Coccidia in sheep in South Australia

Faecal samples from 136 sheep from four different locations in South Australia were examined to determine the types and numbers of Eimeria spp. present. Coccidian oocysts were detected in 80% of the sheep and 11 different species of Eimeria were identified. The species detected (and their prevalence) were E. crandallis/E. weybridgensis (76%), E. ovina (55%), E. ovinoidalis (54%), E. granulosa (49%), E. parva/E. pallida (44%), E. intricata (37%), E. ahsata (31%), E. faurei (24%), and E. punctata (1%). No major differences were observed in the patterns of infection between the four locations examined. Faecal samples were also collected each month for a year from 48 lambs at two of the locations and oocyst counts were found to decrease markedly in all lambs after 6 months of age but to persist at low levels until the end of sampling at 17 months of age.     

Species of coccidia occurring in lambs in S?o Paulo State, Brazil.

The purpose of this experiment was to characterize the species of Eimeria affecting lambs and their infection pattern. Faecal samples were collected from each animal at 14-day intervals, beginning when lambs were 2 weeks old and ending when they were 32 weeks old. The oocysts were counted and identified as E. intricata, E. parva, E. pallida, E. crandallis, E. bakuensis, E. weybridgensis, E. ahsata and E. ovinoidalis. The highest oocyst counts were observed when the lambs were 4-8 weeks old.     

Eimeria infections of sheep in northwest Germany

To investigate the incidence of ovine Eimeria spp. and seasonal dynamics in oocyst output, fecal samples of sheep from three different management systems were collected monthly over a 1-year period and examined for oocysts. A total of 10 species of Eimeria were observed. The most frequent species were E. bakuensis, E. ovinoidalis, E. weybridgensis/crandallis, E. parva and E. ahsata whereas E. faurei, E. granulosa, E. intricata and E. pallida were found less often. Lambs passed larger numbers of oocysts in their feces than either ewes or yearlings.     

Pattern of Eimeria Oocyst Output and Repeatability in Naturally Infected Suckling Rhön Lambs

The faeces of 14 Rhön lambs were examined every second day between 7 and 99 days of age for the presence of Eimeria oocysts. Eimeria ahsata, E. bakuensis, E. faurei, E. granulosa, E. intricata, E.ovinoidalis, E. pallida, E. parva and E. crandallis/weybridgensis were identified. The predominant species were E. ovinoidalis, E. parva, E. crandallis/weybridgensis and E. bakuensis. Using a statistical model, the oocyst excretion rate was described as a sequence of periods with decreasing levels and varying length (‘excretion periods’) interrupted by intervals with no or very low oocyst counts. Several variables could be deduced from these two parameters, including the length of an excretion period and the maximum output during an excretion period. The estimated repeatability for oocyst counts for the different species ranged from 0.05 to 0.41. This result provides a starting point for possible genetic selection based on faecal oocyst counts of Rhön sheep for resistance to Eimeria infections.     

Lamb coccidiosis dynamics in different dairy production systems

The aim of this study was to investigate the spread of infection and population dynamics of ovine coccidosis under dairy sheep production systems in the Mediterranean area, taking into account differences between management systems, lambing season and climatic conditions. Data were collected from six (intensive and semi-intensive) dairy sheep flocks located either in the North or the South of Greece, with groups of lambs born during two consecutive lambing periods (autumn, spring) from each flock. Faecal consistency and oocyst excretion were recorded from faecal samples taken from 220 lambs in total, starting at days 7-9 after lambing and subsequently every 6 days for 5 times. Eleven Eimeria species including the highly abundant pathogenic E. ovinoidalis and E. crandallis were isolated. The onset of excretion was noted from 13 to 33 days after birth with a peak at 19-21 days. The cumulative incidence of infection per flock until the end of the study ranged from 64.29% to 100% during both lambing periods. A significant tendency for animals to get infected earlier during spring lambing was observed. This trend was even higher for lambs from farms located in the South and is possibly related to the higher contamination level of the farms after lambing during that time. Predominantly subclinical cases of coccidiosis were observed during the course of the study with a relatively low proportion of diarrhoeic faeces which did not significantly differ between the two rounds. Considering the significance of dairy sheep production in the area and the economic losses that can be caused by eimeriosis, monitoring of infection levels in the farms, taking into account the lambing period and environmental conditions, is highly recommended.     

Survey of Eimeria spp. oocysts in feces from Louisiana State University ewes.

