Output of gastrointestinal nematode eggs in the feces of captive gazelles (Gazella dama mhorr, Gazella cuvieri and Gazella dorcas neglecta) in a semiarid region of southeastern Spain.

Feces from 62 captive African gazelles, including Mhorr gazelles (Gazella dama mhorr), Cuvier's gazelles (Gazella cuvieri), and Dorcas gazelles (Gazella dorcas neglecta), were examined over the course of a year to quantitate nematode egg excretion patterns. Strongyloides sp. eggs appeared only in G. dama during the rainy season. Trichostrongylidae egg excretion showed a marked seasonal variation, with very low levels during the dry and hot period, a finding that is probably attributable to hypobiosis of the predominant species (Camelostrongylus mentulatus). Eggs of the Nematodirus sp., predominantly Nematodirus spathiger, were excreted throughout the year. No seasonal pattern was observed in Trichuris sp. egg excretion.     

Cutaneous chlorellosis in a gazelle (Gazella dorcas)

Cutaneous chlorellosis in a gazelle caused a chronic granulomatous inflammation in the subcutaneous tissue of the carpus. The diagnosis was based on the intense green color of the lesion and the presence of organisms identified as algae of the order Chlorellales. According to morphologic and ultrastructural features, the genus Bracteacoccus is most likely.     

Periparturient rise in faecal helminth egg counts of Udah sheep in the Zaria area of Nigeria

The trichostrongylid egg output in the faeces of seven lambing and seven barren Udah ewes was compared during the beginning of the rainy season in 1974. Both groups showed an increase in egg counts which reached a considerably higher level in the lambing ewes. The highest level, a mean count of 2 650 eggs/g, was reached 2 weeks after lambing.It is suggested that the increase was due to helminths, mainly Haemonchus sp., which had been inhibited during the dry season and resumed their development at the beginning of the rainy season.The rapid decline in egg counts recorded 5–6 weeks after lambing was considered to be due to self cure associated with high rainfall.     

Immunohistochemical identification of generalized AA-amyloidosis in a mountain gazelle (Gazella gazella)

Generalized amyloidosis was diagnosed post-mortem in a mountain gazelle (Gazella gazella). To test whether the amyloid deposits consisted of amyloid-A fibril protein a series of monoclonal and polyclonal antibodies directed against amyloid-A fibril protein of different species was applied to formalin-fixed paraffin sections using the indirect immunoperoxidase technique. The immunohistochemical results showed a moderate cross-reaction of gazelle amyloid with human, murine, hamster, and canine amyloid-A fibril protein. A strong cross-reaction, however, was found with one of two monoclonal anti-human amyloid-A antibodies and with an antiserum against bovine amyloid-A fibril protein, the amyloid fibril protein of another ungulate. These results demonstrate the presence of amyloid-A fibril protein in the gazelle amyloid and illustrate the diagnostic value of cross-reacting anti-amyloid-A antibodies for the identification of amyloid-A-amyloidosis in species and in individuals in which amyloid has not yet been examined.     

Periparturient rise in faecal nematode egg counts in west African dwarf sheep in southern Ghana in the absence of arrested strongyle larvae

The nematode egg output of two groups of ewes, a pregnant test group (2-3 years of age) mated between March and April and a non-pregnant control group (5-6 years of age) was followed. The worm burdens acquired by worm-free 'tracer' lambs were also followed on the same pasture from March 1988 to February 1989. There was a significant difference (P less than 0.05) in the magnitude of the egg output in the test group compared with the control group. In the test ewes, an initial rise in egg production occurred 2 weeks after lambing and was maintained for five consecutive months. Necropsy worm counts from the 'tracer' lambs revealed that pasture larval levels were directly related to the levels of rainfall. Adult nematodes (Trichostrongylus colubriformis, Trichostrongylus axei, Haemonchus contortus, Oesophagostomum venulosum and Trichuris ovis), and some Moniezia expansa were present in almost all the lambs throughout the year, with the exception of January and February 1989. The absence of immature larvae in these lambs indicates that arrested development is not a feature of the life cycle of these species in Southern Ghana. The occurrence of a periparturient rise of nematode eggs in West African Dwarf ewes, a year-round breeder, means that susceptible lambs could be open to infection throughout the year. Control should, therefore, be conducted by treating ewes after lambing and restricting the breeding season to particular periods of the year.     

The efficacy of ivermectin and levamisole against natural Nematodirus spathiger infection in the Arabian sand gazelle (Gazella subgutturosa marica) and the Arabian mountain gazelle (Gazella gazella) in Saudi Arabia

The efficacy of two broad spectrum anthelmintics (Ivermectin and Levamisole) against the nematode Nematodirus spathiger in the reem (Arabian sand gazelle) and idmi (Arabian mountain gazelle) at King Khalid Wildlife Research Centre (KKWRC) was determined. Gazelles of both species naturally infected with N. spathiger were each divided into 3 groups. One group was treated with Ivermectin, the other group with Levamisole and the last group was left as untreated control. Faecal egg counts were employed to determine the efficacy of the two drugs against N. spathiger infection in both gazelle species. Reduction in arithmetic mean faecal egg counts achieved by Ivermectin and Levamisole in the reem gazelles was 94% and 89.3%, respectively. The reduction in the idmi gazelles was 97.2% and 96.4%, respectively. Hence, both anthelmintics appeared to be more effective in the idmi gazelles than in the reem gazelles, however, there was no significant difference in the faecal egg reduction tests in both animal species.     

