Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-05-29T13:53:42Z No. of bitstreams: 1 2016 - Lidiane Maria da Silva.pdf: 11158526 bytes, checksum: 92a272f4f09e476cee2262d286c61963 (MD5) / Made available in DSpace on 2017-05-29T13:53:43Z (GMT). No. of bitstreams: 1 2016 - Lidiane Maria da Silva.pdf: 11158526 bytes, checksum: 92a272f4f09e476cee2262d286c61963 (MD5) Previous issue date: 2016-02-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The thaminophilid passerines, just as other families of Passeriformes, can be parasitized by different species of coccidia, especially the genera Isospora Schneider, 1881 and Eimeria Schneider, 1875. In this context, this study aimed to identify, characterize and quantify coccidian species from Thamnophilidae in the Itatiaia National Park. Seven expeditions were performed at Itatiaia National Park, of which five were in conserved areas and two in areas around the park. A total of 184 species of birds were captured with mist nets, being 26 thaminophilid passerines. After fecal sampling and processing were observed coccidia of the genera Isospora and Eimeria. The species Isospora parnaitatiaiensis Silva, Rodrigues, Lopes, Berto, Luz, Ferreira, Lopes, 2015 was identified in two different hosts, Pyriglena leucoptera (Vieillot, 1818) and Dysithamnus mentalis (Temminck, 1823), and their oocysts were characterized as polymorphic, since the oocysts from P. leucoptera were more ellipsoidal and the oocysts from D. mentalis were more sub-spherical, which may be the result of speciation process/adaptation to these hosts. The intensities of infection in different hosts were relatively low, since that P. leucoptera and D. mentalis shed together an OoPD of 316 oocysts of I. parnaitatiaiensis, which can be explained by the conserved environment in the Itatiaia National Park and the insectivore feeding habit. Finally, the specificity occurred at the family level, because P. leucoptera and D. mentalis, both of Thamnophilidae family, have been reported as hosts of I. parnaitatiaiensis / Os taminofil?deos, da mesma forma que outras fam?lias de Passeriformes, podem ser parasitados por diversas esp?cies de cocc?dios, principalmente dos g?neros Isospora Schneider, 1881 e Eimeria Schneider, 1875. Neste contexto, este trabalho teve por objetivo identificar, caracterizar e quantificar esp?cies de cocc?dios parasitos de Thamnophilidae do PNI. Foram realizadas sete expedi??es no Parque Nacional do Itatiaia, das quais cinco foram em ?reas mais preservadas e duas em ?reas no entorno do parque, as aves foram capturadas com o auxilio de redes de neblina, ao todos foram capturados 184 esp?cimes de aves sendo 26 taminofil?deos, ap?s o processamento das amostras observou ser cocc?dios do g?nero Isospora e Eimeria. A esp?cie Isospora parnaitatiaiensis Silva, Rodrigues, Lopes, Berto, Luz, Ferreira, Lopes, 2015 foi identificada em dois diferentes hospedeiros da fam?lia Thamnophilidae, Pyriglena leucoptera (Vieillot, 1818) e Dysithamnus mentalis (Temminck, 1823), sendo que seus oocistos foram caracterizados como polim?rficos, j? que os oocistos de P. leucoptera s?o mais elips?ides em rela??o aos oocistos de D. mentalis que tendem ao ser mais sub-esf?ricos, o que pode ser consequ?ncia do processo de especia??o/adapta??o ao hospedeiro. A intensidade de infec??o nos diferentes hospedeiros taminofil?deos positivos foram relativamente baixas, P. leucoptera e D. mentalis tiveram juntos um OoPD de 316 para os oocistos de I. parnaitatiaiensis, o que pode ser justificado pelo ambiente conservado do PNI e pelo h?bito alimentar inset?voro. Finalmente, a especificidade ocorreu em n?vel de fam?lia, pelo fato de P. leucoptera e D. mentalis, ambos da fam?lia Thamnophilidae, ter sido relatados como hospedeiros de I. parnaitatiaiensis

Introduced species are the greatest threat to biodiversity after habitat loss. Understanding the processes that permit organisms to become successful invaders may provide opportunities to prevent or limit their dispersal and establishment and thereby alleviate some of their harmful effects. The goal of my dissertation research has been to investigate whether invasive species have distinctive interactions with parasites, and some of the mechanisms that may underlie that variation. I used one of the world's most successful vertebrate invaders as a case study: the house sparrow (Passer domesticus; Introduction). Previous research in the house sparrow suggested that loss of parasite diversity may contribute to invasion success. However, my work demonstrates that infection with common avian malaria parasites is primarily a function of environmental heterogeneity and is not a predictor of time since introduction for house sparrows that are