The prevalence and identification of Eimeria spp. in the Louisiana State University ewe flock were determined from 109 fecal samples. Unsporulated oocysts were recovered from 94 of the samples and 1208 oocysts representing ten species of Eimeria were identified: E. ahsata, E. crandallis, E. Faurei, E. granulosa, E. intricata, E. ovina, E. ovinoidalis, E. pallida, E. parava and E. punctata. Eimeria ovinoidalis, which is probably the most pathogenic, was the species common to the most number of samples (59.6%); however, E. granulosa, which is non-pathogenic, was the most numerous species (23.7% of the total identified). The prevalence and identification of oocysts from ewes may be useful to evaluate infection potential when considering control programs, especially for lambs.     

Differentiation of Eimeria species infecting sheep during the grazing season on permanent and new pastures under Norwegian conditions

The total and differential oocyst counts of the different Eimeria species in the faeces of Norwegian ewes and lambs were investigated at weekly intervals during the grazing period on permanent and new pastures. The total oocyst counts of lambs on permanent pastures were significantly higher than those on new pastures 3–6 weeks after the beginning of the grazing period. This demonstrates that the oocysts had survived the winter in the pasture.Species differentiation indicated that E. ahsata, E. arlongi, E. crandallis, E. ninakohlyakimovae, E. faurei and E. parva are able to survive the winter in the pasture. E. crandallis occurred in the greatest numbers, and this species might be an important contributor to the clinical symptoms which are frequently observed in Norwegian lambs about 2–3 weeks after the beginning of the grazing period. There were on the other hand, indications that E. pallida has little ability to survive the winter in the pasture. The results were generally similar for most of the species during 2 successive years.The total number of oocysts in the faeces of ewes was low on new as well as on permanent pastures, and the species differentiation showed negligible differences. Consequently, it was concluded that the ewes could not be the source of the high oocyst numbers in lambs on the permanent pastures.     

Diversity and seasonal occurrence of Eimeria species in a mixed flock of communally reared sheep and goats in Mafikeng in the North West Province, South Africa

Diversity and seasonal occurrence of coccidia in a communally reared mixed flock of sheep and goats at Mafikeng, North West Province, South Africa, was determined between March 2008 and February 2009. Faecal specimens were collected directly from the rectum of the animals and the number of oocysts per gram of faeces (opg) determined. The mean monthly opg for goats was significantly higher than that for sheep. Higher oocyst counts were observed during the hot, rainy season than during the cold, dry season. The highest mean values for both the sheep (862.5 opg) and goats (1200 opg) were recorded during March. Six species (Eimeria crandallis, E. bakuensis, E. weybridgensis, E. ahsata, E. intricata, and E. ovinoidalis) were recovered from sheep, with E. crandallis and E. bakuensis occurring most frequently. The last 2 species, together with E. ahsata, are considered among the most pathogenic species in sheep. In goats, 7 species (E. arloingi, E. jolchijevi, E. caprina, E. alijevi, E. caprovina, E. christenseni and E. hirci) were recovered, with E. arloingi and E. jolchijevi occurring most frequently. Up to 5 Eimeria species were recovered from individual specimens in goats while up to 4 were recovered in sheep. No cross-infections between goats and sheep were recorded and no clinical coccidiosis was noted during the study. It is increasingly becoming evident that the pathogenic E. arloingi is one of the most commonly occurring Eimeria species in goats in South Africa.     

Naturally acquired coccidia infection in lambs in Otago

The development of a naturally acquired coccidia infection in lambs in Otago is described using data derived from faecal oocyst counts and specific differentiation of the oocysts. Oocysts first appeared in faeces of lambs 19–37 days after birth. Oocyst production reached a mean peak of 250 000 oocysts per gram when lambs were 40–50 days old and slowly declined with increasing age of lambs. Coccidial infections did not appear to have any obvious effect on weight gain. The numerically most numerous species of coccidia were Eimeria ovina, E. crandallis, E. ninakohlyakimovae, E. parva and E. weybridgensis.     

Ovine coccidiosis: heavy infection in young lambs increases resistance without causing disease

Seven groups of twin lambs, kept with their dams on pasture, were given single oral inoculations of 10,000 oocysts of Eimeria ovinoidalis and 10,000 E crandallis at one, two, four, seven, 14, 21 or 28 days after birth, respectively. All were then challenged with 100,000 of each species at 42 days of age. An eighth group was challenged without having received the earlier 'immunising' inoculum, and a ninth group was not inoculated at all. Bodyweights, faecal consistency, oocyst output, and serum coccidial antibody levels were monitored up to 12 weeks of age. No clinical response was detected to inoculation up to four days of age. Loosening of faeces and a slight setback in weight-gain occurred in lambs inoculated seven, 14 and 21 days after birth; inoculation 28 days after birth caused severe diarrhoea and weight loss. Challenge at 42 days caused severe coccidiosis with 50 per cent mortality in the 'unimmunised' group. In those that had received 'immunising' inoculations, the challenge at 42 days caused some diarrhoea and some weight loss, but much less than in the 'unimmunised' lambs. The later the 'immunisation', the less severe was the disease attributable to the challenge at 42 days. Serum antibody levels correlated fairly closely with resistance to the disease. It was concluded that very young lambs were resistant to the pathogenic effects of some coccidia, but were able to respond to them immunologically.     

