Faecal excretion of intestinal spirochaetes by urban dogs, and their pathogenicity in a chick model of intestinal spirochaetosis

This study aimed to obtain information about the types of spirochaetes colonising urban dogs in Thailand, and to investigate their pathogenic potential in a day-old chick model of intestinal spirochaetosis. Spirochaetes were isolated from the faeces of six of 47 (12.8%) healthy dogs and 11 of 104 (10.6%) dogs with diarrhoea. Their biochemical properties and 16S ribosomal DNA sequences were analysed. Four isolates were identified as Brachyspira pilosicoli, three resembled "Brachyspira pulli", nine clustered with "Brachyspira canis" and one was similar to Brachyspira intermedia. Canine isolates of B. pilosicoli, "B. canis" and "B. pulli", and control strains of Brachyspira hyodysenteriae, B. pilosicoli and Brachyspira innocens colonised experimentally infected day-old chicks. The chicks did not develop diarrhoea, but were significantly lighter than the non-infected group and those infected with B. innocens after 21 days (P<0.05). Using immunohistochemistry, spirochaetes were observed covering the surface epithelium and in the crypts of chicks in all three groups challenged with the canine isolates. Variable histopathological changes were seen, with the greatest inflammatory cell infiltration into the lamina propria occurring in the group infected with "B. pulli". Canine "B. canis", "B. pulli" and B. pilosicoli isolates may have pathogenic potential.     

Faecal excretion of intestinal spirochaetes by urban dogs,and their pathogenicity in a chick model of intestinal spirochaetosis

This study aimed to obtain information about the types of spirochaetes colonising urban dogs in Thailand, and to investigate their pathogenic potential in a day-old chick model of intestinal spirochaetosis. Spirochaetes were isolated from the faeces of six of 47 (12.8%) healthy dogs and 11 of 104 (10.6%) dogs with diarrhoea. Their biochemical properties and 16S ribosomal DNA sequences were analysed. Four isolates were identified as Brachyspira pilosicoli, three resembled “Brachyspira pulli”, nine clustered with “Brachyspira canis” and one was similar to Brachyspira intermedia. Canine isolates of B. pilosicoli, “B. canis” and “B. pulli”, and control strains of Brachyspira hyodysenteriae, B. pilosicoli and Brachyspira innocens colonised experimentally infected day-old chicks. The chicks did not develop diarrhoea, but were significantly lighter than the non-infected group and those infected with B. innocens after 21 days (P < 0.05). Using immunohistochemistry, spirochaetes were observed covering the surface epithelium and in the crypts of chicks in all three groups challenged with the canine isolates. Variable histopathological changes were seen, with the greatest inflammatory cell infiltration into the lamina propria occurring in the group infected with “B. pulli”. Canine “B. canis”, “B. pulli” and B. pilosicoli isolates may have pathogenic potential.     

The prevalence of intestinal parasites in dogs and cats in Calgary, Alberta

The prevalence of endoparasites was evaluated in 619 dogs and 153 cats in the Calgary, Alberta region. Both homed and shelter-sourced pets were evaluated, and prevalence was assessed in various age groups. The overall endoparasite prevalence was 16.5% in canine samples and 7.2% in feline samples. The most common intestinal parasites in dogs were Giardia (8.1%) and ascarids (4.2%). The most common feline endoparasite was ascarids (6.5%). This study will help veterinarians to better plan diagnostic and preventative strategies with regard to companion animal intestinal parasites.     

High prevalence of intestinal zoonotic parasites in dogs from Belgrade, Serbia--short communication

To identify areas of risk for canine-related zoonoses in Serbia, the aim of this study was to provide baseline knowledge about intestinal parasites in 151 dogs (65 household pets, 75 stray and 11 military working dogs) from Belgrade. The following parasites, with their respective prevalences, were detected: Giardia duodenalis (14.6%), Ancylostomatidae (24.5%), Toxocara canis (30.5%), Trichuris vulpis (47.0%) and Taenia-type helminths (6.6%). Of all examined dogs, 75.5% (114/151) were found to harbour at least one parasite species. Of these, mixed infections with up to four species per dog occurred in 44.7% (51/114). Infections with all detected species were significantly higher (p < 0.05) in military working (100%) and stray dogs (93.3%) versus household pets (50.8%). Among all parasites, agents with zoonotic potential including Giardia, Ancylostomatidae and Toxocara were detected in 58.3% (88/151) of all examined dogs with a significant difference (p < 0.05) among the subgroups (100%, 62.7% and 46.2% for military working dogs, stray dogs and household pets, respectively). The high prevalence of zoonotic parasites registered in the dog population from a highly urban area in south-eastern Europe indicates a potential risk to human health. Thus, veterinarians should play an important role in helping to prevent or minimise zoonotic transmission.     