currently expanding their range in Kenya (Chapter 1). Interestingly, in spite of a large proportion of the population being infected with avian malaria, a state that should reduce competitive ability of house sparrow populations, this species is still able to establish themselves among native competitors. Though there are a number of potential mechanisms that could explain this pattern, one of the most convincing explanations is that house sparrows, and perhaps other introduced species, have adaptive differences in immunity. As such, the findings of Chapter 1 inspired two studies in which my collaborators and I showed that house sparrows from two non-native populations seem capable of maintaining normal health, performance and behavior during immune challenge, a response often referred to as parasite tolerance. Specifically, in Chapter 2, we found that when Floridian house sparrows, established since ~1870, were challenged with synthetic pathogens that mimicked infection with a fungi, an RNA virus or Gram-negative bacteria, only individuals challenged by the synthetic bacteria showed measurable sickness behaviors and secretion of an inflammatory protein. In Chapter 3, we compared parasite tolerance in Kenyan house sparrows (introduced in ~2000) and a native congener, the grey-headed sparrow (P. griseus) to a common intestinal parasite of songbirds. We found that both species were tolerant in that they were able to maintain fat reserves, protein reserves and vertical flight ability during infection. However, house sparrows maintained burdens that were, on average, more than 10x those of grey-headed sparrows. Moreover, when examining nutrient allocation in the two species, house sparrows appeared to assimilate nutrients more efficiently than grey-headed sparrows and did not change how nutrients were allocated among immune and reproductive organs during experimental infection. Grey-headed sparrows, however, did shift nutrient allocation among immune and reproductive organs during experimental infection. Together, the larger nutrient pool and maintenance of nutrient allocation patterns in challenged house sparrows suggests that no physiological trade-offs occurred and that house sparrows experienced a lower cost of parasite exposure. In the fourth Chapter, I explored why house sparrows had such high coccidia burdens in comparison to their congeners. We suspected burden was a function of the frequency of exposure to coccidia. Consequently, we explored heterogeneity in foraging preferences and other behaviors in Floridian house sparrows and their role in coccidia burden. As expected, we found that house sparrows did not avoid contaminated food. In fact, they ate contaminated and uncontaminated foods indiscriminately. What was surprising was a lack of correlation between burden and consumption of contaminated foods and all of the behaviors we monitored (i.e., aggression, activity, feeding rates and defecation frequency). Overall, these data suggest that house sparrows do not benefit from typical parasite-avoidance behaviors. In sum, this dissertation research implies that house sparrows respond to parasite infection differently than many other known vertebrates, most likely in an effort to maximize efficient use of resources and, in so doing, augment competitive ability and invasion success.

In der vorliegenden Arbeit wurden 212 Kotproben von Chamäleons auf Parasitenstadien und 75 Tierkörper pathologisch sowie bei einem nachgewiesenen Parasitenbefall histopathologisch untersucht. Ziel war es, anhand dieser Untersuchungen das Vorkommen und die Schadwirkungen von Endoparasiten unter Berücksichtigung der Herkunft, des Alters, des Geschlechts und der Chamäleonart zu beschreiben. Von 212 Kotproben wiesen 55,2% Endoparasitenstadien auf. Bei 54,7% der 64 sezierten und auswertbaren Tiere wurden Endoparasiten nachgewiesen. Der Anteil positiver Proben zeigt zwischen Nachzuchten (55,5%) und Wildfängen (54,1%) keinen wesentlichen Unterschied. In Wildfängen konnten häufiger Endoparasiten mit einem indirekten Lebenszyklus ermittelt werden, Nachzuchten beherbergten dagegen öfter Parasiten mit einem direkten Entwicklungszyklus. In den untersuchten Chamäleons konnten regelmäßig Kokzidien der Gattung Isospora und Oxyuriden nachgewiesen werden. Zestoden konnten in der koproskopischen Untersuchung gar nicht aufgefunden werden, wohingegen sie in der pathologischen Untersuchung sporadisch im Darm diagnostiziert werden konnten. Die Häufigkeit des koproskopischen Nachweises von Parasitenstadien bezogen auf die Gesamtzahl der untersuchten Chamäleons stellte sich wie folgt dar: in 30,4% wurden Protozoon gefunden, 21,7% der Tiere waren mit Kokzidien infiziert (davon 78,3% Isospora spp., 