首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 46 毫秒
1.
Trypanosoma cruzi was demonstrated in blood smears and heart tissue from a 5-year old, female, English Cocker Spaniel that had never been outside of the state of Virginia, USA. Plasma from the dog was positive in a commercially available immunochromatographic dipstick assay for T. cruzi and negative in an immunochromatographic dipstick assay for visceral Leishmania spp. The plasma from the dog had an indirect immunofluorescent antibody titer of 1:800 against epimastigotes of T. cruzi while the titer was 1:50 against promastigotes of L. infantum. The parasite was isolated from the blood in vitro from the dog (TcVT-1 isolate) and used to experimentally infect female C3H and ICR mice. The parasite was nonpathogenic for experimentally inoculated mice. DNA was isolated from parasites grown in vitro and used to determine that the genotype of T. cruzi present in the dog was genotype TcIV. This genotype is common in raccoons, Procyon lotor, in North America and suggests that raccoons may serve as reservoirs for canine infection.  相似文献   

2.
OBJECTIVE: To determine the prevalence of Trypanosoma cruzi infection among dogs in Oklahoma. DESIGN: Cross-sectional study. ANIMALS: 301 owned or impounded dogs related by ownership or general geographic location to 3 dogs determined to have trypanosomiasis. PROCEDURES: Blood samples were obtained from dogs between November 1996 and September 1997. Infection status was determined by use of a radioimmunoprecipitation assay. Second blood samples were obtained from some of the seropositive dogs for study by hemoculture and polymerase chain reaction (PCR) assay. Sites where infected dogs were found were inspected for triatomine insects, and light traps were used for vector trapping. RESULTS: 11(3.6%) dogs were seropositive for T. cruzi infection. Ten of the 11 were owned rural hunting dogs. Protozoal organisms isolated from the blood of 1 seropositive dog were identified as T. cruzi by PCR testing. Only 1 adult Triatoma sanguisuga was captured in a light trap at a site near infected dogs; this insect was not infected. CONCLUSIONS AND CLINICAL RELEVANCE: Our findings suggest that T. cruzi is enzootic in eastern Oklahoma. Measures that would reduce the risk of dogs acquiring T. cruzi infection are unlikely to be acceptable to their owners, and no effective drugs are available for treatment. The presence of T. cruzi-infected dogs poses a threat of transmission to persons at risk of exposure to contaminated blood Veterinarians who practice in the southern United States should be cognizant of this blood borne zoonosis and educate all personnel about appropriate precautions.  相似文献   

3.
Laryngeal paralysis and trypanosomiasis were diagnosed in a 12-year-old Labrador Retriever. Bilateral vocal fold resection and partial excision of the left aryepiglottic fold resolved the dog's respiratory difficulty. Trypomastigotes resembling Trypanosoma cruzi were seen in blood smears during hospitalization. In spite of treatment with nifurtimox and dexamethasone, the dog died. Histologic examination of tissues did not reveal amastigotes of T cruzi or granulomatous myositis previously described in canine trypanosomiasis reported from North America. The lack of granulomatous myositis and amastigotes in muscle is unusual and suggests a strain variation in the behavior of T cruzi.  相似文献   

