Giardiasis in a cattery

Giardia sp infection was believed responsible for chronic, intermittent diarrhea in a group of 14 Persian cats. Seven of the cats were shedding Giardia sp cysts, and 6 of these cats had diarrhea at the time of fecal examination. Conversely, only 1 of 6 clinically normal cats in the group was shedding Giardia sp cysts. Cysts were not detected in feces of 2 cats with diarrhea. Cats less than or equal to 3 years old were more likely to be found shedding cysts. The parasite apparently was eradicated from the cattery by a combination of cage disinfection (1% sodium hypochlorite solution) and oral furazolidone treatment (4 mg/kg of body weight, BID for 5 consecutive days). During treatment, clinical signs resolved, and all cats remained clinically normal 2 months after treatment.     

Efficacy of a combination febantel-praziquantel-pyrantel product, with or without vaccination with a commercial Giardia vaccine, for treatment of dogs with naturally occurring giardiasis

OBJECTIVE: To determine efficacy of treatment with a combination febantel-praziquantel-pyrantel product, with or without vaccination with a commercial Giardia vaccine, in dogs with naturally occurring giardiasis. DESIGN: Prospective trial. ANIMALS: 16 Beagles naturally infected with Giardia duodenalis. PROCEDURES: During phase 1, 6 dogs were treated with the parasiticide for 3 days (4 were also vaccinated). Four weeks later, all 6 dogs were treated with the parasiticide again for 5 days and were bathed and moved to clean cages after the last treatment (phase 2). Nine dogs were treated with the parasiticide for 3 (n = 4) or 5 (5) days and bathed and moved to clean cages after the last treatment (phase 3). Fecal samples were collected twice weekly for 24 days after treatment and tested for cysts with a quantitative zinc sulfate flotation technique and for Giardia antigen with an immunoassay. RESULTS: Dogs in phase 1 were all shedding cysts again by day 24. In phase 2, only 1 dog shed cysts after treatment, and shedding was transient (day 17). In phase 3, neither cysts nor antigen was detected in fecal samples from 2 of 4 dogs treated for 3 days and 4 of 5 dogs treated for 5 days. In 18 of 57 (31.6%) fecal samples, cysts were seen, but results of the immunoassay were negative. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that when a combination febantel-praziquantel-pyrantel product is used to treat dogs with giardiasis, bathing and changing the environment after treatment may be more important in preventing recurrence than duration of treatment.     

Efficacy of Giardia vaccination in the treatment of giardiasis in cats

OBJECTIVE: To assess efficacy of Giardia vaccination as a treatment for giardiasis in experimentally infected cats. DESIGN: Original study. ANIMALS: 16 young-adult cats. PROCEDURE: Cats were experimentally infected by orogastric administration of Giardia cysts. On weeks 4, 6, and 10, cats in the treatment group (n = 8) were given Giardia vaccine SC. For the first 28 weeks after infection, 3 fecal samples from each cat were examined weekly for Giardia cysts, and cyst numbers were counted. Fecal consistency was scored daily for the duration of the study. Results from vaccinated and unvaccinated cats were compared by logistic regression. RESULTS: All cats became infected and were shedding Giardia cysts by the end of week 2. Throughout the study, diarrhea was rare and was mild and transient when it did occur. By week 28, 5 of 8 vaccinated cats and 7 of 8 control cats had patent Giardia infections. Magnitude of infection, based on number of fecal samples with cysts and number of cysts per sample, decreased progressively in both groups over time. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of 3 doses of a Giardia vaccine did not completely eliminate the organism from experimentally infected cats in the study period. Since clinical signs were minimal in both groups of cats, it could not be determined whether vaccination lessened severity of clinical disease. Results may have been negatively influenced by the large inoculation dose. Whether Giardia vaccination is an effective treatment for giardiasis in naturally infected cats remains to be determined.     

