wales, Australia (1997-2017).

Heat Related Illness (HRI) in dogs is expected to increase as heatwaves surge due to global warming. The most severe form of HRI, heat stroke, is potentially fatal in dogs. The current study investigated the incidence and risk factors for HRI in dogs in NSW, Australia, from 1997 to 2017. We identified 119 HRI cases during this period, with a fatality rate of 23%. Dog breeds at elevated risk of HRI were Australian Stumpy Tail Cattle Dog, British Bulldog, French Bulldog, Maremma Sheepdog, Italian Greyhound, Chow Chow, Airedale Terrier, Pug, Samoyed, English Springer Spaniel, Labrador Retriever, Golden Retriever, Cavalier King Charles Spaniel, Border Collie, Staffordshire Bull Terrier, and pooled non-Australian National Kennel Council breeds (which included the American and Australian Bulldog) when compared with cross breeds (i.e., the reference variable). As expected, HRI cases were more likely in December and January, during the Australian summer and during hotter years (e.g., 2016). There were no differences in the risk of HRI between males and females nor between desexed or un-desexed dogs; but older dogs were at increased risk of HRI. These findings underscore the need for data collection that will enable the incidence of HRI in dogs to be monitored and to better understand canine risk factors particularly as temperatures will continue to rise due to global warming. The risk of mortality from HRI underpins the need for education programs focussed on prevention and early identification of HRI so that owners present affected dogs to their veterinarian as promptly as possible.

Radiographic findings in the coxofemoral joint of Australian Cattle Dogs

Australian Cattle Dogs (ACD) are medium-sized animals widely used in fieldwork for managing cattle and sheep. There needs to be more information about the conditions these dogs can develop despite being well-characterized animals since the beginning of the 20th century. Hip dysplasia (HD) is a developmental abnormality between the femoral head and the acetabular fossa, which can be debilitating. However, the available literature has no studies on the prevalence of this condition in dogs of this breed. This study aimed to evaluate radiographs of ACD qualitatively and quantitatively. For this purpose, 49 dogs considered healthy without clinical signs of HD were radiographically assessed, and the animals were classified as dysplastic (D) and non-dysplastic (ND). A frequency of 46.9% of dysplastic dogs was observed, with males being more affected. The cortical index (CI) and angle of inclination (AI) could not differentiate D from ND animals; only the Norberg angle (NA) was effective in this differentiation. No correlation was observed between AI, CI, and AN.

Dingoes, companions in life and death: The significance of archaeological canid burial practices in Australia.

The dingo, also known as the Australian native dog, was introduced in the late Holocene. Dingoes were primarily wild animals but a number resided in Aboriginal people's camps. Traditionally, these individuals were taken from wild litters before weaning and raised by Aboriginal people. It is generally believed that these dingoes were not directly provided for, and upon sexual maturity, returned to reproduce in the wild. However, some died while in the company of people and, were buried in occupation sites. This Australian practice parallels the burial of domestic dogs in many regions of the Asia-Pacific and beyond but has attracted very little research. We explore the historical and archaeological evidence for dingo burial, examining its different forms, chronological and geographic distribution, and cultural significance. Dingoes were usually buried in the same manner as Aboriginal community members and often in areas used for human burial, sometimes alongside people. This practice probably occurred from the time of their introduction until soon after European colonisation. We present a case study of dingo burials from Curracurrang Rockshelter (NSW) which provides insights into the lives of ancient tame dingoes, and suggests that domestication and genetic continuity between successive camp-dwelling generations may have occurred prior to European contact.

A Multicentre Epidemiologic Study of Sudden and Unexpected Death in Adult Cats and Dogs in Australia.

Sudden and unexpected death (SUD) is a common reason for animals to undergo post-mortem examination. There is limited literature examining the causes of SUD in cats and dogs, and no research specific to Australia. The purpose of this study was to investigate the epidemiology and pathology of SUD in cats and dogs in a multicentric study across Australia. Retrospective post-mortem reports of SUD in cats and dogs were obtained from four veterinary schools in Australia distributed across four states. The frequency of SUD between institutes ranged from 2.1% to 6.5%. Dogs composed the majority of the study population (76%), and males outnumbered females, particularly in the feline subpopulation. After necropsy, 37% of SUD remained cause unknown, the largest category in both cats and dogs. When cause was identified, cardiovascular disease was most common in both species, followed by gastrointestinal disease in dogs, and trauma in cats. In dogs, multinomial logistic regression identified age as a risk factor significantly associated with the four largest categories of SUD. This study identified causes of SUD in Australian cats and dogs, including novel causes not previously reported. Further, this study revealed a higher rate of unsolved SUD in Australia than can be found in the literature from other countries.

A cross-sectional investigation of Leptospira at the wildlife-livestock interface in New Zealand.

