1992 Onderstepoort Journal of Veterinary Research, Volume 59, 1992

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CONTENTS

*Volume 59: Number 1*

A host-parasite catalogue of the haematozoa of the sub-Saharan birds	Huchzermeyer, FW, Bennett, GF, Earle, RA & Du Toit, H
Abstract		1
Introduction		1
The distribution of the sub-Saharan species of avian Haemosporidia by host family/subfamily		6
Annotated list of the species of the genus Haemoproteus in sub-Saharan birds		8
Morphological form of the haemoproteids of sub-Saharan birds		16
Annotated list of the species of the genus Leucocytozoon in sub-Saharan birds		17
Morphological form of the leucocytozoids of sub-Saharan birds		21
The species of the genus Plasmodium in sub-Saharan birds		21
Table 1: Prevalence of haemotozoa in sub-Saharan birds		22
Table 2: Annotated host-parasite catalogue of the sub-Saharan birds		39
Acknowledgements		64
References		65
Index		71


*Volume 59: Number 2*

Adult Amblyomma hebraeum burdens and heartwater endemic stability in cattle	Du Plessis, JL, Loock, PJ & Ludemann, CJF	75

The effects of salt loading via two different routes on feed intake, body water turnover rate and on electrolyte excretion in sheep	Meintjes, RA & Olivier, R	91

Description of Aegyptianella botuliformis n. sp. (Rickettsiales: Anaplasmataceae) from the helmeted guineafowl, Numida meleagris	Huchzermeyer, FW, Horak, IG, Putterill, JF & Earle, RA	97

A comparative histological study of the number and size of the myenteric ganglia and neurones in the fore-stomach and abomasum of grey, white and black Karakul lambs	Groenewald, HB & Booth, KK	103

Cardiotoxicity of the skin of the red-banded rubber frog, Phrynomerus bifasciatus (Smith 1847)	Van der Walt, MPK, Van Rooyen, JM, Oberholzer, G & Van Aswegen, G	107

Experimental Albizia versicolor poisoning in sheep and its successful treatment with pyridoxine hydrochloride	Gummow, B, Bastianello, SS, Labuschagne, L & Erasmus, GL	111

Serological differentiation of five bluetongue virus serotypes in indirect ELISA	Du Plessis, DH	119

Bioactive peptides and serotonin, in the gut endocrine cells of the crocodile, Crocodylus niloticus (Laurenti 1768) : an immunocytochemical study	Van Aswegen, G, Kotze, SH, Van der Merwe, NJ & Smith, GA	123

Production and properties of monoclonal antibodies against African horsesickness virus serotype 3	Verschoor, JA, Van Wyngaardt, W, Du Plessis, DH & Van Wyngaardt, S	129

Experimentally-induced Cestrum laevigatum (Schlechtd.) poisoning in sheep	Van der Lugt, JJ, Nel, PW & Kitching, JP	135

Afrotropical Culicoides: C. (Avaritia) loxodontis sp. nov., a new member of the lmicola group (Diptera: Ceratopogonidae) associated with the African elephant in the Kruger National Park, South Africa	Meiswinkel, R	145

Research communications:

Anaplasmosis in Uganda. III. Parasitological and serological evidence of Anaplasma infection in Ugandan goats	Ssenyonga, GSZ, Kakoma, I, Nyeko, JP, Buga, R & Hansen, R	161

Characterization of ovine strains of Mycobacterium paratuberculosis by restriction endonuclease analysis and DNA hybridization	De Lisle, GW, Collins, DM & Huchzermeyer, HFAK	163


*Volume 59: Number 3*

Scanning electron microscopy of the mucosal surface of the forestomachs and abomasa of grey, white and black Karakul lambs	Groenewald, HB	167

Parasites of South African wildlife. XIII. Helminths of grey rhebuck, Pelea capreolus, and of bontebok, Damaliscus dorcas dorcas, in the Bontebok National Park	Boomker, JDF & Horak, IG	175

Subsampling of large light trap catches of Culicoides (Diptera: Ceratopogonidae)	Van Ark, H & Meiswinkel, R	183

