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One hundred and twenty one-day-old chukar partridges were randomly divided into eight groups which received diets with different supplementations. There were four unchallenged groups. One group received salinomycin (50 ppm), two groups received cinnamaldehyde (CINN) (100 and 200 mg/kg of diet), and another one received only the basal diet from the 1st to the 31st day. There were also four corresponding groups orally challenged by 3 × 10 5 Eimeria kofoidi sporulated oocysts at the 21st day. Three samplings were done at the 24th, 26th, and 31st days of rearing for pathological and biochemical assessments. Fecal samples were daily taken to check the pattern of oocyst shedding from the 26th to 31st day. The body weight of birds was measured at 21st and 31st days. Along with the in vivo experiment, an in vitro sporulation inhibition test was carried out. The in vitro results showed that CINN decreased sporulation rate at 1 and 0.5 mg/ml. In vivo, it was found that CINN did not prevent the oocyst shedding. Furthermore, the histopathological findings revealed that CINN and salinomycin had no effect on infection establishment. However, our findings showed that CINN (200 mg/kg of diet) could enhance the body weight and improve antioxidant status. Although our results did not support the in vivo anticoccidial activity of CINN, it had a promising potential to improve antioxidant status and body weight in the chukar partridge., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Aim: To assess the efficacy of toltrazuril against the Eimeria spp. affecting brown kiwi (Apteryx mantelli)., Methods: Droppings were collected from three brown kiwi, aged <6 months old, at a captive rearing facility in the North Island of New Zealand, between 22 February and 20 April 2017, on 14 sampling dates. Only droppings (n=30) that were excreted between 03:00 and 07:00, as determined using video surveillance, were included for analysis, reflecting the peak time for shedding of coccidial oocysts for brown kiwi. Oocysts were quantified in each sample and Eimeria species identified on the basis of oocyst morphology. All samples were collected between 2 and 10 days after the birds had been treated with 25 mg/kg toltrazuril., Results: Eimeria spp. oocysts were identified in 28/30 individual samples and on 14/14 sampling dates. Oocyst counts varied from 0 to 328,080 oocysts per gram (opg), and at least one oocyst count >10,000 opg was measured on 12/14 sampling dates. Three species of Eimeria were observed, with Eimeria apteryxii and E. kiwii most commonly encountered, whereas only one sample contained E. paraurii., Conclusions and Clinical Relevance: In the three birds monitored at this research site, there was a high abundance of E. apteryxii and E. kiwii oocysts in droppings despite recent administration of toltrazuril. These results suggest that the populations of Eimeria spp. affecting brown kiwi at this location appear to possess an ability to survive exposure to toltrazuril. Toltrazuril is widely used at captive rearing facilities to limit the effects of coccidiosis in juvenile kiwi. If a lack of efficacy is confirmed, it will be necessary to investigate alternative treatment regimens alongside broader environmental management strategies.

Field isolates of coccidia from 20 natural outbreaks in the chukar partridge ( Alectoris chukar ) were received from gamebird farms in 10 U.S. states. These were propagated in the laboratory and identified by microscopy and PCR. Of 20 samples, 18 were Eimeria kofoidi, two were Eimeria legionensis only, and one was a mixture of the two species. One isolate of E. kofoidi also contained an unidentified species detected only by PCR, nucleotide sequencing, and phylogenetic analysis. The efficacy of anticoccidial drugs against chukar coccidia was tested with experimental infections in battery cages. Isolates of E. kofoidi were used to infect 2-wk-old chukars. Anticoccidial products were given in the feed at levels approved for other poultry or for chukars. Tests were terminated at 6 days postinoculation with measurement of weight gains, fecal diarrhea scores, and necropsy to observe for lesion severity. Lasalocid (120 ppm) was moderately effective in one test. When tested against four field isolates, other ionophores (monensin, salinomycin, semduramicin) showed moderate effectiveness in reducing lesions and improving weight gains. Rofenaid (a potentiated sulfa mixture), robenidine (30 ppm), diclazuril (2 ppm), and decoquinate (80 ppm) were highly effective. In a test of nine products against a highly virulent field isolate, only diclazuril (2 ppm) and clopidol (125 ppm) reduced the severity of lesions and improved weight gain relative to infected controls, suggesting the extent to which previous drug usage had selected for drug resistance.