4.
Some Leishmania species affect humans in two principal forms: visceral and cutaneous leishmaniosis (CL). Several studies have identified dogs as the main reservoirs of the visceral leishmaniosis (VL) caused by Leishmania infantum. The purpose of this work was to carry out a survey of the canine population associated with human cases of American tegumentary leishmaniosis (ATL), in order to establish the clinical, parasitological, serological and immunological characteristics of the canine disease, in an endemic region for both ATL and Chagas' disease in the province of Salta, in northwestern Argentina. Two hundred and eight dogs from the endemic area were examined and 41 (19.7%) of them presented lesions compatible with leishmaniosis. In order to investigate the presence of antibodies against Leishmania spp. and Trypanosoma cruzi, sera were screened by ELISA using two complex antigens from these parasites and, because of cross-reactions between them, a specific antigen for diagnosis of T. cruzi infection. Sixty-two (29.8%) of 208 dogs were positive for the complex antigen F45 from Leishmania and 50 (24%) were positive for the complex antigen F105 from T. cruzi. Nine dogs (4.3%) were positive for the specific Ag163B6-cruzipain suggesting that these dogs were truly infected with T. cruzi. Furthermore, three of these nine dogs presented Leishmania sp. in their skin lesions and therefore were considered as infected by both, T. cruzi and Leishmania parasites. The prevalence of Leishmania infection detected by lesions and/or positive serology was 27.4% (57/208). On the basis of previous observations regarding the clustered appearance of human ATL, the dog population was divided into two groups: zone A, dogs living within a 100 m radius from houses with human cases, and zone B, dogs living beyond this limit. The prevalence of ATL in dogs was significantly higher in zone A (34.6%) than in zone B (7.3%), suggesting a strong correlation between canine and human cases. The average time required for a parasitological diagnosis by microscopy was six times longer for dog samples than human ones, and the average number of parasites per 100 microscopic fields was 14-fold lower in canine samples. The high prevalence of Leishmania infection and the close association with human cases, demonstrated that dogs are a very susceptible host for Leishmania infection, but the scarcity of parasites in their lesions suggests that they may not be the main reservoir of the parasite in this endemic area.  相似文献   

5.
The prevalence of canine trypanosomosis was investigated in two Chagas disease endemic rural communities located in the central region of Panama. Serologic tests for Trypanosoma cruzi infection revealed a prevalence of 11.1%. Hemocultures coupled with PCR analysis demonstrated a Trypanosoma rangeli infection rate of 5.1%. An overall trypanosome infection index of 16.2% (16/99) was detected in this canine population. One dog had a mixed infection of T. cruzi and T. rangeli. Six of the trypanosome-infected dogs belong to people who were diagnosed of Chagas disease. We conclude that dogs from this rural area of Panama are frequently infected with trypanosomes transmitted by the sylvatic vector, Rhodnius pallescens, and suggest that dogs are important in the peridomestic transmission cycle of trypanosomes as reservoirs and hosts. The epidemiological implications of these findings are discussed.  相似文献   

6.
Several Bartonella spp. associated with fleas can induce a variety of clinical syndromes in both dogs and humans. However, few studies have investigated the prevalence of Bartonella in the blood of dogs and their fleas. The objectives of this study were to determine the genera of fleas infesting shelter dogs in Florida, the prevalence of Bartonella spp. within the fleas, and the prevalence of Bartonella spp. within the blood of healthy dogs from which the fleas were collected. Fleas, serum, and EDTA-anti-coagulated whole blood were collected from 80 healthy dogs, and total DNA was extracted for PCR amplification of Bartonella spp. The genera of fleas infesting 43 of the dogs were determined phenotypically. PCR amplicons from blood and flea pools were sequenced to confirm the Bartonella species. Amplicons for which sequencing revealed homology to Bartonella vinsonii subsp. berkhoffii (Bvb) underwent specific genotyping by targeting the 16S–23S intergenic spacer region.A total of 220 fleas were collected from 80 dogs and pooled by genus (43 dogs) and flea species. Bartonella spp. DNA was amplified from 14 of 80 dog blood samples (17.5%) and from 9 of 80 pooled fleas (11.3%). B. vinsonii subsp. berkhoffii DNA was amplified from nine dogs and five of the flea pools. Bartonella rochalimae (Br) DNA was amplified from six dogs and two flea pools. One of 14 dogs was co-infected with Bvb and Br. The dog was infested with Pulex spp. fleas containing Br DNA and a single Ctenocephalides felis flea. Of the Bvb bacteremic dogs, five and four were infected with genotypes II and I, respectively. Of the Bvb PCR positive flea pools, three were Bvb genotype II and two were Bvb genotype I.Amplification of Bvb DNA from Pulex spp. collected from domestic dogs, suggests that Pulex fleas may be a vector for dogs and a source for zoonotic transfer of this pathogen from dogs to people. The findings of this study provide evidence to support the hypothesis that flea-infested dogs may be a reservoir host for Bvb and Br and that ectoparasite control is an important component of shelter intake protocols.  相似文献   

