PCR-based coprodiagnostic tools reveal dogs as reservoirs of zoonotic ancylostomiasis caused by Ancylostoma ceylanicum in temple communities in Bangkok

A survey of gastrointestinal parasites of dogs and humans from temple communities in Bangkok revealed that 58% of dogs and 3.4% of humans, among those sampled, were infected with hookworms utilising faecal flotation techniques and microscopy. A previously established polymerase chain reaction (PCR)-RFLP approach was utilised to determine the species of hookworms infecting dogs found positive for hookworm eggs. Single infections with Ancylostoma ceylanicum and Ancylostoma caninum were recorded in 77% and 9% of hookworm positive dogs, respectively and mixed infections with both species of Ancylostoma were recorded in 14% of dogs. A single-step PCR for the multiplex detection of Ancylostoma species and Necator americanus DNA in human faeces was developed and applied to characterise the species of hookworms in microscopy positive individuals. Single infection with N. americanus was recorded in five and A.ceylanicum infection in two, out of seven individuals positive for hookworm. This study demonstrates that humans are at risk of acquiring infection with A. ceylanicum in communities where this species of hookworm is endemic in dogs.     

Activity of ivermectin against canine intestinal helminths

The anthelmintic activity of ivermectin was tested in 98 dogs against adult ascarids (Toxocara canis, Toxascaris leonina), hookworms (Ancylostoma caninum, A braziliense), and whipworms (Trichuris vulpis), and against experimentally induced infections (4th-stage larvae) of T canis and A caninum. Dosage levels tested were single subcutaneous injections of 50, 100, 200, or 400 micrograms/kg of body weight with appropriate vehicle-treated controls. A minimum of 4 (usually 5) dogs were tested with each parasite and dosage level. The lowest dosage level, 50 micrograms/kg, and all higher dosage levels expelled greater than 99% of the adult forms of both species of hookworms and intestinal larval forms of A caninum, as determined by worm counts at necropsy. A dosage level of 100 micrograms/kg was required to expel greater than 99% of whipworms and 200 micrograms/kg was necessary to expel adult (91%) and larval (97%) stages of T canis. Ivermectin was only marginally effective (34.2%, 46.2%, 69.2%, and 53.8%) against Toxascaris leonina at 50, 100, 200, and 400 micrograms/kg, respectively, and had no effect against occasional infections with the tapeworms, Dipylidium caninum (14 dogs) and Taenia spp (3 dogs).     

A survey of gastrointestinal helminths in cats of the metropolitan region of Rio de Janeiro, Brazil

The prevalence of gastrointestinal helminth parasites in 135 cats over 1 year of age and inhabiting the metropolitan region of the city of Rio de Janeiro, Brazil was investigated by necropsy. These animals had two distinct origins: 99 cats (29 males and 70 females) were derived by capture in public areas (feral/stray) and 36 (12 males and 24 females) from shelters. The overall prevalence of gastrointestinal helminth parasites was 89.6%. The following parasites, with their respective prevalence in parenthesis, were found: Dipylidium caninum (52.6%), Ancylostoma braziliense (65.9%), Ancylostoma tubaeforme (8.9%), Toxocara cati (25.2%), Toxascaris leonina (11.9%), Physaloptera praeputialis (9.6%). Concurrent infections with two or more parasites were recorded in 59.5% of the individuals. Of the 121 parasitized cats, 94 were feral/strays and 27 were from shelters. Among feral/stray cats, 80 were infected with A. braziliense (85%) and 17 of the shelter felids were infected with D. caninum (63%). Feral/stray cats had higher worm intensities (6411/94-68.2) than shelter cats (992/27-36.7). The helminth parasites most frequently found in feral/stray cats were Ancylostoma braziliense (47.5%) and D. caninum (47%) while in shelter cats, D. caninum was the predominant species (85.2%). Twenty seven cats (22.3%) had only A. braziliense and 19 (15.7%) were parasitized only with D. caninum. Among those cats harboring mixed infections A. braziliense and D. caninum were the species more frequently found (P < 0.001).     