A comparison of lungworm faecal larval counts and trichostrongyloid faecal egg counts between red deer (Cervus elaphus) and red deer x wapiti F1 hybrids

To determine if breed differences in susceptibility to trichostrongyloid and lungworm infection exist, two groups of weaner deer containing seven red deer and red deer x wapiti F1 hybrids were compared using faecal egg counts and faecal larval counts. All animals were run on the same pasture at the same time and treated with the same anthelmintics at the same time. Results indicated that there were significant differences between red deer and red deer x wapiti hybrids, with red deer having higher faecal lungworm counts and red deer x wapiti hybrids having significantly higher faecal egg counts. It is likely that these differences were due to breed. Differences in the efficacy of anthelmintic treatments were also noted between the two groups, with oral oxfendazole being less effective at reducing faecal lungworm counts in red deer X wapiti hybrids than red deer.     

The repeatability of faecal egg counts in Polish Wrzosówka sheep

The number of nematode eggs in the faeces was estimated in Polish Wrzosówka sheep, in the spring and autumn of 1993 and again in 1994. The sheep had been naturally infected. The dominant species were Haemonchus contortus and Teladorsagia circumcincta, but Trichostrongylus spp., Cooperia curticei, Nematodirus spp. and Chabertia ovina were also present. Anthelmintics were not used. Egg counts were skewed, with a range of 0–4100 eggs g⁻¹ (EPG); most sheep had egg counts below 100 EPG. Egg counts were approximately four times higher in spring than in autumn. Repeatability values within a season were all significant and positive. The repeatability of egg counts between seasons was estimated from the correlation between the mean transformed value in spring and in autumn, and was 0.52 in 1993 (P < 0.001) and 0.41 in 1994 (P < 0.05). The results show that animals with higher than average values in spring are likely to have higher than average values in autumn, and suggest that similar mechanisms regulated egg counts in both seasons even though egg counts were much lower in autumn.     

Dynamics of faecal egg counts in rabbits experimentally infected with Strongyloides papillosus

An experiment using rabbits was carried out to determine basic data to maintain the calf strain of Strongyloides papillosus (SPL). Rabbits treated with four different numbers of doses of dexamethasone were exposed to 50,000 or about 100,000 infective larvae of SPL (Himeji strain, 1988). As a result, faecal egg output was valid in individual rabbits, regardless of dexamethasone administration. Eggs appeared in the faeces 9 or 10 days after exposure, and increased to as much as 20,000-573,000 eggs per gram (EPG). Thirteen of 18 rabbits died (72%) 12-29 days after infection. Five surviving rabbits discharged eggs in their faeces for more than 1 month; however, the EPG value of these cases on the last day was comparatively low.     

An outbreak of Salmonella enterica serotype Choleraesuis in goitered gazelle (Gazella subgutrosa subgutrosa) and a Malayan tapir (Tapirus indicus)

An outbreak of Salmonella enterica serotype Choleraesuis enteritis occurred in two juvenile goitered gazelles and an adult Malayan tapir over a period of 5 wk at the Minnesota Zoo. Diagnosis was made postmortem on one gazelle and one tapir, and a second gazelle was diagnosed via fecal culture. The death of the tapir was attributed to S. enterica serovar Choleraesuis septicemia, while salmonellosis was considered to be a contributing factor besides ostertagiasis for the death of one goitered gazelle and for the diarrhea of another goitered gazelle. A third gazelle became ill in the same time period, but Salmonella infection was not confirmed by culture. All exhibited the clinical signs of profuse, watery diarrhea. The gazelles developed a protein-losing enteropathy, and the tapir showed signs of sepsis and endotoxemia. Serotyping and pulsed-field gel electrophoresis revealed the Salmonella isolates to be indistinguishable from each other. One year prior to this outbreak, Salmonella sp. was cultured from a Visayan warty pig (Sus cebifrons) housed in the same building as the tapir. After further investigation into the outbreak, spread of this pathogen was speculated to be associated with human movement across animal areas.     

Gastro-intestinal nematodes of gazelle,Gazella subgutturosa,in Iran

Sixty-five gazelles, Gazella subgutturosa, of different ages and sexes, from different National Parks and Protected Regions of Iran, were examined over a period of 2 years, for gastro-intestinal nematodes. All of the examined animals were infected with one or more nematode species. The following species were found: Marshallagia marshalli, Camelostrongylus mentulatus, Ostertagia occidentalis, O. circumcincta, Trichostrongylus colubriformis, T. vitrinus, Nematodirus gazellae, N. oiratianus, N. spathiger, N. archari, N. abnormalis, N. filicollis, N. sugatini, Nematodirella cameli, N. longissimespiculata, N. antilocaprae, N. gazelli, Skrjabinema ovis, Trichuris ovis, T. gazellae, T. skrjabini and T. discolor. Among the species found, Marshallagia marshalli, Nematodirus spp. and Nematodirella longissimespiculata were the most prevalent helminths.     

