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1.
Prevalence of Cryptosporidium sp in equids in Louisiana   总被引：3，自引：0，他引：3  
In 1985, 22 pony foals reared in a helminth-free environment were tested daily for oocysts of Cryptosporidium sp by use of fecal flotation. Oocysts were found in all foals. Oocysts were first observed in feces collected from foals 9 to 28 days after birth. The mean period of oocyst shedding was 10 days and ranged from 2 to 18 days in individual foals. Diarrhea was observed in 14 of 22 (64%) foals and began before the period of oocyst shedding. Fecal samples also were examined for other infective agents. Salmonella poona was isolated from 1 foal that did not have diarrhea, and coronavirus particles were observed in the feces of 2 foals with diarrhea. Cryptosporidium sp oocysts also were observed in feces of 2 of 17 Thoroughbred foals, 3 of 14 Quarter Horse foals, and 3 of 26 pony foals reared on pastures with their dams. Samples from pasture-reared foals were collected at irregular intervals. Of the 11 Cryptosporidium-positive fecal samples collected from pastured foals, 2 were from foals with diarrhea. A similar survey was conducted during the 1986 foaling season, using the same procedures. Examination of 300 samples from 58 Quarter Horse, Arabian, and pony foals did not detect oocysts. Daily examination of feces from 10 pony foals reared under helminth-free conditions for 30 days also failed to detect Cryptosporidium oocysts.  相似文献   

2.
Twenty-eight foals whose dams were treated IM with ivermectin (200 micrograms/kg of body weight) on the day of parturition were compared with 35 foals whose dams were administered only the vehicle. The effect of ivermectin on the vertical transmission of Strongyloides westeri and foal heat diarrhea was determined by a comparison of results obtained in the 2 groups. Foals from treated mares had significantly fewer S westeri eggs per gram of feces from 17 to 28 days postpartum. There were no differences observed in the frequencies of severity of foal heat diarrhea between the treated and control groups. In another experiment, using the same foals, 32 foals were treated IM with ivermectin (200 micrograms/kg) at 21 days of age and were compared with 31 foals administered only the vehicle. Significantly fewer S westeri eggs were recovered from the ivermectin-treated foals on day 26 to day 32, the completion day of the trial.  相似文献   

3.
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4.
To date, little is known about the prevalence, genotypes and zoonotic potential of Cryptosporidium spp. affecting horses, especially in North America. A cross-sectional study was conducted in New York, USA between February 25th and May 1st 2009. Fecal samples were collected from three hundred and forty nine 1-10-week-old foals and their dams on 14 different broodmare farms. All fecal samples were screened for Cryptosporidium spp. using a direct immunofluorescence assay (DFA). DNA extraction and PCR-RFLP analysis of the small-subunit (SSU) rRNA gene were performed on all the foal samples. PCR-positive samples were subtyped by DNA sequencing of the 60-kDa glycoprotein (gp60) gene. On DFA, 13/175 (7.4%) foal samples and 3/174 (1.7%) mare samples were designated positive for Cryptosporidium spp., whereas on SSU rRNA-based PCR, 9/175 (5.1%) foal samples were positive. Cryptosporidium PCR-positive foals were significantly older (13-40 days, median age of 28 days) compared with negative foals (4-67 days, median 18 days, p=0.02). The number of foals with diarrhea or soft feces was not significantly different between positive and negative foals (p=0.09). PCR-RFLP analysis of the SSU rRNA gene and DNA sequencing of the gp60 gene identified the parasite as subtype VIaA14G2 of the horse genotype. This is the first report of a group of foals affected with the Cryptosporidium horse genotype, which has recently been detected in humans. As other contemporary molecular studies have identified C. parvum in foals, it seems that equine cryptosporidiosis should be considered a zoonosis.  相似文献   

