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.     

Critical evaluation of taeniacidal antibiotic S15-1 (SQ 21, 704) for removal of natural tapeworm infections in dogs and cats

The new taeniacidal antibiotic S15-1 (SQ 21,704) was evaluated against naturally occuring infections of Taenia pisiformis in 53 dogs, Dipylidium caninum in 35 dogs, T taeniaformis in 18 cats, and D caninum in 33 cats. It all instances, the compound was administered in gelatine capsules in a single oral dose. The doses tested were between and 200 mg/kg of body weight in dogs and between 15 and 45 mg/kg in cats. In dogs, doses of 25 mg/kg and greater were 100% effective against T pisiformis, whereas a dose of 50 mg/kg was necessary to clear D caninum. In cats, a single oral dose of 22.5 mg/kg was 100% efficacious against T taeniaeformis, and a single dose of 45 mg/kg (the largest dose tested) clearly seven of eight cats of D caninum. The efficacy was limited to tapeworms only; there was no efficacy against nematodes. The antibiotic was well tolerated by both species with no drug-related vomiting or other side-effects observed.     

Anthelmintic efficacy of febantel combined with praziquantel in dogs

Ninety-four dogs were randomly assigned to 1 of 6 groups (5 treated and 1 untreated control) for evaluation of anthelmintic efficacy. Three anthelmintic formulations were studied: a febantel paste, a praziquantel paste, and a combination paste containing both active ingredients. Treated dogs were dosed once daily for 3 days. The minimal effective dosages in combination were established as 10 mg of febantel and 1 mg of praziquantel/kg of body weight. At those dosages for the combination, 99.5% to 100% of the major nematodes and cestodes identified (ie, Ancylostoma caninum, Trichuris vulpis, Toxocara canis, Dipylidium caninum, and Taenia pisiformis) were eliminated. Febantel paste (10 mg/kg) alone was ineffective against cestodes (14.2% elimination of Dipylidium caninum) and praziquantel paste (1 mg/kg) alone was ineffective (0% to 2.4% elimination) against nematodes.     

Transplanted infections with Toxocara canis as a model for the effectiveness testing of anthelmintics

Patent infections of adult dogs with Toxocara canis induced by transplantation of immature, intestinal stages were examined for their suitability for testing of anthelmintics. Each of 5 dogs were infected four times by transplantation of 80 immature, intestinal stages of Toxocara canis. The dogs were treated with various anthelmintics of well established efficacy (pyrantel, nitroscanate, mebendazole, piperazine) 20 dpi. All anthelmintics tested showed the same efficacy as had been assessed earlier by treatment of dogs infected prenatally with Toxocara canis.     

Prevalence of antibodies against Neospora caninum and Toxoplasma gondii in dogs and foxes in Austria

Sera from 1770 dogs and 94 red foxes from Austria were examined for antibodies against Neospora caninum using the indirect immunofluorescent antibody test (IFAT). 3.6% of the dogs were seropositive with titres ranging from 1:50 to 1:6400. Dogs from rural areas were significantly more often seropositive for N. caninum than those from the urban area of Vienna (5.3% versus 2.1%). There were no significant differences in sex or breed, but a slight increase in seropositivity with age was apparent, indicating postnatal infection. None of the foxes had antibodies against N. caninum. Additionally, sera from 242 dogs and 94 foxes were examined for antibodies against Toxoplasma gondii using the IFAT. Thirty-five percent foxes and 26% of the dogs were positive; 1.7% of the dogs were positive for both parasites. This is the first report of the prevalence of N. caninum infections in dogs and foxes in Austria.     