The growth of Treponema hyodysenteriae and other porcine intestinal spirochaetes in a liquid medium.

A new simple method for the preparation of a liquid medium containing rabbit serum for the propagation of Treponema hyodysenteriae and other porcine intestinal spirochaetes is described. The medium, when dispensed in shallow layers and sealed under 10 per cent CO2 in nitrogen, had a redox potential not greater than -125mV and an initial pH of about 6.9 when buffered with bicarbonate. Growth of T hyodysenteriae developed more rapidly and viable counts reached higher levels at 42 degrees C than at 37 degrees C. Viable counts increased at least 10,000-fold after two to five days' incubation, depending on the temperature. Growth could be initiated from small inocula that failed to produce colonies on blood agar. Using a 1 per cent inoculum, the medium supported the growth of two strains of T hyodysenteriae through 10 serial passages.     

The prevalence of Dirofilaria immitis in dogs in Sydney

Four hundred and four dogs from 9 pounds in Sydney were examined for circulating microfilariae and antigens of Dirofilaria immitis. One hundred of these were also examined post mortem for adult heartworms. The prevalence of infection in the 404 dogs as shown by serology was 11.4%, and 5.9% had circulating microfilariae of D immitis. Adult heartworms were present in 15 of 100 dogs. Dipetalonema reconditum microfilariae were present in 3.7% of dogs. Dirofilariosis is still a common and important parasite of dogs in the Sydney region and chemoprophylaxis is recommended.     

The prevalence of cestodes in farm dogs in mid-wales

Five hundred and eight farm dogs in mid-Wales were treated with arecoline acetarsol during 1975. Cestodes recovered from their faeces were identified as follows: Echinococcusgranulosus, Taenia hydatigena, Taenia multiceps, Taenia ovis, Taenia pisiformis, Taenia serialis, and Dipylidium caninum.Many dogs were treated on three different occasions during the 12 months, and changes in the prevalence over this period were shown. The greatest rise in prevalence rate from January to May was seen for E. granulosus while T. hydatigena was most prevalent in January. All other species, except T. serialis, were found in low numbers throughout the year.     

The prevalence of intestinal parasites in dogs from Prague, rural areas, and shelters of the Czech Republic

The prevalence of intestinal parasites was evaluated by examination of dog faecal samples in the Prague city centre, agricultural areas, and two shelters. The overall prevalence of parasites (i.e., protozoa and helminths, mentioned below) in Prague was 17.6%. Toxocara canis was the most common parasite, and was recovered from 6.2% of dogs, followed by Cystoisospora spp. (2.4%), Cryptosporidium spp. (1.4%), Trichuris sp. (1.1%), Taenia-type (1.0%), Giardia spp. (0.1%), Toxascaris sp. (0.9%), Dipylidium sp. (0.7%), Sarcocystis spp. (0.6%), Capillaria spp. (0.6%), Neospora/Hammondia spp. (0.5%), Ancylostoma sp. (0.4%), Uncinaria sp. (0.4%), and Spirocerca sp. (0.2%). The prevalence of infections with helminths and protozoans in two animal shelters in Prague was examined at the dog's admittance ir reception to the shelters and during housing. T. canis eggs (6.5%), Cystoisospora (4.4%), and Giardia (3.3%) cysts were the most prevalent. Significant increases in the prevalence of some parasites were found after a stay in the shelter. Giardia spp. showed an 11-fold increase in prevalence of dogs placed in the shelters for a longer time; Cryptosporidium spp. had a 7-fold increase, Capillaria spp. a 5-fold, Spirocerca sp., Neospora/Hammondia spp., and Cystoisospora spp. a 4-fold increase over dogs examined at the time of admittance to the shelter (p<0.01). Dog in rural areas were infected significantly more frequently (p<0.01) than those in Prague. In 540 faecal samples from rural areas, the overall prevalence of parasites (i.e., protozoa and helminths mentioned below) was 41.7%. The prevalence of T. canis was 13.7%, followed by Cystoisospora spp. (8.0%), Taenia spp. (3.5%), Sarcocystis spp. (3.0%), Giardia spp. (2.2%), Cryptosporidium spp. (2.0%), Trichuris sp. (1.7%), Toxascaris sp. (1.7%), Dipylidium sp. (1.3%), Neospora/Hammondia spp. (1.3%), Spirocerca sp. (1.1%), Uncinaria sp. (0.9%), Ancylostoma sp. (0.7%), and Capillaria spp. (0.6%). Examinations of dogs in urban and rural areas showed, with the exception of Trichuris sp. in Prague, a higher occurrence of nematode infection in autumn, notably T. canis (chi2>8.3, d.f.=3, p<0.04).     