5.
Rotavirus infection in foals   总被引：4，自引：0，他引：4  
Fecal samples from 86 foals with diarrhea were examined by electron microscopy during a 2.5 year period. Of these, 26 (30%) were positive for rotavirus. All of the cases were found in epizootic areas. The disease was produced in an experimental foal by inoculation via stomach tube of a bacteria-free fecal filtrate containing rotavirus. Examination of postmortem tissues from the duodenum and jejunum of 2 naturally infected foals and an experimentally infected foal revealed replicating virus in the intestinal epithelial cells. A limited survey of complement-fixing antibody to rotavirus in horses from Kentucky, Virginia, and France indicated that all horses had antibody to the virus. The sole exception was 1 foal from which blood samples were collected prior to suckling. These results were presumptive evidence that rotavirus is a major cause of diarrhea in foals, and the presence of antibody in horses from diverse areas is evidence for the ubiquitousness of this infection.  相似文献   

6.
During 1986, fecal specimens were collected 1 or more times from each of 164 horse foals (158 Thoroughbred and 6 mixed light horse type), ranging in age from 0 to 252 days, on 13 farms in central Kentucky. To detect natural infection with Eimeria leuckarti, feces were examined for oocysts. Oocysts were found in 67 (41%) of the foals on 11 (85%) of the farms. The earliest age at which oocysts were first detected was 15 days (1 foal); the latest age was 123 days (1 foal). The mean age for the first appearance of oocysts in the feces of the 67 foals positive for E leuckarti was approximately 70 days. Age of the oldest foal that passed oocysts was 185 days. The longest oocyst shedding period was about 4 months, although oocyst-positive feces usually were found only sporadically during this period.  相似文献   

7.
Rhodococcus equi strains of intermediate virulence (IMV) for mice possess a 20kDa protein designated Virulence Associated Protein B (VapB) and a virulence plasmid of 79-100kb, and can be recovered from the submaxillary lymph nodes of pigs. The pathogenicity of such R. equi strains for foals is unknown. In this study, two foals, 42 and 43 days of age, were infected intratracheally with 10(6) and 10(9) cells of R. equi IMV strain A5, respectively. The foal infected with 10(9) cells of strain A5 became clinically ill, with the onset of illness (pyrexia and depression) occurring 21 days after inoculation. R. equi was isolated from the feces and tracheal washings of the foal from 14 to 28 days after inoculation. The foal infected with 10(6) cells of A5 showed no clinical signs, and no R. equi was isolated from any of the samples of feces or tracheal washings during the 28 days of observation. Two foals of 45 and 50 days of age were infected with 10(5) or 10(6) of virulent R. equi ATCC 33701 having 15-17kDa surface proteins designated VapA. Both exhibited severe clinical signs (pyrexia, depression and anorexia) at 12 and 13 days after inoculation. Histopathological examination revealed that strain A5 caused focal granulomatous pneumonia in the foals. R. equi IMV strain A5 was isolated from lung lesions of both foals and from the contents of the intestinal tracts of the foal infected with 10(9) bacteria. These results suggest that IMV R. equi having VapB is less virulent than virulent R. equi having VapA in foals. This finding supports our previous results on the pathogenicities of R. equi strains having these virulence-associated antigens assessed by mouse pathogenicity tests.  相似文献   

8.
Effects of milk replacer composition and intake on the growth of orphan foals were evaluated. Twenty foals were assigned to four treatments: 1) mare-nursed, 2) commercial foal milk replacer at recommended intakes (standard), 3) commercial foal milk replacer at high intakes (high), and 4) acidified replacer at recommended intakes (acidified). Foals fed milk replacer diets were weaned at 12-24 hours postpartum and fed milk replacer for 50 days. Mare-nursed foals were weaned between 52 and 56 days of age. Foals fed replacer diets gained 12% to 28% less weight than mare-nursed foals up to two weeks of age. However, by four months of age, weights of replacer-fed foals were similar to those of mare-nursed foals and 32 other mare-nursed foals at the farm weaned between three and four months postparium. Foals drank 10 to 12 L/100 kg body weight (BW) in fluid replacer daily over the trial period. During the first week, high intake foals consumed 26% more replacer (p<0.05) than foals fed acidified or standard diets. This higher intake resulted in diarrhea earlier (6-11 days vs 11-22 days) and for a longer time (6.3 days vs 2.5-3.6 days) than in foals fed recommended amounts. Mare-nursed foals developed “foal heat scours” in the second week postpartum. After the first week, foals fed high replacer diet voluntarily consumed the same volume of fluid replacer as foals fed the standard intake. Foals ate less than 1 kg grain mix/100 kg BW daily to one month of age, then increased intake to 1.5-2 kg/ 100 kg BW to weaning. Water intake was 20-40% of daily fluid intake and was correlated (r = 0.85) to dry matter intake. Foals in the high intake group ate less (p<0.05) solid feed and drank less water than foals fed the standard and acidified diets. The foal's stomach capacity appears to limit meal size and thus replacer intake. If recommended feeding intervals are used, replacer intakes by foals are less than 15% BW daily. High volume intakes appeared to prolong diarrhea. Normal growth rates occur when replacer and good-quality feeds are fed concurrently.  相似文献   

