Ticks were collected at approximately bi-monthly intervals between June 1996 and June 1997 from crested francolins, Francolinus sephaena, and from the vegetation on a mixed cattle and wildlife farm in Limpopo Province, South Africa. The birds were infested with the immature stages of 13 tick species, of which Amblyomma hebraeum, Amblyomma marmoreum and Hyalomma marginatumrufipes were the most numerous and prevalent. Ten ixodid tick species were collected from the vegetation, of which the immature stages of Rhipicephalus appendiculatus, Rhipicephalus (Boophilus) decoloratus and Rhipicephalus evertsi evertsi were the most numerous. No adult ticks were collected from the birds and only two from the vegetation. The restricted home range of crested francolins implies that they could serve as a source of tick infestation only for other animals within the same habitat as the birds.

Ticks were collected at approximately bi-monthly intervals between June 1996 and June 1997 from crested francolins, Francolinus sephaena, and from the vegetation on a mixed cattle and wildlife farm in Limpopo Province, South Africa. The birds were infested with the immature stages of 13 tick species, of which Amblyomma hebraeum, Amblyomma marmoreum and Hyalomma marginatumrufipes were the most numerous and prevalent. Ten ixodid tick species were collected from the vegetation, of which the immature stages of Rhipicephalus appendiculatus, Rhipicephalus (Boophilus) decoloratus and Rhipicephalus evertsi evertsi were the most numerous. No adult ticks were collected from the birds and only two from the vegetation. The restricted home range of crested francolins implies that they could serve as a source of tick infestation only for other animals within the same habitat as the birds.

The taxonomic status of some nippostrongyline nematodes deposited in the National Collection ofAnimal Helminths, Onderstepoort, is revised. Heligmonina boomkeri n. sp. is described from Aethomys chrysophilus from South Africa. The most closely related species by the body measurementsand the pattern of the caudal bursa is Heligmonina bignonensis Diouf, Bâ & Durette-Desset, 1997, a parasite of Mastomys erythroleucus from Senegal. It differs from the new species mainly in thenumber of ventral cuticular ridges at mid-body (four versus five) and the left ala in the male is shorterthan the body diameter. The systematic position of Heligmonina spira (Ortlepp, 1939) and Neoheligmonella capensis (Ortlepp, 1939) is confirmed here through their synlophe, which was not previously studied.

The taxonomic status of some nippostrongyline nematodes deposited in the National Collection ofAnimal Helminths, Onderstepoort, is revised. Heligmonina boomkeri n. sp. is described from Aethomys chrysophilus from South Africa. The most closely related species by the body measurementsand the pattern of the caudal bursa is Heligmonina bignonensis Diouf, B Durette-Desset, 1997, a parasite of Mastomys erythroleucus from Senegal. It differs from the new species mainly in thenumber of ventral cuticular ridges at mid-body (four versus five) and the left ala in the male is shorterthan the body diameter. The systematic position of Heligmonina spira (Ortlepp, 1939) and Neoheligmonella capensis (Ortlepp, 1939) is confirmed here through their synlophe, which was not previously studied.

Myocardial lesions were studied in sheep in which gousiekte was induced by experimental dosage of Pachystigma pygmaeum, Fadogia homblei or Pavetta harborii. The single most consistent diagnostic histological feature in 33 animals was hypertrophy of myocardial fibres in the subendocardial region. Fibrosis in the subendocardial region of the apex or left ventricular wall was often scarce or absent in animals with a short latent period, and was not always prominent even in sheep with an intermediate or long latent period. The presence or absence of fibrosis cannot therefore be used to confirm or exclude gousiekte, particularly in cases with shorter latent periods. Light microscopical and ultrastructural lesions in sheep with gousiekte correspond to a large extent to changes reported in humans with dilated cardiomyopathy of unknown cause. It appears that the myocardial lesions in gousiekte represent a final common pathway of cellular damage rather than a manifestation of a specific type of heart disease. The predilection for hypertrophy of myofibres in the subendocardial region is probably related to diminished perfusion that potentiates the primary myocardial dysfunction.

Myocardial lesions were studied in sheep in which gousiekte was induced by experimental dosage of Pachystigma pygmaeum, Fadogia homblei or Pavetta harborii. The single most consistent diagnostic histological feature in 33 animals was hypertrophy of myocardial fibres in the subendocardial region. Fibrosis in the subendocardial region of the apex or left ventricular wall was often scarce or absent in animals with a short latent period, and was not always prominent even in sheep with an intermediate or long latent period. The presence or absence of fibrosis cannot therefore be used to confirm or exclude gousiekte, particularly in cases with shorter latent periods. Light microscopical and ultrastructural lesions in sheep with gousiekte correspond to a large extent to changes reported in humans with dilated cardiomyopathy of unknown cause. It appears that the myocardial lesions in gousiekte represent a final common pathway of cellular damage rather than a manifestation of a specific type of heart disease. The predilection for hypertrophy of myofibres in the subendocardial region is probably related to diminished perfusion that potentiates the primary myocardial dysfunction.