There has been a recent upsurge in human cases of leptospirosis in New Zealand, with wildlife a suspected emerging source, but up-to-date knowledge on this topic is lacking. We conducted a cross-sectional study in two farm environments to estimate Leptospira seroprevalence in wildlife and sympatric livestock, PCR/culture prevalence in wildlife, and compare seroprevalence and prevalence between species, sex, and age groups. Traps targeting house mice (Mus musculus), black rats (Rattus rattus), hedgehogs (Erinaceus europaeus) and brushtail possums (Trichosurus vulpecula) were set for 10 trap-nights in March-April 2017 on a dairy (A) and a beef and sheep (B) farm. Trapped wild animals and an age-stratified random sample of domestic animals, namely cattle, sheep and working dogs were blood sampled. Sera were tested by microagglutination test for five serogroups and titres compared using a Proportional Similarity Index (PSI). Wildlife kidneys were sampled for culture and qPCR targeting the lipL32 gene. True prevalence in mice was assessed using occupancy modelling by collating different laboratory results. Infection profiles varied by species, age group and farm. At the MAT cut-point of ≥ 48, up to 78% of wildlife species, and 16-99% of domestic animals were seropositive. Five of nine hedgehogs, 23/105 mice and 1/14 black rat reacted to L. borgpetersenii sv Ballum. The sera of 4/18 possums and 4/9 hedgehogs reacted to L. borgpetersenii sv Hardjobovis whilst 1/18 possum and 1/9 hedgehog reacted to Tarassovi. In ruminants, seroprevalence for Hardjobovis and Pomona ranged 0-90% and 0-71% depending on the species and age group. Titres against Ballum, Tarassovi and Copenhageni were also observed in 4-20%, 0-25% and 0-21% of domestic species, respectively. The PSI indicated rodents and livestock had the most dissimilar serological responses. Three of nine hedgehogs, 31/105 mice and 2/14 rats were carrying leptospires (PCR and/or culture positive). True prevalence estimated by occupancy modelling in mice was 38% [95% Credible Interval 26, 51%] on Farm A and 22% [11, 40%] on Farm B. In the same environment, exposure to serovars found in wildlife species was commonly detected in livestock. Transmission pathways between and within species should be assessed to help in the development of efficient mitigation strategies against Leptospira.

Unfamiliar human-induced social buffering effect in kennel-residing Australian Cattle Dogs

The "isolation syndrome" is a term used to describe the stress responses observed in highly social species when they lack social interactions. This syndrome affects various aspects of an individual's welfare, including hormonal, behavioral, and physiological systems. Dogs, known for their social nature, have been used as a model to study the effects of social buffering provided by conspecifics or humans. This study aims to investigate the social buffering effect of humans on dogs and determine if it is solely associated with bonding or socialization. The study selected Australian Cattle Dogs with limited social interactions with humans, ensuring that no direct bonds or human socialization were involved. The dogs were randomly assigned to either an isolation or social condition, and cortisol levels were measured before and after the tests to evaluate stress responses. The results showed that isolation led to a significant increase in cortisol levels, indicating a stress response. However, in the presence of unfamiliar humans, cortisol levels did not increase significantly, suggesting a lack of stress response. This finding suggests that humans can serve as social buffers for dogs, even without prior bonding or socialization. Therefore, dogs without systematic human socialization still benefited from the presence of unfamiliar humans.

Birth weight, puppies’ growth and health with limited-ingredient novel protein diet vs standard diet in late pregnancy

Great attention has been given in the last years to the protein source of dog food, and commercial limited-ingredient diets with a single protein are available also for late pregnancy. This work compared the effect of a fish-based limited ingredient diet (LID), and of a standard mixed-protein diet (Mixed), fed to the bitches from the last three weeks of pregnancy and to the puppies at weaning, on birth weight, growth and health of the puppies. From a breeder's records, the weight of 22 Lagotto Romagnolo (LR) and 10 Appenzeller Cattle Dog (ACD) bitches on the day of mating, and of their 199 puppies, were extracted. The effect of diet on puppies' weight on day 0, 6, 30 and 60 was analyzed, considering litter size and sex. The analyses were repeated on puppies' weights normalized on the relative dam's non-pregnant bodyweight. Birth weight was available for 146 puppies, 82 LR and 64 ACD. Median birth weight of LR puppies was 287.5 g (170–400 g); sex ratio was 1.11 (males/females, N = 80). Median birth weight of ACD puppies was 390 g (240–525 g); sex ratio 1.15 (males/females, N = 58). Diet did not significantly affect birth weight in both breeds; however, it showed a significant effect on normalized birth weights (LR, P = 0.016; ACD, P = 0.034), with higher values for LID. At day 30, ACD puppies showed significantly higher weights with the Mixed diet (P = 0.002), and, at day 60, diet significantly affected the normalized weight in both breeds (LR, P = 0.019; ACD, P = 0.001), with higher values for the Mixed type. LID may help the dam to invest the energy in the growth of her litter, however, the same diet resulted in lower puppies' weights around weaning, compared to the Mixed diet. Although our results should be confirmed with larger numbers of animals and more breeds, they set some points worth to be further investigated. The choice of a limited-ingredient single-protein diet can affect litter weight and weight at weaning. Whether, administered to dams and puppies, it can prevent later pathologies, like chronic gastrointestinal diseases or food allergies, is a field of research deserving full attention.

Unambiguous identification of Ancylostoma caninum and Uncinaria stenocephala in Australian and New Zealand dogs from faecal samples.

Hookworms (Ancylostomatidae) are well-known parasites in dogs due to their health impacts and zoonotic potential. While faecal analysis is the traditional method for detection, improvements in husbandry and deworming have decreased their prevalence in urban owned dogs. Drug resistance in Ancylostoma caninum is becoming a discussion point in small animal practices across the region. This study aimed to identify hookworm species present in Australian and New Zealand dogs using molecular techniques. The ITS-2 and isotype-1 β-tubulin assays were used to identify and quantify hookworm species. Results showed absence of coinfection in Australian samples from Greater Sydney region belonging either to A. caninum or Uncinaria stenocephala, while New Zealand samples were a mixture of A. caninum and U. stenocephala. The amplified isotype-1 β-tubulin sequences exhibited susceptibility to benzimidazole drugs. Rare mutations were identified in A. caninum and U. stenocephala sequences, representing a small percentage of reads. This study highlights the importance of molecular techniques in accurately identifying and quantifying hookworm species in dog populations.