<span style="font-family: arial,helvetica;">The tortoise tick <em>Amblyomma marmoreum</em> was collected from large numbers of reptiles and other animals during the course of numerous surveys conducted in South Africa. A total of 1 229 ticks, of which 550 were adults, were recovered from 309 reptiles belonging to 13 species, with leopard tortoises, <em>Geochelone pardalis</em> being the most heavily infested. The 269 birds sampled harboured 4 901 larvae, 217 nymphs and no adult ticks, and the prevalence of infestation was greatest on hel meted guinea fowls, <em>Numida meleagris</em>. Only two larvae were recovered from 610 rodents, including 31 spring hares, <em>Pedetes capensis</em>, whereas 1 144 other small mammals yielded 1 835 immature ticks, of which 1 655 were collected from 623 scrub hares, <em>Lepus saxatilis</em>. The 213 carnivores examined harboured 2 459 ticks of which none were adult. A single adult tick and 6 684 larvae and 62 nymphs were recovered from 656 large herbivores, and a total of 4 081 immature ticks and three adults were collected from 1 543 domestic animals and 194 humans. <br />Adult male and female <em>A. marmoreum</em> were most numerous on reptiles during January and February, and larvae during March. The largest numbers of larvae were present on domestic cattle and helmeted guineafowls in the Eastern Cape Province during March or April respectively, whereas larvae were most numerous on helmeted guineafowls, scrub hares and the vegetation in north-eastern Mpumalanga Province during May. In both provinces nymphs were most numerous between October and December. <em>Amblyomma marmoreum</em> appears to be most prevalent in the western regions of the Western and Eastern Cape and Free State provinces, and the north-eastern regions of the Northern Cape, KwaZulu- Natal, Mpumulanga and Limpopo provinces.</span>

<span style="font-family: arial,helvetica;">During the period between January 1999 and December 2000, the distribution and seasonal patterns of <em>Fasciola gigantica</em> infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe were determined through monthly coprological examination. Cattle faecal samples were collected from 12 and nine dipping sites in the highveld and lowveld communal grazing areas respectively. Patterns of distribution and seasonal fluctuations of the intermediate host-snail populations and the climatic factors influencing the distribution were also determined by sampling at monthly intervals for a period of 24 months (November 1998 to October 2000) in six dams and six streams in the highveld and in nine dams in the lowveld communal grazing areas. Each site was sampled for relative snail density and the vegetation cover and type, physical and chemical properties of water, and mean monthly rainfall and temperature were recorded. Aquatic vegetation and grass samples 0-1 m from the edges of the snail habitats were collected monthly to determine the presence or absence of <em>F. gigantica</em> metacercariae. Snails collected at the same time were individually checked for the emergence of larval stages of <em>F. gigantica</em>. A total of 16 264 (calves 5 418; weaners 5 461 and adults 5 385) faecal samples were collected during the entire period of the study and 2 500 (15.4 %) of the samples were positive for <em>F. gigantica</em> eggs. Significantly higher prevalences were found in the highveld compared to the lowveld (<em>P</em> &lt; 0.001), for adult cattle than calves (<em> P</em> &lt; 0.01) and in the wet season over the dry season (<em>P</em> &lt; 0.01). Faecal egg output peaked from August / September to March / April for both years of the study. <br /><em>Lymnaea natalensis</em>, the snail intermediate host of <em>F. gigantica</em> was recorded from the study sites with the highveld having a significantly higher abundance of the snail species than the lowveld (<em>P</em> &lt; 0.01). The snail population was low between December and March and started to increase in April reaching a peak in September / October. The number of juvenile snails peaked between April and August. The mean number of snails collected was negatively correlated with rainfall and positively correlated with temperature. Mean number of snails collected was also positively correlated with <em>Potamogeton</em> plant species and negatively correlated with <em>Cyperus</em> plant species. However, none of the <em>L. natalensis</em> collected from the habitats were found shedding <em>Fasciola</em> cercariae. Metacercariae were found on herbage from the fringes of the snail habitats between February and August for both years, with most of the metacercariae concentrated on herbage 0-1 m from the banks of the habitats. <br />Based on the findings of this study, anthelmintic treatment should be administered in December / January to control chronic and mature fasciolosis. A second treatment should be given in April / May to reduce pasture contamination and subsequently snail infection, as this is the time the snail population starts to build up. To control acute fasciolosis due to the immature liver flukes a third treatment should be given in August. <br />The first application of molluscicides to control the snail intermediate hosts can be done in June the time when the snail is harbouring the parasite and a second application in September in order to kill new generations of infected snails.</span>

<span style="font-family: arial,helvetica;">Oestrous synchronization involves synchronization of ovarian follicular turnover, new wave emergence, and finally induction of ovulation. The final step can be synchronized by the parenteral administration of either GnRH or oestradiol benzoate. This study investigated corpus luteum and follicular emergence after ovulation had been induced by the administration of either GnRH or oestradiol benzoate. The injection of oestradiol benzoate may have delayed the emergence of the first follicular wave subsequent to the induced ovulation; administration of oestradiol benzoate or GnRH lowered the progesterone rise so that the maximum dioestrous concentration of progesterone on Day 9 was lower when cows were treated during pro-oestrus compared to the spontaneously ovulating controls. One implication of findings from the present study is that induction of ovulation with either oestradiol benzoate or GnRH, administered 24 or 36 h after withdrawal of the CIDR device, respectively, may lower fertility. Future studies must identify the timing of administration relative to the time of CIDR device withdrawal and the optimum concentration of oestradiol benzoate or GnRH that would not have untoward effects on the development of the corpus lutea, particularly within the first week of dioestrus.</span>

<span style="font-family: arial,helvetica;">To obtain updated data on and assess the contribution of trypanosomosis to the disease burden of cattle kept at the edge of the Hluhluwe-iMfolozi Park, a survey was conducted at Mvutshini Dip. Use was made of a purposeful sampling strategy by restricting sampling to animals that the livestock owner considered to be in poor condition. Of a total of 76 blood samples collected, 26 were parasitologically positive and 46 were positive on PCR / RFLP. Almost all infections were due to <em>Trypanosoma congolense</em> savannah subgroup. A total of 63 animals had a PCV <span style="text-decoration: underline;">&lt;</span> 24 % and were considered to be anaemic. Results from the survey show that trypanosome infections contribute significantly to the overall burden of disease in the area. Further research is required to develop appropriate control methods.</span>