7.
The efficacy of two formulations of a topically applied 65% permethrin spot-on for dogs (Defend EXspot Treatment for Dogs, Schering-Plough Animal Health Corp.) was evaluated against experimental infestations of the cat flea, Ctenocephalides felis, and the brown dog tick, Rhipicephalus sanguineus. Thirty dogs were randomly allocated to treatment with 65 % permethrin in diethylene glycol monomethyl ether (original formulation), 65 % permethrin in propylene glycol monomethyl ether (test formulation), or to an untreated control group. Dogs assigned to treatment with a permethrin formulation received either 1 or 2 ml of the formulation in accordance with label directions on Day 0. One hundred unfed, adult cat fleas and 50 unfed, adult ticks were placed on each dog on Days -1, 5, 12, 19, 26, 33, and 40. Live fleas and ticks were counted on each dog on Days 2, 7, 14, 21, 28, 35, and 42. Treatment of dogs with either formulation of 65 % permethrin significantly (P <.05) reduced the number of live fleas and ticks from Days 2 through 42. No statistical differences were noted between the formulations regarding efficacy against C. felis or R. sanguineus.  相似文献   

8.
A novel spot-on formulation combining fipronil, amitraz and (S)-methoprene (CERTIFECT?, Merial Limited, GA, USA) was evaluated in adult Beagle dogs in a study to determine its adulticidal efficacy against the dog flea (Ctenocephalides canis, Curtis, 1826). Sixteen dogs were randomly allocated to treatment groups: 8 dogs served as untreated controls, and 8 dogs were treated once. Treatment consisted of applying a new combination formulation to deliver at least 6.7mg fipronil/kg body weight (bw), 8.0mg amitraz/kg bw, and 6.0mg (S)-methoprene/kg bw. The combination was designed to enhance the efficacy against ticks of the original fipronil/(S)-methoprene combination. Each dog was infested with 100 adult unfed dog fleas within 24h prior to treatment and then at weekly intervals for 8 weeks after treatment. At 24h after treatment or after each subsequent infestation, each dog was combed thoroughly to remove live fleas to be counted. A single treatment with CERTIFECT provided excellent knock-down of fleas within 24h after treatment and controlled re-infestations for up to 7 weeks (efficacy ≥96.5%, p<0.05).  相似文献   

9.
Fleas were identified after removal from 100 dogs and 60 cats following routine presentation at a Veterinary Hospital in Gainesville, FL. Ctenocephalides felis comprised 92.4% and 99.8% of the fleas taken from dogs and cats respectively. Pulex irritans accounted for 7.5% of the fleas found on dogs and for 0.2% of those found on cats. Echidnophagia gallinacia was found on one dog. Of the 100 dogs, 80 were infested with C. felis alone, one with P. irritans alone, and 18 carried a mixed infestation of the two. One animal was infested with all three species. Ctenocephalides canis was not identified amongst the total of 1887 fleas examined.  相似文献   

10.
OBJECTIVE: To determine the effect of an adulticide on flea populations of dogs and to evaluate efficacy of combined use of the adulticide and an insect growth regulator (IGR) in dogs with experimentally induced flea infestations. ANIMALS: 40 adult Beagles. PROCEDURE: Each group of 5 dogs was housed in a separate room. Each dog was infested 3 times with 50 fleas, and fleas were counted beginning on day -21. Groups of dogs and treatments (initiated on day 0) were as follows: 1, adulticide once; 2, adulticide on days 0 and 7; 3, adulticide on days 0, 3, and 7; 4, sham treatment; 5, IGR monthly; 6, IGR monthly plus adulticide once weekly for 6 weeks; 7, IGR monthly plus adulticide twice weekly for 6 weeks; 8, sham treatment. Flea counts were compared between treated and control dogs. RESULTS: By 24 hours after initial treatment, all adult fleas but 1 were dead in treated dogs. In groups 1 and 3, populations increased to 15 to 20 fleas/dog 2 months after treatment, compared with 48 fleas/dog in group 4. After treatment, mean flea counts were significantly lower for groups 1, 2, and 3, relative to group 4. Efficacy of treatment for group 5, relative to group 8, was > 94% after day 84. Efficacy of treatment for groups 6 and 7 was 99% after day 28. CONCLUSIONS AND CLINICAL RELEVANCE: Treatment with adulticide alone or in combination with an IGR had better efficacy, compared with sham treatment or IGR alone. Administration of adulticide twice weekly was not more efficacious than treatment once weekly.  相似文献   