犬贾第虫包囊排出规律的研究

对自然感染贾第虫的比格犬进行粪检调查 ,结果表明犬贾第虫包囊排出呈间歇性 ,其间歇期为 7～ 8d ,排囊后 1 2～ 1 4d达到排囊高峰期 ,峰期持续 2～ 3d,排囊持续时间为 2 5～ 2 7d。用 2只幼犬进行免疫抑制接种犬贾第虫 ,接种后第 7天出现排包囊 ,排囊后 6～ 7d达到排囊高峰期 ,峰期持续 4～ 5d。受染动物出现腹泻 ,体重减轻     

P-58 Three cases of pathological dermal deposits associated with internal diseases in dogs (xanthomatosis, calcinosis and amyloidosis)

Intestinal parasites have been anecdotally associated with pruritus in dogs. A relationship was proposed when the elimination of a specific parasite resolved the pruritus, and re-infection with a parasite caused the pruritus to recur. Ascarids, coccidia, hookworms, tapeworms and whipworms have all been incriminated. Recent reports in the human and veterinary literature have suggested that there may be a relationship between Giardia infection and the development of pruritus and other allergic signs. In order to determine if there is an association between infection with Giardia and pruritus in dogs, faecal samples were collected from 71 pruritic dogs and 101 clinically normal dogs. Three faecal samples from each animal were analysed using a zinc-sulphate concentration technique for the presence of Giardia cysts, and one randomly selected faecal sample from each dog was analysed with an ELISA for Giardia -specific antigen. Ten of 101 dogs (9.9%) in the clinically normal group tested positive with the ELISA, and Giardia cysts were detected in the faeces of seven of these antigen-positive dogs. No Giardia cysts were found in the dogs that tested negative with the ELISA. None of the dogs in the pruritic group tested positive for Giardia by either method. The results indicated a negative association between Giardia infection and pruritic skin disease ( P  = 0.006). Cephalexin was commonly used in the pruritic group, but not in the control group, and may therefore be an explanatory variable.
Funding: Ontario Veterinary College Pet Trust.     

Impact of Giardia vaccination on asymptomatic Giardia infections in dogs at a research facility

Feces were collected from 107 asymptomatic dogs at a research facility in Guelph, Ontario. The prevalence of Giardia infection was 11% (12/107). To assess the effectiveness of Giardia vaccination for treatment of Giardia carriage, 9 additional asymptomatic Giardia antigen-positive dogs were brought into the facility. The Giardia antigen-positive dogs were then randomly allocated to receive either vaccine (n = 10) or a saline placebo (n = 10). Feces were then monitored monthly for 6 mo for Giardia antigen and Giardia cysts. At weeks 4, 8, 12, and 16 following vaccination, there were more Giardia-positive dogs in the vaccinated group (10/10, 9/10, 9/10, 8/10, respectively) compared with the controls (7/10, 7/10, 8/10, 4/10, respectively). At week 20, an equal number of dogs (5/10) were Giardia positive, and at week 24, fewer dogs were positive in the vaccinated group than in the control group (2/10 versus 5/10, respectively). However, there was no significant difference between the 2 groups. Vaccination was, therefore, not an effective treatment for asymptomatic canine Giardia infections in this setting.     

硝唑尼特治疗犬贾第虫病的研究

选择试验犬8只,将其随机分为4个小组,每组2只.连续6 d对8只试验犬分剐进行粪检,确定无贾第虫感染后,用体外纯培养的犬贾第虫滋养体接种试验犬,然后每天采集试验犬新鲜粪便40 g,用硫酸锌漂浮法进行粪检,当检测犬贾第虫感染呈阳性时,分别用1、2、4 mg/kg体质量剂量的硝唑尼特时1、2、3组试验犬进行灌服治疗,第4组试验犬不用药作为对照.用药后,每天以同样的方法检测贾第虫包囊,并计数.结果表明,以2、4 mg/kg体质量给药的试验犬1 d后粪检结果转为阴性,以1 mg/kg体质量给药的试验犬4 d后粪检结果转为阴性.结果表明以2、4 mg/kg体质量剂量的硝唑尼特对犬贾第虫痛有很好的疗效.     