Numerous efforts to date have been implemented in the control of avian coccidiosis caused by the Eimeria parasite. Since the appearance of anticoccidial chemical compounds, the search for new alternatives continues. Today, no product is available to cope with the disease; however, the number of products commercially available is constantly increasing. In this review, we focus on natural products and their anticoccidial activity. This group comprises fatty acids, antioxidants, fungal and herbal extracts, and immune response modulators with proven anticoccidial activity, many of which exist as dietary supplements. Additionally, we offer an overview of the poultry industry and the economic cost of coccidiosis as well as the classical strategies used to control the disease.

Coccidiosis caused by Eimeria spp. is a common parasitic disease posing a serious problem in pigeon keeping. The aim of the study was to determine the species composition, the degree of coccidia infection and the effect of the coccidiostat used in the course of the disease in two pigeon lofts located in the West Pomerania province. The material for the study came from 180 birds. A total of 330 faecal samples were investigated with two methods: Willis-Schlaafs (qualitative) and McMaster's (quantitative). The pigeons were given the Baycox (Bayer) coccidiostat with toltrazuril as an active substance. The medicament was administered for two days at a dose of 20 mg/kg body weight at three-day intervals. Three species of protozoa were isolated: Eimeria labbeana, E. columbarum, E. columbae, and the infections were mixed. The occurrence of E. labbeana was most commonly reported, which was shown, depending on the pigeon loft and the age of the birds, in 89-93% of young pigeons and in 63-55% of adults. The species E. columbarum and E. columbae were found less frequently. Baycox coccidiostat proved to be highly effective against coccidiosis in pigeons and may also be used in prophylaxis.

This selective review of 40 years of coccidiosis research is one of a number on important diseases of poultry to celebrate the 40th anniversary of the birth of Avian Pathology, the journal of the World Veterinary Poultry Association, and is written for the non-specialist. The intention is to provide a flavour of the field problems and intellectual challenges, with emphasis in the areas of immunology and vaccinology that drove research in the 1970s, and to reflect on research progress since.

In the present study, we experimentally manipulated coccidian parasitism and dietary carotenoid availability in a fully factorial experiment in male house sparrows (Passer domesticus Linnaeus), and tested whether carotenoid supplementation reduces the cost of parasitism in terms of condition, moult and immune responses. We found that coccidians have a significant but transient negative effect on body mass, which can be reduced if birds have access to carotenoid supplementation in their diet. Experimental manipulation had no significant effect on the moulting parameters of the birds measured following coccidian infestation and during the whole moulting period. Carotenoid supplementation increased the plasma carotenoid concentration in both infested and medicated birds treated with a coccidiostatic drug; however, after two months exposure to parasites, plasma carotenoid concentration increased only in the carotenoid-supplemented and medicated group whereas no difference was observed between the carotenoid-supplemented and infested and non-supplemented groups. On the contrary, coccidian infestation was not affected by carotenoid supplementation. Experimental infestation decreased the antibody response to sheep red blood cells (SRBCs), although no significant effect was observed in the capacity of the birds to respond to a mitogenic challenge with phytohemagglutinin. Within the experimentally infested groups birds with carotenoid-supplemented food tended to have an increased anti-SRBC humoral immune response. The positive correlation between coccidian infestation and the strength of the humoral immune response against SRBCs in the non-supplemented and infested groups indicates that this part of the immune system plays an important role in defence against these parasites.