Evaluation of the efficacy of d-penicillamine and trientine as copper chelators using an in vitro technique involving ovine red blood cells	Guthrie, AJ, Botha, CJ, Naude, TW & Swan, GE	191

A survey of small stock tick control practices in the eastern Cape Province of South Africa	Spickett, AM & Fivaz, BH	197

A survey of cattle tick control practices in the eastern Cape Province of South Africa	Spickett, AM & Fivaz, BH	203

Deep dissections of the veins of the bovine head : unpublished work by Prof. J.M.W. Le Roux (1926-1991)	Smuts, MMS & Bezuidenhout, AJ	211

The transovarial transmission of Babesia trautmanni by Rhipicephalus simus to domestic pigs	De Waal, DT, Potgieter, FT & Lopez-Rebollar, LM	219

No serological evidence for the presence of swine vesicular disease virus in South Africa	Thomson, GR, Esterhuysen, JJ & Gainaru, MD	223

A comparative study of the thickness of the tunica muscularis in the forestomach and abomasum of grey, white and black Karakul lambs	Groenewald, HB & Booth, KK	225


*Volume 59: Number 4*

The Leucocytozoidae of South African birds: Caprimulgidae, Columbidae, Gruidae and Spheniscidae	Bennett, GF, Earle, RA & Peirce, MA	229

The Leucocytozoidae of South African birds : Passeriformes	Bennett, GF, Earle, RA & Peirce, MA	235

A light microscopical study of the intestinal tract of the Nile crocodile (Crocodylus niloticus, Laurenti 1768)	Kotze, SH, Van der Merwe, NJ, Van Aswegen, G & Smith, GA	249

Arthropod parasites of springbok, gemsbok, kudus, giraffes and Burchell's and Hartmann's zebras in the Etosha and Hardap Nature Reserves, Namibia	Horak, IG, Boomker, JDF, Anthonissen, M & Krecek, RC	253

Parasites of domestic and wild animals in South Africa. XXX. Ectoparasites of kudus in the eastern Transvaal Lowveld and the eastern Cape Province	Horak, IG, Boomker, JDF, Spickett, AM & De Vos, V	259

Parasites of domestic and wild animals in South Africa. XXXI. Adult ixodid ticks on sheep in the Cape Province and in the Orange Free State	Horak, IG & Fourie, LJ	275

The effect of veld-burning on the seasonal abundance of free-living ixodid ticks as determined by drag-sampling	Horak, IG, Braack, LEO, Spickett, AM & Van Niekerk, A	285

A new species of Lipoptena (Diptera: Hippoboscidae) from southern Africa	Visagie, EJ	293

The louse fly Lipoptena paradoxa Newstead, 1907 (Diptera: Hippoboscidae) : description of its adult and puparium and biology in South Africa	Horak, IG, Boomker, JDF & Visagie, EJ	303

Incidence of Feline lmmunodeficiency virus reactive antibodies in free-ranging lions of the Kruger National Park and the Etosha National Park in southern Africa detected by recombinant FIV p24 antigen	Spencer, JA, Van Dijk, AA, Horzinek, MC, Egberink, HF, Bengis, RG, Keet, DF, Morikawa, S & Bishop, DHL	315

Galenia africana L. poisoning in sheep and goats : hepatic and cardiac changes	Van der Lugt, JJ, Schultz, RA, Fourie, N, Hon, LJ, Jordaan, P & Labuschagne, L	323

Research communications:

An orf-like condition caused by trombiculid mites on sheep in South Africa	Otto, QT & Jordaan, LC	335

Flow cytometric analysis of the T cell response in mice infected with Cowdria ruminantium	Du Plessis, JL, Gray, C & Van Strijp, MF	337

