African
Journals Online
Journal of the South African Veterinary Association
Plant poisonings and mycotoxicoses of importance in horses
in southern Africa : review article
Botha, C.J.Naude, T.W.
91-97
Abstract: Well-known plant poisonings such as 'dunsiekte'
(seneciosis) and 'jaagsiekte' (crotalariosis) of horses in
southern Africa are briefly reviewed. Relatively unfamiliar
mycotoxicoses such as stachybotryotoxicosis and perennial rye
grass staggers and potentially occurring exotic intoxications
such as equine nigropallidal encephalomalacia and ergot alkaloid
poisoning are also discussed. This article is aimed at informing
the southern African equine practitioner about probable
poisonings that might occur locally in horses.
Ixodid ticks on cattle belonging to small-scale farmers at
4 communal grazing areas in South Africa : article
Bryson, N.R.Tice, G.A.Horak, I.G.Stewart, C.G.Du
Plessis, B.J.A.
98-103
Abstract: Ixodid ticks were collected during the period
September 1991 to August 1993 from cattle belonging to
small-scale farmers utilising 4 communal grazing areas. Three of
these were in North West Province and 1 in Mpumalanga province,
South Africa. Ten tick species were collected in North West
Province and 7 in Mpumalanga. The adults of Amblyomma
hebraeum, Rhipicephalus appendiculatus and Rhipicephalus
evertsi evertsi were most numerous in North West Province,
while in Mpumalanga Boophilus decoloratus comprised more
than 75% of the total population. Amblyomma hebraeum was
present on all grazing areas, and heavy infestations of adults
occurred during the period October to May on 1 of these. Few B.
decoloratus were collected in North West Province, chiefly
because the sampling method was inadequate, and most of these
were present during early summer (October to December) and late
summer and autumn (March to May). The initially low population of
B. decoloratus in Mpumalanga increased substantially
towards the conclusion of the survey, probably because of the
cessation of dipping. Boophilus microplus was present in
small numbers on 2 grazing areas in the North West Province.
Adult Hyalomma marginatum rufipes reached peak numbers
from December to February and Hyalomma truncatum from
February to April in the North West Province. Only H.
marginatum rufipes was collected in Mpumalanga. Rhipicephalus
appendiculatus was present on all the grazing areas, with
most adults present from December to April. Most adult Rhipicephalus
evertsi evertsi were collected from September to April and Rhipicephalus
simus was present during the period October-April.
The cardiovascular and respiratory effects of medetomidine
and thiopentone anaesthesia in dogs breathing at an altitude of
1486 m : article
Joubert, K.E.Lobetti, R.
104-110
Abstract: The purpose of this study was to evaluate the
cardio-respiratory effects of the combination of medetomidine and
thiopentone followed by reversal with atipamezole as a
combination for anaesthesia in 10 healthy German Shepherd dogs
breathing spontaneously in a room at an altitude of 1486 m above
sea level with an ambient air pressure of 651 mmHg. After the
placement of intravenous and intra-arterial catheters, baseline
samples were collected. Medetomidine (0.010 mg/kg) was
administered intravenously and blood pressure and heart rate were
recorded every minute for 5 minutes. Thiopentone was then slowly
administered until intubation conditions were ideal. An
endotracheal tube was placed and the dogs breathed room air
spontaneously. Blood pressure, pulse oximetry, respiratory and
heart rate, capnography, blood gas analysis and arterial lactate
were performed or recorded every 10 minutes for the duration of
the trial. Thiopentone was administered to maintain anaesthesia.
After 60 minutes, atipamezole (0.025 mg/kg) was given
intramuscularly. Data were recorded for the next 30 minutes. A
dose of 8.7 mg/kg of thiopentone was required to anaesthetise the
dogs after the administration of 0.010 mg/kg of medetomidine.
Heart rate decreased from 96.7 at baseline to 38.5 5 minutes
after the administration of medetomidine (P < 0.05).