13,0% Choleoeimeria spp., 6,5% Eimeria spp., 2,2% Mischinfektion Isospora spp./Choleoeimeria spp.) und 8,5% mit Flagellaten oder Ziliaten. Bei 83,3% der Tiere mit gastrointestinalen Symptomen konnte ein Befall mit Kokzidien der Gattung Isospora nachgewiesen werden. In 38,7% der koproskopischen Untersuchungen konnten Nematoden (65,9% Oxyuriden, 19,5% Askariden/ Heterakiden, 1,4% Rhabdias sp., 2,8% Strongyloides sp., je 0,5 % Spirurida, Heterakiden/Filarien, Oxyuriden/Strongyloiden) und in 2,8% Trematoden (Digenea) aufgefunden werden. Anamnestisch konnten in 35,8% aller Tiere klinische Symptome beobachtet werden, wovon bei 88,2% der erkrankten Tiere ein Endoparasitenbefall nachzuweisen war. Insgesamt 64,1% der sezierten Chamäleons waren mit Endoparasiten befallen, wovon 68,3% Mono- und 31,7% Mischinfektionen beherbergten. In 31,3% der sezierten Chamäleons wurden Nematoden gefunden und der Befall wurde in 55,0% dieser Fälle als hochgradig eingestuft. Es wurden Befallsraten von 25,0% für Strongyloides sp., 23,4% für Askariden/ Heterakiden,15,0% für Filarien, 5,0% für Rhabdias sp., 9,4% für Zestoden, 10,9% für Digenea registriert. In 11,3% der Fälle lagen Mischinfektionen vor. Damit ist ein Endoparasitenbefall bei Chamäleons häufig und kann zu Erkrankungen führen. Die Exposition unterscheidet sich bei Wildfängen und Nachzuchten aufgrund der unterschiedlichen Umgebungsbedingungen. Auch klinisch unauffällige Tiere waren zu 27,8% mit Parasiten befallen, so dass eine klinische Symptomatik nicht zwingend aus einem Parasitenbefall resultiert. Insgesamt betrachtet verdient der Endoparasitenbefall von Chamäleons das Augenmerk von Tierärzten und Tierhaltern und sollte bei augenscheinlich hohem Infektionsdruck zu Gegenmaßnahmen, insbesondere auch einer verbesserten Hygiene, Anlaß geben. / In the present study 212 chameleon fecal samples were examined for parasite stages and 75 carcasses were examined histopathologically and pathologically in a proven case of a parasite infestation. The basis of this study was to describe the occurrence and harmful effects of internal parasites considering the origin, age and sex of the chameleons. Of the 212 fecal samples 55.2% showed stages of endoparasites. Parasites were detected at 54.7% of 64 evaluated and dissected animals. The proportion of positive samples shows no significant difference between offspring (55.5%) and wild specimens (54.1%). In wild specimens common internal parasites could be determined with an indirect life cycle, however offspring harbored more parasites with a direct life cycle. In the studied chameleons coccidia as the genus Isospora and Oxyurids were regularly detected. In the coprological study Cestodes could not be found, while in the pathological examination they could be diagnosed sporadically in the intestine. Based on the total number of investigated chameleons the frequency of detection of parasite stages are presented as follows: Protozoa were found in 30.4%, 21.7% of the animals were infected with coccidia (of which 78,3% Isospora spp, 13,0% Choleoeimeria spp., 6.5% Eimeria spp., 2.2% polyinfections between Isospora spp./ Choleoeimeria spp.) and 8.5% with flagellates or ciliates. At 83.3% of the animals with gastrointestinal symptoms coccidia of the genus Isospora were detected. In 38.7% of the fecal examination nematodes were determined (65.9% Oxyurids, 19.5% Ascarids/ Heterakis, 1.4% Rhabdias sp., 2.8% Strongyloides sp., 0.5% Spirurida, Heterakids/ Filariae, Oxyurids/ Strongyloides sp.) and Trematodes in 2.8% (Digenea) were found. The anamnesis showed that clinical symptoms could be observed in 35.8% of all of the animals, whereas endoparasite infestation could be detected inn 88.2% of the affected animals. Overall, 64.1% of the dissected chameleons were infested with parasites, of which 68.3% harbored mono- and 31.7% polyinfections. In 31.3% of the dissected chameleons nematode infestations were found and 55.0% of these cases were classified as severe. Prevalences were registered: 25.0% for Strongyloides spp., 23.4% for Ascarids/ Heterakids, 15.0% for Filaria, 5.0% for Rhabdias sp., 9.4% for Cestodes, 10.9% for Digenea. In 11.3% of the cases mixed infections were reported. Thus, endoparasite infestation is common among chameleons and can lead to diseases. Exposure differs from wild-specimens and captive-bred due to the different environmental conditions. Also, 27.8% of clinically healthy animals were also infested with parasites, which means that clinical symptoms are not necessarily the result of a parasitic infestation. Overall, chameleon endoparasites deserve the attention of veterinarians and pet owners and should be treated promptly when there is a high likelihood of infection or hygiene is of concern.