Feline giardiasis: observations on natural and induced infections

The excretion of Giardia sp cysts in the feces of naturally and artificially infected cats fluctuated sporadically, and cysts were undetectable several times during 7 weeks of observation. The mean prepatent period for Giardia infection in 7 cats was 9.6 days (range, 5 to 16 days). The amount of the cyst inoculum did not appear to affect the length of the prepatent period. Six of 11 cats had clinical signs consistent with those of giardiasis. Clinical signs and cyst excretion were eliminated after treatment with metronidazole or furazolidone. Moderate oral or parenteral doses of corticosteroids produced little, if any, alteration in the infection. Postmortem examination of 1 inoculated cat revealed Giardia trophozoites in the jejunum and upper portion of the ileum but not in the duodenum, lower portion of the ileum, cecum, or colon. Giardia cysts isolated from cat feces produced infection in Mongolian gerbils but not in C57BL/6J mice.     

The efficacy of a Giardia lamblia vaccine in kittens.

Twenty kittens were vaccinated with a Giardia lamblia vaccine prepared on a commercial scale on day 0 and boosted on day 21 (group 1); while 10 kittens received only saline (group 2). These kittens were challenged on day 35 with 10(6) Giardia lamblia trophozoites by a surgical intraduodenal injection. Three control kittens were not vaccinated and not challenged (group 3). Following challenge, Giardia vaccinated kittens had significantly fewer days in which abnormal stools were observed and reduced food intake occurred compared to saline injected animals. The rate of weight gain between group 1 and group 2 animals was not different in the prechallenge period (day 0 to day 35), but vaccinated animals had a significantly higher weight gain in the postchallenge period (P < 0.05). On day 56, all vaccinated animals were not passing cysts in their feces, while 40% of saline injected kittens had Giardia cysts in their feces. In vaccinated kittens, cysts were never demonstrated in 45% of the animals, while cysts were detected in 90% of the saline injected kittens. Viability of the cysts in vaccinated kittens was 38% while the cysts viability in saline injected kittens was 99%. On postmortem examination, trophozoites could be detected in 5% of vaccinated kittens and 60% of saline injected kittens. Vaccination produced an elevated Giardia specific serum IgG and IgA response prior to challenge and throughout the postinfection period. The Giardia infection in the saline injected group did not induce an elevated specific serum response. Giardia vaccination of kittens provides protection in kittens from an experimental challenge by reducing or eliminating intestinal trophozoites and fecal cyst excretion.     

Infection of dogs by experimental inoculation with human isolates of Giardia duodenalis: clinical and laboratory manifestations

The susceptibility of dogs to experimental inoculation with trophozoites and cysts of human isolates of Giardia duodenalis and the clinical and laboratory profiles of infection of these animals were studied. Two groups (A and B), each comprising three dogs, were inoculated with G. duodenalis trophozoites and cysts, respectively. A third group of two dogs was not inoculated and remained as control. After inoculation feces were collected daily to determine the pre-patent period, by flotation in 33% zinc sulfate solution. Blood samples (5mL) were collected from animals at 15-day intervals during the 165 days of the experimental period and were used to carry out the hemogram and biochemical evaluation of the levels of total protein, albumin, alanine aminotransferase, gamma glutamyltransferase, urea and creatinine. A prepatent period was observed at 5-6 days post-inoculation (p.i.) in the inoculated dogs, with cysts eliminated for approximately 3 months. No alterations were seen in the clinical parameters evaluated. Anemia was observed at 15 p.i. in the inoculated dogs. The mean eosinophil count of inoculated groups was higher than that of the control (p< or =0.05) but none of the biochemical parameters analyzed presented significant differences. The results of this study show that G. duodenalis from human isolates is able to infect dogs with minimal systemic manifestations without producing clinical signs of giardiasis.     