9.
Background: Bacteremia in sick foals is associated with survival, but the association of bacteremia and diarrhea is not reported.
Hypothesis: Neonatal foals with diarrhea will commonly be bacteremic.
Animals: One hundred and thirty-three neonatal foals.
Methods: Records of all foals <30 days of age presenting with diarrhea between January 1990 and September 2007 were reviewed.
Results: Sixty-six of 133 foals (50%) were bacteremic at admission, with 75 isolates from the 66 samples. The blood culture from a further 18 foals (13.5%) grew coryneform bacteria. Nine foals (6.8%) had 2 or more organisms grown on blood culture. One foal had 5 different organisms, interpreted as contamination. Forty-eight foals (36%) had no growth on admission blood cultures. No cultures isolated fungal organisms. Excluding coryneform bacteria, 43 isolates (57%) were Gram-negative organisms and 32 isolates (43%) were Gram-positive organisms. The most common isolate was Enterococcus spp. (22 isolates, 29%), followed by Pantoea agglomerans (13 isolates, 17%). IgG concentration at admission was not associated with blood culture status. Blood culture status was not associated with survival to hospital discharge.
Conclusions and Clinical Importance: Bacteremia is common in neonatal foals with diarrhea. Decisions regarding antimicrobial selection should be made with these differences in mind.  相似文献   

10.
Cryptosporidiosis in two foals   总被引：2，自引：0，他引：2  
Cryptosporidium oocysts were identified by phase contrast microscopy on smears from flotations of greenish-yellow pasty feces obtained from two foals. One foal, a one week old Percheron was recumbent, anorectic and lethargic, believed to be the result of a septicemia of undetermined etiology. Despite therapy and nursing care the animal died. Using light and electron microscopy, numerous stages of Cryptosporidium sp. were seen protruding from the surface of epithelial cells of intestinal villi. The other foal, a six week old Arabian had a mild diarrhea. The diarrhea and passage of oocysts eventually ceased. Immunological tests on sera of both these foals provided no evidence of abnormal immune function. This report is the first to describe cryptosporidiosis in apparently immunocompetent horses.  相似文献   

11.
Background: Diarrhea is common in foals but there are no studies investigating the relative prevalence of common infectious agents in a population of hospitalized diarrheic foals.
Objectives: To determine the frequency of detection of infectious agents in a population of hospitalized foals with diarrhea and to determine if detection of specific pathogens is associated with age, outcome, or clinicopathologic data.
Animals: Two hundred and thirty-three foals ≤ 10 months of age with diarrhea examined at a referral institution.
Methods: Retrospective case series. Each foal was examined for Salmonella spp., viruses, Clostridium difficile toxins, Clostridium perfringens culture, C. perfringens enterotoxin, Cryptosporidium spp., and metazoan parasites in feces collected at admission or at the onset of diarrhea.
Results: At least 1 infectious agent was detected in 122 foals (55%). Rotavirus was most frequently detected (20%) followed by C. perfringens (18%), Salmonella spp. (12%), and C. difficile (5%). Foals < 1 month of age were significantly more likely to be positive for C. perfringens (odds ratio [OR] = 15, 95% confidence interval [CI] = 3.5–66) or to have negative fecal diagnostic results (OR = 3.0, 95% CI = 1.7–5.2) than older foals. Foals > 1 month of age were significantly more likely to have Salmonella spp. (OR = 2.6, 95% CI = 1.2–6.0), rotavirus (OR = 13.3, 95% CI = 5.3–33), and parasites (OR = 23, 95% CI = 3.1–185) detected compared with younger foals. Overall 191 of the 223 foals (87%) survived. The type of infectious agent identified in the feces or bacteremia was not significantly associated with survival.
Conclusions and Clinical Importance: In the population studied, foals with diarrhea had a good prognosis regardless of which infectious agent was identified in the feces.  相似文献   