Between February 1986 and October 1988, 863 amphibians and reptiles were collected in northcentral Texas and examined for coccidial parasites. Thirteen percent of amphibians <26% salamanders, 11% frogs and toads) and 28% of reptiles (54% turtles, 25% snakes) harbored 20 previously described and 16 new species of coccidia; overall prevalence of infection was 176/863 < 20%). Sixteen Ambvstoma texanum were infected with Eimeria ambystomae which represents new host and geographic locality records for the coccidium. Forty anurans were found to be passing coccidia, including Pseudacris streckeri. Bufo valliceos and Gastrophryne olivacea. Four new species of coccidia were described from anurans and include Eimeria flexuosa. E. streckeri. Isospora dellcatus and I_. fraaosum. However, oocysts found in B. v.. valliceps were determined experimentally to represent pseudoparasites. Sixty-eight turtles were infected with coccidia, including Chelvdra serpentina, Kinoeternon flavescens. Pseudemvs texana. Terrapeng ornata and Trachemvs scripta eleoans. Fourteen eimerians (5 of which are described as new species) were found in turtles. The new species from turtles include Eimeria cooteri, E. ornata, E. Btvlosa. E. texana and E. trachemvdis. Interestingly, all 96 lizards examined were negative for coccidia. Fifty-three snakes including 11 colubrids and 1 viperld harbored coccidia of the genera Caryospora. Cryptosporidium. Eimeria and Sarcocystis: prevalence of infection was highest in 3 species of North American water snakes <Nerodia spp.). Seven new species of Eimeria were described from snakes, including E. conanti. E. lnfirmus. E. papillosum. E. rhombifera. E. serpenticola. E. striatula and E. tenuis. There was no preference for coccidia between the sexes of any hosts. Based on limited data from a single anuran host, prevalence was higher during wetter months of spring than in summer. In addition, prevalence was higher in aquatic and semiaquatic snakes than in truly terrestrial species. Preliminary data suggested that using host specificity data of coccidia may be a method of studying host phylogeny and coevolutionary relationships in thamnophiine snakes.

Coccidia are obligate intracellular parasites belonging to the phylum Apicomplexa. Many coccidia are of medical and veterinary importance such as Cystoisospora species and Toxoplasma gondii. The need to discover new anticoccidial therapies has increased due to development of resistance by the parasite or toxicity issues in the patient. The goals of this work were to develop a model for canine coccidiosis while proving that Cystoisospora canis is a true primary pathogen in dogs and to determine the efficacy of a new anticoccidial agent. A canine coccidiosis model would be useful in evaluating new anticoccidial treatments. Oral infections with 5 X 104 (n=2) and 1 X 105 (n=20) sporulated C. canis oocysts were attempted in 22 purpose bred beagle puppies. Clinical signs associated with disease were observed in all dogs. Bacterial and viral pathogens were ruled out by transmission electron microscopy (TEM) and bacterial growth assays. Development of C. canis in cell culture was also evaluated. The efficacy of ponazuril, a new anticoccidial drug, was examined in T. gondii. In vitro studies were conducted to determine the activity of ponazuril on tachyzoites and how this agent affects development of apicomplexcan parasites. The tachyzoite production assay was conducted. Ponazuril at a dose of 1.0 µg/ml had a significant affect on tachyzoite reproduction. Comparisons were made on how ponazuril affects T. gondii and Neospora caninum. Inhibition of T. gondii tachyzoites occurred after the second round of replication and with N. caninum tachyzoites after 4 rounds of replication. Results of TEM revealed ponazuril affects replication of T. gondii and N. caninum differently. The efficacy of ponazuril to prevent and treat acute and chronic toxoplasmosis was investigated. Mice treated prophylactically with ponazuril were completely protected from developing an acute T. gondii infection. Fatal toxoplasmosis was prevented in mice starting treatment 3 and 6 days post infection at a dose of 20 mg/kg. Immunohistochemistry was used to evaluate ponazuril's effect on chronic toxoplasmosis. Sections of brain were scored according to the number of tissue cysts present. Ponazuril also proved to be highly active against toxoplasmic encephalitis in an interferon-gamma knockout mouse model. / Ph. D.

