Parasites of domestic and wild animals in South Africa. I. Oestrus ovis in sheep

Separate groups of 3 oestrid-free lambs were exposed to infestation on irrigated pasture for periods of approximately 33 days each over 30 months, and on dry-land pasture for approximately 42 days over a period of 18 months. With some exceptions, the lambs slaughtered from October – June were found to be infested with Oestrus ovis while, with one exception, those slaughtered from July - September were free. A minimum of 4 sheep’s heads, obtained weekly over 24 months from the Pretoria Municipal Abattoir, was examined for infestation. Of a total of 542 heads examined, 73, 4% were infested, having a mean burden of 15, 2 larvae. Mean larval burdens were slightly greater in hornless than in horned sheep, in Dorper-type than in Merino-type sheep, and in lambs than in sheep with 2 or more permanent incisors. The largest larval burdens were recovered from sheep slaughtered during May and June and the smallest during September and October. The greatest number of 1st instar larvae were recovered during May and June and the smallest during September, but those recovered during the latter month were the largest. With one exception, mature larvae which pupated after 21 March or before 16 August failed to hatch as viable flies. Those which pupated after 16 August hatched as flies after a pupal stage of approximately 50 days and the first flies to hatch were invariably recovered during the first 2 weeks of October. The pupal stage decreased to approximately 25 days during December and January and increased again to approximately 50 days for flies hatching during May. No flies hatched between 18 May and 1 October. The following life cycle for Oestrus ovis is suggested: sheep are repeatedly infested from October - June; thereafter infestation survives in the sheep’s' heads until August, mainly as 1st instar larvae, then as pupae and larvae until fresh infestation takes place during October.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Host-parasite relationships of Paramphistomum microbothrium Fischoeder, 1901, in experimentally infested ruminants, with particular reference to sheep

The life cycle of Paramphistomum microbothrium Fischoeder, 1901, in experimentally infested sheep, goats and cattle was compared and discussed. It is concluded, that of these domestic ruminants, cattle are the normal definitive hosts of P. microbothrium. The worms in cattle grow larger, migrate more rapidly, lay more eggs, live longer and the percentage take after migration is higher than that in either sheep or goats. Massive infestation of sheep and cattle resulted in retarded growth and migration of the worms. Metacercariae exposed to X-rays were dosed to sheep and the effects on the life cycle studied. The pathological anatomy, clinical pathology and symptoms of acute paramphistomiasis are described in detail and their inter-relationship is discussed. Adult cattle and sheep were successfully immunized by repeated dosage of small numbers of metacercariae (500 to I,500). Adult cattle were readily immunized either with single doses of 40,000 to 176,000 un-irradiated metacercariae or with single or divided doses of 40,000 irradiated metacercariae. Although adult sheep could be immunized, this was only completely successful with a single or divided dose of 40,000 metacercariae. Immunization of adult goats was successful with a single or divided dose of 40,000 metacercariae. The effects of immunity on paramphistomes are a marked reduction in numbers, retarded growth and rate of migration. The intradermal allergic test, a modification of the complement fixation test and the formation of precipitates around live worms incubated in sera from infested hosts were investigated.The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Parasites of domestic and wild animals in South Africa. IX. Helminths in blesbok

Four blesbok culled in the Rietvlei Nature Reserve during May 1972 were each infested with Trichostrongylus axei and /mpalaia nudicollis. Some of these animals also harboured Haemonchus bedfordi, Haemonchus contortus, Trichostrongylus falculatus, Skrjabinema alata and Avitellina centripunctata. Thirty-two blesbok were culled in pairs at approximately 4- 5 week-intervals in the Percy Fyfe. Nature Reserve from July 1972 to November 1973. Adult H. contortus were recovered in fair numbers from buck slaughtered from August 1972 to February 1973 and during November 1973. Peak numbers of 4th stage larvae were recovered from individual animals slaughtered during October 1972, February and March, and July to October 1973. Peak burdens of T. falcu latus were recovered during October to December 1972 and November 1973. The largest numbers of adult /. nudicollis were recorded from January to July and during September 1973. Other helminths recovered were T. axei, S . alata and A . centripunctata. Avitellina centripunctata, H. bedfordi and S. alata are new records for the blesbok.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Parasites of domestic and wild animals in South Africa. V. Helminths in sheep on dryland pasture on the Transvaal Highveld

The seasonal incidence of helminth infestation on a farm in the Transvaal Highveld was determined by the slaughter of tracer lambs exposed on pasture for periods of approximately 6 weeks. Haemonchus contortus, the most prevalent nematode, was recovered in the greatest numbers from January- May 1974. Peak counts of Ostertagia circumcincta were made during March and April 1974 and in January 1975, while Trichostrongylus spp. were mainly encountered from March-June. Cooperia spp. were generally recovered from November-May and Moniezia expansa from October-April. H. contortus, O. circumcincta and Cooperia spp. all exhibited increasing degrees of arrested development in the 4th larval stage from February-June.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Parasites of domestic and wild animals in South Africa. XV. The seasonal prevalence of ectoparasites on impala and cattle in the northern Transvaal