12.
试验旨在探究断奶前马驹和母马粪便菌群多样性,为丰富此阶段马驹肠道菌群多样性提供依据。选取5匹5岁（2胎）、平均体重（453.34±54.23）kg、健康的纯血马母马,以及母马所生的5匹马驹,出生日期相近（±5 d）,平均体重（185.65±9.54）kg,3公2母。母马和马驹在相同环境下饲养,母马日粮组成及营养水平相同,马驹除哺乳外采食的粗饲料和精料补充料相同。马驹6月龄断奶,在断奶前1周用灭菌收粪袋采集母马和马驹的粪便样品。结果显示,母马粪便中菌群α多样性Chao1和ACE指数显著高于马驹（P < 0.05）,分别比马驹高18.94%和15.62%;母马与马驹共有的菌种数为1 399个,母马与马驹特有的菌种数分别为150和68个;在门水平,母马与马驹粪便中排在前十的菌分别是厚壁菌门、变形菌门、拟杆菌门、放线菌门、广古菌门、疣微菌门、螺旋体菌门、Unidentified_Bacteria、纤维杆菌门和无壁菌门,母马粪便中厚壁菌门丰度显著高于马驹（P < 0.05）;拟杆菌门母马比马驹高33.93%,差异不显著（P > 0.05）。由此可见,母马粪便菌群多样性显著高于断奶前马驹;母马与断奶前马驹粪便主要菌是厚壁菌门、拟杆菌门和变形菌门,母马粪便中厚壁菌门和拟杆菌门丰度均高于断奶前马驹。  相似文献   

13.
OBJECTIVE: To determine molecular characteristics of Clostridium difficile isolates from foals with diarrhea and identify clinical abnormalities in affected foals. DESIGN: Retrospective study. ANIMALS: 28 foals with C difficile-associated diarrhea. PROCEDURE: Toxigenicity, molecular fingerprinting, and antibiotic susceptibility patterns were determined. Information on signalment, clinical findings, results of clinicopathologic testing, whether antimicrobials had been administered prior to development of diarrhea, and outcome was obtained from the medical records. RESULTS: Twenty-three (82%) foals survived. Toxin A and B gene sequences were detected in isolates from 24 of 27 foals, whereas the toxin B gene alone was detected in the isolate from 1 foal. Results of an ELISA for toxin A were positive for fecal samples from only 8 of 20 (40%) foals. Ten of 23 (43%) isolates were resistant to metronidazole. Molecular fingerprinting revealed marked heterogeneity among isolates, except for the metronidazole-resistant isolates. Sixteen foals had tachypnea. Hematologic abnormalities were indicative of inflammation. Common serum biochemical abnormalities included metabolic acidosis, hyponatremia, hypocalcemia, azotemia, hypoproteinemia, hyperglycemia, and high enzyme activities. Passive transfer of maternal antibodies was adequate in all 12 foals evaluated. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that a large percentage of C difficile isolates from foals with diarrhea will have the toxin A and B gene sequences. Because of the possibility that isolates will be resistant to metronidazole, susceptibility testing is warranted. Clostridium difficile isolates from foals may have a substantial amount of molecular heterogeneity. Clinical and hematologic findings in affected foals are similar to those for foals with diarrhea caused by other pathogens.  相似文献   