Supplemental feeding of deer is a common management action. However, concentrating animals, as feeding does, is known to promote the transmission of disease. We examined how feeding alters three sources of disease: aflatoxins, gastrointestinal parasites, and ticks. To do this, we paired 79 feeder sites throughout Mississippi with ecologically-equivalent sites without feeders. Wildlife visitation increased at feeders compared to sites without feeders. For aflatoxins, we sampled during the summer and hunting season and found low prevalence and levels in feeders and bagged/bulk feed. The greater concern was environmental exposure to aflatoxins. All corn piles exposed to environmental contamination in July contained toxic levels of aflatoxins after eight days. The environmental load of gastrointestinal parasites was elevated for coccidia (4x) and strongylids (3x). Finally, feeding reduced the number of ticks at feeder sites, but did not alter the prevalence of tick-borne diseases within captured ticks compared to sites without feeders.

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2018-08-23T18:54:19Z No. of bitstreams: 1 2017 - Mariana de Souza Oliveira.pdf: 2345749 bytes, checksum: 613f695368567431340caa1eae7f5872 (MD5) / Made available in DSpace on 2018-08-23T18:54:19Z (GMT). No. of bitstreams: 1 2017 - Mariana de Souza Oliveira.pdf: 2345749 bytes, checksum: 613f695368567431340caa1eae7f5872 (MD5) Previous issue date: 2017-08-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Brazil is one of the 5 most megadiverse countries in the world, presenting 14% of all the biodiversity known worldwide. Brazil also has a greater tropical vegetation covering the world, presenting a high number of endemic species, becoming one of the most important countries in the world for investments in bird conservation. The district of Cacaria, in the municipality of Pira?, Rio de Janeiro, Brazil, has an extensive vegetation cover area, but is affected by local cattle breeding, as well as other anthropogenic actions. Birds can have a high diversity of parasites, such as ectoparasites, helminths and coccidia. Coccidian parasites are the main cause of enteritis, behavioral and reproductive changes in most species of birds. . Coccidia studies are relevant both to animal health and to knowledge of the biodiversity of these parasites. In this context, the objective of this study was to examine the feces of wild birds captured in fragments of Atlantic Forest in the district of Cacaria, in southeastern Brazil, to identify and quantify the coccidian parasites that were present, besides relating them to some ecological characteristics of birds. 14 expeditions were carried out on three fragments of Atlantic Forest in Cacaria, resulting in the capture of 143 birds, with 20 of them positive for coccidia. Among the positive samples, coccidia of Isospora and Eimeira classification were found in 12 species of birds. These coccidia were identified according to the literature, species of coccidia not described in the literature until the present moment were considered morphotypes. There was no relation between the bird species and the positive samples, with their respective oopds (Oocyst by defecation). Regarding the ecological characteristics, only living habits in forest environments were significant, showing that the birds of forest environments are less susceptible to infection. Regarding eating habits, there were no significant results / O Brasil ? um dos 5 pa?ses mais megadiversos do mundo, apresentando 14% de toda a biodiversidade conhecida mundialmente. O Brasil tamb?m tem uma maior vegeta??o tropical cobrindo o mundo, apresentando um elevado n?mero de esp?cies end?micas, tornando-se um dos pa?ses mais importantes do mundo para investimentos em conserva??o de aves. O distrito de Cacaria, no munic?pio de Pira?, Rio de Janeiro, Brasil, tem uma extensa ?rea de cobertura vegetal, mas ? afetado pela cria??o de gado local, al?m de outras a??es antr?picas. As aves podem ter uma alta diversidade de parasitas, como ectoparasitas, helmintos e coccidia. Os parasitas coccidianos s?o a principal causa de enterite, altera??es comportamentais e reprodutivas, na maioria das esp?cies de aves. Os estudos de coccidia s?o relevantes tanto para a sa?de animal quanto para o conhecimento da biodiversidade desses parasitas. Neste contexto, o objetivo deste estudo foi examinar as fezes de aves silvestres capturadas em fragmentos de Mata Atl?ntica no distrito de Cacaria, no sudeste do Brasil, para identificar e quantificar os parasitas coccidianos que estavam presentes, al?m de relacion?-los a algumas caracter?sticas ecol?gicas das aves. Foram realizadas 14 expedi??es em 3 fragmentos de Mata Atl?ntica em Cacaria, resultando em captura de 143 aves, com 20 delas positivas para cocc?dios. Dentre as amostras positivas foram encontradas cocc?dios de classifica??o Isospora e Eimeira, em 12 esp?cies de aves. Esses cocc?dios foram identificados de acordo com a literatura, as esp?cies de cocc?dios n?o descritas na literatura at? o presente momento foram consideradas morfotipos. N?o se obteve rela??o entre as esp?cies de aves e as amostras positivas, com seus respectivos oopds (Oocisto por defeca??o). Em rela??o as caracter?sticas ecol?gicas, apenas h?bitos de viv?ncia em ambientes florestais foi significante, apresentando que as aves de ambientes florestais s?o menos suscept?veis a infec??o. J? em rela??o aos h?bitos alimentares, n?o se obteve resultados significativos.