Field evaluation of the efficacy and the safety of a combination of oxantel/pyrantel/praziquantel in the treatment of naturally acquired gastrointestinal nematode and/or cestode infestations in dogs in Europe

In five multicentre field trials, the efficacy and safety of a combination of oxantel/pyrantel/praziquantel (Dolpac), Vetoquinol SA) in the treatment of naturally acquired gastrointestinal nematode and/or cestode infestation in dogs was evaluated in northern and southern Europe. Forty-eight investigators from France, Belgium, Germany, Italy and Spain enrolled 329 dogs to be treated with the tested combination; 235 of these dogs complied with the inclusion criteria of the protocol and had a tested helminth identified on Day 0. A pooled analysis was performed on each of the following helminth species: Toxocara canis, Ancylostoma caninum, Toxascaris leonina, Trichuris vulpis, Uncinaria stenocephala, Taenia spp. and Dipylidium caninum, which were isolated on Day 0. The main efficacy criterion was the egg per gram (epg) percent reduction of the nematodes and the absence of proglottids and or eggs for the cestodes. After treatment, dogs were examined on Day 7, Day 14 and Day 21. The efficacy of the combination against Toxocara canis was 99.1%, 98.8% and 98.9% on Day 7, Day 14 and Day 21, respectively. At the same occasions the efficacy was, respectively, 99.2%, 99.2% and 99.3% against Ancylostoma caninum, 97.3%, 97.2% and 98.4% against Trichuris vulpis, 98.4%, 98.8% and 98.8% against Uncinaria stenocephala, 98.9%, 99.5% and 99.9% against Toxascaris leonina, 97.1%, 100% and 100% against Dipylidium caninum and 100% against Taenia spp.     

Prevalence of dog intestinal nematode parasites in south central West Virginia, USA

Coprological examination was used to determine prevalence of gastrointestinal helminthes in a sample of 231 dogs (117 females and 114 males) during the summer of 2009 at a veterinary clinic in south central West Virginia, USA. Clinical signs (e.g., diarrhea, vomiting, weight gain or loss) were noted in addition to a history of anthelmintic usage. A total of 79 dogs (33.6%) were infected with one or more intestinal nematodes. Most dogs (58) were parasitized with a single species, 19 were parasitized with 2 species, and 2 were parasitized by 3 species. There was no significant difference (i.e., X(2)<3.84; P>0.05) in prevalence of infection between female and male dogs for any of the identified nematode species. The chi-square test for equality of proportions was used to determine prevalence of infection in 3 age categories of dogs (females and males combined): young dogs (≤12 months of age); mature dogs (13-83 months); and old dogs >83 months. Prevalences of infection for Ancylostoma caninum and Toxocara canis were significantly (P<0.005) higher in young dogs, whereas there was no significant difference (P>0.05) in prevalence by age category for Trichuris vulpis. Dogs exhibiting clinical signs were no more likely to harbor intestinal nematodes than dogs that were asymptomatic. Additionally, dogs receiving heartworm treatment were significantly less likely to be parasitized than dogs receiving no heartworm prophylaxis.     

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.     

Nitroscanate A new broad spectrum anthelmintic against nematodes and cestodes of dogs and cats.

SUMMARY: The efficiency of the broad spectrum anthelmintic nitroscanate against tapeworm and nematode infections of dogs was tested in artificially or naturally infected dogs. The safety of the compound was also evaluated in acute, subacute and chronic toxicity tests. At the recommended single dose rate of 50 mg/kg given to the dogs with food, nitroscanate was 98% efficient against Taenia hydatigena, T. ovis and T. pisiformis. The drug was highly efficient against Echinococcus granulosus only at the dose rate of 200 mg/kg given twice but total elimination of worms was not achieved. Natural infections of Dipylidium caninum, Ancylostoma spp and Uncinaria stenocephala were totally eliminated from all dogs at the dose rate of 25 mg/kg or higher. Nitroscanate was 97% efficient against adult Toxocara canis at a single dose of 50 mg/kg. When the dose was repeated 24 hours later total elimination of both mature worms and immature worms in puppies aged 2 weeks was achieved. The repeated dose of 100 mg/kg removed 98% of early immature worms from puppies aged 3 days. The drug was 100% efficient against adult Toxascaris leonina at a single dose of 50 mg/kg and 90.5% efficiency was achieved against early 4th stage larvae by two doses of 50 mg/kg. Nitroscanate was not efficient against Trichuris vulpis. The drug was efficient for the removal of Toxocara cati and Ancylostoma tubaeforme from cats. Nitroscanate caused no serious symptoms of toxicity at dose rates up to 10,000 mg/kg in single or repeated doses in young or older adult dogs. The drug was safely given to dogs during pregnancy, to young puppies and to cats. The regular use of nitroscanate as a broad spectrum anthelmintic for the prevention and control of parasitic infections of dogs is discussed.     