14.
An enzyme-linked immunosorbent assay (ELISA) was used to diagnose Corynebacterium (Rhodococcus) equi infection in foals. In tests done with different antigen-extraction procedures (sodium dodecyl sulfate, sodium deoxycholate, polyoxy-ethylene [9] p-tert-octylphenol, polyoxy-ethylene [9-10] p-tert-octylphenol, sonification, homogenization, and heat treatment at 121 C), Tween 20 was a satisfactory reactive antigen. Using hyperimmune rabbit sera or infected foal sera, we investigated the specificity and the sensitivity of the ELISA with the Tween 20 antigen of the different serotypes or of the isolates. Corynebacterium equi strain ATCC 6939 antigen had the best activity for detecting antibodies to C equi in foals. Sera from 218 healthy horses, 11 healthy foals, 17 healthy newborn foals, a foal with suspected C equi infection, and 5 infected foals were evaluated for antibodies to C equi, using ELISA. The optical density values of 206 healthy horses, 17 healthy newborn foals, and 9 healthy foals were less than 0.1. Infected foal sera, except from foal 3, and serum from a foal with suspected C equi infection had higher optical density values. Using ELISA, specific antibodies against C equi were detected in a naturally infected 6-week-old foal after the foal had a rapid increase in the number of bacteria in the feces and after the initial development of clinical signs of illness at 5 weeks of age. Therefore, ELISA was useful for the early diagnosis of C equi infection in foals.  相似文献   

15.
Abdominal discomfort in the foal presents a diagnostic challenge, because the small size of the foal precludes rectal palpation. Standing lateral horizontal beam abdominal radiographs using conventional techniques were evaluated as a diagnostic aid to identify the presence and location of gastrointestinal disorders in foals presented with colic. Forty foals were radiographed prior to surgery (20 foals), necropsy (7 foals), or clinical diagnosis (13 foals). Clinical, surgical, or necropsy findings were then correlated to radiographic findings. Gastrointestinal disease was accurately identified on radiographs as the source of colic in 25 of 26 foals that had surgical or postmortem confirmation. The site of disease, whether gastric, small intestinal, large intestinal, or a combination, was accurately determined from radiographs. Standing lateral abdominal radiographs were determined to be a valuable diagnostic aid in the foal presented with colic.  相似文献   

16.
Two hundred and twelve Rhodococcus equi strains were isolated from soil, nasal and rectal swabs of horses and immunocompromised human patients in Hungary and serotyped using Prescott's serotyping system. One hundred and forty-seven strains (69.3%) belonged to serotype 1, 22 strains (10.4%) to serotype 2, 6 strains (2.8%) to serotype 3 and 1 strain (0.5%) to serotype 4. Serotypes 5, 6 and 7 were not found and 36 strains (17%) could not be typed. Serotype 1 (72%) was the type most commonly isolated from clinical samples of foals or from the soil of horse facilities. Six out of 8 R. equi strains from humans belonged to serotype 2, and two human strains were untypable. The data show that the prevalence of R. equi serotypes varies in different geographic areas of the country.  相似文献   

17.
Despite empirical clinical association of infection with Clostridium difficile with colitis in horses, a causal link has not been confirmed. The objective of this study was to develop a model of C. difficile-associated diarrhea in foals with normal transfer of passive immunity. Nine 1-day-old pony foals were inoculated intragastrically with spores or vegetative cells of C. difficile. Five foals were challenged with spores, with 2 receiving 10(5) colony-forming units (CFUs) and concurrently 3 receiving 10(7) CFUs once daily for 3 days. Clindamycin was administered orally to disrupt gastrointestinal flora. A further 4 foals were challenged by orogastric administration of 10(10) CFUs of vegetative cells once daily for 3 days or until diarrhea developed. This group did not receive clindamycin. Spore and vegetative cell preparations were negative for toxins of C. difficile and common enteropathogens. Clinical signs varied from mild abdominal discomfort and pasty feces to colic and watery diarrhea in 8 of 9 foals. Four of 5 foals challenged with spores developed mild diarrhea, whereas all foals challenged with vegetative cells developed moderate to severe diarrhea. C. difficile was isolated from feces of all foals between 24 and 72 hours after inoculation and toxins A or B or both were detected in the feces of all foals by an enzyme-linked immunosorbent assay. We concluded that spores and vegetative cells of C. difficile are capable of colonizing the gastrointestinal tract, producing toxins, and inducing clinical signs similar to those encountered in naturally occurring cases. This study fulfilled Koch's postulates for C. difficile-associated diarrhea in foals and provides a model for consistent reproduction of the disease for future studies.  相似文献   