The contribution of simple random sampling to observed variations in faecal egg counts

It has been over 100 years since the classical paper published by Gosset in 1907, under the pseudonym "Student", demonstrated that yeast cells suspended in a fluid and measured by a haemocytometer conformed to a Poisson process. Similarly parasite eggs in a faecal suspension also conform to a Poisson process. Despite this there are common misconceptions how to analyse or interpret observations from the McMaster or similar quantitative parasitic diagnostic techniques, widely used for evaluating parasite eggs in faeces. The McMaster technique can easily be shown from a theoretical perspective to give variable results that inevitably arise from the random distribution of parasite eggs in a well mixed faecal sample. The Poisson processes that lead to this variability are described and illustrative examples of the potentially large confidence intervals that can arise from observed faecal eggs counts that are calculated from the observations on a McMaster slide. Attempts to modify the McMaster technique, or indeed other quantitative techniques, to ensure uniform egg counts are doomed to failure and belie ignorance of Poisson processes. A simple method to immediately identify excess variation/poor sampling from replicate counts is provided.     

Effects of aggregation and sample size on composite faecal egg counts in sheep

Composite faecal egg counts (FEC) are increasingly used to support strategic anthelmintic treatment decisions in grazing livestock. However, their accuracy as estimators of group mean FEC is affected by the number of individual samples included, how thoroughly they are mixed, and the underlying degree of parasite aggregation between individual hosts. This paper uses a Negative Binomial model for parasite aggregation, and a Poisson model for egg distribution within faecal suspensions, in order to optimise composite FEC protocol for commercial sheep flocks. Our results suggest that faecal egg density in a well-mixed composite sample from 10 sheep (3g of faeces from each), estimated by examination of four independently filled McMaster chambers, is likely to provide an adequate estimate of group mean FEC in the majority of situations. However, extra care is needed in groups of sheep for which high levels of FEC aggregation might be expected. The implications of statistical error in FEC estimates depend on how they are used. The simulation-based approach presented here is a powerful tool for investigating the risks of error in FEC-driven treatment decisions in different situations, as well as for the statistical analysis of parasitological data in general.     

A three-dimensional pelvimetric assessment on pelvic cavity of gazelle (Gazella subgutturosa) by computed tomography

The gazelles (Gazella subgutturosa), which are at the risk of extinction and are legally protected, have a cultural and aesthetic value in Turkey. It becomes incredibly important to increase their numbers in order to ensure their survival. In this context, it is required to examine thoroughly the pelvic cavity which contains reproductive organs and is used as the birth canal, as well. This study was conducted to determine the pelvimetric data of the gazelles by scanning their pelvic cavity via a multidetector computed tomography (MDCT) and preparing three-dimensional models of the pelvic cavity. Twelve adult (6 females, 6 males) gazelle carcasses were used in the study. After the pelvic cavity was scanned using the MDCT device with 64 detectors at 80 kV, 200 mA, 639 mGY and 0.625 mm cross-section thickness, the MDCT images were obtained. The three-dimensional models of the images obtained using MIMICS 20.1 (The Materialise Group, Leuven, Belgium) program were prepared. Pelvimetric measurements of the pelvic cavity were taken using these models. It was determined based on the pelvimetric examinations that there was a significant difference between the female and male gazelles in terms of conjugate diameter, vertical diameter, intermediate traversal diameter, and cranial and medial transverse diameter data at p < .05. Also, there was a significant difference in their data related to caudal transverse diameter and ischial arch at p < .01. Consequently, it is thought that the use of pelvimetric values belonging to the pelvic cavity of gazelles would reveal the sexual dimorphism of the species and its differences with other species and would contribute to clinical sciences.     

Quantitative studies of ovine haemonchosis. I. Relationship between faecal egg counts and total worm counts

The successful operation of parasite-control programmes based on monitoring of faecal egg counts stimulated an examination of the quantitative relationship between egg counts and worm counts of Haemonchus contortus in sheep in the Goondiwindi area of south-east Queensland. Sixty-one commercial Merino sheep were selected from flocks where outbreaks of haemonchosis had occurred. Faecal samples were collected prior to euthanasia and eggs and worms subsequently counted and differentiated.A strong relationship ($\text{r}{}^2\text{= 0.83, 71P < 0.001}$) was found between faecal egg counts and the total number of adult H. contortus. The size of the worm population, the time of year, and the ratio of male to female adult worms were minor sources of variation. The relationship was considered to be of value in the implementation of programmes for the diagnosis and control of haemonchosis in sheep flocks in the area.