Four trials, three in the United States and one in South Africa, were conducted to evaluate the potential value of a novel self-medicating applicator in the passive control of gastrointestinal nematodes in cattle and deer, and of flies and ticks on cattle using oil-based treatments. The results of the trials demonstrated that this applicator is an effective and practical device for the passive treatment of both deer and cattle for trichostrongyle infections using the endectocide, moxidectin (Cydectin (R) , Fort Dodge Animal Health, USA), of cattle for horn fly (Haemotobia irritans) infestations using the insecticide, cyfluthrin (CyLence (R) , Bayer AG, Germany) and of cattle for tick infestations (in particular Amblyomma hebraeum and Rhipicephalus appendiculatus) using the acaricides deltamethrin and amitraz (Delete All (R) , Intervet, South Africa).

Partial 1D gene characterization was used to study phylogenetic relationships between 17 serotype O foot-and-mouth disease (FMD) viruses in Ethiopia as well as with other O-type isolates from Eritrea, Kenya, South and West Africa, the Middle East, Asia and South America. A homologous region of 495 bp corresponding to the C-terminus end of the 1D gene was used for phylogenetic analysis. This study described three lineages, viz. African/Middle East-Asia, Cathay and South American. Within lineage I, three topotypes were defined, viz. East and West Africa and the Middle East-Asia together with the South African isolate. The Ethiopian isolates clustered as part of topotype I, the East African topotype. Two clades (based on 12% nucleotide difference) A and B were identified within the East African isolates, with clade A being further classified into three significant branches, A1 (80 % bootstrap support), A2 (89 % bootstrap support) and A3 (94 % bootstrap support). Clade B consisted of two Kenyan isolates. Within topotype I, the 17 Ethiopian isolates showed genetic heterogeneity between themselves with sequence differences ranging from 4.6-14 %. Lineage 2 and 3 could be equated to two significant topotypes, viz. Cathay and South America. Comparison of amino acid variability at the immunodominant sites between the vaccine strain (ETH/19/77) and other Ethiopian outbreak isolates revealed variations within these sites. These results encourage further work towards the reassessment of the type O vaccine strain currently being used in Ethiopia to provide protection against field variants of the virus.

A crossbred calf (3 months old) obtained from a farm where regular control of ticks was practised and found to be free of blood parasites was inoculated with 20 ml pooled blood collected from four field cattle which had very low Trypanosoma theileri parasitaemias (one parasite per 70 l blood as determined by the haematocrit centrifugation technique). Trypanosoma theileri was present in the blood 6 days after injection and a peak parasitaemia of 42 parasites per 70 l blood was recorded by day 12. Hyalomma anatolicum anatolicum nymphs were applied on the ears of the calf on day 8 and they dropped engorged by days 13 and 14. The resulting adult ticks were examined for the presence of T. theileri by severing a leg and making a smear of the clear haemolymph which exuded from the wound. The smear was fixed in methanol and stained with Giemsa stain. The infection rate with T. theileri in the ticks was 43.3 % (26 out of 60). The intensity of infection was very high and various developmental stages of the flagellates were observed (epimastigotes, sphaeromastigotes, trypomastigotes and other intermediate stages). The haemolymph from 12 ticks was also collected in tissue culture medium and the trypanosomes survived for 25 weeks before eventually dying. The results demonstrated unequivocally the high vectorial capacity of the tick H. a. anatolicum for T. theileri.

A new species of Cooperia, for which the name Cooperia pigachei n. sp. is proposed, was recovered from a mountain reedbuck, Redunca fulvorufula, from the Sterkfontein Dam Nature Reserve, Free State Province, and is described and illustrated. It is close to Cooperia neitzi Mnnig, 1932 and the South African race of Cooperia rotundispiculum in having more than 14 longitudinal cuticular ridges and in that the lateral cervical synlophe is of the closed type. The new species differs from all the other species of the genus in that the lateral branches of the dorsal ray are large and T-shaped. The spicules are robust, over 0.3 mm long and have large, curved shoes on their tips.

The effect of a continuous disinfection programme, using the non-toxic disinfectant Virukill, in layers, on the spread and impact of infectious coryza, caused by Haemophilus paragallinarum was evaluated. In this experiment, both unvaccinated layers and layers vaccinated against infectious coryza were used. Duplicate smaller groups of vaccinated and unvaccinated chickens were challenged with different serovars of both NAD-dependent as well as NAD-independent isolates of Haemophilus paragallinarum. One group of chickens challenged with each of the different bacterial serovars was treated with the continuous disinfection programme, while the other group remained as the untreated controls. The clinical signs of infectious coryza were evaluated over a period of 20 days in each group. The egg production over this period was also evaluated. It was found in all experimental challenges, that the severity of the symptoms was reduced in the birds receiving the continuous disinfection programme. The drop in egg production was also found to be less severe in the treated groups when compared to the untreated control groups. The duration of infection was found to be either unchanged, or shorter in the birds treated with the continuous disinfection programme. In none of the experimental challenges was the duration or expression of clinical signs of IC increased due to the continuous disinfection programme.