Book review		339

Author index		341

Subject index		347

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Now showing 1 - 20 of 40

A comparative histological study of the number and size of the myenteric ganglia and neurones in the fore-stomach and abomasum of grey, white and black Karakul lambs
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Verwoerd, Daniel Wynand; Groenewald, Hermanus B.; Booth, Kenneth Kurt
Homozygous grey Karakul lambs are born with a lethal genetic factor responsible for death at weaning age. When put in a high roughage diet under field conditions they develop distended, thin-walled rumens and sand impacted abomasa. Homozygous white Karakul lambs have a similar factor but survive for a longer period. Black Karakul lambs are not affected. The present study was undertaken to compare by image analysis the number and size of the myenteric ganglia, and the number of myenteric neurones in the walls of the fore-stomach and abomasum of 24-h-old grey, white and black Karakul lambs. One square centimetre samples were taken from analogous areas of the rumen, reticulum, omasum and abomasum of 38 embalmed Karakul lambs. Haematoxylin and eosin stained histological sections of each sample were studied with a Vids 2 Image Analyzer. One way analysis of variance indicated a significant difference between the groups regarding the number and size of the myenteric ganglia and in the number of myenteric neurones in the reticulum, rumen and abomasum. The number and size of the ganglia and the number of neurones was greatest in the black lambs and decreased progressively in the white and grey lambs. The omasum was not affected. It is suggested that the paucity of myenteric ganglia and neurones in the regions examined is instrumental in causing the lethal condition described above.
Description of Aegyptianella botuliformis n. sp. (Rickettsiales: Anaplasmataceae) from the helmeted guineafowl, Numida meleagris
(Pretoria : Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Putterill, John Fraser; Earle, R.A.; Verwoerd, Daniel Wynand; Huchzermeyer, Fritz W.; Horak, Ivan Gerard
Aegyptianella botuliformis n. sp. (Rickettsiales: Anaplasmataceae) isolated from helmeted guineafowls Numida meleagris from the Kruger National Park is described. The rickettsia occurs within a membrane-bound vacuole in the cytoplasm of erythrocytes with up to 8 organisms in a mature inclusion. The initial body resembles that of Aegyptianella pullorum. The tightly packed, sausage-shaped intermediate forms are a distinctive morphological feature, seen as irregular, pleomorphic forms under light microscopy. While more larvae and nymphs of Amblyomma hebraeum and Amblyomma marmoreaum were found on the birds than larvae of an Argas sp., it is believed that the latter are the vectors of A. botuliformis n. sp. In addition to the Kruger National Park, positive blood smears were obtained from guineafowls at other localities in the Transvaal.
Adult Amblyomma hebraeum burdens and heartwater endemic stability in cattle
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Du Plessis, J.L.; Loock, P.J.; Ludemann, C.J.F.; Verwoerd, Daniel Wynand
Several conclusions of importance to studies on the epidemiology of heartwater were drawn from an investigation in which the numbers of adult Amblyomma hebraeum ticks, to which a closed herd of Hereford cattle were exposed over a period of 6½ years, were manipulated. With a tick Cowdria ruminantium infection rate of 3-5 %, an endemically stable situation was created by dipping the herd only when an average of 10 adult male and female A. hebraeum ticks were counted on 10 animals. When the average was increased to 15 during the calving period, 97 % of calves acquired a tick-mediated immunity at the age of 6 months. Because only adult ticks confined to the hindquarters are counted, this procedure is recommended as a feasible and practical guideline to stock owners wishing to determine a dipping programme that would ensure endemic stability. The indirect fluorescent antibody test gave a true reflection of the infection rate through ticks in calves 3-6 months old, but not in older animals that had been re-infected more than once. This is because on one hand antibody may persist for 2 years after withdrawal from tick exposure and on the other the artificial re-infection of cattle with a tick acquired immunity is not always followed by a rise in antibody titres and may even result in seronegativity. Four cows infected and re-infected through licks, remained immune to challenge for 2 years after withdrawal from tick exposure. Within the confines of one farm 3 isolates of C. ruminantium that differed in pathogenicity and immunogenicity were recovered from ticks. One of these isolates was almost non-pathogenic to cattle.