Effects of repeat fenbendazole treatment in dairy calves with giardiosis on cyst excretion, clinical signs and production

In this 90-day study, 60 male Holstein dairy calves were experimentally infected with Giardia duodenalis. Calves were randomly blocked by weight into treatment (N=30) and placebo (N=30) groups. Beginning on study Day 0, calves in the treatment group were administered an oral dose of 5mg/kg of fenbendazole once daily for three consecutive days. Calves in the placebo group received a daily oral treatment of 5 ml of saline for 3 days. These treatments were repeated on Days 30 and 60 of the study. Fecal samples were collected from calves once per week and examined for the presence of Giardia cysts. Calves were monitored daily for clinical signs of intestinal disease and all episodes of diarrhea recorded. Calves were weighed once per week and total feed intake, on a dry matter basis, was calculated daily. Following each treatment, the number of calves shedding Giardia cysts in the fenbendazole group was reduced (p<0.001) compared to the saline group. Also, calves in the fenbendazole group had fewer cysts (p<0.05) detected in their feces following treatment compared with calves that received saline. Within 2 weeks post treatment, the number of infected animals and fecal Giardia cysts returned to placebo levels. This pattern of reinfection was consistent after every treatment period. Calves receiving fenbendazole had fewer total days with diarrhea (p<0.01) and the average number of days each calf had diarrhea was reduced (p<0.05), compared to the placebo group. There were no differences in mean body weight, average daily gain, or feed intake between the treatment or placebo groups. This study demonstrates that fenbendazole is an effective treatment for giardiosis, resulting in a clinical benefit and reducing the number of infective cysts shed by calves. However, this treatment regime had no impact on production parameters and reinfection occurred rapidly in these calves.     

Anthelmintic efficacy of flubendazole paste against nematodes and cestodes in dogs and cats

Small dogs and cats, naturally infected with nematodes and cestodes, were used in a critical test under laboratory conditions to determine the palatability and efficacy of flubendazole as a past formulation. Subsequently, a control test in dogs was conducted under field conditions. A 4.4% past formulation was given at a dosage of 22 mg/kg of body weight once a day for 2 or 3 consecutive days. In a critical test in dogs, the efficacy against Toxocara canis was 97.4% after a 2-day administration and 100% after 3 days. Toxascaris leonina seemed to be the most susceptible worm species, since either 2 or 3 treatments were 100% active. The efficacy against Uncinaria stenocephala was 97.5% after 2 treatments; the same dose level for 3 days improved the efficacy to 100%. The efficacy was 100% for the removal of Trichuris vulpis after a daily dosage for 2 days and 96.7% after 3 days. One of 2 dogs infected with Taenia pisiformis was cleared of the infection after a 2-day treatment, and 3 of 4 dogs were cleared after a 3-day regimen. All cats were cleared of Toxocara cati after 2 or 3 days of treatment. One of 2 cats infected with Hydatigera taeniaeformis was cleared of the infection after a 2-day treatment; a 3-day treatment in 7 cats was 100% effective. The results in the laboratory test in dogs were confirmed under field conditions by a control test, based on the reduction of eggs per gram of feces count after treatment. The paste formulation was well accepted by all dogs and cats without any side effects.     

Treatment of giardiasis in adult Greyhounds, using ipronidazole-medicated water

Two of 3 adult Greyhounds with clinical signs of giardiasis were treated by the addition of ipronidazole hydrochloride to their water supply (126 mg/L) for 7 days. Within 15 hours, the dogs had improved clinically, and large numbers of degenerating Giardia cysts were passed. After 54 hours, cyst shedding had ceased. The nontreated control dog continued to shed Giardia cysts. During an additional 7 days, the dogs were treated with ipronidazole-medicated water (378 mg/L) and remained clinically normal.     

Prevalence and factors associated with fecal shedding of Giardia spp. in domestic cats

The prevalence of cats shedding Giardia cysts (13.6%) in the present study was found to be higher than previously reported (1% to 11%) and may reflect a higher sensitivity for the diagnostic test used. The presence of Cryptosporidium spp. oocysts, coccidial oocysts, and a clinical history of chronic (>2 weeks) gastrointestinal signs were significantly associated with the presence of Giardia spp. cysts in the feces. There were no associations between the presence of Giardia spp. cysts and type of housing, acute gastrointestinal signs, vomiting, gender, source of cat (i.e., animal shelter versus private breeder), or gastrointestinal parasites other than Cryptosporidium spp. and intestinal coccidial agents.     