Taking preventive measures has a major impact on the overall health status of poultry in every breeding and it can prevent considerable economic losses in this way. The aim of this study was to obtain basic knowledge about the occurence of coccidia oocysts in the faeces and the occurrence of pathological changes in the intestinal mucosa of broiler chickens after the use of selected feed supplements. Experiment was made during winter 2013 and summer 2014 with 250 specimens of one-day broiler chickens. Four experimental groups (prebiotics, probiotics, homeopathy, coccidiostats) and one control group were created. Treated groups were administered by Selected feed supplements were served to chickens during 14 days since the sixth day of their life. Mixed faeces samples were collected twice a week and processed in the laboratory. Also the frequency of coccidia oocysts was monitored under the light microscope. Intestines were collected during the slaughters of chickens (five pieces from every group) and tested to confirm or disprove pathological changes associated with coccidiosis of poultry. Intestines were collected three times after seven days. The Reduced frequency of occurrence of coccidia oocysts in faeces of chickens in all groups of the winter and the summer trial period was demonstrated, while pathological changes of the intestinal mucosa were not proved.

In der vorliegenden Arbeit wurden 212 Kotproben von Chamäleons auf Parasitenstadien und 75 Tierkörper pathologisch sowie bei einem nachgewiesenen Parasitenbefall histopathologisch untersucht. Ziel war es, anhand dieser Untersuchungen das Vorkommen und die Schadwirkungen von Endoparasiten unter Berücksichtigung der Herkunft, des Alters, des Geschlechts und der Chamäleonart zu beschreiben. Von 212 Kotproben wiesen 55,2% Endoparasitenstadien auf. Bei 54,7% der 64 sezierten und auswertbaren Tiere wurden Endoparasiten nachgewiesen. Der Anteil positiver Proben zeigt zwischen Nachzuchten (55,5%) und Wildfängen (54,1%) keinen wesentlichen Unterschied. In Wildfängen konnten häufiger Endoparasiten mit einem indirekten Lebenszyklus ermittelt werden, Nachzuchten beherbergten dagegen öfter Parasiten mit einem direkten Entwicklungszyklus. In den untersuchten Chamäleons konnten regelmäßig Kokzidien der Gattung Isospora und Oxyuriden nachgewiesen werden. Zestoden konnten in der koproskopischen Untersuchung gar nicht aufgefunden werden, wohingegen sie in der pathologischen Untersuchung sporadisch im Darm diagnostiziert werden konnten. Die Häufigkeit des koproskopischen Nachweises von Parasitenstadien bezogen auf die Gesamtzahl der untersuchten Chamäleons stellte sich wie folgt dar: in 30,4% wurden Protozoon gefunden, 21,7% der Tiere waren mit Kokzidien infiziert (davon 78,3% Isospora spp., 13,0% Choleoeimeria spp., 6,5% Eimeria spp., 2,2% Mischinfektion Isospora spp./Choleoeimeria spp.) und 8,5% mit Flagellaten oder Ziliaten. Bei 83,3% der Tiere mit gastrointestinalen Symptomen konnte ein Befall mit Kokzidien der Gattung Isospora nachgewiesen werden. In 38,7% der koproskopischen Untersuchungen konnten Nematoden (65,9% Oxyuriden, 19,5% Askariden/ Heterakiden, 1,4% Rhabdias sp., 2,8% Strongyloides sp., je 0,5 % Spirurida, Heterakiden/Filarien, Oxyuriden/Strongyloiden) und in 2,8% Trematoden (Digenea) aufgefunden werden. Anamnestisch konnten in 35,8% aller Tiere klinische Symptome beobachtet werden, wovon bei 88,2% der erkrankten Tiere ein Endoparasitenbefall nachzuweisen war. Insgesamt 64,1% der sezierten Chamäleons waren mit Endoparasiten befallen, wovon 68,3% Mono- und 31,7% Mischinfektionen beherbergten. In 31,3% der sezierten Chamäleons wurden Nematoden gefunden und der Befall wurde in 55,0% dieser Fälle als hochgradig eingestuft. Es wurden Befallsraten von 