Dose-response effects of diclazuril against pathogenic species of ovine coccidia and the development of protective immunity

Twin lambs at pasture with their ewes, were divided into seven groups of 10 lambs. One group of 10 lambs served as a non-infected, untreated control. Five groups of 10 lambs were infected with 10,000 oocysts of Eimeria crandallis and 10,000 oocysts of Eimeria ovinoidalis when they were 3 weeks old (day 21 of the study). This produced a good level of infection with high oocysts production and diarrhoea in the lambs. Fourteen days after the primary, artificial challenge (day 35) four of these groups were treated with oral diclazuril at 0.25, 1.0, 2.0 or 4.0mg/kg. Diclazuril treatment was highly effective, dramatically reducing symptoms of diarrhoea and reducing faecal oocyst output by 79.7%, 97.3%, 99.4% and 99.5% respectively in the treated groups within four days. Two weeks post-treatment, and 28 days after the primary coccidial challenge (day 49 of the study), five groups of lambs were re-challenged with 100,000 oocysts of E. crandallis and 100,000 oocysts of E. ovinoidalis (secondary challenge). A group of lambs which had received neither the primary coccidia infection, nor drug treatment (susceptible controls) were also given the secondary challenge. All lambs given the secondary challenge produced high numbers of coccidia and exhibited varying degrees of diarrhoeic faeces. The lambs, which had previously received the higher doses of diclazuril at 2.0 and 4.0mg/kg, developed clinical signs of coccidiosis. These lambs were completely susceptible despite having received the early primary immunising infection of coccidia on day 21. The effects of the secondary challenge were more severe in the groups dosed with the two highest levels of diclazuril than in the susceptible control lambs, which had presumably been exposed to continued low levels of pasture contamination and had acquired a limited degree of immunity from this exposure. It would appear that treatment at the higher dose levels not only eliminated most of the oocysts from the primary challenge but also adventitious infection derived from the grazing paddocks. In contrast, lambs which had received the two lower drug levels of diclazuril (0.25 and 1.0mg/kg) whilst producing large numbers of oocysts, had only transient diarrhoea following secondary challenge. It was concluded that when used as a metaphylactic treatment, diclazuril works rapidly and is effective within four days of administration. Overall, a single dose of diclazuril at either 0.25-1.0mg/kg appears to be highly effective in the control of coccidiosis in young lambs at pasture whilst allowing the development of protective immunity against subsequent heavy coccidia challenge.     

Ovine coccidia in Papua New Guinea

Eimeria oocysts were found in 89% of fecal samples collected from the rectum of 75 sheep from 3 locations in Papua New Guinea. Eighty five percent of the hosts which were positive for coccidia had multiple infections with up to 6 different species of Eimeria. In order of decreasing predominance in the 67 Eimeria-positive samples the species were: E. ovina (72%); E. parva (58%); E. ovinoidalis (48%); E. ahsata (45%); E. crandallis (39%); E. faurei (28%); E. intricata (24%); E. granulosa (4%). Fecal oocyst counts showed the highest mean of 1252 oocysts per gram (o.p.g.) for E. parva and a maximum of 8000 for E. ovina.     

绵羊球虫感染情况和种类调查

应用饱和蔗糖溶液漂浮法对河南、山东和东北等地的1052只绵羊球虫感染情况及种类进行了调查,结果表明球虫总感染率为94.8%,对968份阳性样本中的球虫卵囊进行形态学鉴定,共检出12种艾美耳球虫,分别为阿撒他艾美耳球虫、巴库艾美耳球虫、小型艾美耳球虫、贡氏艾美耳球虫、类绵羊艾美耳球虫、颗粒艾美耳球虫、苍白艾美耳球虫、马耳西卡艾美耳球虫、温布里吉艾美耳球虫、错乱艾美耳球虫、槌形艾美耳球虫和浮氏艾美耳球虫。调查结果发现绵羊最多可同时感染9种球虫,多数为2~5种,混合感染率为71.8%;1岁以下和1岁以上绵羊球虫感染率分别为99.4%和86.0%,平均OPG值分别为7907.36和3263.89;舍饲和放牧绵羊球虫感染率分别为97.0%和89.0%;夏、秋季为球虫主要流行季节。     

Eimeria infections in cows in the periparturient phase and their calves: oocyst excretion and levels of specific serum and colostrum antibodies.

