Cats and Toxoplasma: Implications for Public Health

Cats are popular as pets worldwide because they are easy to care for and provide companionship that enriches the lives of human beings. Little attention has been focused on their potential to contaminate the environment with zoonotic pathogens. One such pathogen, the protozoan parasite Toxoplasma gondii, rarely causes clinical manifestations in cats or immunocompetent humans; however, it can have serious adverse effects on human foetuses and immunocompromised patients. Many human infections are believed to be acquired from eating undercooked or raw meat, such as pork and lamb ( Tenter et al. Int. J. Parasitol., 30, 2000, 1217 ; Dubey et al. J. Parasitol. 91, 2005, 1082 ). However, the prevalence of T. gondii infection in human populations that do not consume meat or eat it well‐cooked suggests that the acquisition of infection from the environment, via oocysts in soil, water or on uncooked vegetables, is also important ( Rawal. Trans. Royal Soc. Trop. Med. Hyg., 53, 1959, 61 ; Roghmann et al. Am. J. Trop. Med. Hyg., 60, 1999, 790 ; Chacin‐Bonilla et al. Am. J. Trop. Med. Hyg., 65, 2001, 131 ). In the past 20 years, two changes occurred that significantly increased the size of the cat population in the USA. Pet cat ownership grew from 50 million to 90 million animals, and animal welfare activists created feeding stations for abandoned and free‐roaming cats. As many cat owners allow their cats to deposit faeces outside and cats maintained in colonies always defecate outside, ample opportunity exists for T. gondii oocysts to enter the environment and be transmitted to humans. Prevention efforts should focus on educating cat owners about the importance of collecting cat faeces in litter boxes, spaying owned cats to reduce overpopulation, reducing the numbers of feral cats and promoting rigorous hand hygiene after gardening or soil contact.     

Antimicrobial Resistance in Wildlife: Implications for Public Health

The emergence and spread of antimicrobial‐resistant (AMR) bacteria in natural environments is a major concern with serious implications for human and animal health. The aim of this study was to determine the prevalence of AMR Escherichia coli (E. coli) in wild birds and mammalian species. Thirty faecal samples were collected from each of the following wildlife species: herring gulls (Larus argentatus), black‐headed gulls (Larus ridibundus), lesser black‐back gulls (Larus fuscus), hybrid deer species (Cervus elaphus x Cervus nippon) and twenty‐six from starlings (Sturnus vulgaris). A total of 115 E. coli isolates were isolated from 81 of 146 samples. Confirmed E. coli isolates were tested for their susceptibility to seven antimicrobial agents by disc diffusion. In total, 5.4% (8/146) of samples exhibited multidrug‐resistant phenotypes. The phylogenetic group and AMR‐encoding genes of all multidrug resistance isolates were determined by PCR. Tetracycline‐, ampicillin‐ and streptomycin‐resistant isolates were the most common resistant phenotypes. The following genes were identified in E. coli: bla_TEM, strA, tet(A) and tet(B). Plasmids were identified in all samples that exhibited multidrug‐resistant phenotypes. This study indicates that wild birds and mammals may function as important host reservoirs and potential vectors for the spread of resistant bacteria and genetic determinants of AMR.     

当前犬类免疫失败原因及对策

对犬类按程序进行免疫注射,是预防犬类传染病发生的关键。但无论在农村还是城市,在养犬过程中,少数犬虽接种过疫苗却仍还发生犬类病毒性传染病。据统计,4年多来,笔者在诊治的482个犬瘟热病例中,接种过疫苗仍然发病的有33只,免疫失败者占6.85%;在205个犬细小病毒病病例中,接种过疫苗仍然发病的有8只,免疫失败者占3.90%。1免疫失败的原因分析1.1疫苗因素疫苗质量良莠不齐。决定犬类免疫效果关键是疫苗本身质量。目前国内市场上普遍应用的病毒性疫苗主要分为弱毒(活)疫苗和灭活疫苗两类,有国产的,有进口的,有单价的,有多联的。疫苗质量差异很大…     

Free‐Roaming Dogs in Nepal: Demographics,Health and Public Knowledge,Attitudes and Practices

