No description available.

Despite the popularity of companion animal ownership in Australia, recent and comprehensive information with regard to the prevalence, epidemiology and public health significance associated with gastrointestinal parasites of pet dogs and cats in Australia is largely lacking. The primary aims of this study were to close this knowledge gap and to evaluate the veterinarian’s perception, awareness and knowledge of GI parasites in their locality, from a veterinary and public health stand-point. This included sourcing information with regard to commonly recommended deworming protocols. The awareness of pet owners regarding parasitic zoonoses and the degree of education provided to them by veterinarians was also determined. A total of 1400 canine and 1063 feline faecal samples were collected from veterinary clinics and refuges from across Australia. The overall prevalence of gastrointestinal parasites in dogs and cats was 23.9% (CI 21.7-26.1) and 18.4% (CI 16.1-20.7), respectively. Overall Giardia duodenalis was the most prevalent parasite in dogs (9.3%, CI 7.8-10.8) followed by hookworm (6.7%, CI 5.4-8.0). Isospora felis was the most prevalent parasite in cats (5.6%, CI 4.2-7.0), followed by Toxocara cati (3.2%, CI 2.1-4.3). A highly sensitive and species-specific PCR-RFLP technique was utilized to differentiate the various hookworm species which can infect dogs and cats directly from eggs in faeces. Ancylostoma ceylanicum was detected for the first time in Australia in 10.9% of the dogs found positive for hookworm. This was a significant finding in terms of the zoonotic risk associated with this parasite. The zoonotic potential of Giardia and Cryptosporidium was investigated by genetically characterising isolates recovered from dogs and cats. All but one of the Giardia isolates successfully genotyped were host specific, indicating a low zoonotic risk. It was hypothesized that the lack of zoonotic Giardia Assemblages was a consequence of there being a low prevalence of Giardia in the human population. The Cryptosporidium recovered from dogs and cats was determined to be Cryptosporidium canis and Cryptosporidium felis respectively, a finding which supports growing evidence that Cryptosporidium in companion animals is of limited public health significance to healthy people. Very few of the veterinarians surveyed in the study routinely discussed the zoonotic potential of pet parasites with clients. Most of the veterinarians recommended the regular prophylactic administration of anthelmintics throughout a pet’s life. The low national prevalence of GI parasites reported is most likely a consequence of the widespread use of anthelmintics by pet owners. There is an over-reliance on anthelmintics by veterinarians to prevent and control parasites and their zoonotic risk. This has resulted in veterinarians becoming complacent about educating pet owners about parasites. A combination of routinely screening faecal samples for parasites, strategic anthelmintic regimes and improved pet owner education is recommended for the control of GI parasites in pet dogs and cats in Australia.

A simultaneous survey of canine and human gastrointestinal (GI) parasites was conducted in three socioeconomically disadvantaged, tea-growing communities in Assam, India. The aims of this study were to determine the epidemiology of GI parasites of zoonotic significance in dogs and geohelminth infection in humans using a combination of molecular biological and classical parasitological and epidemiological tools. A total of 328 and 101 dogs participated in the study. The prevalence of GI parasites in dogs was 99%. Parasitic stages presumed to be host-specific for humans such as Ascaris spp., Trichuris trichiura and Isospora belli were also encountered in dog faeces. A polymerase chain reaction - linked restriction fragment length polymorphism (PCRRFLP) was developed to identify the species of Ascaris eggs in dog faeces. The results supported the dog's role as a significant disseminator and environmental contaminator of Ascaris lumbricoides, in communities where promiscuous defecation by humans exist. The prevalence, intensity and associated risk factors for infection with Ascaris, hookworms and Trichuris were also determined among the human population. The overall prevalence of Ascaris was 38% and 43% for both hookworms and Trichuris. The strongest predictors for the intensity of geohelminths included socioeconomic status, age, household crowding, level of education and lack of footwear when outdoors. The zoonotic potential of canine Giardia was investigated by genetically characterising G. duodenalis isolates recovered from humans and dogs at three different loci. Phylogenetic analysis placed canine Giardia isolates within the genetic groupings of human isolates. Further evidence for zoonotic transmission was supported by strong epidemiological data. A highly sensitive and specific PCR RFLP based test was developed to detect and differentiate the species of canine hookworms directly from eggs in faeces. Thirty-six percent of dogs were found to harbour single infections with A. caninum, 24% single infections with A. braziliense and 38% mixed infections with both species. This newly developed PCR-based test provided a rapid, highly sensitive and specific tool for the epidemiological screening of canine Ancylostoma species in a community. A combination of canine population management, effective anthelmintic regimes and improvements in health education and sanitation is recommended for the control of canine and human gastrointestinal parasites in these communities.