Hookworms of feral cats in Florida

Thirty feral cats (Felis catus) from Alachua county (northern Florida) and 30 from Palm Beach county (southern Florida) were examined for hookworms. Two species, Ancylostoma tubaeforme and Ancylostoma braziliense, were identified. Forty-five cats (75%) were infected with A. tubaeforme, with a mean intensity of 48 hookworms per cat. Twenty cats (33%) were infected with A. braziliense, with a mean intensity of 28 worms per cat. The prevalence of A. tubaeforme was greater than that of A. braziliense in Alachua (P=0.002) and Palm Beach (P=0.004) counties. The intensity of A. tubaeforme infections was higher in Palm Beach county than Alachua county (P=0.013). The intensities of A. tubaeforme and A. braziliense were positively correlated (increased together) in Palm Beach county (P=0.011). These hookworms have also been identified in bobcats (Felis rufus), gray foxes (Urocyon cinereoargenteus), and red foxes (Vulpes vulpes) in Florida. The prevalence of A. tubaeforme was significantly greater in feral cats than those reported in bobcats (P<0.001). The prevalence of A. braziliense was significantly greater in feral cats than in those reported in gray foxes (P=0.008). The hookworm that infects Florida panthers and bobcats, A. pluridentatum, was not found.     

Helminths in dogs belonging to people in a resource-limited urban community in Gauteng, South Africa

One hundred and sixty-four faecal samples, 148 adhesive tape swabs and 132 blood samples were collected from dogs in Boksburg, Gauteng, to assess the prevalence of helminth parasites in the area. Sixty-nine of these dogs were also necropsied and helminths recovered from the gastro-intestinal tracts. Ancylostoma caninum was the most common helminth and was present in 88% of the dogs, followed by Dipylidium caninum in 39% of dogs, Toxocara canis in 36%, Ancylostoma braziliense in 20%, Spirocerca lupi in 14%, Toxascaris leonina in 9%, Trichuris vulpis in 6%, Joyeuxiella pascualei in 6% and Taenia spp. in 4%. Microfilariae of Dipetalonema reconditum were found in 2% of the blood samples. The results of this study extend the geographic distribution of T. vulpis. With the exception of Spirocerca and Dipetalonema, all these helminths are potentially zoonotic, and may pose a threat to community health.     

Efficacy of an ivermectin/pyrantel pamoate chewable formulation against the canine hookworms, Uncinaria stenocephala and Ancylostoma caninum.

The effectiveness of the combination of pyrantel pamoate (5 mg kg-1) and ivermectin (6 micrograms kg-1) against the canine hookworms Uncinaria stenocephala and Ancylostoma caninum was determined. This combination is intended for monthly use as a heartworm preventative and for treatment and control of canine hookworms. The formulation was found to be effective (99.6% reduction in worm burdens) against both species of hookworms in experimentally infected dogs. No adverse effects due to the drug combination were observed in any dog during the course of this study.     

Gastro-intestinal helminths of domestic dogs in the Republic of South Africa

Of the gastro-intestinal helminths found in 1 063 dogs from different parts of the country, Dipylidium caninum, the most prevalent cestode, occurred in 19,7% of the animals. Echinococcus granulosus was present in 10 dogs, 8 of which were from urban areas, and Taenia hydatigena in 69 dogs. Taemia multiceps was recovered from dogs only in the Cape Province and the Orange Free State. Toxocara canis was present in 81 of the necropsies carried out on 253 dogs from the Pretoria municipal area, while Ancylostoma spp. were present in 175 dogs. In the Pretoria area Ancylostoma caninum (11,9%) was more prevalent than Ancylostoma braziliense (6,2%).     

Comparison of febantel tablets and Vercom paste against gastrointestinal nematodes of dogs.