Anthelmintic activity of paraherquamide in dogs

Paraherquamide, an oxindole alkaloid metabolite of Penicillium paraherquei and Penicillium charlesii, was tested against the common gastrointestinal nematodes of dogs at a single oral dosage of 0.5, 1.0, or 2.0 mg kg⁻¹. Efficacy was poor (less than 85%) against Ancylostoma caninum, Uncinaria stenocephala, Toxascaris leonina, Trichuris vulpis, and Strongyloides stercoralis at the low- and mid-dosage levels. At the high dosage level, good efficacy (91%) was observed only against S. stercoralis. Adverse reactions were observed in all dogs at every dosage level and included depression, ataxia, and protrusion of the nictitating membrane.     

Comparison of efficacy of selamectin, ivermectin and mebendazole for the control of gastrointestinal nematodes in rhesus macaques, China

An experiment was conducted to evaluate the efficacy of ivermectin and mebendazole compared with selamectin against gastrointestinal nematodes in rhesus macaques. A total of 60 rhesus macaques (Macaca mulatta), which were all infected with gastrointestinal nematodes, were randomly assigned to three treatment groups (selamectin, ivermectin and mebendazole) and one control group. Fecal samples for determining nematode egg counts were collected pre- and post-treatment. All treatments resulted in decrease in the number of eggs per gram (EPG) in the post-treatment sample compared with the pre-treatment sample. Reductions of mean egg counts from day -3 levels were 99.4% for selamectin, 99.2% for ivermectin and 99.4% for mebendazole on trial day 11, respectively. However, no significant difference was found among treatment groups. According to the data demonstrating a similar efficacy in selamectin-, ivermectin- and mebendazole-treated rhesus macaques, it was effective and convenient to apply either selamectin and ivermectin or mebendazole in rotation on the local conditions.     

Seroprevalence and risk factors associated with Neospora caninum infection in different dog populations in Spain

In this study, Neospora caninum seroprevalence and some associated risk factors were investigated in four different dog populations in Spain. N. caninum seropositivity was significantly higher in farm dogs (51%, 51/100) (P<0.001) and lower in household dogs (2.9%, 3/102) (P<0.0001). The seroprevalence in hunting (23%, 23/100) and stray (24.5%, 23/94) dogs was moderate, and no significant differences were observed between these two populations (P>0.05). A significantly higher number of dogs showed titres of 1:50-1:100 (68%, 68/100) than >or=1:200 (33%, 33/100) titres (P<0.0001). N. caninum antibodies were more often detected in mixed breed than pure breed dogs (P<0.01), but when data were stratified by dog type a significant association was not found (P>0.05). A significantly higher prevalence of N. caninum was observed in dogs over 1 year old (P<0.01), indicating that horizontal transmission may be the most important route of infection. The presence of N. caninum antibodies was significantly more frequent in Leishmania infantum-seropositive hunting (P<0.05) and stray dogs (P<0.00001). This study confirms that farm, stray and hunting dogs can be considered at-risk dog populations for N. caninum infection in Spain.     