Thesis (M. Agricultural Management (Animal Production)) -- University of Limpopo, 2018 / Ethno veterinary medicine practices are popular among the resource constrained small-holder farmers. Nonetheless, the effectiveness of traditional remedies particularly the indigenous plants has not been extensively documented. Hence, this study was conducted to determine efficacy of indigenous plant extracts used by small-holder farmers in Chief Albert Luthuli Local Municipality, Mpumalanga Province, South Africa for internal parasites control. Information on indigenous plants used for the control of internal parasites of livestock by local farmers in the study area was gathered through a questionnaire survey. A total of 188 livestock farmers (both males and females) of mixed ages were interviewed. Thirteen different plants were frequently mentioned by the respondents as remedies for livestock internal parasites. Of these, seven plants could be identified up to their families and species. Plant species collected were Dicerocaryum sp (50%), Pappeacapensis (61%), Aloe ferox (90%), Helichrysum sp (56%), Senecio congestus (83%), Senecio barbertonicus (67%) and Gardenia sp (73%). These plants were extracted using distilled water and analysed to determine their efficacy through in vitro assays; Egg hatch, larval development and larval mortality assays. All the assays were performed at different concentrations of 2.5mg/ml, 5.0mg/ml and 7.5mg/ml. The nematode third stage larvae were incubated for 24hr, 48hr and 72hr during the larval mortality assay. The present study showed that all the seven-plant species under investigation possessed some anthelmintic activities of varying strength. The highest egg hatch inhibition was observed from the extracts of Senecio barbertonicus with 100 % and the lowest from Dicerocaryum eriocarpum with 2.25 %, for larval development the highest was Gardenia sp 100 % and the lowest Helichrysum sp 26 % at concentration 7.5 mg/mL respectively. Whereas, the highest in larval mortality assay was Senecio barbertonicus and Gardenia sp achieved 100 % after 48hrs and the lowest was Dicerocaryum eriocarpum with49.89 % after 72hrs at concentration 7.5 mg/mL respectively. The use of other different forms of extraction media is recommended because different results can observe and be compared with the results of the present study. Toxicity studies on the indigenous plants observed to have stronger anthelmintic activities would assist in the future recommendation of these remedies for large scale or commercial use as anthelmintic drugs. Keywords: ethno veterinary medicine, gastrointestinal parasites, anthelmintic

Made available in DSpace on 2016-08-15T20:27:55Z (GMT). No. of bitstreams: 1 AnaCDSB_TESE.pdf: 11862899 bytes, checksum: db329299185e2c022af1f916b746aae8 (MD5) Previous issue date: 2014-11-14 / The increase in anthelmintic resistance in gastrointestinal nematodes on small ruminants became a worldwide issue on the development of livestock. In order to assess the resistance scenario in that context in the Rio Grande do Norte region, in vivo and in vitro resistance tests were carried out in 30 rural properties using chemicals in the avermectin, salicylanides, benzimidazoles and imidatiazols groups. For the in vivo test, group I was used as control and four other experimental groups received oral medication, being group II given albendazole (10 mg/kg), group III levamisole (7.5 mg/kg), group IV closantel (5.0 mg/kg) and group V ivermectin (0.2 mg/kg). The nematode infection was determined using fecal egg count (FEC) essays and the efficiency of each treatment was analyzed by the fecal egg count reduction test (FECRT). For the in vivo e in vitro tests, using tiabendazole, the necessary concentration to inhibit 50% of egg hatching (EC50) and assays with a 50% inhibition of larval development (LD50) were assessed, however 50% of larval development and migration inhibition assays (LD50) essays were carried out using ivermectin. For