Nested PCR-based detection of Toxoplasma gondii in German shepherd dogs and stray cats in South Korea

The prevalence of Toxoplasma gondii was surveyed by using a nested polymerase chain reaction (PCR) that was targeted to T. gondii B1 gene in German shepherd dogs and stray cats. Sixty-four (46.3%) out of 138 German shepherd dogs and 50 (47.2%) out of 106 stray cats were tested positive by the nested PCR assay, respectively. There was no significant difference in gender or age in German shepherd dogs and stray cats. In the five positive dogs and five positive cats, the nucleotide partial sequence of the T. gondii B1 gene was identified by direct sequence analysis. All the sequences were identical to each other and the corresponding sequence, T. gondii B1 gene (Accession No. AF179871). The results suggest that the prevalence of T. gondii is high, and the nested PCR assay is useful for early detection of T. gondii for asymptomatic dogs and cats.     

A prevalence survey and risk analysis of filariosis in dogs from the Mt. Vesuvius area of southern Italy.

A dog microfilariae prevalence and risk factor survey was conducted in 51 contiguous municipalities of the Mt. Vesuvius area (Campania region, southern Italy) in order to add data to the limited epidemiological information available regarding filarial worms in this zone. Between May 1999 and June 2000, blood samples were collected from 351 asymptomatic dogs. Blood samples were examined using a modified Knott's technique and histochemical staining in order to count and identify microfilariae. The results were subjected to statistical analysis and choroplethic municipal maps (MMs) were drawn by a geographical information system (GIS) software. Microfilariae were detected in 63 of the 351 dogs surveyed, constituting a total filarial prevalence of 17.9%. In particular, 56 dogs (15.9%) showed only microfilariae of Dipetalonema reconditum; three dogs (0.8%) only microfilariae of Dirofilaria repens; two dogs (0.6%) microfilariae of both D. reconditum and D. repens and two dogs (0.6%) microfilariae of both Dirofilaria immitis and D. repens. High D. reconditum prevalence was associated with hunting practice, masculine gender and older dogs. There was also a tendency to find high prevalence in dogs sampled in the afternoon.In conclusion, the presence of microfilariae of D. reconditum in 92% of microfilaraemic dogs indicates that this filarial worm was the predominant filarial species in dogs in the Mt. Vesuvius area.In addition, the general trends of the MMs showed that D. immitis and D. repens were present only in a few municipalities, whereas D. reconditum was widely and homogeneously spread throughout the entire study area.     

Preliminary findings on the efficacy of selamectin in the treatment of dogs naturally infected with Dirofilaria repens

Subcutaneous dirofilariosis caused by Dirofilaria repens is common in dogs and it is an emerging helminthozoonosis in Europe, Asia, Africa and also in Hungary. Macrocyclic lactones are used for preventing the infection; however, their activity against the microfilariae and mature stages of this species is questionable. Selamectin is widely used for the prophylaxis of heartworm (D. immitis) infection. The objective of the present study was to test the microfilaricidal efficacy of the topical formulation of selamectin in dogs naturally infected with D. repens . A total of 78 Beagle dogs were examined for the presence of circulating microfilariae by Knott's test. Twenty-three of the microfilaraemic dogs were divided into four groups and included in the trial. The dogs received monthly or biweekly selamectin treatment and were subjected to monthly blood testing for a period of 252 or 336 days. At the end of the study, 65% of the dogs were not microfilaraemic and the rest had low number of microfilariae in their blood. These results indicate that chronic spot-on selamectin treatment may be a useful tool also in the control of canine subcutaneous dirofilariosis.     

Canine dirofilariosis in two cities of southeastern Spain

Several cases of human subcutaneous/ocular dirofilariosis caused by Dirofilaria repens from an area in the southeastern Spain where previous epidemiological studies have shown a very low prevalence of this species in dogs, have been studied in our laboratory. Since the prevalence of this species in dogs did not correspond to the incidence of human cases in the zone studied, a preliminary epidemiological survey was carried out on 114 dog blood samples from two kennels and one veterinary clinic. Knott, polymerase chain reaction (PCR) with specific primers for Dirofilaria immitis and D. repens, and ELISA with adult E/S D. immitis and adult somatic D. repens antigens for the detection of specific IgG, were used. Fifty-three out of the 114 samples analyzed were positive for Knott and/or PCR to D. immitis or to D. repens. D. repens was the species with the highest prevalence, 84.6 and 37.1%, respectively, in each kennel. IgG antibodies against D. immitis and D. repens, were detected in 11 samples which gave negative results to both Knott and PCR. These results demonstrate a very high prevalence of D. repens that could be associated with the increasing incidence of human subcutaneous/ocular cases recently detected in this zone.     