Heart rate then increased with the administration of thiopentone
to 103.2 (P < 0.05). Blood pressure increased from
169.4/86.2 mmHg to 253.2/143.0 mmHg 5 minutes after the
administration of medetomidine (P < 0.05). Blood
pressure then slowly returned towards normal. Heart rate and
blood pressure returned to baseline values after the
administration of atipamezole. Arterial oxygen tension decreased
from baseline levels (84.1 mmHg) to 57.8 mmHg after the
administration of medetomidine and thiopentone (P <
0.05). This was accompanied by arterial desaturation from 94.7 to
79.7 % (P < 0.05). A decrease in respiratory rate from
71.8 bpm to 12.2 bpm was seen during the same period. Respiratory
rates slowly increased over the next hour to 27.0 bpm and a
further increases 51.4 bpm after the administration of
atipamezole was seen (P < 0.05). This was maintained
until the end of the observation period. Arterial oxygen tension
slowly returned towards normal over the observation period. No
significant changes in blood lactate were seen. No correlation
was found between arterial saturation as determined by blood gas
analysis and pulse oximetry. Recovery after the administration of
atipamezole was rapid (5.9 minutes). In healthy dogs, anaesthesia
can be maintained with a combination of medetomidine and
thiopentone, significant anaesthetic sparing effects have been
noted and recovery from anaesthesia is not unduly delayed.
Hypoxaemia may be problematic. Appropriate monitoring should be
done and oxygen supplementation and ventilatory support should be
available. A poor correlation between SpO2 and SaO2
and ETCO2 and PaCO2 was found.
The effect of storage conditions on samples for the
evaluation of copper status in blesbok (Damaliscus
pygargus phillipsi) : article
Quan, M.Mulders, M.S.Meltzer, D.G.A. 111-114
Abstract: Investigaltions to determine the effect of
sample storage on the concentration of copper in liver tissue and
on the activity of erythrocyte superoxide dismutase were
undertaken in preparation for a study of blesbok (Damaliscus
pygargus phillipsi) that were suspected to be suffering from
copper deficiency. Two liver samples were collected from each of
20 culled blesbok in a manner that simulated the collection of
biopsies from the live animal. These samples were stored either
in 10 % formalin or frozen at -20 ºC until analysed 4 1/2 months
later. The effect of different methods of sample storage on
superoxide dismutase activity was determined. Erythrocytes
collected from 3 Jersey cows and 5 culled blesbok were washed and
divided into 0.5m portions, stored at room temperature (~20 ºC),
in a refrigerator (4 ºC), frozen at -20 ºC in a freezer, and in
liquid nitrogen (-200 ºC). An analysis of superoxide dismutase
activity was undertaken using a commercial assay kit at intervals
of 2-4 days until the levels of activity had fallen
significantly. The copper concentration in formalin-preserved
liver samples was significantly lower than that measured in
frozen liver tissue apparently as a result of leaching. The
activity of superoxide dismutase in cattle blood was unchanged
for 4 days at room temperature but fell appreciably after 2 days
at 4 ºC and -20 ºC. Enzyme activity remained unchanged for 200
days in erythrocytes stored in liquid nitrogen. Superoxide
dismutase activity levels in healthy blesbok were considerably
lower than those measured in Jersey cows and remained unaffected
for up to 6 days in samples stored at 4 ºC and 20 ºC. The level
of activity fell significantly thereafter. Samples stored in
liquid nitrogen were unchanged after 40 days.
A comparison of the surgical caseloads of selected
companion animal hospitals and a veterinary academic hospital in
South Africa : article
Van Niekerk, L.J.Verstraete, F.J.M.Odendaal, J.S.J.
115-118
Abstract: Educational institutions should be aware of the
frequency of surgical procedures in private practice, to assist
both the student and the lecturer in evaluating the relative
importance of procedures and to structure training programmes
accordingly. The surgical caseload for 1 year at a veterinary
academic hospital and 13 private companion animal hospitals
registered with the South African Veterinary Council were
compared. Surgical records were entered into a spreadsheet and
sorted according to 96 selected surgical procedures to facilitate
comparisons. Surgical procedures were in turn grouped according
to date, species, degree of difficulty and frequency of
occurrence. Feline procedures were more commonly performed in
private hospitals. The academic hospital's caseload was dominated
by major and advanced procedures while the private hospitals
carried out more minor procedures. At the private hospitals more
general surgery, and ear, nose and throat surgery aswell as
dental procedures were performed, while at the academic hospital
more ophthalmic, orthopaedic, thoracic and neurosurgical
procedures were carried out. The most commonly performed
procedures at the academic hospital differed from those at the
private hospitals. No seasonal trends were evident.