the molecular analysis Haemonchus contortus/property were isolated for the calculation of the frequency of resistant and sensitive alleles for single nucleotide polymorphisms (SNPs): F220Y, F167Y and E198A. The results obtained from in vivo tests showed that resistance was detected for all of the drugs, with leavamisole and closantel appearing as the most effective treatments with FECRT results of 84.3% and 74.6%, respectively. In the in vitro assays, tiabendazole had a result in the hatching test of EC50 0.598 µg/ml (95% IC: 0.323-0.818), while exhibiting in the larval development test a LD50 and LD99 0.518 µg/ml(95% IC: 0.432-0,887) and 4.359 µg/ml (95% IC: 3.047-8.178), respectively. For ivermectin in the larval development test, DL50 0.637 µg/ml(95% IC: 0.382 0.903 µg/ml) e DL99 19.56 µg/ml(95% IC: 11.44 46.55 µg/ml) was observed, while in the migration essay the LD50 value was 16.337 µM (95% IC: 12.7-21.3 µM). In the molecular analysis a higher frequency of the resistant allele for SNP F200Y was observed, presenting higher percentage values of 85.81% and 73.11%, while the F167Y resistant alleles had lower values ranging from 2.93% to 43.73%. In the E198A SNP, only sensitive alleles were detected. Assessing the scenario of anthelmintic resistance in the region, one notices that it s established for the main existing drugs on the market / O aumento na resistência anti-helmíntica em nematóides gastrintestinais de pequenos ruminantes tornou-se um problema global para o desenvolvimento da pecuária. Nesse contexto, a fim de avaliar o cenário da resistência na região do Rio Grande do Norte foram realizados em 30 propriedades rurais testes de resistência in vivo e in vitro utilizando produtos químicos dos grupos das avermectina, salicilanilidas, benzimidazóis e imidatiazóis. Para o teste in vivo utilizou-se o grupo I controle quatro grupos experimentais, sendo grupo II albendazol (10 mg/kg), grupo III levamisol (7,5 mg/kg), grupo IV closantel (5,0 mg/kg) e grupo V ivermectina (0,2 mg/kg). A infecção por nematóides foi determinada utilizando ensaios de ovos por grama de fezes (OPG) e a eficiência de cada tratamento pelo teste de redução da contagem de ovos nas fezes (FECRT). Para os teste in vitro, foi utilizando tiabendazol, com concentrações necessária para inibir 50% de eclosão dos ovos (EC50) e ensaios com inibição de 50% do desenvolvimento larval, porém com a ivermectina foram realizados ensaios de inibição de 50% do desenvolvimento e migração larval (DL50). Para análise molecular foram isolados Haemonchus contortus em cada propriedade avaliada para cálculo da frequência de alelos resistentes e sensíveis para os polimorfismos de nucleotídeo único (SNPs): F200Y, F167Y e E198A. Os resultados obtidos com os testes in vivo e in vitro mostraram que a resistência foi detectado em todas as drogas testadas, com o levamisol e closantel apresentando-se como os tratamentos mais eficientes, com resultados FECRT de 84,3% e 74,6%, respectivamente. Nas análises in vitro o resultado do tiabendazol no teste de eclosão foi EC50 0,598 µg/ml (IC95%: 0,323-0,818), enquanto que no desenvolvimento larval uma DL50 e DL99 de 0,518 µg/ml(IC95%: 0,432-0,887) e 4,359 µg/ml(IC95%: 3,047-8,178), respectivamente. Para ivermectina no teste de desenvolvimento larval foi observado DL50 0,637 µg/ml(CI95%: 0,382 0,903 µg/ml) e DL99 19,56 µg/ml(CI95%: 11,44 46,55 µg/ml), enquanto que no de migração o valor da DL50 foi 16,337 µM (CI95%: 12,7-21,3 µM). Na análise molecular observou-se uma frequência maior do alelo resistente para o SNP F200Y apresentando porcentagens mais altas com valores de 85,81% e 73,11%, enquanto que o F167Y apresentou valores menores de alelos resistentes variando entre 43,73% e 2,93%. No SNP E198A foram detectados alelos apenas sensíveis. Avaliando o cenário da resistência anti-helmíntica na região, percebe-se que está estabelecida para as principais drogas existentes no mercado

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.