The prevalence of ectoparasites on a total of 36 impala (Aepyceros melampus) slaughtered monthly from February 1975 to February 1976 and a total of 24 cattle slaughtered monthly from March 1976 to March 1977 in the Nylsvley Provincial Nature Reserve was determined. Six species of ixodid ticks were collected from the impala and these, in order of abundance, were: Rhipicephalus evertsi evertsi, Rhipicephalus appendiculatus, Amblyomma hebraeum, Boophilus decoloratus, Ixodes cavipalpus and Hyalomma marginatum rufipes. Only 340 (2,7%) of the 12 757 ticks collected from the impala were adult. The 4 species of lice present on the impala were, in order of abundance: Damalinia aepycerus, Linognathus aepycerus, Damalinia elongata and Linognathus nevilli. The cattle harboured 8 species of ixodid ticks. In order of abundance, these were: R. appendiculatus, R. evertsi evertsi, A. hebraeum, Hyalomma truncatum, H. marginatum rufipes, B. decoloratus, Rhipicephalus simus and I. cavipalpus. A total of 14 186 ticks was collected from the cattle and of these 4 660 (32,9%) were adults. Clear seasonal prevalences could be determined for certain ticks only. Adult A. hebraeum reached peak numbers on cattle from November to March, adult H. marginatum rufipes from December to February and adult H. truncatum during January and February. Larvae of R. appendiculatus reached peak numbers on cattle and impala from March or April to July, nymphae from June to October and adults from December to March. Peak numbers of larvae of R. evertsi evertsi were recovered from impala from May to July and nymphae during July, while adults were present on cattle throughout the survey period, with peaks being recorded during December and February.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.National Programme for Environmental Sciences of the Council for Scientific and Industrial Research. Sentrachem (Pty) Ltd. University of Pretoria

Parasites of domestic and wild animals in South Africa. VII. Helminths in pigs slaughtered at the Pretoria Municipal Abattoir

A total of 52 pigs slaughtered at the Pretoria Municipal Abattoir over a period of 1 year was examined for parasitic helminths. Twenty-six of these pigs were marketed by farmers and 26 by speculators. Of the pigs marketed by farmers 73,1% were found to be infested:-30,8% with Ascaris suum, 65,4% with Ascarops strongylina, 3,8% with Metastrongylus apri, 26,9% with Oesophagostomum spp., 15,4% with Trichostrongylus colubriformis and 15,4% with Trichuris suis. All the pigs marketed by speculators were infested :-7,7% with A. suum, 92,3% with A . strongylina, 11,5% with Oesophagostomum spp., 65,4% with Physocephalus sexalatus, 7, 7% with T. colubriformis and 11,5% with T. suis. The findings obtained in surveys conducted in Canada, Greece, India, the Philippines, the United Kingdom and the United States of America are quoted for comparison. Trichostrongylus colubriformis and Oesophagostomum quadrispinulatum are recorded for the first time in pigs in the Republic of South Africa.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Studies on paramphistomiasis. III. A method of testing the viability of paramphistome metacercariae

A comparatively rapid and economical method of assessing the viability of P. microbothrium metacercariae was developed by modifying the technique described by Wikerhauser (1960). The effects of various methods of storage and of age on metacercarial viability were determined. The highest viability was observed for metacercariae five to 16 days of age. A close correlation between in vitro viability and actual in vivo viability was recorded.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Parasites of domestic and wild animals in South Africa. X. Helminths in impala

Two to four impala in the Nylsvley Nature Reserve were culled each month from February 1975- February 1976. Two trematode species, 1 cestode species and 13 species of nematodes were recovered from these antelope. Of these, Fasciola gigantica, Gongylonema pulchrum, Haemonchus placei and Trichostrongylus falculatus are new records for impala. In general, H. placei, Longistrongylus sabie and Impalaia tuberculata exhibited a similar pattern of seasonal occurrence. Adult worms were present during November-February, while marked inhibition in the development of large numbers of 4th stage larvae occurred from April-September or October. Cooperia hungi, Cooperioides hamiltoni and Cooperioides hepaticae followed a similar pattern, but inhibition in the 4th larval stage was not as marked and lasted from June-September. No seasonal pattern of prevalence could be determined for Trichostrongylus spp. The worm burdens of young impala increased with the age of the animals and reached a peak when the impala were 1 year old.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.The National Programme for Environmental Sciences of the Council for Scientific and Industrial Researc

Parasites of domestic and wild animals in South Africa. XII. Artificial transmission of nematodes from blesbok and impala to sheep, goats and cattle

Sheep were successfully infested artificially with the larvae of Haemonchus contortus, Trichostrongylus axei, Trichostrongylus falculatus and Impalaja nudicollis, cultured from the faeces of blesbok naturally infested with these nematodes. Haemonchus placei, Longistrongylus sabie, Trichostrongylus colubriormis, T. falculatus, Impalaia tuberculata and Cooperia hungi likewise became established in sheep, goats and calves dosed with larvae cultured from the faeces of infested impala. Sheep and goats could also be infested with Cooperioides hamiltoni and Oesophagostomum columbianum of impala origin, but Cooperioides hepaticae could not be transmitted either to these hosts or to calves.This article has been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-Format

Parasites of domestic and wild animals in South Africa. XIV. The seasonal prevalence of Rhipicephalus sanguineus and Ctenocephalides spp. on kennelled dogs in Pretoria North

The seasonal prevalence of Rhipicephalus sanguineus and Ctenocephalides spp. on kennelled dogs in Pretoria North was determined by the regular examination of 3, initially, and later 2 dogs from March 1975-January 1977. Once the ticks had become established in the kennel peak burdens of immature ticks (larvae plus nymphae) were present on the dogs during early summer 1975 and from midsummer-late summer 1976 and early midsummer 1976/77. Peak numbers of adult ticks were present in midsummer 1975/76, from late summer-autumn and during early spring 1976 and during midsummer 1976/77. Few adults and even fewer immature ticks were present on the dogs during winter 1976 and the infestation overwintered in the pens as engorged nymphae. The flea population took 10 months to become well established. Thereafter, the periods late summer-autumn 1976 and early midsummer 1976/77 (when the survey stopped) were the most favourable and winter-spring 1976 the least favourable for adult fleas. The immature ticks preferred the sides and bellies, adult ticks the necks, and fleas the bellies of the dogs.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format