Coccidiosis

A commercial dog breeding unit experienced problems with acute diarrhoea, often haemorrhagic, in young German Shepherd Dog litters. No aetiologic diagnosis had been made. In order to determine whether coccidial infections were implicated, a survey was conducted to ascertain shedding of oocysts by dams, acquisition of coccidial infection by neonatal pups and to determine whether bouts of diarrhoea were associated with peak oocyst production. Oocysts of Isospora canis and I. burrowsi/I. ohioenis were recovered from 26.0% of faecal specimens from bitches and from 51.7% of similar specimens from litters. No association between shedding of oocysts by bitches and their litters could be demonstrated, nor was there consistent association between bouts of diarrhoea and peaks of oocyst shedding.

Hemograms and acute-phase proteins in adult male New Zealand White rabbits that had been experimentally infected orally with sporulated oocysts of Eimeria stiedai were evaluated over a 28-day period. Fifty animals were used, divided into two groups: group A infected with 1 × 10(4) sporulated oocysts of E. stiedai and group B inoculated with distilled water. On the seventh day after infection, the infected animals presented anemia and leukocytosis with neutrophilia and monocytosis. Protein fractionation by means of electrophoresis identified 19 acute-phase proteins with molecular weights ranging from 24 to 238 kD. Ceruloplasmin, transferrin and haptoglobin showed high levels on the seventh day after infection, with gradual increases in their concentrations until the end of the experimental period. Thus, from the data of the present study, E. stiedai is considered to be a pyogenic etiological agent for which the infection level can be monitored through the leukocyte count and serum co...

Five different species of Eimeria viz. E. acervulina, E. maxima, E. necatrix, E. tenella and E. brunetti were identified. The highest percentage (50%) was found with mixed infection. Specieswise infection with E. tenella was recorded in the present study. Monthwise highest prevalence ...

Bovine besnoitiosis, caused by the apicomplexan parasite Besnoitia besnoiti is considered an emergent disease in Europe. This study aimed to determine the prevalence and geographic distribution of B. besnoiti in cattle herds in continental Portugal and to identify potential spatial clustering of infection. A stratified two-stage cross-sectional serological survey was carried out between March 2012 and May 2013 with the five administrative NUTS II regions, Norte, Centro, Lisboa, Alentejo, and Algarve, as the stratification level. Sera from 391 herds in 220 parishes and 83 municipalities were analyzed by a serial testing strategy, with the modified agglutination test (B-MAT) as the first screening assay and the immunofluorescent antibody test (IFAT) as the confirmatory test. Within-herd prevalence of positive herds varied between 0.7 and 72.4% and was ≥10.3% in half of the infected herds. Using a Bayesian approach, the true prevalence of B. besnoiti in cattle herds was determined to be 5.1% (confidence interval (CI), 3.1-7.8%) and the mean within-herd prevalence of positive herds was 33.0% (CI, 20.3-46.0%). The sensitivity and specificity of the B-MAT were estimated to be 96.9% (CI, 93.7-98.8 %) and 99.7% (CI, 99.6-99.8%), whereas those of the IFAT were 89.6% (CI, 86.0-92.5%) and 99.7% (CI, 98.5-99.9%), respectively. Spatial scan statistics analysis identified one spatial cluster covering the majority of the Alentejo region. Seropositive herds were detected for the first time outside Alentejo, in the region Centro and in the northeast of Portugal. Further epidemiological research is needed to identify eco-biological factors, which could explain the geographic clustering of B. besnoiti in Portugal.

In this clinical case report, winter coccidiosis was aimed to present in a six months old calf. The material of this case was one of the diarrheic calves brought to the Clinic of Internal Medicine unit of Veterinary Faculty of Kafkas University from a farm in which two of the calves had died. At the clinical and parasitological examination of the calf, it was diagnosed that peracute coccidiosis caused by Eimeria zuernii. The number of oocysts per gram of faeces (OPG) was determined as 78.000. Oocysts were composed of 95% E. zuernii and 5 % E. bovis. This case occurred in winter season was described as ‘winter coccidiosis’. Sulpamezathine and supportive therapy were used for treatment of the case and recovery was observed. As a result, the cases of peracute coccidiosis in calves naturally infected by E. zuernii should be considered in winter.

