Scielo RSS <![CDATA[Journal of the South African Veterinary Association ]]> vol. 79 num. 1 lang. en <![CDATA[SciELO Logo]]> <![CDATA[<b>Medical and veterinary doctors, social scientists and agricultural researchers meet to carry forward the fight against cysticercosis, a neglected and fatal disease of the poor</b>]]> <![CDATA[<b>Veterinary education in South Africa: The Classes of 1934 & 1935</b>]]> The Class of 1934 included 2 graduates who created milestones for the veterinary profession in South Africa. Jack Boswell was the first Onderstepoort graduate to start his own private practice without ever joining the government service. George van der Wath has the distinction of being the only South African veterinarian to become Chairman of the prestigious South African Wool Board. Ashton Tarr was President of the South African Veterinary Medical Association from 1966-1969. Concise descriptions are given of the varied life histories of the 14 members of the Classes of 1934 and 1935. All except Boswell initially joined government service, one serving mainly in the Colonial Service before eventually returning to South Africa. Three spent their entire careers in the South African Veterinary (Field) Services, finally occupying very senior positions in that division. One ended his career lecturing at a university. Lambrechts was the first veterinarian to occupy the 'resurrected' post of Director of Veterinary Services reserved for field veterinarians. Only one of the graduates opted for research, but went farming after obtaining a DVSc degree. Three spent the greater part of their careers in private practice, Thiel from as early as 1937. Two went into municipal (public health) service, one becoming director of an abattoir. Only one saw military service in World War II. Two died before they were 50 years old. Unfortunately, virtually nothing is known about Erasmus' career. At 97 Thiel holds the distinction of being the oldest Onderstepoort graduate. <![CDATA[<b>Efficacy of 3 anthelmintics in communally grazed sheep as reflected by faecal egg count reduction tests in a semi-arid area of South Africa</b>]]> A survey was conducted on the occurrence of anthelmintic resistance of nematodes in communally grazed sheep in a semi-arid area near Mafikeng South Africa, from January to March 2006. In the herds belonging to twelve smallholder sheep farmers, the efficacies of albendazole, levamisole and closantel were tested by faecal egg count reduction tests where 80 % efficacy was considered the cut off for anthelmintic resistance. The results of the faecal egg count reduction tests showed more than 80 % efficacy with all the drugs used in most cases, but there were notable exceptions. In 1 case, closantel had an efficacy of 72%, albendazole had an efficacy of 68 % and levamisole showed efficacies of 58%, 60% and 75 =% respectively on 4 farms. The occurrence of anthelmintic resistance in this farming sector is of concern and steps should be taken to prevent its further spread and development to avoid a situation developing as on numerous commercial sheep farms in South Africa where resistance is common. <![CDATA[<b>Epidemiology, disease and control of infections in ruminants by herpesviruses - An overview</b>]]> There are at least 16 recognised herpesviruses that naturally infect cattle, sheep, goats and various species of deer and antelopes. Six of the viruses are recognised as distinct alphaherpesviruses and 9 as gammaherpesviruses. Buffalo herpesvirus (BflHV) and ovine herpesvirus-1 (OvHV-1) remain officially unclassified. The prevalence of ruminant herpesviruses varies from worldwide to geographically restricted in distribution. Viruses in both subfamilies Alphaherpesvirinae and Gammaherpesvirinae cause mild to moderate and severe disease in respective natural or secondary ruminant hosts. Accordingly, the economic and ecological impact of the viruses is also variable. The molecular characteristics of some members have been investigated in detail. This has led to the identification of virulence-associated genes and construction of deletion mutants and recombinant viruses. Some of the latter have been developed as commercial vaccines. This paper aims to give an overview of the epidemiology and pathogenesis of infection by these viruses, immuno-prophylaxis and mechanisms of recovery from infection. Since there are 128 ruminant species in the family Bovidae, it is likely that some herpesviruses remain undiscovered. We conclude that currently known ruminant alphaherpesviruses occur only in their natural hosts and do not cross stably into other ruminant species. By contrast, gammaherpesviruses have a much broader host range as evidenced by the fact that antibodies reactive to alcelaphine herpesvirus type 1 have been detected in 4 subfamilies in the family Bovidae, namely Alcelaphinae, Hippotraginae, Ovibovinae and Caprinae. New gammaherpesviruses within these subfamilies are likely to be discovered in the future. <![CDATA[<b>A serological prevalence survey of <i>Brucella abortus</i> in