11.
Prevalence of fleas on dogs and cats in an area of central London   总被引：1，自引：0，他引：1  
An account is given of the prevalence of fleas obtained at post-mortem examination from dogs and cats in the Camden Town area of central London during the period 1972–1976. From a total of 193 dogs, fleas were collected from 20 2%. The following species were represented: Ctenocephalides felis felis, Ctenocephalides canis and Orchopeas howardi. Of a total of 316 cats, 56% harboured fleas, all of which were found to be Ctenocephalides felis felis. The advantages of using cadavers rather than live cats and dogs for studies of this kind are noted and comparisons are made with the findings of other authors. The public health importance of the cat and dog flea in relation to human dermatitis is discussed.  相似文献   

12.
The humoral and cellular immune responses of dogs infected with either a non-pathogenic Trypanosoma cruzi isolated from a North American dog (Tc-D) or a pathogenic T. cruzi isolate from an opossum (Tc-O) were studied over a 240 day period. Antibody to T. cruzi epimastigote antigens prepared from Tc-O or Tc-D isolates were first detected by ELISA by Day 26 post infection (PI), peaked by day 175 PI and remained elevated throughout the experimental period in both Tc-O and Tc-D infected dogs. Differences in antibody levels between infected groups were not detected. Western blot analyses were performed using Tc-O and Tc-D epimastigote antigens probed with pooled sera and sera from individual Tc-O and Tc-D infected dogs prior to infection (Day 0), and during the acute (Day 16-35 PI), indeterminate (Day 50-135 PI) and chronic (Day 235 PI) stages of infection. Generally, the patterns, number of protein bands, and temporal appearance of the protein bands identified by pooled sera and sera from individual dogs within each antigen preparation were similar. However, similarities and differences were present in antibody responses between sera from Tc-O and Tc-D infected dogs. Blastogenic responses of peripheral blood mononuclear cells (PBMC) from Tc-O and Tc-D infected dogs to mitogens (concanavalin A, phytohemagglutinin and pokeweed) were not significantly different from controls at any time during the experimental period. The PBMC from both groups of dogs were unresponsive to epimastigote antigens during the acute stage of infection. Statistically significant differences (P less than 0.05) in PBMC responsiveness from controls were observed on Days 70 and 175 PI. Responses decreased to pre-infection levels by Day 240 PI. These studies demonstrate that although two North American T. cruzi isolates have markedly different virulence for dogs, some aspects of their cellular and humoral immune responses are similar while other responses, such as antibody recognition of specific T. cruzi antigens, vary.  相似文献   

13.
American trypanosomiasis is an infectious disease of importance for public health and caused by the protozoa Trypanosoma cruzi mainly transmitted by triatomine bugs. The precise role of cats in the peridomestic transmission of T. cruzi and the mechanism by which cats become infected remain uncertain. The objective of this work was to determine the prevalence of T. cruzi infection in domestic cats from an urban area of tropical Mexico by serological and molecular methods and evaluate associated risk factors. A total of 220 domestic cats from Merida Yucatan, Mexico, were studied. Animals older than 3 months were blood sampled. Serum and DNA were obtained. Specific T. cruzi IgG antibodies were detected using a commercial indirect ELISA with an anti-cat antibody HRP labelled. Positive cases were confirmed by Western blot (WB). Polymerase chain reaction (PCR) was also performed using the primers TC1 and TC2. From the 220 cats, 8.6% had antibodies against T. cruzi using ELISA test and later confirmed by WB. In 75 cats (34%), the sequence of ADNk of T. cruzi was amplified. The bad-regular body condition was the only risk factor associated with PCR positive to T.cruzi (P < 0.001). In Mexico, there are no previous epidemiological reports that demonstrate the importance of the cat as a reservoir of T. cruzi. Few individuals were identified with a serological response because they were probably at an early stage of infection or antibodies were not detected because they could be immunocompromised (FIV, FeLV or others). It is necessary to monitor PCR-positive patients and conduct further studies for better understanding of the epidemiology and pathogenesis of Chagas disease in domestic cats.  相似文献   