In Nepal, most dogs are free to roam and may transmit diseases to humans and animals. These dogs often suffer from malnutrition and lack basic health care. Minimal information is available about their demographics and about public attitudes concerning dogs and diseases. We carried out a study in Chitwan District (central Nepal), to collect baseline data on free‐roaming owned dog demographics, assess knowledge, attitudes and practices of dog owners concerning dogs and rabies, evaluate rabies vaccination coverage and anthelmintic treatment of dogs, measure dogs' response to rabies vaccination and assess dog health through body condition scores and parasites. We conducted household interviews with owners of free‐roaming female dogs (n = 60) and administered dogs with rabies vaccination and anthelmintics. Dog owners regularly fed free‐roaming dogs but provided minimal health care; 42% of respondents did not claim ownership of the dog for which they provided care. We collected skin, faecal and blood samples for parasite identification and for measuring rabies virus‐specific antibodies. Ninety‐two per cent of dog owners were aware of the routes of rabies virus transmission, but only 35% described the correct post‐exposure prophylaxis (PEP) following a dog bite. Twenty‐seven per cent of the dogs had measurable rabies virus‐specific antibody titres and 14% had received anthelmintics in the previous year. Following rabies vaccination, 97% of dogs maintained an adequate antibody titre for ≥6 months. Most dogs appeared healthy, although haemoprotozoans, endoparasites and ectoparasites were identified in 12%, 73% and 40% of the dogs, respectively. Poor skin condition and parasite load were associated. Seventy‐four per cent of the females had litters in 1 year (mean litter size = 4.5). Births occurred between September and February; we estimated 60% mortality in puppies. We concluded that vaccination coverage, PEP awareness and anthelmintic treatment should be emphasized in educational programmes focussed on animal welfare, veterinary and public health.     

Toxoplasma gondii and Chlamydophila abortus in Caprine Abortions in Tobago: a Sero‐Epidemiological Study

A sero‐epidemiological study was conducted on a goat farm that experienced an abortion epidemic in the 2005 breeding season in Tobago. Serum samples of goats (aborting and non‐aborting) and cats were collected, in addition to the use of stored sera from the farm sampled in 2003 and 2004. Farm records on the reproductive and mortality rates for year 2003, 2004 and 2005 were also reviewed. The sera were screened for Toxoplasma gondii antibodies using the latex agglutination test (LAT), Chlamydophila abortus with an enzyme‐linked immunosorbent assay (ELISA) and Brucella abortus using the buffered plate agglutination test (BPAT). Farm records revealed that for the period 2003–2005, the average kid per doe rate decreased from 2.1 to 1.5, the mortality rate increased from 6.3% in 2002 to 19.4% in 2004 and the fertility rate decreased from 98–99% (2002–2004) to 89% (2005). There was a dramatic increase in the abortion rate from <1% (2002, 2003 and 2004) to 29.2% (2005). Of a total of 161 sera tested comprising 12 from 2003, 89 from 2004 and 70 from 2005, 0 (0.0%), 21 (23.6%) and 45 (64.3%) were positive for T. gondii agglutinins (i.e. titres ≥1 : 64) and the differences were statistically significant (P < 0.05; χ²). Of all serum samples tested, only 1 (1.1%) of 89 from 2004 was positive for C. abortus while all the sera tested were negative for B. abortus. Amongst the 24 does which aborted in 2005 and were available for testing in mid‐2005, 15 (62.5%) had reciprocal titres of ≥1 : 2048, three (12.5%) each had titres of 1 : 1024, 1 : 256 and ≤1 : 16 i.e. negative. The seroprevalence and titres of does that aborted, 20 (87.0%) of 23, all with titres ≥1 : 256 suggesting current infection, were statistically significantly (P < 0.05; χ²) higher than was detected amongst does that delivered normal kids, 25 (53.25) of 47 with 22 (48.8%) having titres of ≥1 : 256. One (50.0%) of two cats caught and tested was seropositive with a reciprocal titre of 128. This is considered the first documentation of T. gondii agglutinins in caprine abortion as well the detection of C. abortus antibodies from livestock in Trinidad. It is concluded that of the three zoonotic abortifacient pathogens tested for, T. gondii appeared to have played some aetiological role in the abortion epidemic investigated.     