25,0% für Strongyloides sp., 23,4% für Askariden/ Heterakiden,15,0% für Filarien, 5,0% für Rhabdias sp., 9,4% für Zestoden, 10,9% für Digenea registriert. In 11,3% der Fälle lagen Mischinfektionen vor. Damit ist ein Endoparasitenbefall bei Chamäleons häufig und kann zu Erkrankungen führen. Die Exposition unterscheidet sich bei Wildfängen und Nachzuchten aufgrund der unterschiedlichen Umgebungsbedingungen. Auch klinisch unauffällige Tiere waren zu 27,8% mit Parasiten befallen, so dass eine klinische Symptomatik nicht zwingend aus einem Parasitenbefall resultiert. Insgesamt betrachtet verdient der Endoparasitenbefall von Chamäleons das Augenmerk von Tierärzten und Tierhaltern und sollte bei augenscheinlich hohem Infektionsdruck zu Gegenmaßnahmen, insbesondere auch einer verbesserten Hygiene, Anlaß geben. / In the present study 212 chameleon fecal samples were examined for parasite stages and 75 carcasses were examined histopathologically and pathologically in a proven case of a parasite infestation. The basis of this study was to describe the occurrence and harmful effects of internal parasites considering the origin, age and sex of the chameleons. Of the 212 fecal samples 55.2% showed stages of endoparasites. Parasites were detected at 54.7% of 64 evaluated and dissected animals. The proportion of positive samples shows no significant difference between offspring (55.5%) and wild specimens (54.1%). In wild specimens common internal parasites could be determined with an indirect life cycle, however offspring harbored more parasites with a direct life cycle. In the studied chameleons coccidia as the genus Isospora and Oxyurids were regularly detected. In the coprological study Cestodes could not be found, while in the pathological examination they could be diagnosed sporadically in the intestine. Based on the total number of investigated chameleons the frequency of detection of parasite stages are presented as follows: Protozoa were found in 30.4%, 21.7% of the animals were infected with coccidia (of which 78,3% Isospora spp, 13,0% Choleoeimeria spp., 6.5% Eimeria spp., 2.2% polyinfections between Isospora spp./ Choleoeimeria spp.) and 8.5% with flagellates or ciliates. At 83.3% of the animals with gastrointestinal symptoms coccidia of the genus Isospora were detected. In 38.7% of the fecal examination nematodes were determined (65.9% Oxyurids, 19.5% Ascarids/ Heterakis, 1.4% Rhabdias sp., 2.8% Strongyloides sp., 0.5% Spirurida, Heterakids/ Filariae, Oxyurids/ Strongyloides sp.) and Trematodes in 2.8% (Digenea) were found. The anamnesis showed that clinical symptoms could be observed in 35.8% of all of the animals, whereas endoparasite infestation could be detected inn 88.2% of the affected animals. Overall, 64.1% of the dissected chameleons were infested with parasites, of which 68.3% harbored mono- and 31.7% polyinfections. In 31.3% of the dissected chameleons nematode infestations were found and 55.0% of these cases were classified as severe. Prevalences were registered: 25.0% for Strongyloides spp., 23.4% for Ascarids/ Heterakids, 15.0% for Filaria, 5.0% for Rhabdias sp., 9.4% for Cestodes, 10.9% for Digenea. In 11.3% of the cases mixed infections were reported. Thus, endoparasite infestation is common among chameleons and can lead to diseases. Exposure differs from wild-specimens and captive-bred due to the different environmental conditions. Also, 27.8% of clinically healthy animals were also infested with parasites, which means that clinical symptoms are not necessarily the result of a parasitic infestation. Overall, chameleon endoparasites deserve the attention of veterinarians and pet owners and should be treated promptly when there is a high likelihood of infection or hygiene is of concern.