Prevalence and infection pattern of naturally acquired giardiasis and cryptosporidiosis in range beef calves and their dams

The prevalence and infection pattern of naturally acquired giardiasis and cryptosporidiosis in 20 ranch raised beef calves and their dams from birth to weaning was determined. Rectal fecal samples were collected from calves at 3 days of age and weekly thereafter; cows' fecal samples were collected at the time of calving, 1 week later and four times during the summer grazing period. Blood samples were collected from the calves at 3 days of age to determine IgG(1) concentrations. Giardia lamblia cysts were shed by all 20 calves (100%) at some date during the duration of the study. However, only one calf (5%) shed Cryptosporidium parvum on two sample dates during the trial. Giardia cysts were first detected at 3.9+/-1.37 weeks of age with a range of 2-7 weeks of age. The geometric mean number of Giardia cysts in the calf feces increased from none at 1 week of age to a maximum of 2230 cysts/g of feces at 5 weeks of age and then decreased to 2 cysts/g at 25-27 weeks of age. Infection rate of calves shedding Giardia cysts peaked at 85% at 5 weeks of age and then decreased to 21% at 25-27 weeks of age. Giardia cysts, shed by calves peaked 1 week after initial shedding and decreased (P<0.05) for the remainder of the trial with the exception of week 3. There was a lower (P<0.05) percentage of calves shedding Giardia cysts weeks 3-10 and 15-25 compared to when shedding was first detected. All calves had complete or partial transfer of passive immunity as measured by IgG(1) levels. The rate of infection (15%) and the geometric mean number of Giardia cysts in the cows' feces (38.49 cysts/g) numerically increased at 1 week post-calving compared to levels at calving. The rate of infection (40%) numerically increased and the geometric mean number of Cryptosporidium andersoni oocysts in the cow feces (37.48 oocysts/g) increased (P<0.05) at 1 week post-calving and decreased to 0 at 13-16 weeks post-calving. This study is the first to document the cumulative prevalence and infection patterns of Giardia and Cryptosporidium in beef cattle under ranch conditions.     

Genotyping of Giardia intestinalis from domestic and wild animals in Japan using glutamete dehydrogenase gene sequencing

To determine the genotypes of Giardia intestinalis from domestic and wild animals in Japan, Giardia isolates obtained from feces of 24 dogs kept in households and breeding kennels, three companion cats, five dairy calves and three wild monkeys, Macaca fuscata, were genotyped using the 177 bp sequence of the glutamete dehydrogenase gene (gdh). The genotypes were assemblages A, C, D or A/D for dog isolates, Assemblage F for cat isolates, assemblages A or E for calf isolates and assemblage B for monkey isolates. This is the first report on the genotypes of Giardia isolates from cats, calves and wild monkeys in Japan.     

Number of Cryptosporidium parvum oocysts or Giardia spp cysts shed by dairy calves after natural infection

OBJECTIVE: To determine the total number of Cryptosporidium parvum oocysts and Giardia spp cysts shed by dairy calves during the period when they are most at risk after natural infection. ANIMALS: 478 calves naturally infected with C. parvum and 1,016 calves naturally infected with Giardia spp. PROCEDURE: Oocysts or cysts were enumerated from fecal specimens. Distribution of number of oocysts or cysts versus age was used to determine the best fitting mathematic function. Number of oocysts or cysts per gram of feces for a given duration of shedding was computed by determining the area under the curve. Total number of oocysts or cysts was calculated by taking the product of the resultant and the expected mass of feces. Results: Intensity of Cparvum oocyst shedding was best described by a second-order polynomial function. Shedding increased from 4 days of age, peaked at day 12, and then decreased. An infected 6-day-old calf would produce 3.89 x 10(10) oocysts until 12 days old. Pattern of shedding of Giardia spp cysts was best described by exponential functions. Intensity of shedding increased from 4 days of age, peaked at day 14, and then decreased. An infected calf would produce 3.8 x 10(7) cysts from day 50 until day 56. CONCLUSIONS AND CLINICAL RELEVANCE: The large number of oocysts and cysts shed indicates that shedding by dairy cattle poses a risk for susceptible calves and people. Estimates reported here may be useful to aid in designing cost-effective strategies to manage this risk.     