cattle of rural communities in the province of KwaZulu-Natal, South Africa</b>]]> A serological survey of Brucella abortus in cattle originating from communal grazing areas of Kwa Zulu Natal was carried out between March 2001 and December 2003. The survey was designed as a 2-stage survey, considering the diptank as the primary sampling unit. In total 46 025 animals from 446 diptanks of 33 magisterial districts were sampled and tested using the Rose Bengal test and Complement Fixation Test. The apparent prevalence at district level was adjusted for clustering, diagnostic test sensitivity and specificity, and mapped using ArcView version 3.3. The prevalence of brucellosis in communal grazing areas of Kwa-Zulu Natal was found to be 1.45 % (0.84-2.21 %) and varied from 0 to 15.6 % between magisterial districts. In 19 of the 33 magisterial districts no serological reactors were observed. A large variation in prevalence was found within diptank areas. Brucellosis was found to be most prevalent in the northeastern area of the province. The findings of the survey are discussed. <![CDATA[<b>The occurrence of dermatosparaxis in a commercial Drakensberger cattle herd in South Africa</b>]]> Dermatosparaxis is a heritable collagen dysplasia causing skin extensibility and fragility. In Belgian Blue cattle this mutation has been described as a 3 base pair (bp) change followed by a 17bp deletion in the gene coding for procollagen 1 N-Proteinase (pNPI). An outbreak in a commercial Drakensberger herd in South Africa followed the introduction in late 2000 of a 3-year-old bull that developed skin lesions in 2001 and was culled in 2002. Some of his offspring were similarly affected, 1 of which was kept as a breeding bull after his sire's death. Two affected calves were referred to the Onderstepoort Veterinary Academic Hospital in October 2005. Detailed examination revealed only skin abnormalities limited to the lateral extremities of the thorax, abdomen and pelvis, viz. either acute lacerations of varying sizes, slow healing defects or thin scars in chronic cases. During a subsequent farm visit, 13 animals with similar wounds were seen in the herd of 146 animals. Electron microscopic examination of skin biopsies revealed haphazard arrangement and loose packing of dermal collagen fibrils within collagen fibres. The fibrils showed size variation and slightly irregular outlines on cross-section, consistent with mild dermatosparaxis. DNA samples of affected calves were analysed using primers designed to amplify the region of the pNPI gene that contained the mutation described in Belgian Blue cattle, but this mutation could not be demonstrated in any of the animals tested. It is concluded that a form of dermatosparaxis with a different gene mutation from that described in Belgian Blue cattle exists in Drakensberger cattle in South Africa. This possibly also explains the milder and more delayed clinical signs and the milder dermal collagen ultrastructural abnormalities. <![CDATA[<b>Estimating exposed pulp lengths of tusks in the African elephant <i>(Loxodonta africana africana)</i></b>]]> Captive and wild African elephants frequently suffer tusk fractures. Several institutions shorten the tusks of captive elephants to reduce fractures and injury as a result of behaviour within enclosures. Fracturing or coronal amputations that expose pulp lead to pain for the elephant. Estimating coronal pulp lengths may thus help to minimise the risk of pulp exposure during amputations. We aimed to determine the length of the pulpbeyond the lip margin from an external tusk characteristic. Tusks collected from elephants in Namibia and the Kruger National Park had similar morphological relationships. This statistical property allowed us to correct for missing data in our data sets. Pulp volume and pulp length correlated with tusk circumference at the lip. Even so, the circumference at the lip could not predict the length of the pulp in the crown external to the lip. Our findings suggest that tusks, irrespective of sex or age, amputated further than 300 mm from the lip should not expose pulp. <![CDATA[<b>Occurrence of <i>Theileria parva</i> infection in cattle on a farm in the Ladysmith district, KwaZulu-Natal, South Africa</b>]]> Theileria parva causes widespread morbidity and mortality in cattle in endemic regions. An outbreak of theileriosis occurred on a farm near Ladysmith in KwaZulu-Natal, South Africa, which is not a declared Corridor disease-infected area. A survey of Red Brangus cattle from all age groups and areas of the farm was performed. Transmission of the parasite from infected animals on the farm to susceptible animals by tick transmission and tick-stabilate injection, was attempted. The survey indicated high numbers of animals with antibody titres to T. parva but only 6 infected animals, based on real-time PCR and RLB analysis. The transmission experiments failed to transmit the parasite. The study shows the difficulty in elucidating a source of infection and determining the dynamics