Canine urolithiasis: epidemiology and analysis of urinary calculi

The incidence of canine urolithiasis was found to lie between 0–5 to 1 per cent of the canine population. Epidemiological and analytical data were collected for 1731 urinary stones, and causal relationships investigated. Calculi were found in 72 breeds. While they were relatively common among dachshunds, dalmatians, cocker spaniels, Pekingese, bassets, poodles, schnauzers and small terrier breeds, urinary stones were relatively rare among German shepherd dogs, boxers, collies, chow chows, old English sheepdogs, spitz and rottweiler breeds. Struvite, which was found in 55-6 per cent of all calculi, proved to be the most common constituent, followed by cystine (22-5 per cent) and ammonium urate (6-6 per cent). Xanthine calculi were rare (six cases), while silicium dioxide calculi were present in only one case. The likelihood of calculi in male animals was twice that of bitches, although the latter were found to be more prone to infection of the urinary tract. Adiposity was present in 29 per cent of all dogs with calculi. The average age of the animals was seven years. In 98-7 per cent of all cases the calculi were found in the lower urinary tract, and surgical removal of the stones was required in 87-5 per cent of cases. The main types of calculi appear among specific breeds, which indicates that a careful breeding programme may help to reduce the frequency of urinary calculi.     

Glycerol,Methyl‐Formamide and Dimethyl‐Formamide in Canine Semen Cryopreservation

The aim of the present work was to compare the efficiency of methyl‐formamide (MF), dimethyl‐formamide (DF) and glycerol (GL) as cryoprotectants in canine semen cryopreservation. For the experiment, pooled semen was submitted to one of the three cryoprotectants, with a final concentration of 3% in egg yolk–TRIS extender. Semen was subjectively evaluated for total and progressive motility, vigour and morphology. Sperm membrane functional integrity was assessed by hypo‐osmotic swelling test (HOST), and longevity was assessed using the thermoresistance test (TRT). Fresh semen showed normal physical and morphological characteristics. After thawing, differences were observed between semen frozen using GL and DF, regarding total and progressive motility and vigour (p < 0.05), but not between MF and GL or MF and DF. Means for total motility, progressive motility, vigour and morphologically normal spermatozoa were, respectively, 69.0 ± 5.4%, 61.0 ± 7.4%, 2.9 ± 0.5 and 57.1 ± 5.0% for GL; 59.0 ± 8.9%, 50.0 ± 10.0%, 2.5 ± 0.7 and 66.9 ± 7.7% for MF; and 44.0 ± 21.0%, 37.0 ± 19.8%, 2.1 ± 0.6 and 61.1 ± 5.5% for DF. On HOST, GL was superior (p < 0.05) to MF and DF (57.8 ± 12.4%, 35.8 ± 18.4% and 34.4 ± 9.4%, respectively). During the TRT, both GL and MF were superior to DF, with no differences between GL and MF. In conclusion, the use of MF as cryoprotectant showed results similar to GL, and can be considered as an alternative in canine semen cryopreservation. Further studies testing different concentrations of MF may improve its effects on cryopreservation of canine semen.     

Prevalence and epidemiology of selected enteric infections of livestock in Trinidad

In a study of diarrhoeic and non-diarrhoeic livestock (cattle, pigs and sheep) from 50 farms in Trinidad, the prevalence of bacterial (Campylobacter, Salmonella, Yersinia and Escherichia coli), parasitic (coccidia, Cryptosporidium and enteric helminths) and viral (rotavirus) enteropathogens in faeces or rectal swabs was determined. Occurrence of the enteropathogens was tested for association with age, health status, animal species and mixed infections.

Of 423 diarrhoeic animals tested, Salmonella was isolated from 21 (5.0%), Campylobacter from 191 (45.2%) and Yersinia from three (0.7%), while the corresponding prevalence from 270 non-diarrhoeic controls was eight (3.0%) (χ² 1.19, P = 0.28), 119 (44.1%) (χ² 0.04, P = 0.85) and four (1.5%) (χ² 0.8, P = 0.39), respectively. Verocytotoxigenic E. coli and heat-labile toxin-producing E. coli were isolated from 51 (13.7%) and five (1.3%), respectively, of 373 diarrhoeic animals but the corresponding prevalence from 258 non-diarrhoeic animals was 39 (15.1%) (χ² 0.15, P = 0.7) and five (1.9%) (χ² 0.07, P = 0.8), respectively. Cryptosporidium oocytes were detected in 67 (16.5%) of 406 diarrhoeic animals and from 31 (12.1%) of 257 non-diarrhoeic animals (χ² 2.13, P = 0.15). For 147 diarrhoeic animals tested for coccidia, 64 (43.5%) were positive compared with 34 (37.8%) of 90 non-diarrhoeic animals (χ² 0.54, P = 0.49).

The prevalence of rotavirus infection was significantly (P 0.001, χ² 37.8) higher in diarrhoeic animals (39.9%, 112 of 281) than in non-diarrhoeic animals (13.4%, 26 of 194).     