Faecal Eimeria oocyst excretion and levels of antibodies to first generation merozoite antigen of E. bovis in sera and colostra were followed in 86 and 70 cow-calf pairs in northern (group EF) and central Germany (group H), respectively, over periods of 3 weeks before to 3 weeks after calving in cows and from birth to an age of 63 days in calves. Oocysts were found in 30 and 7.7% of cows in groups EF and H, respectively. They belonged to 10 (group EF) and four Eimeria spp. (group H) with E. bovis, E. ellipsoidalis, E. auburnensis and E. zuerni as the most frequently occurring species. Prevalence and intensity of oocyst excretion varied with time resulting in peak values around the date of parturition, particularly in the case of E. bovis. Peak values at the time of parturition were also seen in case of strongyle egg excretion. Seven (group H) and nine Eimeria spp. (group EF) were found in the calves. The predominant species E. ellipsoidalis, E. zuerni, E. bovis and E. auburnensis were detected for the first time earlier after birth (3-5 weeks) than the others. The prevalence of Eimeria infections increased to 67.1% (group EF) and 50.1% (group H) 9 weeks after birth. Specific IgM and IgA antibody levels (the latter only determined in group EF) in cow sera remained almost constant throughout the observation period, whereas IgG(1) and IgG(2) levels were reduced at the time of parturition. Levels of specific antibodies in sera and colostra were significantly correlated. Except IgM antibodies, significant inverse correlations were found in cows between intensity of infection with E. bovis and specific serum IgG (group H) and IgG(2) (group EF) antibodies. Antibodies to E. bovis were detected in calves sera only after colostrum intake with significant correlations between levels in calves sera and colostra. Levels decreased, starting within the first week of life (most conspicuously in case of IgM and IgA) until the third week. Subsequently, but except IgG(1) antibody concentrations increased until the end of the observation period. Interrelations between antibody levels and the total amount of E. bovis oocysts excreted by the calves until the ninth week of life varied with the age of the animals. Inverse relationships in the first 3 weeks of life as suggested by negative correlation coefficients could not be proven statistically. Thus, there is no unambiguous proof for immunoprotection of calves against E. bovis via maternal immunity. Considering antibody levels in the 3-9 weeks old calves significant direct correlations with E. bovis oocyst excretion were found in case of IgM, IgG(2) and IgA, reflecting an active immune response of young calves to coccidial infection.     

Interaction between coccidia and Nematodirus battus in lambs on pasture

Five thousand oocysts of each of two species of coccidia, Eimeria crandallis and E ovinoidalis or 30,000 infective larvae of Nematodirus battus, given as single infections to three- to five-week-old lambs, caused only transient diarrhoea and had no effect on growth. Lambs infected first with coccidia and two weeks later with N battus suffered severe diarrhoea, weight loss and some deaths. Simultaneous administration of the coccidia and the nematodes increased the clinical severity of the syndrome and increased the numbers of nematode eggs produced.     

Demonstration of antibodies to Eimeria species in lambs by an enzyme-linked immunosorbent assay

Soluble extracts were prepared from sporulated oocysts, unsporulated oocysts and merozoites of Eimeria crandallis, E faurei and E ovinoidalis. They were assessed for antigenicity and specificity by ELISA using rabbit antisera to sporulated oocysts or merozoites. Antibody levels were examined in sera from colostrum-deprived coccidia-free lambs, conventionally reared lambs and lambs which had received experimental infections. Maternal antibody was demonstrated in colostrum and in serum taken at 24 hours from all conventionally reared animals but not colostrum-deprived animals. Antibody levels in conventional animals dropped over the first five weeks of life and rose again during the next five weeks. Antibody was not detected in coccidia-free animals. Monospecific infections of E faurei or E ovinoidalis demonstrated antibody responses to primary and secondary infections. Some specificity of response was suggested with E faurei infection. The antigen preparations showed considerable cross-reactions between species. These serum antibody responses, although appearing too late for individual diagnosis, may assist diagnosis on a flock basis.     