Thirty adult dogs with naturally acquired gastrointestinal nematode infections were assigned at random to ten replicates and treated daily for 3 days with either a combination febantel/praziquantel (Vercom) paste, febantel tablets or placebo tablets. Numbers of hookworm and whipworm eggs after treatment were reduced similarly for both drug formulations when compared with pretreatment egg counts, whereas these counts increased in the controls. Vercom paste reduced the hookworm egg count by 99.9% and the whipworm egg count by 99.6%. The febantel tablet decreased the hookworm egg count by 99.9% and the whipworm egg count by 100%. As determined at necropsy, the controlled test efficacy against adult hookworms and whipworms was similar for the Vercom paste and the febantel tablets. The controlled test efficacies of Vercom paste against Ancylostoma caninum, Ancylostoma braziliense, and Trichuris vulpis were, respectively, 99.7%, 100% and 95.8% and those of febantel tablets were 98.2%, 100% and 99.7%. These results indicate that the nematocidal efficacy of febantel against these nematodes remains unchanged in these two formulations. No adverse reactions to either febantel tablets or to Vercom paste were observed.     

Helminths in dogs from a peri-urban resource-limited community in Free State Province,South Africa

This study focused on the helminth parasites of dogs in the Bloemfontein area of the Free State Province of South Africa. Samples were collected from 63 stray dogs destined for euthanasia. Complete sets of samples, consisting of blood, faeces, adhesive tape swabs and organs (heart, lungs and complete gastro-intestinal tract) from each dog were examined for helminth parasites. Dipylidium caninum was the most common helminth, and was recovered from 44% of dogs, followed by Taenia spp. (33%), Toxascaris leonina (32%), Ancylostoma caninum (27%), Toxocara canis (21%), Ancylostoma braziliense (19%), Spirocerca lupi (13%) and Joyeuxiella sp. (5%). Although human infection with S. lupi and Joyeuxiella sp. are unlikely, all the other helminths reported in this study are zoonotic, and therefore pose a threat to community health in Bloemfontein.     

477例门诊犬寄生虫种类和感染情况的调查

对2012年-2015年西北农林科技大学西安动物医院门诊确诊的477例犬寄生虫感染资料进行分类统计和分析,以期了解西安地区犬寄生虫的种类和感染情况,对犬寄生虫的防控提供依据。结果显示,从感染犬中共检出14种寄生虫,每种寄生虫的阳性率依次为:吉氏巴贝斯虫51.79%(247/477),等孢球虫16.15%(77/477),贾第鞭毛虫11.74%(56/477),犬弓首蛔虫6.71%(32/477),疥螨4.41%(21/477),蠕形螨4.41%(21/477),犬复孔绦虫3.78%(18/477),犬钩口线虫2.31%(11/477),犬耳痒螨1.89%(9/477),吸吮线虫0.63%(3/477),华支睾吸虫0.42%(2/477),弓形虫0.42%(2/477),犬尾旋线虫0.21%(1/477),犬恶丝虫0.21%(1/477)。混合感染两种及以上寄生虫的犬占5.45%(26/477)。肠道寄生虫中的等孢球虫、贾地鞭毛虫、犬弓首蛔虫和犬钩口线虫等容易发生混合感染。寄生虫和病毒合并感染犬占8.39%(40/477),犬细小病毒(CPV)、犬瘟热病毒(CDV)和犬冠状病毒(CCV)常与犬肠道寄生虫合并感染。许多寄生虫感染与犬的年龄有密切关系,季节对寄生虫感染也有影响。原虫感染特别是吉氏巴贝斯虫感染应当引起重视。控制犬与寄生虫传播媒介的接触、改善犬的饲养管理条件对寄生虫感染的预防十分重要。     

Persistent efficacy of moxidectin canine sustained-release injectable against experimental infections of Ancylostoma caninum and Uncinaria stenocephala in dogs