The effects of salt loading via two different routes on feed intake, body water turnover rate and on electrolyte excretion in sheep
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Verwoerd, Daniel Wynand; Meintjes, R.A.; Olivier, Roelina
The effect of dosing identical amounts of sodium chloride, via 2 different routes, on feed intake and water and electrolyte balance was investigated in sheep. Feed intake and plasma sodium concentrations were unaffected by salt loading, while water intake, fractional turnover of body water, plasma and urine potassium concentrations and urine sodium concentration changed significantly from control values (P< 0,05). With a few exceptions, parameters were in general similar irrespective of the route whereby sodium chloride was administered.
Serological differentiation of five bluetongue virus serotypes in indirect ELISA
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Du Plessis, D.H.; Verwoerd, Daniel Wynand
The serological reactivity in indirect ELISA of five different bluetongue virus (BTV) serotypes (4, 10, 15, 16 & 20) was compared using polyclonal antisera raised against virus particles and an outer structural protein, VP2. Rabbit and sheep antisera against BTV-10 produced higher ELISA values with their homologous antigens than with heterologous serotypes. A hyperimmune rabbit serum specific for virus particles was able to distinguish heterologous serotypes from each other, but a sheep serum from an infected animal was not. An antiserum directed against VP2, the protein responsible for serotype specificity in neutralization tests, was not serotype-specific in ELISA and cross-reacted with other serotypes. The discriminatory ability of a BTV-4 antiserum was improved by cross-absorption with heterologous antigens. This greatly reduced the ELISA signals with heterologous serotypes and produced an antiserum that was effectively serotype-specific.
Cardiotoxicity of the skin of the red-banded rubber frog, Phrynomerus bifasciatus (Smith 1847)
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Van der Walt, M.P.K.; Van Rooyen, J.M.; Oberholzer, G.; Van Aswegen, G.; Verwoerd, Daniel Wynand
The skin of the red-banded rubber frog is said to secrete an unidentified toxin. Whole skin extract as well as HPLC fractions were tested for toxicity on viable, isolated cardiomyocytes. The skin extract and one of its fractions were shown to be cardiotoxic. Whole-cell clamping tests demonstrated that both extract and fraction interfered with the function of the potassium channels of the cardiomyocytes and that the toxic substance has an affinity for the IK₁ channels. Investigations are in progress to isolate and characterize the toxic substance.
A host-parasite catalogue of the haematozoa of the sub-Saharan birds
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Bennett, G.F.; Earle, R.A.; Du Toit, Hester; Verwoerd, Daniel Wynand; Huchzermeyer, Fritz W.
The prevalence of avian haematozoa in 826 species of birds representing 73 families of sub-Saharan birds as recorded in the literature or in the files of the International Reference Centre for Avian Haematozoa and the Veterinary Research Institute is presented. The most commonly occurring blood parasites were members of the genus Haemoproteus which were represented by 63 species which occurred in 19,1% of the sample. Twenty-five species of Leucocytozoon were recorded in 8,3% of the birds and represented the second most frequently encountered group of haematozoa. Species of Plasmodium, Trypanosoma, and filarioids (as microfilariae) occurred in 3,5%, 2,5% and 2,8% respectively of the birds sampled; species of Aegyptianella, Atoxoplasma, Babesia and Hepatozoon were infrequently seen. An annotated list of the birds examined for haematozoa is presented and brief descriptions of the species of Haemoproteus and Leucocytozoon in birds of the sub-Saharan zone are included.
Experimental Albizia versicolor poisoning in sheep and its successful treatment with pyridoxine hydrochloride