Seroprevalence of antibodies to Neospora caninum in urban and rural dogs in north-west Italy

Sera were collected from 490 dogs from north-west Italy. One hundred and eighty-eight dogs were urban, while 302 dogs were rural. Among the latter, 190 were shepherd dogs and 112 were cattle farm dogs. Sera were tested for the presence of antibodies against Neospora caninum using the Neospora agglutination test. Seroprevalence at 1/40, 1/80, 1/160 dilution titres was significantly higher in rural (36.4%, 19.5%, 9.9% respectively) than in urban dogs (20.2%, 10.6%, 4.8% respectively). Seroprevalence did not differ significantly in males and females. In shepherd dogs, prevalence increased according to dogs' age, thus suggesting a post-natal exposure by horizontal transmission. The observed higher seroprevalence in rural dogs suggests the importance of lifestyle and alimentary habits (i.e. aborted foetuses, placentas and small mammals) in the acquisition of N. caninum infection. Our results confirm that dogs are exposed to N. caninum and play an important role in the epidemiology of N. caninum.     

Prevalence of Dirofilaria immitis and Dipetalonema reconditum infection in dogs: 805 cases (1980-1989).

Clinical records of 6,977 dogs examined at the small animal clinic of the University of Tennessee College of Veterinary Medicine from January 1980 through December 1989 were analyzed to determine the prevalence and changing frequency of Dirofilaria immitis and Dipetalonema reconditum infection. Using the Knott's test on these dogs, 805 (11.54%) tested positive for microfilariae, with D immitis in 430 dogs (6.16%), and Dip reconditum in 375 dogs (5.37%). Statistical analysis confirmed that the prevalence of D immitis and that of Dip reconditum were essentially equal in the population of dogs included in this study. There was a slight decrease in the prevalence of D immitis over the 10 years examined, but the prevalence of Dip reconditum remained constant. The results were not affected by year-to-year variability in the number of examinations performed. On the basis of our findings, in eastern Tennessee, those veterinarians who diagnose heartworm infection by the presence of microfilariae without differentiating the species involved, risk misdiagnosing 50% of the cases. If the patterns of prevalence seen in recent years continue, the chances of error may actually increase.     

Serum alpha-tocopherol concentrations in German shepherd dogs with chronic degenerative radiculomyelopathy

The concentration of serum alpha-tocopherol was measured in German shepherd dogs with chronic degenerative radiculomyopathy, and in German shepherd dogs and dogs of other breeds unaffected by the condition. The mean concentration was significantly higher in German shepherd dogs with the condition than in other breeds of dog unaffected by it, but it was not significantly higher than in unaffected German shepherd dogs. Estimates of components of variance indicated that the concentration varied more widely in individual affected dogs than in unaffected dogs, irrespective of breed. These results suggest that chronic degenerative radiculomyopathy in German shepherd dogs is unlikely to be due to uncomplicated vitamin E deficiency.     

Effects of whelping and season of the year on the interoestrous intervals in dogs

An analysis of 319 interoestrous intervals of 36 beagles, 36 German shepherd dogs and 20 labrador retrievers was made to study the influence of whelping on the length of this interval and the within-year variation in length of interoestrous intervals and timing of the oestrous periods. The mean interoestrous interval was significantly longer for beagles (247±5 days) than for German shepherd dogs and labrador retrievers (both 198±5 days)(P<0–001). For bitches that had not whelped there were no significant differences between breeds (beagles 172+10; German shepherd dogs 166±6; and labrador retrievers 172±7 days). The mean interoestrous interval after whelping was significantly lengthened in all breeds (P<0–001). This increase was more pronounced for beagles (84 days)(P<0–001) than for German shepherd dogs (58 days) and labrador retrievers (52 days). Heat periods were evenly distributed over the year for the labrador retrievers and German shepherd dogs that were kept as family pets. For the beagles kept as a colony and housed outdoors without heating or supplementary light, there were significant differences between months (P<0001), with a peak in May. The longest interoestrous intervals were found in beagle bitches that had been in oestrous and whelped during autumn.     

