Investigating the relationship between feed and helminthic burden of captive birds of prey in Hong Kong.

The life cycle of most parasitic helminthes is related to their hosts feeding habits. Thus we need to investigate the impact of diet on the host's helminthic parasite burden. Not many studies in captive raptors have been conducted and published regarding parasitic infections. The aim of this study is to evaluate the helminthic burden of raptors kept in captivity and establish a relationship with the feed provided. A total of N = 51 different species of captive birds of prey were fed different diets consisting in different combinations of day old chicks, chicken breast, whole chicken carcass and mice. Their feces were sampled and the parasite burden was determined. A negative binomial model was successfully fitted to the data and the feeds "mice" (P < 0.001) and "whole chicken carcass" (P < 0.001) significantly contributed to an increase in the observed burden. Significant differences were also found between species (P < 0.001). Raptors fed adult animal carcasses and offal may explain the increase in the observed burden as these feeds have a larger probability of being contaminated by a larger variety of helminthic fauna.

Horse infection with intestinal helminths in relation to age, sex, access to grass and farm system.

A 11-year survey on helminth intestinal infection of horses was done in seven provinces of southern Poland. 21,641 faecal samples were collected from horses of different age, sex, breed and management system originating from 84 farms. Age was the major factor influencing the cyathostome egg excretion, the maximum being observed in yearlings and second year horses. Parascaris was found mostly in foals and yearlings. The main factor for Anoplocephala was the access to pasture. The level of cyathostome egg shedding (EPG) could be related to sex (geldings had higher values of EPG), breed (Thoroughbred had higher EPG than other breeds), and type of farm (large farms had higher EPG than others). The change during the survey of anthelmintic treatment (from benzimidazole or pyrantel embonate to avermectins) was associated with lower cyathostome EPG, and this was probably due to partial resistance to benzimidazole. The seasonality of egg shedding (lowest from November to January included) was due to management (leaving the pasture to stable, anthelmintic treatment in October). The influence of climate on EPG was significant but small, annual rainfalls and average temperature being associated negatively and positively, respectively, with high cyathostome EPG.

An examination of the relative reliability of laboratory case submissions in determining the prevalence of anthelmintic resistance in sheep nematodes in New Zealand, and the possible influence of test analysis methodology on such data.

AIM: To evaluate the likely reliability of laboratory case submissions in assessing the prevalence of anthelmintic resistance in sheep nematodes in New Zealand, and to examine the possible influence of two alternative faecal nematode egg count reduction (FECR) analysis methodologies on such data. METHODS: A comparison was made between the prevalence of anthelmintic resistance determined using faecal egg count reduction tests (FECRTs) conducted on randomly selected sheep farms in a national survey with those derived from similar case material submitted to a veterinary pathology laboratory on a more ad-hoc basis. A comparison was also made between two alternative FECR analysis methodologies using the latter data. One methodology involved a partially differentiated procedure in which FECRs for individual nematode genera were only undertaken in those instances where reductions in total strongylid faecal nematode egg counts (FECs) (excluding Nematodirus) of <95% were recorded. The other was a fully differentiated method where reductions in FECs for individual parasites were undertaken in all cases. RESULTS: Although there were some differences between them the results showed that there were considerable similarities between the prevalence data obtained from both the national survey and laboratory case submissions. This was particularly evident in relation to the overall pattern of involvement of the various nematode genera and the types of anthelmintic concerned. A comparison between laboratory case submission data analysed using a partially differentiated FECR methodology with that of a fully differentiated procedure, however, suggested that the use of the former practice was likely to lead to the 'true' prevalence of resistance being underestimated. CONCLUSIONS: The results of this study indicate that examination of FECRT case submissions to veterinary laboratories may offer a useful source of information regarding changes in the prevalence of anthelmintic-resistant sheep nematodes in New Zealand. They also lend support to suggestions that the recently completed national survey may have provided a conservative estimate of the prevalence of such resistance.

A survey of anthelmintic use and internal parasite control in farmed deer in New Zealand.

AIM: To survey parasite control programmes and anthelmintic usage over a 12-month period on deer farms in New Zealand. METHODS: A questionnaire of general farm data, policy and procedures for anthelmintic use, anthelmintic programmes for weaner and older deer, general information and understanding of parasite management practices was posted to 500 deer farmers in November 2004. RESULTS: Two hundred and twenty-seven (45.4%) replies were received, and 198 (39.6%) were suitable for analysis. Ninety four percent of respondents used anthelmintics at least once in the 12-month period; 53% treated all classes of deer and 22% treated only weaners. Seventy-four percent based anthelmintic dose on weight of the heaviest animal, and 36% used a weigh scale. Weaner deer (n=175 farms) were treated 1-13 (mean 3.2) times in their first 12 months, at the earliest commencing in January and at the latest in November. The mean interval between treatments ranged from 41 to 46 days. Yearling and adult hinds and stags were treated at least once (range 1-7 times) on 55-64% of farms, depending on class of animal. Moxidectin was the anthelmintic most commonly used (46-58%, depending on class of animal), followed by abamectin, eprinomectin, oxfendazole, ivermectin, albendazole, levamisole and doramectin. Perceived efficacy was the most common reason for choosing a type of anthelmintic. Weight gain and body condition were the most common measures used for monitoring parasitism in weaners and older deer, respectively, and few respondents used faecal egg and/or larval counts. Coughing and/or scouring were associated with parasitism in weaners on 13-14% of farms, and deaths associated with lungworm and gastrointestinal parasites were recorded on 5% and 3% of farms, respectively. Veterinary input to diagnosis was involved in 23% of events. Production losses and/or death of yearling and/or adult deer due to parasitism were reported by 27% of respondents. When planning anthelmintic treatment programmes, 63% of respondents followed advice from veterinarians. Thirty four percent always placed deer on clean or spelled pastures after treatment, while 32% did that often. Fifteen percent had incorporated forages and/or herbs with assumed anthelmintic properties into their parasite control programme. Forty-four percent were very confident of a return on investment when using anthelmintics for their deer. Respondents stated that their knowledge of the life cycle of the major parasites of deer was very good (8%), reasonably good (61%), poor (28%), or nil (3%). CONCLUSION: Anthelmintics are used on almost all deer farms, and practices and programmes vary considerably. Opportunities exist for veterinarians to assist deer farmer clients to improve their parasite control programmes.

Etiology and prophylaxis of helminthiasis in sheep in Burkina Faso.

Helminths of "Mossi" sheep from traditional livestock were investigated at three different seasons (humid, cold dry, and hot dry seasons) in the village of Donsin from the central land of Burkina Faso. Three prophylaxis plans using Fenbendazole were tested. Primary parasites identified were: Oesophagostomum sp., Trichostrongylus sp., and Haemonchus contortus. These parasites were noticed mainly during the rainy season with mean egg per gram (epg) numbers of 500 +/- 141.42 in August-September, at the end of the rainy season. At this same period, hematocrit (22%) and body weights (17 kg of live weight) (LW) were low. These values progressively increased to reach their highest levels (32% and 27 kg of LW respectively) in February. The prophylactic plan consisting of two treatments with oral drench of 5 mg/kg LW of Fenbendazole turned out to be the most efficacious and the most economical.

Pathogenesis of helminths in equines.

This review summarizes information on the clinical signs, gross and microscopic lesions associated with nematode and cestode infections and discusses the development of these conditions in the equine host.