Chronic intestinal inflammation and intestinal disease in dogs

Normal individuals maintain tolerance to the endogenous bacterial flora residing within their alimentary tract, a phenomenon mediated by the gastrointestinal lymphoid tissue. Loss of this tolerance is a key factor in the development of chronic intestinal inflammation. Manifestations of such uncontrolled inflammation in humans include inflammatory bowel disease and celiac disease. Dogs may similarly be affected, and although the etiopathogenesis is likely similar, the lesions differ. This review includes discussion of the factors involved in breakdown of mucosal tolerance, the immunologic basis of canine enteropathies, and the use of novel immunotherapies for these diseases.     

The use of multilocus enzyme electrophoresis to characterise intestinal spirochaetes (Brachyspira spp.) colonising hens in commercial flocks

Multilocus enzyme electrophoresis (MLEE) was used to identify, examine genetic relationships and look at disease associations of a collection of 53 intestinal spirochaete isolates previously recovered from the faeces of adult hens on 14 farms in Qld, Australia. The MLEE results were compared with those previously obtained using species-specific PCR amplifications. The isolates were divided into five Brachyspira species groups by MLEE: Brachyspira murdochii (n=17), B. intermedia (n=15), B. pilosicoli (n=14), B. innocens (n=2) and "B. pulli" (n=1). Three new MLEE groups each containing single isolates also were identified. The results of the PCR assay for B. pilosicoli were concordant with the MLEE results, but the 23S rDNA-based PCR for B. intermedia had failed to detect 8 of the 15 isolates. The B. innocens/B. murdochii nox-based PCR had correctly identified all the isolates of B. murdochii, but did not identify either of the two B. innocens isolates. Using MLEE, isolates from two farms (14%) were identified as B. murdochii, whilst the pathogenic species B. intermedia and B. pilosicoli were present in hens from eight (57%) and five (36%) farms, respectively, and were identified together in four (29%) farms. All seven of the farms with production problems or wet litter were colonised with B. intermedia and/or B. pilosicoli. Six farms had multiple spirochaete isolates available for examination. Two broiler breeder farms both had five isolates of B. pilosicoli that shared the same MLEE electrophoretic type (ET), whilst one laying hen farm had three isolates of B. intermedia that all belonged to the same ET. Hence on each of these farms a predominant strain of a pathogenic species was present. On the other farms isolates of the same species were more diverse and belonged to different ETs. These results show that the epidemiology of intestinal spirochaetal infections in broiler breeder and laying hen flocks can vary considerably between farms, although the reasons for these differences were not established.     

The prevalence of a group 2 coronavirus in dogs in Japan

Canine coronavirus (CCoV) has been reported to cause acute diarrhea mainly in young pups. CCoV and feline coronavirus are classified as group 1 coronaviruses. However, it has recently been reported in the United Kingdom that the group 2 coronavirus gene, which is more closely related to the bovine coronavirus (BCoV) and human coronavirus strain OC43, has been detected in respiratory tract tissue samples from dogs with respiratory disease. In this study, we examined the prevalence of antibodies to group 2 coronaviruses in domestic dogs and cats in Japan by a neutralization test using BCoV. All 104 feline serum samples were negative (<1:5) for anti-BCoV antibodies. In contrast, of the 898 canine serum samples, 160 (17.8%) were positive for anti-BCoV antibodies, and the antibody titers ranged from 1:5 to more than 1:640, with 1:160 being the most frequent. No correlation was found between the titers of the anti-BCoV and anti-CCoV antibodies in the 198 serum samples of dogs with a known history of CCoV vaccination. We amplified, by RT-PCR, group 2 coronavirus-specific hemagglutination/esterase genes in the oral swabs of a total of 10 young pups presenting with or having recovered from respiratory signs, or having anti-BCoV antibodies, with the result that 2 pups were positive for the hemagglutination/esterase genes. These results strongly suggest that an unknown group 2 coronavirus as well as the known enteritis-causing CCoV (group 1 coronavirus) is prevalent among domestic dogs in Japan.     