The Prevalence of Coccidian Species in Sheep in Kars Province of Turkey

Coccidia were detected in the faeces of 556 out of 592 sheep (93.9%) in sheep in Kars province. The prevalence of coccidiosis was significantly higher (p>0.01) in young (97.9%) and immature sheep (96.6%) than in adult sheep (90.2%). Mixed infections were widespread (71.5%). Ten species of Eimeria were recognized. These species (and their prevalences) were: Eimeria ovinoidalis (47.7%), E. bakuensis (E. ovina) (46.6%), E. parva (37.1%), E. granulosa (27.7%), E. ahsata (23.4%), E. pallida (23.2%), E. faurei (15.1%), E. intricata (13.9%), E. crandallis (13.7%) and E. punctata (2.3%). Eimeria punctata is reported in sheep from Turkey for the first time. The mean oocyst count from infected animals was 3451±409 opg (range 50–117 600). The mean was higher (9529±502) in young sheep. Differences in the counts from young, immature and adult sheep were statistically significant (p>0.01). However, no clinical cases of coccidiosis were encountered.     

The coccidia of sheep and goats in Senegal

A survey of the coccidia in domestic sheep and goats was undertaken to ascertain the type of Eimeria species and the number of different coccidial species in individual faecal samples. Simultaneously the prevalence and the oocyst output was investigated in 2234 sheep and 577 goats during a 12-month period. Eight Eimeria species were encountered in sheep: E. ahsata, E. crandallis, E. faurei, E. intricata, E. ovina, E. ovinoidalis, E. pallida and E. parva.

In goats the following species were found: E. ahsata, E. arloingi, E. christenseni, E. crandallis, E. faurei, E. intricata, E. ninakohlyakimovae and E. parva.

The prevalence in sheep was 94% and in goats 85%, multiple parasitism was the rule. No seasonal fluctuation was observed in the prevalence or oocyst output. The sheep and goats' oocyst output was moderate, the mean for both being in the range of 1000–5000 oocysts/g of faeces.     

Oocyst Counts in Crossbred Ewes under Tree-Crop Plantation in the Forest Zone of Ghana

In this paper, the Eimeria oocyst output of two groups, pregnant ewes (group 1) and non-pregnant controls (group 2), which were followed from September 1993 to August 1994, is described. In both groups of animals the level of oocyst output was high during the minor rainy season. However, during the periparturient period the pregnant ewes showed the higher oocyst output. The oocyst output in both groups fell to similar levels after weaning of the lambs in March 1994. The species of Eimeria identified in order of dominance were Eimeria parva, E. pallida, E. faurei, E. ahsata, E. ovina, E. intricata, E. granulosa and E. ninakohlyakimovae. There were no differences in the species composition of oocysts in both groups of animals.     

Endoparasites in calves of beef cattle herds: management systems dependent and genetic influences

Prevalences and intensities of excretion of faecal stages of Giardia duodenalis, Cryptosporidium parvum, Eimeria spp., Strongyloides papillosus and strongyles were determined in a German upland area in German Angus (GA) and German Simmental (GS) suckler of beef cattle herds covering two winter housing periods and the grazing season between them. Influences of the housing systems applied (maintenance on deep litter with (DL+) and without run-out (DL--), on slatted floor (SF) or by winter run-out yarding (WO)), breed differences and genetic influences by the sire were determined by statistical analyses; levels of IgG antibodies to E. bovis antigen were measured by ELISA. G. duodenalis was observed with a maximum prevalence of 38% in 4 weeks old calves, a cumulative incidence of 58% 9 weeks after birth and with generally low intensities. C. parvum infections were relatively rare with cumulative incidences of 20--25% in week 5 after birth. Highest prevalences were associated with housing system DL-- and a long-lasting calving period. Cumulative incidence of Eimeria spp. was almost 100%. E. bovis predominated by far followed by E. ellipsoidalis/zuernii. Mean maximum intensity of 1000 OpG occurred in week 7 after birth. Up to an age of the calves of 7 weeks >75% of all oocysts belonged to E. bovis. Prevalences and excretion intensities were lowest under the housing conditions SF and WO. Maternal antibodies in calves to E. bovis antigen were directly and inversely correlated with mean OpG values in GA and GS calves, respectively. S. papillosus was common with a cumulative incidence of 53% 9 weeks after birth and occurred independent of the housing system. Mean strongyle egg prevalence was 50% with 50--100 EpG by means throughout the grazing season. Egg excretion intensity in the early months of grazings was correlated with the age of the calves at turnout to pasture. Under the conditions of housing system DL-- GA calves could better control S. papillosus infections than GS calves whereas the latter were generally more effective in controlling the protozoa. Results of ANCOVA suggest significant paternal influences on S. papillosus infections in both breeds and on the protozoal infections in GA calves. The former could be disclosed independent of the housing system whereas environmental factors played an important role in the latter cases.