Haemonchus spp. in sheep farmed under
resource-poor conditions in South Africa - effect on haematocrit,
conjunctival mucous membrane colour and body condition : article
Vatta, A.F.Krecek, R.C.Van der Linde, M.J.Motswatswe,
P.W.Grimbeek, R.J.Van Wijk, E.F.
Hansen, J.W. 119-123
Abstract: A longitudinal study was conducted on the
differential faecal egg counts, haematocrits and body condition
scores of sheep belonging to resource-poor farmers at Rust de
Winter, Gauteng province, and Kraaipan, North West Province,
South Africa. The animals were scored for level of anaemia using
the FAMACHA(c) method, an assay for the clinical
evaluation of anaemia caused by Haemonchus spp. Periods of
higher Haemonchus egg counts occurred from October to
March for sheep at Rust de Winter and from September/October to
February or April for sheep at Kraaipan. Lower haematocrit values
were registered during these periods as was a higher incidence of
anaemic conjunctival mucous membrane colour scores compared to
the period April to September. No clear relationship between the
faecal egg counts and the body condition scores was evident.
Although wider application of the FAMACHA(c) system in
sheep raised by resource-poor farmers should be investigated, the
present study indicates that this method may certainly prove to
be a valuable worm control strategy for such livestock owners.
Canine filariosis caused by Dirofilaria immitis
in Mozambique : a small survey based on the identification of
microfilariae : research communication
Schwan, E.V.Durand, D.T. 124-126
Abstract: Dirofilaria immitis was diagnosed in 4 of
13 indigenous dogs from the Province of Zambézia, Mozambique, by
acid phosphatase staining of microfilariae. The finding
reconfirms the occurrence of the parasite in Mozambique after 3
decades and emphasises the need for extensive surveys.
Additionally, in 1 of the infected dogs, microfilariae of Dipetalonema
reconditum were detected, which is the 1st record of this
parasite in Mozambique.
Effect of clenbuterol on growth, nitrogen and energy
balances and endocrine status in food-restricted sheep : research
communication
Cardoso, L.A.Taveira, O.
127-130
Abstract: The aim of this study was to examine the effect
of the b2-adrenoceptor clenbuterol on food-restricted
sheep. Clenbuterol was administered as a dietary admixture (4 mg/
kg diet) to a group of male Serra da Estrela sheep (n =
6).The animals were housed individually in metabolic cages and
fed for 45 days at 65 % of estimated requirement for energy
maintenance. An untreated group with the same energy intake level
was included as a control. Changes in body mass, nitrogen and
energy balances and insulin, insulin-like growth factor (IGF-1),
and triiodothyronine (T3) levels in the experimental
animals were monitored. During the 4th week of the trial,
clenbuterol-treated sheep showed increased mass gains, greater
energy retention and serum IGF-1 levels and decreased T3
serum concentrations. This study showed that clenbuterol may
induce a protective effect in sheep subjected to periods of food
deprivation, based on the body mass and digestible energy effects
manifested by treated animals.
The prevalence of Cowdria ruminantium
in free-living adult Amblyomma hebraeum
collected at a communal grazing area and in 2 wildlife reserves
in South Africa : short communication
Bryson, N.R. Horak, I.G. Venter, E.H.Mahan, S.M.Simbi,
B.Peter, T.F. 131-132
Abstract: In order to detect the prevalence of Cowdria
ruminantium in the vector tick, Amblyomma hebraeum,
free-living, unfed adult ticks were collected with the aid of
pheromone/CO2 traps. Ticks were collected at the
Rietgat communal grazing area, as well as in the southwestern
Kruger National Park and in the Songimvelo Game Reserve, all
located in heartwater-endemic areas of South Africa. The presence
of C. ruminantium in these ticks was determined by
polymerase chain reaction (PCR) analysis. Ticks from the Rietgat
communal grazing area were assayed in 2 batches and 4.7% of the
one and 11.3% of the other were positive for infection, while
5.7% of the ticks collected in the Kruger National Park and 25%
in the Songimvelo Game Reserve were positive. These results
support the contention that a vector-wildlife cycle of
transmission of C. ruminantium, the cause of heartwater in
domestic ruminants, can be maintained in the absence of the
latter animals.