14.
OBJECTIVE: To evaluate efficacy of monthly administration of selamectin, fipronil, and imidacloprid against Ctenocephalides felis in dogs. DESIGN: Randomized controlled trial. ANIMALS: 44 healthy dogs. PROCEDURE: Dogs known to be free of fleas were infested with 100 unfed adult fleas on days -28 and -21. On days 0, 30, 60, 90, and 120, dogs (12/group) were treated by topical administration of selamectin (6 mg/kg [2.7 mg/lb] of body weight), fipronil (7.5 mg/kg [3.4 mg/lb]), or imidacloprid (10 mg/kg [4.5 mg/lb]); 8 untreated dogs were used as controls. On day -6 and every 2 weeks after initial treatment, comb counts of viable adult fleas were made, and fleas (< or =50/dog) were replaced onto the dog from which they were removed. On day 89, fleas were not replaced. On day 91 and every 7 days until the end of the study, dogs were challenged with 20 adult fleas. RESULTS: 14 days after initial treatment, geometric mean flea counts were reduced by 97.5 to 99.1 % for all treatments, compared with pretreatment counts on day -6. Selamectin, fipronil, and imidacloprid reduced geometric mean flea counts by 99.7 to 100% from day 29 to the end of the study. CONCLUSIONS AND CLINICAL RELEVANCE: Selamectin is as effective as fipronil and imidacloprid in reducing C felis infestation in dogs housed for 3 months in a flea-infested environment under conditions known to support the flea life cycle, and in protecting against subsequent weekly challenges with C felis for an additional 2 months.  相似文献   

15.
The inhibitory activities of fipronil (10% (w/v) solution), (S)-methoprene (9% (w/v) solution), and fipronil/(S)-methoprene (10 and 9% (w/v) solution, respectively) combination against eggs and emerging adult cat fleas (Ctenocephalides felis) and adulticidal activity were tested on experimentally infested dogs. Thirty-two Beagle dogs were selected for this study and eight replicates of four animals were formed based on body weight within sex. One dog in each replicate was randomly allocated to treatment with: (1) untreated control; (2) fipronil 10% (w/v) solution, (3) (S)-methoprene 9% (w/v) solution, and (4) fipronil 10% (w/v) and (S)-methoprene 9% (w/v) combination solution. Treatments were applied once topically on Day 0 at the rate of 0.067 ml/kg. On Days -12, -1, 21, and weekly to Day 84 each dog was infested with approximately 200 fleas and comb counted approximately 24h later, or 2 days (our 48 h) after in the case of Day -1 infestation. On Days -11, 1, 22, and weekly to Day 85 each dog was again infested with approximately 200 fleas. Flea eggs were collected over approximately 24 h beginning 3 days after infestation. Fleas were combed off of the dogs and counted at the end of the egg collection period (approximately 96 h count). One aliquot of up to about 100 eggs, if available, from each animal at each infestation time was incubated for approximately 72 h to determine larval hatch and the other for 35 days to determine the number of adults that developed. The 10% (w/v) fipronil spot-on provided excellent control (>95%) of adult fleas on dogs for 5 weeks. Similarly, the combination spot-on of 10% (w/v) fipronil and 9% (w/v) (S)-methoprene provided excellent control of adult fleas, i.e., >95% for 5 weeks. From week 6 post-treatment onward, the relatively low inhibition of adult flea emergence substantiated the lack of significant ovicidal/larvicidal activity in the fipronil (10%, w/v) treatment group. However, the combination product provided excellent (>90%) ovicidal activity for 8 weeks and high (91.4%) inhibition of adult flea emergence for 12 weeks. In addition, a synergistic effect of the two compounds in combination was demonstrated with fipronil enhancing the ovicidal and inhibition of adult flea emergence activity of (S)-methoprene against cat flea eggs. When all stages of the life cycle of the cat flea are considered, the combination spot-on product provided a high level of total flea control yielding a curative effect against adult fleas and inhibition of flea development stages with little to no potential reinfestation pressure on the animal or in the environment for 12 weeks.  相似文献   

16.
A dog was treated for fleas with the application of pennyroyal oil obtained by the owner at a health food store. Vomiting ensued within 2 hours, and despite emergency treatment, the dog died within 48 hours. At necropsy, pennyroyal oil was determined to be the cause of death.  相似文献   