In a cross sectional survey conducted during the period June 2001 to July 2002, the geographical distribution of ticks on cattle in the Sudan was determined. Seventeen locations were surveyed from Northern, Central, Eastern, Western, Blue Nile and White Nile Provinces. Total body collections of ticks were made from 20 cattle at each location. Four tick genera and 11 species were identified. The tick species collected included Amblyomma lepidum, Amblyomma variegatum, Boophilus decoloratus, Hyalomma anatolicum anatolicum, Hyalomma dromedarii, Hyalomma impeltatum, Hyalomma marginatum rufipes, Hyalomma truncatum, Rhipicephalus evertsi evertsi, Rhipicephalus sanguineus group and Rhipicephalus simus simus. Major ecological changes have occurred due to extensive animal movement, deforestation, desertification and establishment of large mechanized agricultural schemes. These factors have certainly affected the distribution of ticks and tick-borne diseases in the Sudan. The absence of A. variegatum and A. lepidum in northern Sudan was not surprising, since these tick species are known to survive in humid areas and not in the desert and semi-desert areas of northern Sudan. The absence of B. annulatus in northern and central Sudan is in accordance with the finding that this tick species is restricted to the southern parts of the central Sudan. The presence of H. anatolicum anatolicum in Um Benin in relatively high abundance is an interesting finding. The present finding may indicate that the southern limit of this species has changed and moved southwards to latitude 13o N. It is concluded that major changes in tick distribution have taken place in the Sudan

Helminths cause great economic loss in livestock in Africa, and can be categorized as either direct or indirect losses. Arid and semi-arid lands (ASAL) in Kenya comprise 71 % of total land area and harbour the largest population of cattle, sheep and goats. However, little information on the distribution and impact of gastro-intestinal (GIT) parasitism in these animals is available. This survey was conducted to establish the prevalence of GIT parasites infecting calves, sheep and goats and their relative importance in Magadi division, which is semi-arid. Faecal samples were obtained directly from the rectum of 109 calves, 133 goats and 20 sheep and submitted to the laboratory for faecal worm egg counts, and coccidial oocysts examination using a modified McMaster method. The significance of differences in mean egg count per gram (epg) between animal species and herds (farms) were assessed using analysis of variance. The overall prevalence of nematodes in the calves, sheep and goats was 69.2 %, 80 % and 82 %, respectively. About 10 % of sheep and goats had epgs higher than 1 000, the remainder having light to moderate infections. The overall prevalence of coccidial oocysts in calves, sheep and goats was 30 %, 44 % and 45 %, respectively. Poor productivity in ASAL areas, where nutrition is often poor, is likely to be pronounced in the presence of parasite infections. These findings indicate that viable internal parasite control should be implemented in the study area in order to increase the productivity of the livestock there.

years, but recently there have been reports of prophylaxis failure under natural conditions. In this study, use of the drug for prophylactic purpose against trypanosomosis in small ruminants was investigated. Forty-two sheep and 44 goats were divided into four treatment groups. Groups 1 and 2 were treated with isometamidium chloride (Samorin(R), Rhone Merieux, Lyon, France) at 3-month intervals while groups 3 and 4 were used as controls. All the animals were exposed to natural tsetse challenge and monitored for serum isometamidium levels and anti-trypanosome antibodies. Seven days after drug administration, isometamidium levels were significantly higher in goats 13.7 + 0.07 ng/mℓ than in sheep 6.2 + 0.06 ng/mℓ. However, the elimination half-life in the sheep was 14.2 + 0.92 days and was significantly higher (P 0.05) than that of the goats 12 + 0.5 days. This study established that isometamidium metabolism differs between sheep and goats and this difference may have important implications in high tsetse challenge areas.

The crude prevalence of antibodies to Babesia bovis infection in cattle was estimated by serology using indirect ELISA during the period January to April, 1999. Sera were obtained from 1 395 dairy cattle (of all ages, sexes and breeds) on smallholder farms, the majority being kept under a zero grazing regime. The crude prevalence of antibodies to Babesia bovis was 6 % for Tanga and 12% for Iringa. The forces of infection based on the age sero-prevalence profile, were estimated at six for Iringa and four for Tanga per 100 cattle years-risk, respectively. Using random effect logistic regression as the analytical method, the factors (variables) of age, source of animals and geographic location were hypothesised to be associated with sero-positivity of Babesia bovis in the two regions.

A pregnant female Cape giraffe (Giraffa camelopardalis giraffa) died from an unknown cause in the Aitana Zoo, Alicante, Spain. Neither clinical signs nor macroscopic lesions were observed at necropsy. The alimentary tract was removed and examined for parasites. A total of 2 724 nematodes were found, including Camelostrongylus mentulatus, Trichostrongylus axei, Ostertagia ostertagi, Teladorsagia circumcincta, Teladorsagia trifurcata, Marshallagia marshalli, Trichostrongylus vitrinus, Trichostrongylus colubriformis, Spiculopteragia asymmetrica and Trichuris giraffae. Only T. giraffae and C. mentulatus have been previously reported from giraffes. The other nematodes are common in mouflons, fallow and red deer, which can usually be found in the same paddock as the giraffes in Aitana Zoo. Although its occurrence is unusual in this host, C. mentulatus was the most abundant nematode in our giraffe. This parasite has been related to disease, and even death, in several wild ruminants.