Suspected primary immune deficiency in a Donge de Bordeaux
dog : short communication
Lobetti, R.G.
133-134
Abstract: A young Donge de Bordeaux dog was presented with
chronic intermittent antibiotic responsive gastrointestinal and
respiratory disease. Further evaluation showed bacterial
lymphadenitis, bacterial tracheitis, normal white cell and
differential cell counts, hypogammaglobulinaemia, and the absence
of B-lymphocytes but the presence of T-lymphocytes in the
lymphoid tissue stained with lymphocyte markers. As the dog came
from a narrow genetic base, with related dogs showing similar
clinical signs, possible B-cell congenital immune deficiency was
suspected.
Host preference of the sheep scab mite, Psoroptes ovis :
short communication
Meintjes, T.Fourie, L.J.Horak, I.G.
135-136
Abstract: Sheep scab mites, Psoroptes ovis,
collected from a Merino donor sheep, were used to infest Merino
and Dorper sheep, and Angora and Boer goats. Mites were placed on
the sheep on 1 or 2 occasions and on 5 occasions on the goats.
All the animals were examined at regular intervals for the
presence of scab lesions and living mites. Both sheep breeds
developed lesions, but those on the Merino sheep were always
larger than those on the Dorper sheep at the same intervals after
infestation. None of the goats developed lesions or showed signs
of irritation, or harboured any mites.
The rate of spread of sheep scab within small groups of
Merino and Dorper sheep : short communication
Meintjes, T.Fourie, L.J.Horak, I.G. 137-138
Abstract: A single Merino sheep, artificially infested
with the sheep scab mite, Psoroptes ovis, and a similarly
infested Dorper sheep were placed with 9 uninfested Merino or 9
uninfested Dorper sheep respectively during winter and the rate
of spread of infestation on the uninfested sheep observed. The
same procedure was repeated in summer. It took 14 and 8 weeks
respectively in winter before all sheep in the 2 groups displayed
lesions of sheep scab, whereas in summer it took 10 and 12 weeks
before all sheep had lesions.
A case of anaemia in a neonatal warthog (Phacochoerus
aethiopicus) and evaluation of serum-soluble iron in
warthogs : short communication
Kenny, D.E.Braselton, W.E.Taylor, R.A.Morgan, T.Hesky,
R.B. 139-141
Abstract: A 38-day-old male warthog (Phacochoerus
aethiopicus) with marked anaemia (haematocrit = 14 %)
presented to the Denver Zoological Gardens hospital with ataxia,
tachypnoea, suspected stunted growth and cardiomegaly. The piglet
demonstrated some features consistent with both iron deficiency
anaemia and autoimmune haemolytic anaemia. Serum-soluble iron was
below the level of detection (<8.96 mmol/l). Iron
deficiency anaemia is a well recognised entity in domestic swine
reared on concrete and denied access to soil. Fifteen captive
warthogs were subsequently evaluated for serum soluble iron
content (mean = 21.62±4.36 mmol/l) as well as 5 neonatal
warthog piglets that required hand-rearing. Only 1 of 5 neonatal
warthog piglets had measurable serum soluble iron (9.50 mmol/l).
These data suggest that warthogs are similar to domestic swine
and are born with low iron stores. Some form of iron
supplementation should be considered for captive neonatal warthog
piglets, especially if they are reared on concrete.
30th Annual Scientific Meeting : Parasitological Society of
Southern Africa : conference abstracts 142-159
Abstract: The following are abstracts of papers and
posters presented at the 30th Annual Scientific Meeting - A
Parasite Odyssey - 9-12 September 2001, Villia Via, Gordon's Bay,
South Africa.
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