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Bastianello, Stella S.; Labuschagne, Leonie; Erasmus, G.L.; Verwoerd, Daniel Wynand; Gummow, Bruce
Five sheep developed severe nervous signs after being drenched with Albizia versicolor podmaterial. Four of these sheep were treated with pyridoxine hydrochloride (a vitamin B₆) when the symptoms of toxicity became life-threatening. All the treated sheep recovered dramatically and completely after treatment while the untreated one died 2 h after receiving pod-material. A therapeutic dose of 20-25 mg pyridoxine hydrochloride/kg body mass given twice with an 8 h interval is the recommended treatment regimen. The route of administration will depend on the severity of symptoms. Chemical pathology and post-mortem findings are discussed.
Flow cytometric analysis of the T cell response in mice infected with Cowdria ruminantium
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Du Plessis, J.L.; Gray, C.; Van Strijp, M.F.; Verwoerd, Daniel Wynand
A 3-fold increase in the numbers of Lyt-2⁺ T cells in the circulating blood of mice infected and reinfected with the Welgevonden stock of Cowdria ruminantium, as determined by flow cytometry, is supportive evidence that immunity in heartwater is cell-mediated. The rise in Lyt-2⁺ cells only after reinfection of the mice is further evidence that the development of immunity in heartwater is dependent on the unhindered and adequate replication of C. ruminantium.
Incidence of Feline lmmunodeficiency virus reactive antibodies in free-ranging lions of the Kruger National Park and the Etosha National Park in southern Africa detected by recombinant FIV p24 antigen
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Spencer, J.A.; Van Dijk, A.A.; Horzinek, Marian C.; Egberink, H.F.; Bengis, Roy G.; Keet, D.F.; Morikawa, S.; Bishop, D.H.L.; Verwoerd, Daniel Wynand
Lion sera from the Kruger National Park (KNP) dating back to 1977 and from the Etosha National Park (ENP), obtained from 1989 to 1991 , have been analysed by ELISA and Western blot analyses using a genetically engineered antigen representing the p24 structural protein of feline immunodeficiency virus (FIV). It was concluded that some 83% of 98 KNP lion sera reacted with the p24 antigen, while none of 28 ENP lion sera reacted. A few other KNP felids (cheetahs and genets) gave samples that did not react with the FIV p24 antigen. For the KNP lions, apart from a lower prevalence in cubs (50%), no particular trends were demonstrated in terms of age, sex, date or origins of the samples. In Western blot and radio-immunoprecipitation analyses the lion sera reacted with the engineered p24 antigen, as well as with the p15 and p24 gag proteins and the p50 gag precursor protein from FIV, indicating that the agent is probably a lentivirus related to FIV. The ELISA with the engineered p24 antigen required less serum and appears to be more sensitive at detecting FlY-reactive antibodies than assays with available commercial kits.
The louse fly Lipoptena paradoxa Newstead, 1907 (Diptera: Hippoboscidae) : description of its adult and puparium and biology in South Africa
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Visagie, Elize J.; Verwoerd, Daniel Wynand; Horak, Ivan Gerard; Boomker, Jacob Diederik Frederik
Lipoptena paradoxa Newstead, 1907 is re-described using scanning electron microscopy and its puparium is described for the first time. The distribution of the fly is restricted to the eastern half of South Africa, generally at altitudes below 600 m. Its preferred hosts are all browsing antelope namely, bushbuck, nyalas, kudus and common duikers. The largest numbers of flies were present on kudus in the Kruger National Park from July or August to January and large numbers were recovered from these animals' tails from November to January. Considerably more female than male flies were collected.
A new species of Lipoptena (Diptera: Hippoboscidae) from southern Africa
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Visagie, Elize J.; Verwoerd, Daniel Wynand
A new species of Lipoptena Nitzsch, 1818 was found on springbok Antidorcas marsupialis Zimmerman, 1780 in the Cape Province and the Orange Free State, South Africa. The flies, for which the name Lipoptena annalizeae is proposed, can be differentiated from the closely related Lipoptena sepiacea Speiser, 1905 on size, palps, chaetotaxy, pulvilli, and the shape of the posterior genital plates of the males. The morphology of the puparium of the new species is also described and compared with that of the puparia of Lipoptena paradoxa Newstead, 1907 and Lipoptena binocula (Speiser, 1908). A revised key to the southern African species and a summary of host records and distributional information is also presented.