Expression of Genes in the Canine Pre‐implantation Uterus and Embryo: Implications for an Active Role of the Embryo Before and During Invasion

The aim of the present study was to assess genes expressed in maternal uterine tissue and pre‐implantation embryos which are presumably involved in maternal recognition and establishment of canine pregnancy. For this purpose, 10 pregnant bitches were ovariohysterectomized between days 10 and 12 after mating. Four non‐pregnant bitches served as controls. Early pregnancy was verified by flushing the uterine horns with PBS solution. The collected embryos (n = 60) were stored deep‐frozen (?80°C). Uterine tissue was excised, snaps frozen in liquid nitrogen and homogenized using TRI Reagent. All embryos from one litter were thawed together and also homogenized in TRI Reagent. RT‐PCR was performed to prove mRNA expression of progesterone receptor, key enzymes of the prostaglandin synthesis pathway, selected growth factors, cytokines, immune cell receptors, major histocompatibility complex (MHC) and matrix‐metalloproteinases (MMP). Only pregnant uteri revealed the presence of mRNA for interferon (IFN)‐γ, IL‐4 and CD‐8, which resembles the milieu in humans and other mammalians. Similarly, in day 10 embryos, mRNA for transforming growth factor‐β, insulin‐like growth factor‐1,‐2, hepatocyte growth factor, leukaemia inhibitor factor, tumour necrosis factor‐α, interleukin‐1β,‐6,‐8, cyclooxygenase‐2, CD4⁺ cells, and MMP‐2 and ‐9 were detected, but not MHC‐I or ‐II. We therefore suppose that the canine embryo, like its human counterpart, actively initiates measures to prevent attacks from the maternal immune system to prepare its own adhesion, nidation, growth and further development.     

Canine urolithiasis in Sweden and Norway: Retrospective survey of prevalence and epidemiology

It was estimated that 23 to 24 dogs per 10,000 in Sweden were operated on for urolithiasis between 1956 and 1982. During this period urinary calculi were confirmed in 2898 dogs of 95 breeds, chiefly in chondrodystrophic and well proportioned (not short legged) miniature breeds. The distribution between the sexes in the period 1956 to 1970 was estimated at 57 per cent male and 43 per cent female in the chondrodystrophic breeds, 74 per cent male and 26 per cent female in the well proportioned miniatures, and 83 per cent and 17 per cent female in the large breeds; in the dalmatian (1956 to 1982) 94 per cent were male and 6 per cent female. Urinary calculi were found at a younger age in the chondrodystrophic breeds (1956 to 1970) than in the well proportioned miniature dogs and in large dogs (P<0–001). It was estimated that five dogs per 10,000 in Norway were operated on for urolithiasis between 1956 and 1970. During this period urinary calculi were diagnosed in 71 dogs of 28 breeds. Seventy-nine per cent were male and 21 per cent were female. Urolithiasis in dogs appears to be chiefly constitutionally dependent. Chondrodystrophic breeds and small breeds are particularly susceptible.     

Canine idiopathic dilated cardiomyopathy. Part I: Aetiology, clinical characteristics, epidemiology and pathology

Dilated cardiomyopathy (DCM), characterized by chamber dilatation and myocardial systolic and diastolic dysfunction, is one of the most common heart diseases in dogs. The aetiology of the myocardial hypokineis is seldom known in the individual case of DCM, although several theories concerning genetic, nutritional, metabolic, inflammatory, infectious, or drug- or toxin-induced myocardial disease have been discussed. DCM is often referred to as being breed-specific for Boxers, Doberman Pinschers, English Cocker Spaniels and other breeds. Review of reports on histopathologic findings in canine DCM reveals two histologically distinct forms of DCM; (1) cardiomyopathy of boxers and of Doberman pinschers, corresponding to the "fatty infiltration-degenerative" type, and (2) the form seen in many giant, large- and medium-sized breeds, including some boxers and Doberman pinschers, which can be classified as the "attenuated wavy fiber" type of DCM. The classification of canine idiopathic DCM according to histologic findigns seems superior to classification suggesting breed-specific syndromes, as some breeds (i.e. boxers and Doberman pinschers) may be affected by both diseases. However, ante mortem aetiological diagnosis of DCM is difficult. DCM carries a poor prognosis in dogs, and few prognostic indicators have been identified.     