No description available.

A reduction in voluntary feed intake is a major factor in the lost productivity of grazing lambs infected by gastrointestinal parasites yet the mechanisms involved are poorly understood. Potential pathways involved in parasite-induced feed intake depression were investigated in lambs with minimal previous exposure to parasites and artificially infected by the small intestinal parasite Trichostrongylus colubriformis. Six in vivo experiments were conducted on lambs housed in individual pens or metabolism crates with similar feeding and experimental procedures. In Experiment 1 (Chapter 4) the effect of T. colubriformis infection on short term feed intake in lambs and of some pharmacological agents on feed intake depression were investigated. Prior to and for the duration of infection, lambs were fed once per day and feed intake recorded at regular intervals over the day (8 h). Following the onset of feed intake depression in the infected group (9 weeks after commencing dosing), all animals were treated with an analgesic (codeine phosphate per os), an anti-inflammatory agent (indomethacin per os), a CCK antagonist (L364-718 by subcutaneous injection) or saline (control) in a replicated Latin square design (n = 8). Although the pattern of feed consumption was similar in infected and non-infected lambs, average daily intake was reduced 32 % and short term intake (recorded at 10 minute intervals for the first hour of feeding, 15 minute intervals for the second hour and hourly for the next 6 hours of feeding) reduced 40 % by infection. This identified the key component by which intake was depressed and enabled the use of a short term intake model and short duration of action compounds to identify the pathways involved in intake depression in this sequence of experiments. None of the pharmacological treatments increased intake in the infected group. These results suggest a reduction in the rate of consumption due to reduced hunger signals, rather than change of meal eating patterns, is the major cause of feed intake depression. Specific conclusions about the pathways investigated using the pharmacological agents could not be obtained. Experiment 2 (Chapter 5) was designed to investigate the roles of pain and osmolality on feed intake depression. Digesta samples collected prior to and during parasite infection and before and after feeding had similar osmolalities (240-260 mosmol/l) which indicated that feeding or infection had no effect on osmolality of digesta. Following the onset of feed intake depression in infected animals, all animals were treated in a Latin square design (n = 4) with no treatment, saline, local anaesthetic (xylocaine) or analgesic (codeine phosphate) solution 15 minutes before feeding, by slow injection into the duodenum. There was no effect of these treatments on food intake. In the second part of the experiment, hyperosmotic solutions (mannitol and NaCI) markedly depressed short term intake in non-infected animals, suggesting a role for osmoreceptors in intake regulation. However these effects were not blocked by local anaesthetic so the depressed intake may have resulted from generalised malaise rather than from specific osmoreceptor effects. In Experiment 3 (Chapter 6) the role of peripheral CCK on intake depression was examined by a dose-response study utilising the CCK antagonist, loxiglumide. Intravenous injection of 5, 10 or 20 mg/kg LW of loxiglumide to infected lambs 10-15 minutes before feeding (n = 6) had no effect on feed intake at any of the dose levels. In experiment 4 (Chapter 7) loxiglumide was infused intravenously for 10 minutes (30 mg/kg/h) before feeding and for the first 2 h (10 mg/kg/h) after feed was offered to minimise any effect of the rate of clearance of loxiglumide on the lack of feed intake response. As well, the rate of marker disappearance from the abomasum was recorded in both infected and non-infected animals. Continuous infusion of loxiglumide did not attenuate parasite induced intake depression nor did it have any effect on abomasal emptying. Abomasal volume was reduced by infection (66.3 vs 162 ml) as was the fractional outflow rate (2.2 vs 2.8 ml/min) but these differences were accounted for by the lower level of feed intake in the infected animals. In Experiment 5 (Chapter 8) brotizolam, a benzodiazepine appetite stimulant, thought to act on the hypothalamus, was administered in a dose-response study to infected and non-infected animals (n = 4) immediately prior to feeding or following termination of the first meal (45 minutes after feeding) and the feed intake response recorded. Brotizolam elevated both the short term (0-0.75 h), daily (22 h) intake and all time intervals in the first 5 h after feeding in infected and non-infected animals when administered after the first meal but when administered prior to feeding elevated intake only over the first 6 h of feeding. In both cases the magnitude of the response was greater