The effect of veld-burning on the seasonal abundance of free-living ixodid ticks as determined by drag-sampling
(Pretoria : Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Spickett, Arthur M.; Van Niekerk, Andrea; Verwoerd, Daniel Wynand; Horak, Ivan Gerard; Braack, L.E.O.
A supervised veld-burn in the Sclerocarya caffra/Acacia nigrescens Savanna landscape zone in the south-eastern region of the Kruger National Park was carried out during September 1988. The effect of the fire on the free-living tick population was determined by comparing the numbers of ticks collected by monthly drag-sampling in the burnt zone with those collected in an adjacent unburnt zone over a 2-year period. A total of 13 ixodid tick species were involved. Tick numbers were reduced after the burn but rose again after varying periods of time. The length of these periods depended upon a number of variables. These included tick species, patterns of seasonal abundance, and host preferences. The original reduction in numbers seemed to result in subsequent cyclical population fluctuations and in some instances overcompensation was noted. Veld-burning as a control technique may be effective with tenuously adapted tick species or reduced populations and may be enhanced by the exclusion of major hosts for a critical period after the fire.
Parasites of domestic and wild animals in South Africa. XXXI. Adult ixodid ticks on sheep in the Cape Province and in the Orange Free State
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Fourie, L.J.; Verwoerd, Daniel Wynand; Horak, Ivan Gerard
Four to 10 Dorper sheep on each of 12 farms in the Cape Province and 3 farms in the Orange Free State were examined for adult ixodid ticks at approximately 2- to 4-weekly intervals over periods varying from 4 to 18 months, commencing during January, February or April 1989. The farms in the Cape Province were located in the north-west, south-west and south of the province. Those in the Orange Free State were situated in the north-east and in the south. The sheep in the Cape Province harboured 10 species of ixodid ticks and the seasonal abundances of Ixodes rubicundus, Rhipicephalus evertsi evertsi, Rhipicephalus gertrudae and Hyalomma truncatum were determined. The animals in the Orange Free State were infested with 7 tick species and the seasonal abundances of I. rubicundus, R. evertsi evertsi and Hyalomma marginatum rufipes were determined.
Parasites of domestic and wild animals in South Africa. XXX. Ectoparasites of kudus in the eastern Transvaal Lowveld and the eastern Cape Province
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Spickett, Arthur M.; De Vos, Valerius; Verwoerd, Daniel Wynand; Horak, Ivan Gerard; Boomker, Jacob Diederik Frederik
Sets of four kudus were shot and examined for arthropod parasites at approximately monthly intervals from April 1981 to March 1983 in the southern part of the Kruger National Park, eastern Transvaal Lowveld. These animals harboured 10 ixodid tick species of which Boophilus decoloratus followed by Amblyomma hebraeum were the most abundant. The seasonal abundances of these ticks and of Amblyomma marmoreum, Rhipicephalus appendiculatus, Rhipicephalus evertsi evertsi and Rhipicephalus zambeziensis were determined. The kudus were also infested with 3 lice and 1 louse fly species, as well as the nymphs of a pentastomid. Sixteen kudus were shot in the Andries Vosloo Kudu Reserve, eastern Cape Province and 9 on an adjacent farm. These animals were infested with 12 tick species. A. hebraeum followed by Rhipicephalus glabroscutatum were the most abundant on kudus in the reserve and R. glabroscutatum followed by Haemaphysalis silacea on the animals on the farm. The seasonal abundances of A. hebraeum, A. marmoreum, H. silacea, R. appendiculatus, R. glabroscutatum and a Rhipicephalus sp. (near R. oculatus) were determined on the kudus in the reserve. The kudus were also infested with 3 lice and 1 louse fly species. Two kudus examined in the Addo Elephant National Park were infested with 6 tick, 1 louse and 1 louse fly species.
Arthropod parasites of springbok, gemsbok, kudus, giraffes and Burchell's and Hartmann's zebras in the Etosha and Hardap Nature Reserves, Namibia