Survey and molecular characterization of Cryptosporidium and Giardia spp. in owned companion animal, dogs and cats, in Japan

Compared with other countries, surveys of these parasites have been rarely performed in companion animals of Japan in spite of their significance for public health. Here, we investigated pet dogs and cats in Japan for the first time, and genetically analyzed the isolates to evaluate the risk of zoonotic infections. Seventy-seven fecal samples were collected from privately owned dogs and 55 samples from owned cats in Osaka city, Japan. Cryptosporidium oocysts were identified in 3/77 dogs (3.9%) and 7/55 cats (12.7%), and Giardia infection in 2/77 dogs (2.6%) and 1/55 cats (1.8%). Amplification of the target regions for genotyping was successful, Cryptosporidium isolates in dogs and cats were identified as C. canis and C. felis, respectively, and those of Giardia in dogs and cats were G. intestinalis Assemblages D and F. The discharge period of the oocysts varied within 3-16 weeks and that of the cysts was 12 weeks. To date, zoonotic types of both parasites have been identified in other animals in Japan, and further large-scale studies are needed to determine the distribution of zoonotic genotypes in these animals, especially those closely associated with humans.     

Duration of naturally acquired giardiosis and cryptosporidiosis in dairy calves and their association with diarrhea

OBJECTIVE: To determine duration of infection and association of infection with diarrhea for dairy calves with naturally acquired cryptosporidiosis and giardiosis. DESIGN: Cohort study. ANIMALS: 20 Holstein calves on a single dairy farm. PROCEDURE: Fecal samples were collected 3 times/wk for the first 45 days after birth, then weekly until calves were 120 days old and examined for Giardia duodenalis cysts and Cryptosporidium parvum oocysts. Calves were monitored for diarrhea during the first 45 days after birth; during each episode of diarrhea, fecal samples were examined for parasitic, bacterial, and viral pathogens. RESULTS: All 20 calves shed Giardia cysts and Cryptosporidium oocysts at some time during the study. Mean ages at which Giardia cysts and Cryptosporidium oocysts were first detected were 31.5 and 16.3 days, respectively. Mean number of Giardia cysts in feces remained high throughout the study, whereas Cryptosporidium occysts decreased to low or undetectable numbers 2 weeks after infection. Eighteen calves had a total of 38 episodes of diarrhea during the first 45 days after birth. Giardia duodenalis was the only pathogen identified during 6 (16%) episodes, C parvum was the only pathogen identified during 9 (24%) episodes, and G duodenalis and C parvum were identified together during 10 (26%) episodes. CONCLUSIONS: Prevalences of giardiosis and cryptosporidiosis were high in these calves, and both parasites were associated with development of diarrhea. Cryptosporidium parvum was an important pathogen when calves were < 1 month old, but G duodenalis was more important when calves were older. Calves cleared C parvum infections within 2 weeks; however, G duodenalis infections became chronic in these calves.     

P‐56 Evaluation of the association between Giardia infection and pruritic skin disease in dogs

Intestinal parasites have been anecdotally associated with pruritus in dogs. A relationship was proposed when the elimination of a specific parasite resolved the pruritus, and re‐infection with a parasite caused the pruritus to recur. Ascarids, coccidia, hookworms, tapeworms and whipworms have all been incriminated. Recent reports in the human and veterinary literature have suggested that there may be a relationship between Giardia infection and the development of pruritus and other allergic signs. In order to determine if there is an association between infection with Giardia and pruritus in dogs, faecal samples were collected from 71 pruritic dogs and 101 clinically normal dogs. Three faecal samples from each animal were analysed using a zinc‐sulphate concentration technique for the presence of Giardia cysts, and one randomly selected faecal sample from each dog was analysed with an ELISA for Giardia‐specific antigen. Ten of 101 dogs (9.9%) in the clinically normal group tested positive with the ELISA, and Giardia cysts were detected in the faeces of seven of these antigen‐positive dogs. No Giardia cysts were found in the dogs that tested negative with the ELISA. None of the dogs in the pruritic group tested positive for Giardia by either method. The results indicated a negative association between Giardia infection and pruritic skin disease (P = 0.006). Cephalexin was commonly used in the pruritic group, but not in the control group, and may therefore be an explanatory variable. Funding: Ontario Veterinary College Pet Trust.