Efficacy of a single administration of a spot-on solution containing imidacloprid 10%/moxidectin 2.5% in eliminating Dirofilaria repens microfilariae in naturally infected dogs

In the past decade reports of canine subcutaneous dirofilariosis, caused by the mosquito-transmitted nematode Dirofilaria repens, increased in number in several countries in Europe, along with a rise of human cases. Given the merit to the new approaches for the control and treatment of this infection, the present study evaluated the efficacy of a single application of the spot-on formulation containing imidacloprid 10%/moxidectin 2.5% (Advocate(?), Bayer Animal Health) in the elimination of D. repens microfilariaemia in naturally infected dogs. In September 2009, 18 dogs with a natural infection by D. repens were enrolled in the study. In October 2009 all the dogs were treated once with Advocate(?) and the presence/absence of circulating MF and skin lesions after treatment was evaluated monthly until April 2010. From November 2009 to April 2010 15 dogs scored negative for D. repens while one dog remained negative till March 2010 when it died. Two dogs had a recurrence of microfilariaemia in December 2009 and January 2010 respectively. Nine infected dogs showed skin lesions at the beginning of the trial, which disappeared after treatment in 7 dogs, whereas the other two symptomatic dogs did not show any dermatological improvement until the end of the trial even though they scored negative for D. repens microfilariae. This study demonstrated that a single dermal administration of Advocate(?) is effective in eliminating microfilariae of D. repens and likely has a certain degree of activity in killing subcutaneous adult worms as well. This study demonstrates the efficacy of Advocate(?) in the treatment of dermatitis caused by D. repens. Also, these results are of importance towards further control programs aiming to reduce the number of bites infectious for mosquitoes and the risk of infection for both humans and dogs.     

MR-imaging of lumbosacral intervertebral disc degeneration in clinically sound German shepherd dogs compared to other breeds

German shepherd dogs are overrepresented in the group of dogs with cauda equina compression syndrome due to degenerative lumbosacral stenosis. A congenital predisposition for early degeneration of the lumbosacral intervertebral disc has been suspected. Our aims were to assess the morphologic appearance of the lumbosacral intervertebral disc and the lumbosacral junction in healthy German shepherd dogs compared to other breeds and to evaluate for an early onset of degenerative changes. The lumbosacral spine of 110 clinically sound German shepherd dogs and 47 healthy dogs of other large breeds was examined using magnetic resonance (MR) imaging. The degeneration of every intervertebral disc was graded using an established classification system. Signal intensity of the entire lumbosacral disc and the nucleus pulposus was determined independently. Lumbosacral malalignment was assessed according to a previously described method. The findings for the German shepherd dogs were compared to those of the other breeds. Although most dogs were younger than 18 months at the date of examination, significantly higher grades of degeneration were detected for the lumbosacral intervertebral disc of German shepherd dogs (P < 0.003). Degeneration of the lumbosacral intervertebral disc was independent from findings in the other lumbar discs. We conclude that the German shepherd dog has a predisposition for degenerative changes in the lumbosacral intervertebral disc.     

The leukemia inhibitory factor receptor gene is not involved in the etiology of pituitary dwarfism in German shepherd dogs

Pituitary dwarfism in German shepherd dogs is characterized by combined pituitary hormone deficiency (CPHD) and intrapituitary cyst formation. Activation of the leukemia inhibitory factor (LIF)-LIF receptor (LIFR) signal transduction pathway results in a similar phenotype in (transgenic) mice. We therefore assessed the role of the LIFR in the etiology of pituitary dwarfism in German shepherd dogs. A polymorphic microsatellite marker (UULIFR) was used to analyze the segregation of the LIFR gene in 22 German shepherd dogs from 4 pedigrees, each including one dwarf. There was no allelic association between UULIFR and the dwarfism phenotype. Based on our findings LIFR was excluded as a candidate gene for CPHD.     

德国牧羊犬复孔绦虫种类鉴定和遗传进化分析

为了对采集自3只德国牧羊犬小肠内的复孔绦虫进行种类鉴定和遗传进化分析,通过形态学方法对分离到的虫体进行孔雀绿染色后显微镜观察,并进一步基于线粒体部分基因(pcox1和pnad1)进行PCR扩增和序列分析.显微镜观察结果表明,分离到的虫体形态和内部结构符合犬复孔绦虫的特征.通过对扩增的靶基因序列及其遗传进化分析发现,3个...     