in infected animals than in non-infected animals. Brotizolam appeared to increase the rate of eating without having a major impact on meal eating patterns when administered before feeding. Where administration was after the first meal, the effect was due to an "extra" meal being consumed. These findings showed that infected animals can respond to central stimulators of intake although the mechanism of the response is not known. Opioids were implicated in intake depression as the rate of intake rather than meal patterns appeared to be the major parameter depressed under parasitism. This was examined in experiment 6 (Chapter 9) where animals (n = 6) were fasted for 26 h or not fasted, then treated with saline (control), brotizolam (intake stimulant) or naloxone (opioid antagonist) immediately prior to feeding. Fasting stimulated feed intake in the short term (100 % increase in 75 min) and over the day (12 % increase) in both infected and non-infected animals. Following fasting, infected animals ate a similar amount of feed to the non-infected, fasted animals and more than the non-infected, non-fasted animals. The signals resulting from a one day fast were sufficient in the short term to override parasite induced mechanisms causing feed intake depression. Naloxone suppressed the intake stimulatory effects of a 26 h fast in both infected and non-infected animals, which supports a role for endogenous opioids as hunger signals. Where animals were not fasted, naloxone reduced intake only in the non-infected animals which suggested endogenous opioid levels may be lower in infected animals than in non-infected animals. In the final experiment (Experiment 7, Chapter 10) the role of central hunger and satiety mechanism were investigated. Infected and non-infected animals (n = 6) were treated with naloxone or saline by intravenous injection, or saline and met-enkephalinamide (an opioid analogue) by intracerebral infusion, or naloxone and the opioid analogue simultaneously to investigate the role of central opioids in feed intake depression. To determine the role of CCK induced satiety signals on feed intake at a central level, loxiglumide and CCK were infused separately and in combination for 30 minutes prior to feeding and for the first 60 minutes of feed on offer, into a lateral cerebral ventricle of the brain of infected and control animals (n = 6). The opioid analogue tended to increase intake in infected animals but the effect was not significant probably because the dose used was too low to elicit a response in sheep. Naloxone depressed intake only in the infected animals, which conflicted with the results of Experiment 4. As a consequence these results were inconclusive because of the single low dose of opioid analogue used and the conflicting naloxone responses. CCK alone depressed intake by 39-52 % only in infected animals and this effect of the 90 minute infusion was evident over the 8 h short term recording period. Loxiglumide attenuated the feed intake depressive effects of CCK in the infected animals to the extent that intake was elevated above control levels. Loxiglumide alone was an intake stimulant in both infected and non-infected animals. Intake was increased over the entire 8 h but mostly in the second hour when intake was increased by 188 % in infected animals and by 16 % in the non-infected animals and resulted in almost continuous eating. These results showed loxiglumide will temporarily block the effect of parasite infection on feed intake in sheep when administered centrally and the fact that it blocked the effects of exogenous CCK on intake indicated that the effect is mediated via CCK receptors. In conclusion GIT parasite infection reduced both short term and daily feed intake apparently by a change in rate of intake rather than any alteration in meal patterns. It was further suggested that anyone of a number of potential peripheral pathways, including changes to osmolality, gut emptying, pain and inflammation of the gut, alone is not involved in anorexia in sofar as the compounds used could block these factors and the results support the idea that intake depression is mediated via a central mechanism. Intake in infected animals responded to a much greater extent when fasting, i.c.v. loxiglumide or brotizolam were employed. Feed intake thus appears to be regulated through the same mechanisms in infected and non-infected animals. The results from compounds affecting the central mechanism suggest central CCK receptors are important in parasite induced anorexia, possibly by changing the onset of satiety or by interacting with endogenous opioids to reduce the rate of feed intake. Secondly reduced endogenous opioids may be causing the reduction in the rate of feed consumption alone or as a result of other interactions. It was concluded that intake in parasitised animals could be increased to that of control animals by employing procedures and compounds thought to act on the hypothalamus.