<p>The objective of this thesis was to investigate the effect of dietary enzymatically treated yeast (ETY) in weanling pigs and evaluate the effect of ETY in broiler chickens during a coccidia challenge. Two studies were carried out to investigate this objective.</p> <p>The first experiment examined the effect of ETY on the growth performance, nutrient digestibility, immune response, and gut health of weanling pigs. A total of 192 weanling pigs (6.0 ± 1.04 kg) were allocated to 4 corn, soybean-based diets with increasing concentrations of ETY (0, 1, 2, or 4 g/kg) for a 43-d trial. There were 8 replicate pens (4 replicate pens per sex) and 6 pigs per replicate for each dietary treatment. The experiment was set up as a randomized complete block design. Dietary ETY supplementation did not affect the growth performance of weanling pigs. The ATTD of neutral detergent fiber (NDF) linearly increased (P < 0.05) at d 28. The concentrations of serum antioxidant and antibody markers increased (P < 0.05) from d 14 to d 43; a linear increase (P < 0.05) in catalase was observed on d 14 with increasing ETY supplementation in the diets. The inclusion of ETY in the diet did not affect the mRNA abundance of anti-inflammatory markers in the ileal mucosa of pigs but increased (P < 0.01) glutathione peroxidase 4. Ileal villus height (VH) and villus height to crypt depth (VH:CD) ratio were greater (P < 0.05) in pigs fed ETY supplemented diets relative to control pigs. However, jejunal VH and the VH:CD ratio was not affected by ETY inclusion in the diet. Pigs fed diets with increasing ETY levels had higher (P < 0.05) ileal digesta butyrate concentration relative to control pigs, but not propionate or acetate. </p> <p>The second experiment examined the effect of ETY on the growth performance, nutrient digestibility, and intestinal health of broiler chickens during a coccidia challenge. From d 1 to 14 post hatching, 480 broiler chickens (49.9 ± 3.95 g) were allocated to 3 corn-soybean meal-based diets with increasing concentrations of ETY (0, 1, or 2 g/kg). There were 16 replicate cages and 10 birds per cage. The experiment was designed as a randomized complete block design with body weight (BW) used as a blocking factor. On d 14 post hatching, the birds were combined and re-randomized within each of the 0, 1, or 2 ETY g/kg experimental diets. Following this, the number of birds was reduced to 8 birds per cage with 8 replicate cages. Each of the 3 diet groups was split into a challenge or no-challenge group. This resulted in a 3 × 2 factorial arrangement of treatments with 3 experimental diets and 2 challenge states. The BW ratio before re-randomization was maintained across all treatments during the reallotment. On d 15 post hatching, the birds in the challenge group were orally gavaged with 1 mL solution containing 25,000, 25,000, and 125,000 oocysts of E. maxima, E. tenella, and E. acervulina, respectively. The birds belonging to the no-challenge group were orally gavaged with 1 mL phosphate buffered saline. Data were analyzed using the MIXED procedure of SAS, and polynomial contrasts were used to estimate the linear and quadratic effects of ETY. The coccidia challenge (CC) decreased (P < 0.01) the BW gain, feed intake, and G:F of broiler chickens from d 14 to 21. Increasing supplementation of dietary ETY improved (P < 0.05) the G:F of birds. Also, the CC reduced (P < 0.01) the apparent total tract utilization of dry matter (DM), nitrogen (N) and gross energy (GE). The CC reduced (P < 0.01) the apparent metabolizable energy (AME) and the nitrogen corrected apparent metabolizable energy (AMEn) of diets fed to broiler chickens. On d 21, dietary ETY linearly increased (P < 0.01) the apparent ileal digestibility of DM, N, and GE in broiler chickens. The CC increased (P < 0.01) the mRNA gene expression of TNFα, IL-1β, IL-10, and IL-6. There was a tendency (P < 0.1) for ETY to reduce IL-1β expression in broiler chickens on d 21. Additionally, ETY supplementation increased (P < 0.05) the gene expression of occludin in the ceca of broiler chickens but not claudin 1. Serum catalase increased (P < 0.05) with increasing supplementation of dietary ETY in broiler chickens on d 21. Dietary ETY linearly increased (P < 0.05) the ileal villus height to crypt depth ratio and ileal goblet cell count and density in broiler chickens. The ileal and excreta oocyst counts decreased (P < 0.01) with increasing supplementation of dietary ETY in coccidia-challenged broiler chickens on d 21. </p> <p>In summary, ETY inclusion in diets of weanling pigs partially reduced reactive oxygen species damage and enhanced intestinal health without negatively affecting growth performance. Hence, ETY could be favorable in attenuating some of the deleterious effects of post-weaning stress in weanling pigs. Dietary ETY also reduced oxidative damage, improved growth performance, enhanced nutrient utilization, and augmented intestinal development in broiler chickens. However, the inclusion of ETY did not mitigate the adverse effects of a coccidia challenge in broiler chickens. Therefore, further studies may be necessary to investigate the prospect of ETY as a dietary strategy for combating coccidiosis.</p> <p><br></p>