Coccidia are common pathogenic parasites in pigeons (Columba livia). Coccidiosis is most commonly seen in young pigeons and only rarely in adult birds. Infections in domestic pigeons are typically mixed and commonly include Eimeria columbarum and Eimeria labbeana. The reported prevalence of infection is 5.1%-71.9%, and worldwide mortality in juvenile pigeons varies from 5% to 70%, with most deaths occurring in the third and fourth month of life. This article summarizes the life cycle of E. columbarum and E. labbeana, the route of transmission, and the common clinical and pathologic signs of coccidiosis. Chemotherapeutic options discussed include amprolium, sulfonamides, clazuril, and toltrazuril. Reasons to use toltrazuril include the growing resistance against other drugs, such as sulfonamides and amprolium, the extended effectiveness compared with other substances, for example, clazuril, and the ability of pigeons to develop immunity during treatment.

The anticoccidial efficacy of amprolium, clazuril, and monensin were studied in sandhill cranes (Grus canadensis) infected with a mixture of Eimeria spp. oocysts. Five groups of four 1-day-old sandhill crane chicks were maintained on a crumbled ration containing no coccidiostat, amprolium at 2.2 ppm, clazuril at 1.1 ppm, clazuril at 5.5 ppm, or monensin at 99 ppm. After 2 wk on their respective feeding regimens, birds in each of the five groups were administered 25 x 10(3) pooled sporulated Eimeria spp. oocysts per os and observed for another 3 wk. A sixth group of four chicks served as nonmedicated, nonchallenged control during the study. Clinical signs and lesions consistent with disseminated visceral coccidiosis were observed in all challenged controls and birds fed amprolium and clazuril. Birds in these groups died 9-10 days after challenge. In contrast, only one monensin-medicated bird had clinical signs of disseminated visceral coccidiosis, and it died 13 days after challenge (DAC). This and an asymptomatic bird that were necropsied at study termination had less-severe gross and microscopic lesions of disseminated visceral coccidiosis. Two of three monensin-treated birds that survived challenge passed from 50 to 500 coccidial oocysts 11 to 18 DAC but were negative at study termination. Of the coccidiostats tested, monensin, at the dietary level of 99 ppm, was the only anticoccidial drug that provided protection against experimentally induced disseminated visceral coccidiosis in sandhill cranes.

Three antihaematozoal drugs were tested for the treatment of pigeons naturally infected with Haemoproteus columbae. Butalex (Buparvaquone) was found effective against the parasite either by using the recommended dose (R. D.) or the double (D. D.) dosis. The R. D. of Berenil (Diminazene aceturate) was not effective while the D. D. reduced the number of gametocytes circulating in the infected blood. Triquine was found very toxic to the pigeons both the R. D. and the D. D.

The efficacy of toltrazuril against heavy experimental Eimeria labbeana and E. columbarum infections in racing pigeons was investigated. Pigeons were treated with toltrazuril at a dose of 20 mg/kg body weight before, during, and after the pre-patent period. In pigeons treated during pre-patency (1-5 days postinoculation [PI]), a 99.9% reduction in oocyst output was observed at day 7 PI. Treatment during patency (6-7 days PI) resulted in an interruption of oocyst shedding within 3 to 4 days. Pigeons treated with toltrazuril up to 14 days before the experimental infection showed on average a reduction of more than 97% in the number of oocysts in individual fecal samples. Finally, at reinfection, the immune response of pigeons previously treated during pre-patency was not altered compared with the response of infected unmedicated controls.

Diclazuril, a new anticoccidial drug, was tested in young pheasants artificially infected with the three most common pathogenic species of Eimeria, E colchici, E duodenalis and E phasiani. In two replicate experiments each with 40 birds the mortalities in the infected controls were 50 and 25 per cent. Diclazuril was administered in the feed at dose levels of 1, 2 and 4 ppm from the day before the inoculation of coccidia until the end of the test on day 6 after infection. The 1 ppm dose failed to inhibit the development of the parasite completely, as was shown by a reduction of the weight gain of the birds and the output of a small number of oocysts. Diclazuril at 2 or 4 ppm adequately controlled the infection, with weight gains similar to those of the uninfected controls. At all dose levels, mortality, intestinal lesions and diarrhoea were prevented.