of new infections in a herd where multiple possible sources are present and treatment with tetracyclines has taken place. <![CDATA[<b>The use of electrochemically activated saline as a uterine instillation in pony mares</b>]]> Twelve pony mares were randomly assigned to either a control or a treatment group and inseminated with fresh, raw semen from a single stallion of known fertility in a cross-over trial design. Pregnancy was diagnosed by transrectal ultrasound 12-14 days post-ovulation and then terminated by administration of a luteolytic dose of cloprostenol. Treatment mares received a uterine instillation of 100 ml of electrochemically activated (ECA) saline 4-12 hours post-insemination. Control mares received no treatment post-insemination. Per cycle pregnancy rate was 58.3 % in the control group and 50 % in the treatment group. There was no statistical difference (P = 1.000) in pregnancy rate between the 2 groups. The principles of ECA and applications of ECA saline are discussed. <![CDATA[<b>A comparison of the oral application and injection routes using the Onderstepoort Biological Products Fowl Typhoid vaccine, its safety, efficacy and duration of protection in commercial laying hens</b>]]> This study was undertaken to establish whether the Onderstepoort Biological Products Fowl Typhoid (OBPft) vaccine registered as an injectable vaccine was effective and safe when administered orally to commercial layers. Its efficacy and duration of protection were compared with application by intramuscular injection. Commercial brown layer hens were used as they were found to be highly susceptible to Salmonella gallinarum infections. In the vaccine safety trial birds were euthanased at timed intervals spanning 4 weeks postvaccination. Necropsies were performed and samples were taken and tested. No clinical signs or mortalities could be attributed to the OBPft vaccine nor could active shedding of the vaccine strain be detected. Slight pathological changes were noted with both routes of vaccination; however, these changes were transient, returning to normal within the observation period. The injected groups showed a better serological response with the rapid serum plate agglutination (RSPA) test than the orally vaccinated groups. In the duration of protection trial, birds were challenged at 3-8-week intervals post-vaccination. All unvaccinated birds died. Protection 8 and 16 weeks after vaccination was above 60 %, by 24 weeks after challenge, the vaccine protection was below 30 %. It was found that there was no significant difference (P < 0.05) in the protection offered by either the oral or injected route of vaccination with the OBPft vaccine. <![CDATA[<b>A serological survey of African horse sickness in Botswana</b>]]> A retrospective serological survey of African horse sickness (AHS) in Botswana covering a 10-year period (1995-2004) is reported. The survey involved horses showing clinical symptoms of the disease; the horses had not been vaccinated against AHS. Over the period surveyed, serological evidence suggestive of infection with AHS virus (AHSV) was found in 99 clinical cases out of which 41.4 % (41/99) cases were found during the 1st half (1995-1999) and 58.6 % (58/99) cases were found in the 2nd half of the survey period (2000-2004). These serological findings are discussed in relation to AHSV serotypes isolated from diseased horses in Botswana before and during the period of this serological survey. <![CDATA[<b>Acute normovolaemic haemodilution - 2 case studies</b>]]> Acute normovolaemic haemodilution (ANH) is a technique used to preserve a patient's owns red blood cells and reduce the incidence of heterogeneous blood transfusion. This paper describes the use of the technique in a dog and a kitten. A significant benefit of ANH can be shown in the canine case presented. The doglost 1800 mℓ of blood during surgery but the haematocrit was only reduced to 33 % 6 hours after the end of surgery. The kitten, however, did not benefit from ANH. It lost a small volume of blood during surgery and developed complications. This paper also describes some of the potential complications that may occur. To the best of my knowledge, this is the 1st clinical description of ANH in a dog and a cat. <![CDATA[<b>Acute lead intoxication in a pregnant mare</b>]]> Lead (Pb) intoxication in horses is usually a chronic phenomenon with clinical signs associated with central nervous dysfunction. This report gives details of a case of acute Pb intoxication in a 9-year-old American Saddlebred mare with severe, progressive and ultimately fatal neurological deterioration. During the 4 days of hospitalisation, clinical signs progressed from intermittent headshaking and depression to severe, continuous, uncontrollable manic behaviour. At autopsy, three grey-coloured, hard metal particles were present in the gastrointestinal tract and subsequently found to contain 2614 ppm Pb. Lead concentrations in the brain, liver, stomach and kidney were 29, 4, 6 and 2 ppm wet weight, respectively.