The efficacy of moxidectin canine sustained-release injectable administered at fixed intervals before administration of an oral hookworm challenge was evaluated in 40 laboratory dogs. Groups of eight dogs were treated with the moxidectin sustained-release formulation by SC injection approximately 3, 4, 5, or 6 months before being given oral inoculations with 300 Ancylostoma caninum larvae on Day 0 and 400 Uncinaria stenocephala larvae one day later. Dogs were euthanized 21 days after parasite inoculations. Fecal samples and the intestinal contents collected at necropsy from each dog were examined for hookworms. Fecal egg count reductions based on geometric means relative to controls were 99.2% (3 months) to 81.2% (6 months). The reduction in A. caninum worm recoveries at 3, 4, 5, and 6 months based on geometric means were 94.7%, 90.3%, 82.0%, and 60.2%, respectively. The mean reductions in U. stenocephala worm counts at these intervals were 94.6%, 85.3%, 71.6%, and 48.2%,respectively.     

Effects of milbemycin oxime on adult hookworms in dogs with naturally acquired infections

Previous work indicated that adult Ancylostoma caninum can be removed from experimentally infected dogs, using a formulation of milbemycin oxime at dosage of 0.5 mg/kg of body weight. To determine the efficacy of this treatment in dogs naturally infected with adult hookworms, 24 mixed-breed dogs with patent hookworm infections were purchased from an out-of-state vendor, and 6 male and 6 female dogs were assigned to either a control group or a group that would be treated. Dogs were treated 10 days after their arrival and were euthanatized 1 week after treatment. Beginning 3 days before treatment, fecal samples were collected daily from all dogs, and the number of Ancylostoma eggs per gram of dry weight of feces was determined from each sample. By 1 week after treatment, the mean number of eggs being passed by the treated dogs had dropped from 12,700 to 10 eggs/g of dried feces; there was no apparent change in fecal egg counts for dogs of the control group. At necropsy, the mean number of adult A caninum in dogs of the treated and control groups was 1.3 and 56, respectively; in these naturally infected dogs, efficacy of treatment was calculated to be 97.8%. The mean number of adult Trichuris vulpis recovered in dogs of the control and treated groups at necropsy was 24 and 0, respectively, which yielded treatment efficacy of 100%. Although Uncinaria stenocephala and Toxocara canis appeared also to be removed by use of this dosage, too few dogs were in the study to calculate meaningful efficacies.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prevalence of dog intestinal parasites and risk perception of zoonotic infection by dog owners in São Paulo State, Brazil

Coprological examination was used to estimate the prevalence of gastrointestinal parasites in stray and domiciled dogs from Botucatu, S?o Paulo State, Brazil. Risk factors for dog infection were assessed in relation to demographic, husbandry and management data. The dog owners completed a questionnaire survey on some aspects of dog parasitism such as parasite species, mechanisms of infection, awareness of zoonotic diseases and history of anthelmintic usage. Parasites were found in the faeces of 138 dogs, with an overall prevalence of 54.3%. Dogs harbouring one parasite were more common (31.4%) than those harbouring two (18.5%), three (3.2%) or four (1.2%). The following parasites and their respective frequencies were detected: Ancylostoma (37.8%), Giardia (16.9%), Toxocara canis (8.7%), Trichuris vulpis (7.1%), Dipylidium caninum (2.4%), Isospora (3.5%), Cryptosporidium (3.1%) and Sarcocystis (2.7%). Stray dogs were found more likely to be poliparasitized (P<0.01) and presented higher prevalence of Ancylostoma, T. canis and Giardia (P<0.01) than domiciled ones. Toxocara canis was detected more frequently in dogs with <6 months of age (P<0.05) and no effect of sex or breed could be observed (P>0.05). Except for Ancylostoma, that showed a significantly higher prevalence in dogs living in a multi-dog household (P<0.01), parasite prevalences were similar in single- and multi-dog household. The answers of dog owners to the questionnaire showed that the majority does not know the species of dog intestinal parasites, the mechanisms of transmission, the risk factors for zoonotic infections, and specific prophylactic measures. The predominance of zoonotic species in dogs in the studied region, associated with the elevated degree of misinformation of the owners, indicates that the risk of zoonotic infection by canine intestinal parasite may be high, even in one of the most developed regions of Brazil.     