The efficacy of toltrazuril in comparison with clazuril on heavy experimental Eimeria labbeana and E. columbarum infections in pigeons was investigated. The minimum required dose of toltrazuril to completely suppress oocyst excretion is 20 mg/kg body weight for 1 day. After treatment with toltrazuril, there was a dose-dependent period during which pigeons remained negative; at a dosage of 35 mg/kg or higher, this period was at least 4 weeks. Clazuril at the recommended dose of 2.5 mg/pigeon resulted in a rapid suppression of oocyst excretion, but oocysts were again observed in the feces 20 days after treatment. The fact that oocysts appeared again in the feces 3 to 5 weeks after treatment can probably be explained only by a persistence of endogenous stages, which are not affected during treatment, rather than by a reinfection. Reinfection of the previously medicated and infected pigeons 30 days after the first infection provided some data on possible induced immunity.

Racing pigeons were artificially infected with a mixed inoculum of Eimeria labbeana (85 per cent) and E columbarum (15 per cent) and treated orally with 2.5 mg clazuril either on day 1, 2, 3, 4, 5, 6 or 7 after infection. The impact of the treatment on the different developmental stages was evaluated by oocyst output and by histological examination of the duodenum and jejunum. The life cycle always became completely interrupted, but maximal effects were noted when treatment was given on day 4, 5 or 6 after infection. Treatment during patency completely interrupted oocyst excretion within three days after dosing. Degenerative changes in schizonts and gametocytes were always observed. The histology revealed a reduced number and abnormal structure of developing merozoites; a ballooned aspect and presence of numerous small vacuoles in the microgametocytes; the absence of typical wall-forming bodies in macrogametocytes and a complete absence of oocysts. It is concluded that clazuril has a coccidiocidal effect on the asexual and sexual developmental stages of both Eimeria species, resulting in a complete interruption of the life cycle.

The effectiveness of clazuril (Appertex), a new anticoccidial agent for the treatment of pigeons is described in the present study. Clazuril, a benzene-acetonitrile derivative, is administered in a single dose. In laboratory studies, 121 carrier pigeons infected with E. labbeana and E. columbarum were treated once with clazuril in gelatin capsules at dose levels of 10 mg, 5 mg, 2.5 mg, 1.25 mg, 0.63 mg or with a placebo. When a single dose of 2.5 mg and higher was administered, all faecal samples became negative for oocysts within seven days after treatment. In the field studies, 1531 young and full-grown carrier pigeons, from 116 infected dove-cotes, were treated with 1 tablet of 2.5 mg clazuril. Seven days after treatment, the faecal samples of 105 dove-cotes were negative for oocysts of E. Labbeana and E. columbarum; in six dove-cotes, infection was also virtually reduced to zero. Performance in racing was not affected by treatment and side-effects were not observed.

Litter samples obtained from a ring-necked pheasant propagation farm in Illinois contained coccidia: 57.5% of the oocysts were Eimeria duodenalis, 24.9% were E. tetartooimia, 8.8% were E. phasiani, and 8.8% were E. pacifica. Ionophorous anticoccidial drugs were tested for efficacy against the pheasant coccidia. All three drugs reduced oocyst production and prevented mortality in young pheasants; unmedicated infected controls had a 40% mortality rate. Monensin at 120 ppm in the feed was coccidiocidal against E. duodenalis and E. tetartooimia, partly coccidiocidal against E. pacifica, and only partly coccidiostatic against E. phasiani. Salinomycin at 60 ppm in the feed was highly efficacious and coccidiocidal against all four species, but the salinomycin-medicated pheasants gained the least of all medicated birds. Lasalocid at 120 ppm in the feed was the most effective, with nearly complete coccidiocidal activity against all four coccidial species.