Taeniacidal efficacy of SQ 21,704 in dogs by various types of oral administration and in comparison with niclosamide and bunamidine hydrochloride

The streptothrinin antibiotics SQ 21,704 was evaluated against naturally occurring Taenia pisiformis and Dipylidium caninum infections in dogs when they were given at a dose level of 37.5 mg/kg of body weight in four different rations: loaf-type canned meat; chunk-type canned meat; dry (gravy-type) meal; and dry (pelleted) meal. The SQ 21,704 was 100% efficacious against both T pisiformis and D caninum infections when given with the chunk, gravy, and pelleted rations. When given with the loaf-type canned meat, it was 100% effective against T pisiformis and 60% efficacious against D caninum. The SQ 21,704 was effective against both tapeworm species when given orally as a liquid at a dose level of 37.5 mg/kg, formulated as an aqueous suspension containing 94 mg of activity per milliter. The SQ 21,704 was also tested in dogs when given orally in gelatin capsules at a dose level of 37.5 mg/kg without fasting, and was 100% efficacious against both tapeworm species. The results of a comparative taeniacidal study demonstrated that SQ 21,704 was 100% effective in removing both T pisiformis and D caninum when administered orally at a dose level of 37.5 mg/kg, whereas niclosamide and bunamidine hydrochloride were only partially effective at their recommended dose levels. One of five dogs treated with niclosamide at a dose level of 157 mg/kg was positive at necropsy, giving an orally efficacy of 80%. Three of five dogs treated with bunamidine hydrochloride at a dose level of 49 mg/kg were positive at necropsy, giving an overall efficacy of 40%.     

Efficacy of milbemycin oxime against naturally acquired or experimentally induced Ancylostoma spp and Trichuris vulpis infections in dogs.

The efficacy of milbemycin oxime was evaluated at dosages of 0.25, 0.50, and 0.75 mg/kg of body weight in dogs naturally infected with mature Ancylostoma spp, at a dosage of 0.50 mg/kg in dogs with experimentally induced immature and mature A caninum, and at dosages of 0.55 to 0.86 mg/kg in dogs naturally infected with mature Trichuris vulpis. Milbemycin oxime was 95 and 99% effective against mature Ancylostoma spp at dosages of 0.50 and 0.75 mg/kg, respectively, but only 49% effective at a dosage of 0.25 mg/kg. Efficacy was 49% against pulmonary L3-L4 stages of A caninum (36 hours after inoculation), greater than 80% against L4 (120 hours after inoculation) and early L5 stages (216 hours after inoculation), and greater than 90% against experimentally induced mature stages (360 hours after inoculation). Milbemycin oxime was also 97% effective in the removal of mature Tr vulpis from naturally infected dogs. Adverse reactions were not observed following treatment in any of the dogs.     

Canine neosporosis in Hungary: screening for seroconversion of household, herding and stray dogs

In order to assess the seroprevalence of canine neosporosis 651 blood samples were collected from 586 household, 41 herding and 24 stray dogs, at small animal clinics in four large cities and other places of Hungary. Nineteen (2.9%) showed positivity in the IFAT with titres between 1:80 and 1:10240. Two dogs with high titres of antibodies to Neospora caninum had neuromuscular signs (imbalance, tremor) and a further one developed papulomatous, ulcerative and necrotizing dermatitis. There was no correlation between titers and age, sex, breed or keeping place. Although more male dogs had antibodies to N. caninum than females in case of both household and herding dogs, this association was not significant. No breed predisposition was observed. However, dogs with seroconversion were significantly more prevalent among rural (6%) than among urban dogs (1%), indicating that dogs in the countryside may have contact with or access to potentially infected offal from cattle and other intermediate hosts more frequently than those in large cities. Furthermore, significantly more herding dogs (29.3%) had antibodies to N. caninum than household dogs (1.2%), confirming the association between the occurrence of neosporosis and dog keeping on farms. The 12 dogs found seropositive among herding ones lived on 6 farms, on 5 of which seropositive cattle were also identified. This is the first report on the prevalence of N. caninum infection in dogs in Hungary.     