Field trials of the anthelmintic efficacy of nitroscanate and mebendazole in dogs

The efficacies of nitroscanate and mebendazole against nematodes and Dipylidium caninum were compared by the examination of the faeces of 155 dogs. In unweaned puppies nitroscanate acted significantly faster and was significantly more effective than mebendazole against Toxocara canis. In adult dogs, both drugs had a low efficacy against Trichuris vulpis but a similarly good efficacy against other nematodes, with a tendency for nitroscanate to be more effective in reducing the prevalence of Ancylostoma caninum. Nitroscanate reduced the prevalence of D caninum infections considerably more than mebendazole.     

Application of in vitro anthelmintic sensitivity assays to canine parasitology: detecting resistance to pyrantel in Ancylostoma caninum

Resistance of the canine hookworm Ancylostoma caninum to anthelmintic therapy with pyrantel is an emerging problem in canine veterinary practice. Detecting anthelmintic resistance in parasites of pets is problematic because traditional resistance-monitoring techniques used with livestock parasites, such as the faecal egg count reduction test, are often impractical for use in small animals. We used two field-collected isolates of A. caninum in an abbreviated critical trial to test their pyrantel resistance status. The strains showed high-level and low-level resistance, with in vivo pyrantel efficacies of 28% and 71%, respectively. We noted a distinct worm density dependence effect on faecal egg count during the critical trial; egg counts in the dogs containing the low-level resistant isolate were 41% higher 6 days after drug treatment, despite the removal of 71% of the adult worms by the drug treatment. We then assessed four candidate in vitro assays for their ability to detect pyrantel resistance in A. caninum larvae, using these two isolates. The assays included a new format termed the larval arrested morphology assay (LAMA), based on observation of the effects of pyrantel on the body shape adopted by infective stage A. caninum larvae in vitro. Our data suggests that three of these assays, the LAMA, the larval motility assay (LMA), and larval feeding inhibition assay (LFIA) show promise with regards to detection of pyrantel resistance in A. caninum, but the complexity of the LFIA would likely limit its suitability for field studies. In vivo pyrantel efficacies of 28% and 71% in the two A. caninum isolates were associated with a 17-fold shift in the in vitro IC(50) values measured using the LAMA. Further testing with isolates of varying degrees of resistance is required to determine which of these assays is suitable as a rapid in vitro laboratory test for pyrantel resistance in A. caninum. The present study also indicates that potential exists for the novel LAMA or the LMA to be of use in detecting pyrantel resistance in the human hookworms, Necator americanus and Ancylostoma duodenale.     

Efficacy of nemadectin, a new broad-spectrum endectocide, against natural infections of canine gastrointestinal helminths

Nemadectin, a new broad-spectrum endectocide, was highly efficacious against natural infections of all the major canine gastrointestinal helminths. At single oral dosages of 0.2-0.4 mg kg-1 body weight (BW), a liquid formulation administered in gelatin capsules was 100% effective in eliminating natural infections of Toxocara canis, Toxascaris leonina, Ancylostoma caninum and Uncinaria stenocephala. Tablets (267 mg) containing 4.6% nemadectin given at a rate of 1/3 tablet per 20 kg BW (0.2 mg nemadectin kg-1) were 100% active against T. canis, A. caninum and U. stenocephala. With both formulations, an increase in the dose rate to 0.6-0.8 mg kg-1 BW resulted in 99-100% elimination of Trichuris vulpis infections. No adverse reactions were observed in any of the treated dogs.     

Antibodies to selected canine pathogens and infestation with intestinal helminths in golden jackals (Canis aureus) in Israel.