17.
Yersinia pestis, causative agent of plague, occurs throughout the western United States in rodent populations and periodically causes epizootics in susceptible species, including black-tailed prairie dogs (Cynomys ludovicianus). How Y. pestis persists long-term in the environment between these epizootics is poorly understood but multiple mechanisms have been proposed, including, among others, a separate enzootic transmission cycle that maintains Y. pestis without involvement of epizootic hosts and persistence of Y. pestis within epizootic host populations without causing high mortality within those populations. We live-trapped and collected fleas from black-tailed prairie dogs and other mammal species from sites with and without black-tailed prairie dogs in 2004 and 2005 and tested all fleas for presence of Y. pestis. Y. pestis was not detected in 2126 fleas collected in 2004 but was detected in 294 fleas collected from multiple sites in 2005, before and during a widespread epizootic that drastically reduced black-tailed prairie dog populations in the affected colonies. Temporal and spatial patterns of Y. pestis occurrence in fleas and genotyping of Y. pestis present in some infected fleas suggest Y. pestis was introduced multiple times from sources outside the study area and once introduced, was dispersed between several sites. We conclude Y. pestis likely was not present in these black-tailed prairie dog colonies prior to epizootic activity in these colonies. Although we did not identify likely enzootic hosts, we found evidence that deer mice (Peromyscus maniculatus) may serve as bridging hosts for Y. pestis between unknown enzootic hosts and black-tailed prairie dogs.  相似文献   

18.
Blood culture and serologic testing were used to study the prevalence of Trypanosoma cruzi infection in a group of 85 dogs from southern Louisiana rural environment. These dogs were known to have been in contact with wild mammalian hosts of the hemoflagellate. Results were compared with blood culture and serologic test results in 103 dogs from a rural environment and with limited known wild mammalian T cruzi host contact. Serologic test results for the 188 dogs from the rural environment were compared with results for 176 dogs from an urban animal shelter and for 100 household pet dogs from an urban southern Louisiana environment. Blood culture was not performed on urban dogs. Culture results were negative in all dogs from rural environments. Serologic evidence of infection was obtained for 4 of the 85 (4.7%) dogs of rural environment with known host contact. Of 176 dogs from the animal shelter, 4 (2.3%) had high antibody titer to T cruzi, and 11 others had low titer (less than 2 adjusted ELISA units [aEU]). Two and 4 dogs of the housed urban and rural groups, respectively, had antibody titer to T cruzi that was less than 2 aEU. Results indicate that prevalence for exposure to T cruzi antigen is higher in dogs with high potential contact with the vector and wild mammalian hosts of T cruzi, whether they are from rural or urban environment. Furthermore, results indicate that similar studies on high-risk human populations may be indicated.  相似文献   

19.
Lesions of experimental flea bite hypersensitivity in the dog   总被引：2，自引：0，他引：2  
Hypersensitivity to fleas was induced in flea-naive dogs by controlled challenge exposure to virgin fleas. By week 10 of the investigation, immediate (15 minute) and delayed (24-48 hours) responses could be elicited in the skin by flea bites. Histologically, the immediate response consisted of edema and eosinophils which sometimes overlapped with a delayed inflammatory response comprised of perivascular lymphocytes and fewer histiocytes. These inflammatory patterns correlated with type I or immediate, and type IV or cellular, allergic reactions. The combined immediate and delayed responses to fleas in the dog are as observed by other investigators in man and guinea pigs.  相似文献   

20.
A polymerase chain reaction (PCR) method was developed for the detection of Toxoplasma gondii. A universal- and a T. gondii-specific primer was used to amplify a region of the small subunit ribosomal RNA gene. This approach allows for a theoretical detection limit of 0.01 zoite of T. gondii per sample assayed. Experiments showed that this PCR method could detect 0.1 pg of T. gondii DNA, which represents about one organism. Polymerase chain reaction tests using DNAs of cat, dog, swine, cattle, human, Sarcocystis cruzi, Eimeria ahsata, E. vermiformis, and Escherichia coli indicated no cross-reaction with nucleic acids of hosts, related coccidia, or bacteria. Data on the sensitivity and specificity suggest that this PCR assay could be extremely useful for the diagnosis of toxoplasmosis in human and veterinary medicine, as well as for food safety surveys.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号