Effect of milbemycin oxime against Ancylostoma caninum in dogs with naturally acquired infection

Twenty-six mixed-breed (14 males, 12 females) dogs were used in a double-blind study to evaluate the effect of milbemycin oxime against naturally acquired infection with Ancylostoma caninum. Dogs were ranked and paired, on the basis of number of hookworm eggs/g of feces, and treatment was randomly assigned. Each dog was given either the study drug or placebo (1 tablet/11.4 kg [0.5 mg/kg] of body weight). Eggs per gram of feces enumeration was done on days 3 and 7 after treatment, and dogs were euthanatized on day 7. On day 3, 5 of the 13 dogs in the milbemycin-treated group had hookworm eggs in the feces (results of the McMaster test). In these dogs, mean number of eggs per gram of feces had decreased markedly (from 5,289 to 452) and, by day 7, was 114. At necropsy, 16 A caninum adults were recovered from 2 of the milbemycin-treated dogs. On day 3, 12 of the 13 dogs in the placebo-treated group had hookworm eggs in the feces. Mean number of eggs per gram of feces in these dogs decreased slightly (from 5,243 to 2,646), but did not decrease further by day 7. A mean number of 54.4 A caninum adults was recovered from 12 of the 13 placebo-treated dogs at necropsy. Milbemycin oxime had 97.8% efficacy against A caninum. Results also indicated that milbemycin oxime may be effective against Trichuris vulpis, but not against Dipylidium caninum.     

An epidemiological study of gastrointestinal parasites of dogs from Southern Greater Buenos Aires (Argentina): age, gender, breed, mixed infections, and seasonal and spatial patterns

A total of 2193 fecal samples from owned dogs were collected during the 2003-2004 period in Southern Greater Buenos Aires, and were evaluated for the presence of intestinal parasites by a flotation-centrifugation method. The overall prevalence was 52.4%, and the 11 species found were: Ancylostoma caninum (13%), Isospora ohioensis complex (12%), Toxocara canis (11%), Trichuris vulpis (10%), Sarcocystis sp. (10%), Giardia duodenalis (9%), Isospora canis (3%), Hammondia-Neospora complex (3%), Dipilydium caninum (18 cases), Cryptosporidium sp. (5 cases), and Toxascaris leonina (1 case). There was no significant difference in the overall prevalence between genders (female = 50.4%, male = 54.6%), and breeds (pure = 52.3%, mixed = 53%), but prevalence in puppies (<1 year) was higher than in adult dogs (62.7% versus 40.8%, respectively). Only the prevalence of A. caninum differed between genders, with higher values for males. The prevalences of six of the parasite species showed a decreasing trend with increasing host age, and an inverse pattern was found for two other species. The prevalences of three protozoa were significantly higher in pure-breed dogs, and those of two nematodes were significantly higher in mixed-breed dogs. The prevalences of T. canis, A. caninum, and T. vulpis were spatially heterogeneous with a clear Southwest-Northeast gradient. Only prevalences of Sarcocystis sp. and G. duodenalis showed seasonal variation. The frequency distribution of the number of species per fecal sample did not differ from a random distribution. Results obtained throughout the world were discussed.     

Prevalence and Treatment of Tapeworms in Horses

A study was initiated to determine the prevalence of tapeworms in horses in Southern Ontario and to investigate the efficacy of pyrantel pamoate, niclosamide and mebendazole. Fecal samples were taken from 580 horses of various breeds, ages and sexes in 24 locations and Anoplocephala perfoliata was found in 13.6%. This was regarded as a minimum, the true rate being probably significantly higher and the reasons for this are discussed. A brief review of the life cycle and effects of tapeworms in horses and a comparison of two flotation techniques for the diagnosis of A. perfoliata eggs in feces is given.Pyrantel pamoate, niclosamide and mebendazole were compared for efficacy in field and critical trials. In field trials, pyrantel base and niclosamide at 6.6 and 50 mg/kg respectively were found to be effective, but in critical trials their efficacy was poor, 15 and 5.6% respectively. These anthelmintics at these dose rates caused only an elimination of the terminal egg bearing segments and were without significant effect on the entire tapeworm. When pyrantel base was administered at 13.2 and 19.8 mg/kg (twice and three times the therapeutic dose rate for nematodes respectively) the efficacy was 97.8 and 100%. It would appear that pyrantel pamoate administered at 13.2 mg pyrantel base/kg is an effective therapeutic dose for tapeworms in horses. Further dose titration studies are needed for niclosamide. Mebendazole was without effect at up to four (35.2 mg/kg) times the therapeutic dose for nematodes.     