La résistance aux lactones macrocycliques (LM) constitue une préoccupation croissante dans le contrôle des nématodes parasitaires, notamment l'Haemonchus contortus chez les ruminants. Parmi les mécanismes étudiés dans la résistance aux LM chez les nématodes d’importance en santé animale, il y a les pompes ABC, principalement les glycoprotéines-p, connues pour leur rôle dans la détoxification des LM chez les strongles. Il n'existe toutefois aucune étude sur l'extrusion des lipides par les pompes ABC en tant que produits excrétoires/sécrétoires provenant d'H. contortus (Hc-PES). Nous émettons l’hypothèse que les pompes ABC chez H. contortus sont à la fois impliquées dans l’extrusion de LM (contribuant à la résistance aux antihelminthiques) et dans l’efflux de lipides secrétés par le parasite. Notre objectif était de caractériser le rôle des pompes ABC chez H. contortus dans le contexte de la résistance aux LM et de l'extrusion des lipides. L'efficacité de l'ivermectine, un membre de LM, a été évaluée dans 8 fermes étudiées par un test de réduction de la numération des œufs dans les selles (TRNOS). Les niveaux d'expression des pompes ABC ont été évalués dans des isolats de champ d’H. contortus avec des résultats TRNOS faibles (présumé souches résistantes). D’ailleurs, des vers adultes d’H. contortus ont été incubés avec trois inhibiteurs de pompes ABC, dont le Fumitremorgin C, le Kétoconazole et le Mk-571 à concentrations différentes. Les lipides ont été identifiés par CL/SM dans les milieux de culture récupérés à 2 h, à 4 h et à 8 h après l'incubation d’H. contortus dans les groupes contrôle et traités. L'expression des gènes Hco-pgp-2 et Hco-pgp-3 était augmentée chez les isolats de champ d’H. contortus. Nous avons identifié 1045 lipides appartenant à diverses catégories. L'extrusion des lipides en Hc-PES a changé en présence d'inhibiteurs de pompes ABC, en particulier pour les lipides composés de structures correspondant à celles pour le transport par les pompes ABC. Nous avons donc conclu que les pompes ABC chez H. contortus représentent un système de multi-extrusion et sont impliquées dans la sécrétion de lipides avec importance dans l’interaction avec l’hôte, mais aussi dans la résistance aux LM chez le nématode. / Macrocyclic lactones (MLs) resistance is a growing concern in controlling parasitic nematodes, particularly Haemonchus contortus in the ruminants’ industry. ABC transporters are known to participate in translocating various lipophilic molecules, including MLs and lipids. Some ABC transporters, mostly P-glycoproteins are known to be involved in MLs detoxification in parasitic nematodes; but there is no data about extrusion of lipids by ABC transporters as Excretory/Secretory Products in H. contortus (Hc-ESP). We hypothesize that ABC transporters in H. contortus have a dual role participating in the efflux of MLs, thus contributing to anthelmintic resistance, and in the extrusion of lipids out of the parasite. This study aimed to characterize the role of H. contortus ABC transporters in the context of ML resistance and the extrusion of lipids. Ivermectin (a member of MLs) efficacy was evaluated in 8 studied farms by the fecal egg count reduction test (FECRT). The expression levels of ABC transporters were evaluated in field isolates of H. contortus with low FECRT results (suspected of resistance). H. contortus adult worms were incubated with three ABC inhibitors, such as Fumitremorgin C, Ketoconazole and Mk-571 with different concentrations. Lipids were identified by LC/MS in culture media at 2h, 4h and 8h post incubation with H. contortus in control and treated groups. Hco-pgp-2 and Hco-pgp-3 were found upregulated in H. contortus field isolates. We identified 1045 lipid molecules belonging to different categories. Interestingly, the lipid profile in Hc-ESP was altered in the presence of ABC transporter inhibitors, which shows structural features compatible as substrates for nematode transporters’ activity. Therefore, ABC transporters in H. contortus participate in extrusion of lipids and also may help in detoxification of MLs, becoming a multipurpose pumping system involved in ML resistance and secretion of lipids at the interplay with the host and among nematodes.