Public Health and Vector‐Borne Diseases – A New Concept for Risk Governance

Public Health is defined as an interdisciplinary multilevel approach that deals with questions of preventing diseases at the population level. In this context, this paper focuses on vector‐borne diseases as an important threat with an increasing impact on human and animal health. Emphasis is laid on an integrated health approach (‘One‐Health’ initiative) as it recognizes the interrelated nature of both human and animal health. The importance of vector‐borne diseases to new and emerging diseases in Europe was demonstrated, for example, by the recent outbreak of West Nile virus infections in Greece, Northern Italy and Hungary; the spread of Crimean‐Congo haemorrhagic fever virus across Turkey, south‐western countries of the former USSR and the Balkans; the dramatic increase in hantavirus infections in Germany in 2012; and the dengue virus outbreak in Portugal in the same year. This paper provides a systematic approach for the analysis, assessment and governance of emerging health risks attributed to vector‐borne diseases by using a holistic approach developed by the International Risk Governance Council (IRGC), called the ‘IRGC Risk Governance Framework’. It can be used by decision‐makers and general Public Health authorities in order to evaluate the situation regarding any specific pathogen or Public Health risk and to decide if additional measures should be implemented.     

Meta‐Analyses of Factors Associated with Leptospirosis in Domestic Dogs

Factors related with leptospirosis in domestic dogs have been reported worldwide. The aims of this study were to identify factors associated with this disease described in different observational studies and to combine the coinciding factors in at least four studies using meta‐analyses, to obtain a pooled odds ratio (OR) as measure of infection risk. A literature search was performed in electronic databases, electronic databases of specific journals and search engines to find studies published in English, Spanish and Portuguese available from January 1960 to January 2015. Two hundred and eighteen factors were identified in 31 publications including cross‐sectional and case–control studies. Finally, independent meta‐analyses were performed with six different variables, which included between 4 and 8 articles. The pooled OR indicated that the variables ‘mixed‐breed dogs’, ‘flooding occurrence in the habitat of the dog’ and ‘working dogs’ were risk factors for leptospirosis, while ‘being a dog less than 1 year old’ was a protective factor; however, all these associations were not statistically significant. Otherwise, the variables ‘male dog’ and ‘urban dog’ were statistically significant risk factors for infection. This study highlights the need for more formal studies on the epidemiology of canine leptospirosis. Nevertheless, the study revealed that some risk factors for infection coincided in different observational studies. These factors could be considered to raise suspicion about the disease, especially when there is a history of exposure to the bacteria.     

北京市犬只狂犬病强制免疫工作风险管理体系分析

本文通过对北京市犬只狂犬病强制免疫工作进行全面风险分析,识别相关风险,采用德尔菲法和风险矩阵法,构建了风险指标体系并开展了风险评估。结果显示存在"缺乏免疫点认定的工作机制"等风险30种,其中极高风险2个,分别为"应免疫犬只未实施免疫"和"免疫效果监测结果不合格";存在"监督检查不到位"等风险控制点42个,其中高等级关键控制点5个,分别为"监督检查不到位""责任落实不到位""人员专业知识不足""定点免疫单位内部管理问题"和"实施免疫人员问题";存在"区县兽医行政主管部门"等12个风险事件责任方,其中高关键度方3个,分别为"区县兽医行政主管部门""区县动物卫生监督所"和"定点免疫单位"。根据风险评估结论,运用风险管理策略,提出了犬只狂犬病强制免疫风险管理措施,为动物防疫管理工作所涉及到的"风险防控体系建设"提供了理论依据。     

Parasites of Dogs from Indian Settlements in Northwestern Canada: A Survey with Public Health Implications

A total of 959 faecal samples were obtained from dogs in 12 native communities in Northern Saskatchewan, Central and Northern Alberta and the Northwest Territories. All samples were examined using a flotation technique. Samples from an area of endemic human amoebic infections were also examined by a formol-ether sedimentation method. Eighteen necropsies were performed.

Entamoeba histolytica cysts were recovered from dog faeces at Loon Lake, Saskatchewan.

Toxocara canis had low incidence in Saskatchewan and Central Alberta, and appeared to be almost non-existent further North. Toxascaris leonina was found in all areas surveyed. Canine hookworm infections were plentiful in all areas, the highest incidence being recorded from Northern Alberta and Northwest Territories. Many Taenia (or Echinococcus) infections were found consistently in all areas. Only one infection with Dipylidium caninum was discovered.

Metorchis conjunctus infections were found to be common in the Saskatchewan reserves. Infections with Diphyllobothrium sp. were found in all communities with access to good fishing. One specimen of Dioctophyma renale was recovered at necropsy.

Infections with parasites of no known zoonotic importance such as Trichuris, Alaria and Isospora species were also recorded.