Seroepidemiology of Toxoplasma gondii and Neospora caninum in dogs from the state of Paraíba, Northeast region of Brazil

A cross-sectional study was conducted to determine the seroprevalence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies and to investigate the risk factors related to antibodies against T. gondii and N. caninum in dogs of the city of Campina Grande, state of Paraiba, Northeast region of Brazil. For this purpose, 286 blood samples were collected from dogs during the rabies vaccination campaign, in September 2003, and on this occasion questionnaires addressing epidemiological aspects of the infections were given to each dog owner. The sera were analyzed for anti-T. gondii and anti-N. caninum antibodies by indirect fluorescent antibody tests. Of the total of 286 dogs, 129 were positive for T. gondii (titer16) with a prevalence value of 45.1% (95% CI=39.24-51.07%). For N. caninum, 24 dogs were positive (titer50), with a prevalence value of 8.4% (95% CI=5.45-12.23%). Antibodies to T. gondii and N. caninum were found simultaneously in 14 dogs (4.9%; 95% CI=2.7-8.08%). For T. gondii infection, the risk factors associated with seroprevalence was the age of the animals, with dogs older than one year presenting higher values of odds ratio, and co-habitation of cats in the household. For N. caninum infection, dogs that have street contact had higher odds of seropositivity than dogs that remained exclusively in a domestic environment.     

In vitro activity of neem (Azadirachta indica) and cassava (Manihot esculenta) on three pre-parasitic stages of susceptible and resistant strains of Teladorsagia (Ostertagia) circumcincta

Canines are definitive hosts of Neospora caninum (Apicomplexa). For horizontal transmission from canines to occur, viable oocysts of N. caninum must occur in the environment of susceptible intermediate hosts. Canids in Australia include wild dogs and Aboriginal community dogs. Wild dogs are those dogs that are not dependent on humans for survival and consist of the dingo, feral domestic dog and their hybrid genotypes. Aboriginal community dogs are dependent on humans, domesticated and owned by a family, but are free-roaming and have free access throughout the community. In this study the extent of N. caninum infection was determined in a total of 374 dogs (75 wild dogs and 299 Aboriginal community dogs) using a combination of microscopic, molecular and serological techniques. Oocysts of N. caninum were observed in the faeces of two juvenile Aboriginal community dogs (2/132; 1.5%). To estimate N. caninum prevalence, a new optimised cut-off of 18.5% inhibition for a commercial competitive ELISA was calculated using a two-graph receiver-operating characteristic (TG-ROC) analysis and IFAT as the gold standard resulting in equal sensitivity and specificity of 67.8%. Of the 263 dog sera tested the true prevalence of N. caninum antibodies was 27.0% (95% confidence limit: 10.3-44.1%). The association between the competitive ELISA results in dogs less than 12 month old and older dogs was significant (P=0.042). To our knowledge this is the first large scale parasitological survey of the Aboriginal community dogs and wild dogs from Australia. The high prevalence of N. caninum infection in Aboriginal community dogs illustrates that horizontal transmission of N. caninum is occurring in Australia. These results demonstrated that N. caninum in dogs is widespread, including the semi-arid to arid regions of north-western New South Wales and the Northern Territory. The populations of free-ranging dogs are likely to be important contributors to the sylvatic life cycle of N. caninum.