For the assessment of coccidial oocyst production by chickens, some modified form of the McMaster counting method is commonly used. The objective of this study was to evaluate a standard method and to compare it to a new, faster method, in which all the preparative stages before counting are carried out in the same container into which the original faecal sample was collected. A stock suspension containing purified oocysts of all seven valid Eimeria species that parasitize chickens was prepared, from which seven concentrations of oocyst suspensions were made. Since the faecal material in a sample influences the ability of oocysts to float up in a McMaster chamber, the new method was tested to establish the optimal amount of faeces in the original sample. Control oocyst suspensions containing no faeces were also tested, and three series of counts using the new method were compared with the standard McMaster method. The results were statistically analysed by agreement analysis. Repeatability and between-operator variation of both methods were also tested by agreement analysis. Counting by the standard McMaster method underestimated the true number of oocysts. The new method gave counts in agreement with the true number of oocysts if using 1 g of faeces per sample. With 2 g of faeces, counts were obtained that agreed with counts by the standard McMaster method. Both methods showed agreement between repeated measurements. The new method used on a sample containing 2 g of faeces provides a convenient alternative to the standard modified McMaster method. A 1-g faecal sample increases agreement with the true numbers of oocysts. Processing of a sample with the new method is about nine times faster than with the standard method.

Coccidiosis is the most predominant parasitic disease affecting Japanese quails (Coturnix coturnix japonica) in commercial farms. Coccidiosis as a subclinical infection is difficult to diagnose without parasitological examinations. Oocysts of two Eimeria species, E. bateri and E. tsunodai, were determined in the analysed quail flock. Infected birds were administered Baycox 2.5% at the dose of: group I--7 mg toltrazuril/kg BW per day provided in drinking water (1.5 ml/0.5 1 H2O) that was available 24 h for 2 days, group II--14 mg/kg BW (3 ml/0.5 1 H2O), and group III-- 24.5 mg/kg BW (5 ml/0.5 1 H2O); in groups II and III, the solutions were available 8 h/24 h for 2 days. After the first day of the treatment, the number of excreted oocysts (OPG - oocysts per gram) increased, a steady decrease in oocyst counts began on the second day of Baycox administration and lasted until a three-day period when no oocyst were determined in faecal samples. Regardless of the dose applied, toltrazuril...

The influence of the major histocompatibility (B) complex on acquired immunity to the avian coccidium Eimeria tenella was studied in 217 F4 segregants (B 2B 2, B 2B 5, B 5B 5) of a cross between inbred lines 61 (B 2B 2) and 151 (B 5B 5) and segregating haplotype combinations of UNH105 (B 23B 23B 23B 24, B 24B 24), a noninbred line of New Hampshire chickens. Chickens were immunized at 6 weeks of age with 500 oocysts daily for 5 days, then challenged 14 days later with 10000 oocysts. Responses to infection were evaluated by cecal lesion scores, body weight gain, delayed wattle reaction (DWR), and spleen weight. The F4 segregants of genotypes B 2B 5 and B 5B 5 exhibited greater immunity to challenge than B 2B 2 chickens. B 5B 5 chickens showed a significantly greater DWR following immunization and larger spleens 6 days after the challenge than either of the other genotypes. However, both BIBS and B 5B 5 chickens demonstrated significantly lower lesion scores than B 2B 2 chickens. There were no significant differences in weight gain among these genotypes. Among 139 line UNH105 segregants, B 23B 23 hosts had significantly lower lesion scores than B 24B 24 chickens. No other differences in immune response among line UNH105 genotypes were detected.

The aim of this study was to investigate, under conditions similar to commercial broiler production, the effect of the herbal extract blend (HE) at a quantity of 1g per kg feed (200 mg respectively of herbal extract, Allium sativum, Salvia officinalis, Echinacea purpurea, Thymus vulgaris and Origanum vulgare), used individually or in combination with mannan oligosaccharide (MOS; 1g per kg feed) or chitosan (3ml containing 2% deacetylated chitin per kg feed) on the performance parameters of broiler chickens, the results of the slaughter analysis, litter moisture and the number of oocysts excreted in feces. The experiment was conducted on 4,500 broiler chickens of both sexes kept in straw-bedded pens. Chickens were randomly assigned to 5 experimental treatments with 5 replicates (pens) of 180 birds. The experimental design included negative and positive (diclazuril, 1 mg per kg feed) control groups. The examined herbal extract blend used individually during natural exposure to the coccidia improved, compared to the negative control diet, the performance parameters to a greater extent than coccidiostat, lowered the litter moisture content and reduced the oocyst output. Combined dietary supplementation with a herbal extract blend of chitosan or mannan oligosaccharide did not result in further improvement.