The lectin-binding characteristics of the epithelial lining of the thoracic air sacs of the chicken were determined. Con A, LCA and PSA bound to the apical membrane as well as to the cytoplasm distal to the nucleus of the surface epithelium, indicated the presence of a-linked mannose as well as Nacetylchitobiose- linked a-fucose residues in the glycoproteins. GSL I bound to the apical membrane and cytoplasm distal to the nucleus, but not to the cilia of the epithelium, where-as MPL, DBA and RCA120 bound to the apical membrane, cilia and cytoplasm, indicated the presence of a-linked Nacetylgalactosamine residues. However, neither SJA or SBA showed any binding, indicating the absence of b anomers of galactosyl (b1.3)N-acetylgalactosamine and b-linked N-acetylgalactosamine residues. UEA I bound to the apical membrane and cilia, as well as to the cytoplasm of a few cells, indicated the presence of a-linked fucose residues. PNA bound to the apical membrane of some, but not all, surface epithelium cells, indicated the presence of galactosyl (b1.3)N-acetylgalactosamine residues. WGA bound to the apical membrane and cilia, as well as to the cytoplasm of a few cells, indicated the presence of neuraminic acid residues.

The lectin-binding characteristics of the epithelial lining of the thoracic air sacs of the chicken were determined. Con A, LCA and PSA bound to the apical membrane as well as to the cytoplasm distal to the nucleus of the surface epithelium, indicated the presence of a-linked mannose as well as Nacetylchitobiose- linked a-fucose residues in the glycoproteins. GSL I bound to the apical membrane and cytoplasm distal to the nucleus, but not to the cilia of the epithelium, where-as MPL, DBA and RCA120 bound to the apical membrane, cilia and cytoplasm, indicated the presence of a-linked Nacetylgalactosamine residues. However, neither SJA or SBA showed any binding, indicating the absence of b anomers of galactosyl (b1.3)N-acetylgalactosamine and b-linked N-acetylgalactosamine residues. UEA I bound to the apical membrane and cilia, as well as to the cytoplasm of a few cells, indicated the presence of a-linked fucose residues. PNA bound to the apical membrane of some, but not all, surface epithelium cells, indicated the presence of galactosyl (b1.3)N-acetylgalactosamine residues. WGA bound to the apical membrane and cilia, as well as to the cytoplasm of a few cells, indicated the presence of neuraminic acid residues.

A survey conducted in five villages in a resource-poor farming community in Qwa-Qwa, using the rapid rural appraisal technique and a questionnaire survey, showed that a significant proportion of the farmers (84 %) use traditional or alternative methods to control ectoparasites, while 16 % use commercial acaricides (c2 = 7.1; P < 0.05). Alternative control methods included the use of used engine oil, household disinfectant and paraffin. Killing of ticks was the main reason for control (40 %), with disease control being second (20 %). Other reasons given for controlling ticks were to prevent damage to teats, to provide animals with a clean appearance and to protect hides. Some 40 % of farmers were aware of the effects of ticks on their animals. There is a need for farmer education that will provide information on integrated tick management and its advantages over absolute reliance on commercial acaricides.

A survey conducted in five villages in a resource-poor farming community in Qwa-Qwa, using the rapid rural appraisal technique and a questionnaire survey, showed that a significant proportion of the farmers (84 %) use traditional or alternative methods to control ectoparasites, while 16 % use commercial acaricides (c2 = 7.1; P 0.05). Alternative control methods included the use of used engine oil, household disinfectant and paraffin. Killing of ticks was the main reason for control (40 %), with disease control being second (20 %). Other reasons given for controlling ticks were to prevent damage to teats, to provide animals with a clean appearance and to protect hides. Some 40 % of farmers were aware of the effects of ticks on their animals. There is a need for farmer education that will provide information on integrated tick management and its advantages over absolute reliance on commercial acaricides.

Merino sheep in Thornveld, Dorper sheep and Angora goats in inland Valley Bushveld, Angora goats and Boer goats in Valley Bushveld on the coastal plateau, and springbok, Antidorcas marsupialis, and black wildebeest, Connochaetes gnou, in Karroid Mountainveld, all in the Eastern Cape Province, were examined for the larvae of nasal bot flies. The sheep and goats were infested with the larvae of Oestrus ovis, and Dorper sheep and Boer goats harboured more larvae than Angora goats on the same farms. Most infestation was present from November to May in Merino sheep in Thornveld, from February to June in Dorper sheep in inland Valley Bushveld, and from May to September in Angora and Boer goats in Valley Bushveld on the coastal plateau. These patterns of seasonality appeared to be regulated by the severity of the summer temperatures at the various localities. The springbok were infested with the larvae of Rhinoestrus antidorcitis, most of which seemed to mature from June to August. All larval sages of Oestrus variolosus and Gedoelstia hässleri were present in the black wildebeest, and large numbers of 1st instar larvae of G. hässleri appeared to accumulate on the dura of the wildebeest from June to August.