Canine dirofilariasis in the canton of Ticino and in the neighboring areas of northern Italy

The distribution of canine dirofilariosis in Southern Ticino (Switzerland) and in the neighbouring provinces of Varese and Como (Italy) was investigated. Blood samples were collected from 308 dogs which had remained in the local area and were outdoor-housed, older than 1.5 years and had not been treated previously with preventive or microfilaricidal drugs. Microfilariae of Dirofilaria immitis and D. repens were found in 33 (10.7%) and 17 (5.5%) dogs, respectively. Ten more dogs (3.2%) tested positive for circulating antigens. Four infected dogs lived in Southern Ticino: two harboured D. immitis, one D. repens and one had a mixed infection. In addition, 3887 mosquitoes were captured in five sample sites by means of dog-baited traps. Culex pipiens, Aedes geniculatus and Ae. vexans were the most abundant species. Infective stages of D. immitis were observed in local strains of Ae. geniculatus and Cx. pipiens, following engorgement on a microfilaraemic dog and the successive rearing in laboratory conditions. A chemo-prophylactic scheme in four administrations between July and October is recommended for Southern Switzerland.     

Molecular survey of Dirofilaria immitis and Dirofilaria repens by direct PCR for wild caught mosquitoes in the Republic of Korea

Adult mosquito collections using New Jersey light traps and Black-hole light traps were conducted to determine the potential vectors and the relative mosquito infection rates of Dirofilaria immitis and Dirofilaria repens in Gyeonggi and Gangwon Provinces, Republic of Korea, 2005. Dirofilaria spp. were confirmed by polymerase chain reaction (PCR) using species-specific primers for D. immitis and D. repens. Minimum field infection rates (MFIR) [MFIR = (number infected pools/total number of mosquitoes) x 1000] of 12 pools/2059 total number mosquitoes (5.8) and 21 pools (10.1) of the wild caught mosquitoes were positive by PCR for D. immitis and D. repens, respectively. Dual infections of both D. immitis and D. repens were detected by PCR in eight pools (3.9). Anopheles sinensis sensu lato (includes An. sinensis s.s., An. pullus, An. kleini, An. belenrae, and An. lesteri), An. sineroides, Aedes vexans nipponi, Culex pipiens and Armigeres subalbatus were found to be infected and are potential vectors of D. immitis and D. repens in Korea. Infections observed in mosquitoes represent potential health risks for domestic animal and human populations.     

Total and relative deficiency of gut mucosal IgA in German shepherd dogs demonstrated by faecal analysis

The concentration of immunoglobulins in faecal extracts was investigated as a method of assessing the production of immunoglobulins by the gut mucosa of 137 dogs. There were significant correlations between the concentrations in faecal extracts and the concentrations produced in duodenal organ cultures. Seventy-six German shepherd dogs had significantly lower median immunoglobulin A (IgA) concentrations in their faecal extracts than 63 controls of various breeds. Sixteen of the German shepherd dogs had IgA concentrations below the 95 per cent confidence limit of the control population and six had no demonstrable faecal IgA. The faecal concentrations of immunoglobulin G and albumin were significantly higher in the German shepherd dogs than in the controls, but their immunoglobulin M concentrations were similar.     

Visceral leishmaniasis in the German shepherd dog. I. Infection, clinical disease, and clinical pathology

Two groups of three German shepherd dogs each were inoculated with Leishmania chagasi or Leishmania donovani amastigotes and the infection was followed for 82 days. The dogs developed a persistent infection, became thin, and developed splenomegaly and lymphadenomegaly by 55 days after inoculation. All dogs developed a normocytic, normochromic anemia of increasing severity. Thrombocytopenia and leukopenia occasionally occurred. Blood tryptophan levels were decreased significantly in infected dogs. Increased total serum protein, with hypergammaglobulinemia and hypoalbuminemia, was present in all dogs to various degrees. There was a marked increase in gamma globulins, with smaller increases in alpha and beta globulins. Many of the clinicopathologic changes observed in these dogs were similar to the disease as it occurs in man. The German shepherd dog may be a useful laboratory model for the study of visceral leishmaniasis.     