Mice recovering from a primary infection with an intestinal protozoan parasite, Eimeria falciformis (Apicomplexa: Eimeriidae), showed a classic delayed-type hypersensitivity (DTH) reaction to oocyst antigen challenge. This reaction was characterized by a biphasic pattern of footpad swelling. The first swelling peaked at 2 h after antigen challenge, whereas the second swelling peaked at 24 to 48 h after challenge. The DTH reaction was transferable with a T-cell-enriched spleen cell population from mice that had recovered from E. falciformis infection. Cytotoxic depletion of immune T cells with anti-L3T4 antibody and complement abrogated DTH transfer, indicating that L3T4-positive T cells were required. A T-cell-enriched spleen cell population from acutely infected mice suppressed the transfer of DTH with immune cells from recovered animals, implicating the existence of infection-induced immunoregulatory cells controlling the parasite-specific immune response during infection. Immune ...

Isospora suis ist ein einzelliger Parasit des Schweins und der Erreger der Saugferkelkokzidiose. Diese Erkrankung zeigt eine hohe Morbidität in betroffenen Ferkelzuchtbetrieben und ist damit ein wichtiger wirtschaftlicher Faktor in der Schweineproduktion. Im Verlauf der Infektion wird die Schleimhaut des Dünndarmepithels in Jejunum und Ileum stark geschädigt, was zu charakteristischen unblutigen Durchfällen führt. Eine Folge der reduzierten Nährstoffaufnahme im so geschädigten Dünndarm sind verminderte Absetzgewichte und ein starkes Auseinanderwachsen der Würfe, zusätzlich können Sekundärinfektionen mit anderen Darmpathogenen die Mortalitätsrate erhöhen. Trotz der wirtschaftlichen und veterinärmedizinischen Bedeutung der Saugferkelkokzidiose sind die Interaktionen zwischen Wirt und Parasit bislang nur unzureichend aufgeklärt. Dieser Übersichtsartikel befasst sich mit dem Lebenszyklus von I. suis und den klinischen und parasitologischen Charakteristika der Saugferkelkokzidiose. Weiters werden verschiedene Modelle der experimentellen Infektion und etablierte in vitro-Methoden zur Erforschung von I. suis vorgestellt. Er gibt einen Überblick über die natürliche Altersresistenz gegen Infektionen mit I. suis, die Immunantwort verschiedener Wirte bei anderen Kokzidieninfektionen (Eimeria spp., Cryptosporidium muris) und eine Zusammenfassung der Besonderheiten des Immunsystems des Schweins und seiner Entwicklung in den ersten Lebenswochen. Isospora suis, an intestinal protozoan parasite of swine, is the causative agent of neonatal coccidiosis, a disease with high morbidity in affected pig-breeding units and consequently of high economic importance. Infection leads to damage of the mucosal surface in the jejunum and ileum and to non-haemorrhagic diarrhoea. As a result, weight gain of piglets is reduced and secondary infections with other enteric pathogens may lead to increased mortality. Despite its economic and veterinary importance, host-parasite interactions are still poorly understood. To examine these interactions experimental infection models are established using outbred piglets infected with defined numbers of parasites on different days of life. This review discusses the life cycle of Isospora suis and the clinical and parasitological characteristics of porcine neonatal coccidiosis including pathology, and compare the different experimental infection models and the tools for studying Isospora suis in vitro. Moreover, it summarises findings about natural age resistance of pigs against infections with Isospora suis, our current knowledge about immune response to other coccidial infections, e.g. with Eimeria spp. in different hosts, and gives a short overview on peculiarities of the porcine immune system and its development in young animals which may play a role in porcine coccidiosis.

Polyclonal anti-idiotype 1073 (anti-Id 1073), raised against a monoclonal antibody specific for the protective epitope(s) of Eimeria tenella sporozoites, induced cell-mediated immune (CMI) responses in bursectomized chickens. Whereas alhydrogel-adsorbed anti-Id 1073 was sufficient to engender the CMI response at 4 h after injection, induction of the CMI response at 24 h required both alhydrogel and muramyl dipeptide sterol. Exposure of immunized chickens to live parasites prompted a dichotomous effect on the CMI response engendered by anti-Id in that the 4-h CMI response was preferentially stimulated and the 24-h CMI response was down regulated. Both types of CMI response were transferable to naive chickens by T cells from anti-Id 1073 immune donors or by parasite-specific T cells from clones 21 and 27. These T-cell clones were generated from chickens immunized by repeated infections with E. tenella and showed in vitro proliferative responses to anti-Id 1073. The abilities of T cell...