Comparative evaluation of molecular assays for the identification of intestinal spirochaetes from diseased pigs

Rapid identification of porcine Brachyspira species is required in order to differentiate pathogenic from non-pathogenic species. The aim of our study was to compare a recently described genetic method based on polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP), nox RFLP-PCR assay, and three species-specific PCRs described previously in the literature with a 16S rRNA gene RFLP-PCR discriminatory reference assay (16S RFLP-PCR) for the identification of Brachyspira spp. of swine origin. In this study, 20 porcine spirochaetal strains were identified and compared to 33 reference strains by 16S RFLP-PCR and nox RFLP-PCR and three species-specific PCRs. RFLP-PCR methods showed concordant results for 47 strains and discordances for 6 strains (2 differently identified and 4 not revealed by nox RFLP-PCR). In our hands species-specific PCRs showed concordant results with 16S and nox RFLP-PCR for 43 strains and discordances for 10 strains (2 differently identified and 8 not amplified). The same results observed testing the 20 field-isolated spirochaetes were obtained for the corresponding porcine faecal samples. The detection limit was 10(2) -10(3) cells/g of faeces for 16S rRNA gene PCR and 10(4) cells/g of faeces for nox PCR. In our experience nox RFLP-PCR appeared successful for the speciation of B. hyodysenteriae reserving 16S RFLP-PCR for all other pathogenic and non-pathogenic Brachyspira species. Among the species-specific PCR assays tested only that for B. pilosicoli was useful in our hands.     

The prevalence of Sarcocystis spp in dogs and red foxes.

Protozoan parasites of the genus Sarcocystis have been recognised for many years as intramuscular cysts of numerous vertebrates. It is only comparatively recently that the two-host nature of the life cycle has been recognised and that the intramuscular cysts are a stage in the developmental cycle of coccidian parasites of flesh eating mammals (Fayer 1974, Fayer and Johnson 1973, 1974, Rommel and others 1972, Dubey 1976). Carnivores ingest the intramuscular cysts from herbivores and presumably from other animals too and eventually shed sporulated tetrazoic sporocysts in their faeces. The cystic stages which occur in the flesh of herbivores are probably non-pathogenic but the earlier stages in which schizonts develop in vascular endothelium may be severely pathogenic. Sarcocystis cruzi, S ovicanis and S porcifelis are known to be severely pathogenic in cattle, sheep and pigs respectively (Dubey 1976). Observations on the prevalence of Sarcocystis spp in the faeces of working farm dogs, greyhounds and foxes (Vulpes vulpes) are recorded.     

The prevalence of Echinococcus granulosus in farm dogs in mid-Wales

One hundred and fourteen farms in Powys, mid-Wales, were visited on two occasions approximately 8 months apart during 1975. All the farm dogs were dosed with arecoline acetarsol and the faecal purges were examined for the presence of Echinococcus granulosus.Sixty-seven farms (58.8%) contained at least one infected dog on at least one of the visits but only 36 farms and 43 farms had infected dog at the first and second visits, respectively.Four hundred and twenty-nine dogs provided at least one sample and 108 (25.2%) of these samples contained E. granulosus. Only seven dogs were infected at both visits.The mean numbers of worms found in the samples were 241.6 and 156.4 at the first and second visits, respectively, but almost 50% of the positive samples contained fewer than 26 worms. The worms were identified as the sheep strain, the known cause of hydatid disease in man in Wales.     

The haemogram of dogs with intestinal parasites in Zaria, Nigeria

One hundred and fifty-four dogs brought to the Ahmadu Bello University Veterinary Clinic for routine examination, in which an eosinophil count of 8% or higher was observed on laboratory examination, were found to be infested with one or more types of intestinal parasites. These included hookworms, tapeworms, coccidia, ascarids and spirocerca, with hookworms accounting for 51% of parasites found. Although dogs of all ages were affected, a higher incidence was observed in those under 2 years. The clinical and public health significance of these findings are emphasized.     

Hepatozoon canis: The prevalence of antibodies and gametocytes in dogs in Israel

A survey for the prevalence of antibodies to Hepatozoon canis and for intraneutrophilic H. canis gametocytes in the peripheral blood neutrophils of dogs in Israel showed that 33.1% were seropositive, while only 1% of the dogs sampled had detectable parasites in their blood smears. Exposure to H. canis is widespread but it appears that most infected dogs undergo a subclinical infection and only a small proportion develop clinical disease.Abbreviations IFAT indirect fluorescent antibody test