Prevalence of the Dirofilaria immitis infection in dogs from Merida, Yucatan, Mexico

The aim of the present study was to estimate the prevalence of Dirofilaria immitis infection, and to examine the relationship between host factors (gender, age and breed) and D. immitis infection in dogs. The study was designed as a cross-sectional study. A total of 676 dogs were examined for D. immitis infection. Adult worms (necropsy) and blood samples were collected from all animals for diagnosis of D. immitis. Blood samples were examined using a modified Knott's and thick drop techniques. Fifty-six of 676 dogs were diagnosed infected with D. immitis. The odds of infection were 2.85 times higher in female dogs, compared to male dogs (OR = 2.85, 95% CI = 1.5-5.5, P = 0.01). In addition, the odds of infection were 2.11 times higher in > or =3 years old dogs, compared with younger dogs (OR = 2.11, 95% CI = 1.1-4.2, P = 0.03). This information is important for a better understanding of the epidemiology of D. immitis in dogs in Yucatan, Mexico.     

Molecular genetic and expression analysis of alpha-tocopherol transfer protein mRNA in German shepherd dogs with degenerative myelopathy

Degenerative Myelopathy (DM) is a progressive neurological disorder of the spinal cord preferentially occurring in German shepherd dogs. The pathogenesis of the disease is unknown. However, there are indications that vitamin E deficiency may be involved in the pathogenesis of DM. Therefore, we analyzed the expression and the nucleotide sequence of the canine alpha-tocopherol transfer protein (alpha Ttp) of German shepherd dogs with DM in order to determine whether a deficiency or a defect of the alpha Ttp could be a primary factor in the pathogenesis of DM, as found in human patients with Ataxia with vitamin E deficiency (AVED). The cDNA of the coding region of the canine alpha Ttp-mRNA was generated from total liver RNA using RT-PCR and 5' RACE technique. We determined the sequence of 707 out of 834 base pairs or 84.8% of the canine alpha Ttp coding region. Sequence comparison of canine alpha Ttp between affected and control dogs revealed no differences in either nucleotide or predicted amino acid sequence. Using Northern blot analysis alpha Ttp-mRNA expression was solely found in the liver of the dogs, rats and humans, while various other organs showed no alpha Ttp-mRNA expression. No significant differences in expression levels of canine alpha Ttp mRNA were found between DM and control dogs. Our data suggest that the canine alpha Ttp gene is unlikely to be involved in the pathogenesis of DM in German shepherd dogs.     

Von Willebrand's disease in the German shepherd dog

Two litters of German shepherd dogs were evaluated for a haemorrhagic tendency that was characterised by excessive bleeding from the umbilicus at birth, haemorrhage and haematoma formation at vaccination, excessive bruising, and lameness due to haemarthrosis. Platelet counts, clotting times and Von Willebrand's factor (VWF) assays were assessed in all dogs. Factor VIII determination was performed in 1 puppy and its parents. Based on the clotting times and VWF assay, 6 puppies (4 male and 2 female) showed type I Von Willebrand's disease (VWD), 5 (4 male and 1 female) possible type II VWD, and 4 were unaffected. One puppy with possible type II VWD had very low factor VIII activity; its sire had a normal factor activity, whereas the dam was in the low-normal range. This article reports type I and possible type II VWD in 2 related litters of German shepherd dogs, the latter being rare in German shepherd dogs.     

Relative IgA deficiency and small intestinal bacterial overgrowth in German shepherd dogs

Serum immunoglobulin concentrations and densities of IgA-producing immunocytes in intestinal mucosa were compared in a group of clinically healthy dogs of various breeds, a group of clinically healthy German shepherd dogs, and a group of German shepherds with bacterial overgrowth in the proximal small intestine. Serum concentrations of IgA, but not IgM or IgG, were significantly lower in the clinically healthy German shepherd dogs than in other purebreed and mixbreed dogs, indicating that production of IgA by gut-associated lymphoid tissue might be relatively low in this breed. However, densities of IgA-producing cells were not significantly different comparing these two groups, suggesting that any impairment of mucosal IgA production is more likely to be related to defective synthesis or secretion of IgA than to reduced numbers of IgA-producing immunocytes. Comparable findings in German shepherd dogs with small intestinal bacterial overgrowth provided further indirect evidence that local immunity might be defective in this breed, since these luminal bacteria would be expected to stimulate mucosal IgA production. However, it is not clear whether such a defect is directly responsible for the overgrowth, or whether there is an indirect relationship between defective local immunity and bacterial overgrowth in German shepherd dogs.