There has been growing interest in the development of natural methods of coccidiosis prophylaxis. Vaccination against coccidiosis with live oocysts is regarded as effective in the control of avian coccidiosis, but in some conditions, such as poor sanitary management or incorrect application of the vaccine, may lead to poorer performance, measured as reduced weight gain and feed efficiency, in comparison with prophylactically medicated birds. Such reports are the reason for widespread reluctance to use anticoccidial vaccine in broilers. This paper reviews broiler studies in which nutritional methods as performance and/or immune-supporting factor with regard to anticoccidial vaccination, were investigated. The results of some of the studies presented in the article indicate that feed additives with immunostimulating properties, along with proper protein levels in the diet, may have a beneficial effect in cocci-vaccinated broilers.

The aim of the experiment was to evaluate the anticoccidial efficacy of supplementing feeds with herbal extract blend containing garlic (Allium sativum), sage (Salvia officinalis), echinacea (Echinacea purpurea), thyme (Thymus vulgaris) and oregano (Origanum vulgare) extracts in broiler chickens experimentally infected with 170.000 sporulated oocysts of Eimeria acervulina, E. tenella, E. maxima and E. necatrix at 12 days of age. A total of 280 Ross 308 broilers were randomly allocated into 5 groups with 7 replicates of 8 chickens per replicate. The experimental dietary treatments were formulated by supplementing the basal maize-soyabean meal diet. The experimental design allocated the groups as follows: 1. uninfected birds and an unsupplemented diet; 2. uninfected birds and the diet supplemented with the herbal extract blend at a level of 1 g/kg feed (200 mg of each herbal extract/kg); 3. infected birds and an unsupplemented diet; 4. infected birds and a diet with the addition of coccidiostat diclazuril at a level of 1 mg/kg feed; and 5. infected birds and a diet supplemented with the herbal extract blend at a level of 1 g/kg feed (200 mg of each herbal extract/kg). Throughout the 42 days of the experimental period, performance parameters, mortality, lesion score, oocyst output, and serum carotenoid concentration were recorded. Dietary supplementation with the herbal extract blend increased growth performance to the level found in the group fed the coccidiostat and in the non-challenged groups. The number of oocysts per gram of excreta did not differ significantly between the groups fed the herbal extract blend and the group receiving the coccidiostatic supplement. The herbal extract blend had no effect on mortality, lesion score, with the exception of the duodenum, or blood carotenoid concentration.

Sera obtained from pampas-deer (Ozotoceros bezoarticus) captured in two different Brazilian environments were analyzed for the presence of anti-Neospora caninum antibodies by the indirect fluorescent antibody test (IFAT). Samples were collected from 23 animals from a savanna area in the National Park of Emas, in the state of Goiás, Brazil. This area is surrounded by cultivated lands and allows very little contact between wild and domestic animals. Another batch of samples was collected from 16 animals from the Pantanal region, in the state of Mato Grosso, Brazil. This area is a flood plain where domestic animals have intensive contact with cervids. The 39 samples were analyzed (IFAT ≥ 1:50), and the values for the occurrences found in the animals from each region were compared by the test for comparison of two proportions. Of the 39 cervids examined, 38.46% (15) had anti-N. caninum antibodies. Three (13%) of the 23 samples from the National Park of Emas, and 12 (75%) of the 16 samples from the Pantanal were positive, with significant differences between regions (p < 0.001). These results suggested that the presence of domestic animals, mainly dogs and cattle, may be responsible for the greater occurrence of N. caninum in the Pantanal cervids.Thus, as a recommendation of the Conservation Units that care for the pampas-deer, attention should be taken to carefully monitor the flow of diseases between the domestic animals and this species.

The effectiveness of diatomaceous earth (DE) as a treatment against parasites and to increase feed efficiency and egg production of organically raised free-range layer hens was evaluated in 2 breeds of commercial egg layers [Bovan Brown (BB) and Lowmann Brown (LB)] that differ in their resistance to internal parasitic infections. Half the hens of each breed were fed diets supplemented with DE (2%). Their internal parasite loads were assessed by biweekly fecal egg counts (FEC) and by postmortem examination of the gastrointestinal tract. Supplementing DE in diets of LB hens, the more parasite-resistant breed, did not significantly affect their FEC and adult parasite load. However, BB hens treated with dietary DE had significantly lower Capillaria FEC, slightly lower Eimeria FEC, fewer birds infected with Heterakis, and significantly lower Heterakis worm burden than control BB hens. Both BB and LB hens fed the diet containing DE were significantly heavier, laid more eggs, and consumed ...