Merino sheep in Thornveld, Dorper sheep and Angora goats in inland Valley Bushveld, Angora goats and Boer goats in Valley Bushveld on the coastal plateau, and springbok, Antidorcas marsupialis, and black wildebeest, Connochaetes gnou, in Karroid Mountainveld, all in the Eastern Cape Province, were examined for the larvae of nasal bot flies. The sheep and goats were infested with the larvae of Oestrus ovis, and Dorper sheep and Boer goats harboured more larvae than Angora goats on the same farms. Most infestation was present from November to May in Merino sheep in Thornveld, from February to June in Dorper sheep in inland Valley Bushveld, and from May to September in Angora and Boer goats in Valley Bushveld on the coastal plateau. These patterns of seasonality appeared to be regulated by the severity of the summer temperatures at the various localities. The springbok were infested with the larvae of Rhinoestrus antidorcitis, most of which seemed to mature from June to August. All larval sages of Oestrus variolosus and Gedoelstia hssleri were present in the black wildebeest, and large numbers of 1st instar larvae of G. hssleri appeared to accumulate on the dura of the wildebeest from June to August.

A single-tube duplex nested polymerase chain reaction (sdn-PCR) was developed for the detection of and discrimination between ovine herpesvirus-2 (OvHV-2) and alcelaphine herpesvirus-1 (AlHV-1). These viruses respectively cause sheep- and wildebeest-associated malignant catarrhal fever (SAMCF and WA-MCF). In the first step of the sdn-PCR, two primers with high annealing temperatures based on conserved regions of the tegument genes were used for DNA amplification. In the second step, two primer sets based on variable regions of the respective OvHV-2 and AlHV-1 genes and with annealing temperatures > 11 °C below the primers used in the first step, were used. Internal regions of different sizes from amplicons produced in the first step were amplified. This single-tube test obviates the need for two separate assays to detect both viral types, thereby reducing time, labour and cost.

A single-tube duplex nested polymerase chain reaction (sdn-PCR) was developed for the detection of and discrimination between ovine herpesvirus-2 (OvHV-2) and alcelaphine herpesvirus-1 (AlHV-1). These viruses respectively cause sheep- and wildebeest-associated malignant catarrhal fever (SAMCF and WA-MCF). In the first step of the sdn-PCR, two primers with high annealing temperatures based on conserved regions of the tegument genes were used for DNA amplification. In the second step, two primer sets based on variable regions of the respective OvHV-2 and AlHV-1 genes and with annealing temperatures 11 C below the primers used in the first step, were used. Internal regions of different sizes from amplicons produced in the first step were amplified. This single-tube test obviates the need for two separate assays to detect both viral types, thereby reducing time, labour and cost.

The efficacy of an amitraz / cypermethrin pour-on preparation (1 % w/v each) was tested against natural tick infestations of buffaloes, eland and blesbok in three separate trials. The eland were also treated with a 0.02 % abamectin (w/v) acaricidal pour-on preparation. The amitraz / cypermethrin pour-on was effective against Amblyomma hebraeum, Rhipicephalus evertsi evertsi, Rhipicephalus appendiculatus and Hyalomma marginatum rufipes on the buffaloes. Both acaricides were effective against R. appendiculatus and Rhipicephalus (Boophilus) decoloratus in the eland. The amitraz / cypermethrin acaricide was effective against R. (Boophilus) decoloratus in the blesbok. Ticks can cause damage to the skins, secondary infections, abscesses, anaemia, loss of condition, tick toxicosis and act as vectors of infectious diseases. Introduction of hosts and / or ticks from endemic to non-endemic areas because of translocation of game, may lead to severe losses. The pouron acaricides tested were effective against natural tick infestations and should always be used according to the manufacturer's instructions and efficacy claims.

The efficacy of an amitraz / cypermethrin pour-on preparation (1 % w/v each) was tested against natural tick infestations of buffaloes, eland and blesbok in three separate trials. The eland were also treated with a 0.02 % abamectin (w/v) acaricidal pour-on preparation. The amitraz / cypermethrin pour-on was effective against Amblyomma hebraeum, Rhipicephalus evertsi evertsi, Rhipicephalus appendiculatus and Hyalomma marginatum rufipes on the buffaloes. Both acaricides were effective against R. appendiculatus and Rhipicephalus (Boophilus) decoloratus in the eland. The amitraz / cypermethrin acaricide was effective against R. (Boophilus) decoloratus in the blesbok. Ticks can cause damage to the skins, secondary infections, abscesses, anaemia, loss of condition, tick toxicosis and act as vectors of infectious diseases. Introduction of hosts and / or ticks from endemic to non-endemic areas because of translocation of game, may lead to severe losses. The pouron acaricides tested were effective against natural tick infestations and should always be used according to the manufacturer's instructions and efficacy claims.