Blood and fecal samples, collected from 46 healthy adult free-ranging golden jackals captured in two different locations in Israel, were examined. A serological Study was conducted to investigate the prevalence of circulating antibodies reacting with four common canine pathogens: canine distemper virus (CDV), canine parvovirus (CPV), Ehrlichia canis and Leishmania infantum. Faecal flotation and haematological tests were also performed. The seroprevalence of CPV, E. canis, CDV, and L. infantum were 72.3% (34/47), 54.3% (25/46), 52.2% (24/46), and 6.5% (3/46) respectively. Faecal flotation tests revealed a high prevalence of Ancylostoma caninum (13/17, 76%) and a low prevalence of Dipilidium caninum infestation. Examination of blood smears revealed Hepatazoon canis gamonts in one jackal. Golden jackals are among the most common free-ranging carnivores in Israel and neighboring countries. Their habitats are in proximity to densely populated areas and they bear close phylogenic relation to the domestic dog. These facts, combined with the high prevalence of the jackals' exposure to the major canine pathogens demonstrated in this study, suggest that they may serve as a reservoir for the transmission of certain diseases to domestic dogs.     

Uredofos: anthelmintic activity against nematodes and cestodes in dogs with naturally occurring infections.

A new broad-spectrum anthelmintic, uredofos, was tested in 146 dogs by single and multiple oral dosing. Single doses of 100 and 50 (but not 25) mg/kg were totally effective in removing Dipylidium caninum and Taenia spp from 46 dogs with infections of tapeworms. Among groups of 15 to 20 dogs, the average percentage efficacies against Toxocara canis for single soese of 100, 50, and 25 mg/kg were 98, 96, and 81%, respectively. The average percentage of efficacies against hookworm (Ancylostoma caninum) were greater than 96% in dogs treated with single doses of 100, 50, or 25 mg/kg and were 100% in the 35 dogs given 2 or 3 treatments (24-hour intervals) at dose levels of either 25 or 50 mg/kg. The whipworm, Trichuris vulpis, was not efficaciously eliminated by single doses of 25, 50, and 100 mg/kg (av percentage of efficacies of 30, 35, and 71%, respectively). Efficacy against T vulpis markedly improved when 2 doses were given at a 24-hour interval (av percentage of efficacies were 89% at dose level of 25 mg/kg and 99% at dose level of 50 mg/kg). At either dose (25 or 50 mg/kg), 3 daily treatments were no more efficacious against whipworms than were 2 doses. There was no evidence of drug toxicosis in any dogs tested. It was concluded that uredofos is highly effective against canine tapeworms, ascarids, and hookworms when given as a single dose of 50 mg/kg and against whipworm when given at dose level of 50 mg/kg/day for 2 days.     

Prevalence of dogs with intestinal parasites in Tochigi, Japan in 1979, 1991 and 2002

A total of 772 canine fecal specimens were collected in Tochigi in 1979, 1991 and 2001. The frequency of dogs that were kept indoor in 2002 (72.8%) was significantly higher than that for 1979 (21.2%, P < 0.001) and 1991 (40.6%, P < 0.01). The frequency of parasitized dogs in 2002 (18.8%) was significantly lower than that for 1979 (41.9%, P < 0.01). The findings of this study confirm the declining trend in Japan in the prevalence of helminth parasites in dogs, particularly Ancylostoma caninum and Trichuris vulpis. The reduction in the frequency of dogs with helminths may be mainly a result of the improvement in the environment and the routine use of filaricides.     

Efficacy of nitroscanate against naturally acquired infection with Ancylostoma caninum, Dipylidium caninum, and Trichuris vulpis in dogs

Eighteen dogs with naturally acquired helminth infections were used to evaluate the efficacy of nitroscanate against Ancylostoma caninum, Dipylidium caninum, and Trichuris vulpis. Approximately 15 minutes before treatment, the dogs were given 100 to 200 g of canned dog food. Ten dogs were treated with nitroscanate (50 mg/kg of body weight, PO), and 8 dogs were given placebo tablets PO. The dogs were euthanatized and necropsied 10 days after treatment and helminths were recovered from the small intestine and cecum. On the basis of the number of worms recovered from treated dogs vs the number recovered from control dogs, we determined the efficacy of nitroscanate to be 99.6% against A caninum, 99.8% against D caninum, and 0% against T vulpis.