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Anthonissen, M.; Krecek, R.C.; Verwoerd, Daniel Wynand; Horak, Ivan Gerard; Boomker, Jacob Diederik Frederik
A total of 48 springbok, 48 gemsbok, 23 kudus and 6 giraffes were examined for ticks and lice, while 9 Burchell's zebras and 6 Hartmann's mountain zebras were examined only for ticks. Springbok and gemsbok were shot in both the Etosha National Park in the north and the Hardap Nature Reserve in the south of Namibia. All the other animals were shot in the Etosha National Park. A total of 7 ixodid tick species and 8 lice species were recovered. The springbok carried few ticks. The adults of a Rhipicephalus sp. (near R. oculatus) were most numerous on the gemsbok, especially during November. The kudus were the only animals harbouring Rhipicephalus zambeziensis. Adult Hyalomma truncatum, followed by adult Hyalomma marginatum rufipes, were most abundant on the giraffes and adult Rhipicephalus evertsi mimeticus were commonest on the zebras.
A light microscopical study of the intestinal tract of the Nile crocodile (Crocodylus niloticus, Laurenti 1768)
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Kotze, Sanet H.; Van der Merwe, N.J.; Van Aswegen, G.; Smith, G.A.; Verwoerd, Daniel Wynand
Although the histology of the intestinal tract of Crocodylus niloticus is touched on in overall studies on reptilian intestinal tract, a more comprehensive light microscopical study on this area is lacking. Specimens for histological examination were taken from the duodenum, the jejunum, the ileum and the rectum. The data obtained revealed that the mucosa is thrown into folds and simple, slightly branched tubular intestinal glands. The mucosal folds diminished in height and eventually disappeared upon reaching the ileorectal junction. The epithelium covering the folds and crypts was of the simple columnar type. Clear marginal cells, goblet cells and argentaffin cells were observed throughout the intestinal tract. No Paneth cells were seen in this study. The lamina propria was rich in lymphocytic infiltrations while the muscularis mucosa consisted mainly of an outer longitudinal layer, the inner circular layer being rudimentary or absent. The submucosa was extremely narrow, and the circular and longitudinal layers of the tunica muscularis contained distinct layers of dense fibrous connective tissue. The histology of the intestinal tract of C. niloticus is shown to be in line with the situation in crocodilians and also exhibits a resemblance to that of carnivorous mammals.
The Leucocytozoidae of South African birds : Passeriformes
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Bennett, G.F.; Earle, R.A.; Peirce, Michael A.; Verwoerd, Daniel Wynand
The leucocytozoids of ten families of Passeriformes - Estrildidae, Fringillidae, Laniidae, Nectariniidae, Passeridae, Ploceidae, Promeropidae, Pycnonotidae, Sturnidae and Zosteropidae-are reviewed. Leucocytozoon roubaudi from the Estrildidae, L. fringillinarum from the Fringillidae, L. balmorali from the Laniidae, L. gentili from the Passeridae, L. bouffardi from the Ploceidae, L. brimonti from the Pycnonotidae and L. zosteropis from the Zosteropidae are re-described. Leucocytozoon dutoiti, L. nectariniae, L. deswardti, L. pycnonoti and L. sturni are new species described from the Fringillidae (Carduelinae), Nectariniidae, Promeropidae, Pycnonotidae and Sturnidae respectively while L. monardi is considered to be a synonym of L. gentili and L. molpastis is considered to be a synonym of L. brimonti.
The Leucocytozoidae of South African birds: Caprimulgidae, Columbidae, Gruidae and Spheniscidae
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Bennett, G.F.; Earle, R.A.; Peirce, Michael A.; Verwoerd, Daniel Wynand
Four species of Leucocytozoon, L. caprimulgi of the Caprimulgidae (nightjars), L. marchouxi of the Columbidae (pigeons and doves), L. grusi of the Gruidae (cranes) and L. tawaki of the Spheniscidae (penguins) are re-described. Leucocytozoon turtur is declared a synonym of L. marchouxi.
Deep dissections of the veins of the bovine head : unpublished work by Prof. J.M.W. Le Roux (1926-1991)
(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute., 1992) Smuts, M.M.S. (Malie Marie Sophie), 1933-; Bezuidenhout, A.J. (Abraham Johannes), 1942-; Verwoerd, Daniel Wynand; Seegers, Christine D.

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