18.
REASONS FOR PERFORMING STUDY: Anecdotal speculation suggests that prognosis for survival of mares and foals following correction of uterine torsion has improved over the past 30 years. OBJECTIVES: To determine statistically the outcome of uterine torsion according to duration of clinical signs, stage of gestation, parity, physical examination findings, method of correction, prognosis for survival and reproductive health of the mare, and prospects for the foal within the neonatal period. METHODS: This retrospective study combined cases from 4 equine referral hospitals. RESULTS: The stage of gestation at which uterine torsion occurred was a risk factor for survival of mare and foal. Overall mare survival was 53/63 (84%); when uterine torsion occurred at < 320 days gestation, 36/37 (97%) of mares survived compared to 17/26 (65%) survival rate when uterine torsion occurred at > or = 320 days gestation. Overall foal survival was 54% (29/54). When uterine torsion occurred at < 320 days gestation, 21/29 (72%) foals survived compared to 8/25 (32%) when uterine torsion occurred at > or = 320 days gestation. Thirty mares were discharged from the hospital carrying a viable fetus following uterine torsion correction and 25/30 (83%) of these mares delivered live foals that survived beyond the neonatal period. CONCLUSIONS: Prognosis for survival for mares and foals following uterine torsion is good and improves if torsion occurs < 320 days compared to > or = 320 days gestation. CLINICAL RELEVANCE: Gestational timing of uterine torsion should be considered when advising clients about the prognosis for survival of the mare and foal. The prognosis for a mare delivering a live foal is good if the mare is discharged from the hospital following uterine torsion correction with a viable fetus.  相似文献   

19.
Epidemiologic and etiologic data about diarrhea in foals were collected under a planned prospective recording and monitoring study. The survey and monitoring procedures included a survey to obtain an overview of current horse management practices on participating farms, a daily health record survey to obtain information on mares and their foals, and collection of feces from 19 of 144 diarrheic foals and 10 age-matched nondiarrheic foals for electron microscopy, ELISA for rotavirus, and bacteriologic culture. Coronavirus was detected in the feces of diarrheic as well as clinically normal foals. Rotavirus was detected in the feces of diarrheic foals only. With regard to agents found in the feces, there was no significant (P less than 0.05) difference between diarrheic and nondiarrheic foals. Half of the 297 foals on which data were available developed diarrhea. Most foals that developed diarrhea lacked other clinical manifestations of disease. Basic cleanliness at foaling was associated with a lower percentage of foals developing diarrhea. Prophylactic use of antibiotics and vitamins in newborn foals was associated with a higher percentage of foals developing diarrhea. A higher percentage of foals born to visiting mares developed diarrhea, compared with foals born to resident mares.  相似文献   

20.
OBJECTIVE: To determine whether foals with pneumonia that were treated with erythromycin, alone or in combination with rifampin or gentamicin, had a higher risk of developing adverse effects, compared with foals treated with trimethoprim-sulfamethoxazole (TMS), penicillin G procaine (PGP), or a combination of TMS and PGP (control foals). DESIGN: Retrospective study. ANIMALS: 143 foals < 240 days old. PROCEDURE: Information on age, sex, breed, primary drug treatment, total days of treatment with the primary drug, and whether the foal developed diarrhea, hyperthermia, or respiratory distress was obtained from the medical records. Relative risk (RR) and attributable risk (AR) were calculated to compare risk of adverse reactions between foals treated with erythromycin and control foals. RESULTS: Only 3 (4.3%) control foals developed diarrhea; none developed hyperthermia or respiratory distress. Foals treated with erythromycin had an 8-fold risk (RR, 8.3) of developing diarrhea, compared with control foals, and increased risks of hyperthermia (AR, 25%) and respiratory distress (AR, 15%). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that use of erythromycin to treat foals with pneumonia was associated with an increased risk of diarrhea, hyperthermia, and respiratory distress, compared with use of TMS or PGP.  相似文献   

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