EDITORIAL SCIENTIFIC AND CLINICAL
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History of veterinary education in Australia Neurological diseases following bacterial and protozoal infections Lameness model in sheep Effects of barefoot trimming EGFR and HER-2 as prognostic makers in mammary tumours Bacteria in semen fractions in dogs
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History Knowledge about managing the husbandry and health of domesticated animals arrived with the first shipment of convicts and officers to the Australian colony. With a favourable climate and no infectious diseases, the introduced animals were able to multiply with little input from qualified veterinarians for the first 100 years of European settlement. Because of the economic and social conditions in Britain in the 19th century, a few young, qualified veterinarians migrated to Australia because they anticipated better opportunities. Graham Mitchell was one of these, arriving in Melbourne in 1855 and he was responsible for establishing veterinary education in Australia. The model he developed, which is still followed by Australian veterinarians, was upgrading his qualifications as needed, conducting research to improve his knowledge, and writing and contributing to community organisations. William Tyson Kendall, the acknowledged founder of veterinary education and the profession in Australia, and John Anderson Gilruth, who was instrumental in fostering original research at The University of Melbourne Veterinary School and the Veterinary Research Institute, are other influential figures in the fascinating history of the transition from education for a trade to education for a profession.1 Production animals This review2 is the third of a series for veterinary practitioners who deal with neurological diseases in ruminants.3,4 After a general introduction to infectious disease, the authors describe the clinicopathological presentations of infectious diseases of the central nervous system. These depend on the neuroanatomical site of infection, the agent involved and the nature of the inflammatory response. The effects of bacterial infections, including chlamydia, and protozoal infections are described. A study from the CSIRO describes the development of a model of lameness in sheep for assessing the efficacy of analgesics.5 A range of analgesic and local anaesthetics can alleviate some of the pain and discomfort caused by castration and surgical mulesing in sheep. However, none of the non-steroidal antiinflammatory drugs (NSAIDs) are currently registered for sheep in Australia or the European Union. This study aimed to develop a model that was reproducible and involved both local and systemic inflammation, as well as short-term pain, for eventual use in quantifying the ability of NSAIDs to reduce pain and inflammation. The response to a subcutaneous injection of 0.10 mL turpentine into a pastern was examined © 2011 The Author Australian Veterinary Journal © 2011 Australian Veterinary Association
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avj_813
EDITORIAL
In this issue – August 2011
279..281
with and without the NSAID meloxicam. The weight borne on the turpentine-treated limb and sensitivity at the injection site was lowest 2 h after treatment and recovered to be similar to controls at 24 h, although local tissue inflammation was still present at 72 h. Results showed that meloxicam provided some alleviation of pain but local tissue inflammation was not significantly affected. The authors conclude that this model could be suitable for more detailed studies comparing the efficacy of analgesics for indications in sheep. Equine Many studies have investigated the effect of shoeing on horse feet under static and dynamic conditions and the effect of different ground surfaces. There is some suggestion that keeping horses barefooted and using trimming may promote the health of the undershot hoof, but few studies have investigated barefoot trimming techniques under modern management conditions. This study included seven adult Arabian horses that had been barefooted for 3–4 years.6 The hooves had been allowed to grow naturally with minimal farrier interventions for the previous year. All four feet had a barefoot trim, which involved lowering the heels to allow the frog and bars to contact the ground, and the dorsal hoof wall was aligned with the pastern axis. The goal was to trim the wall and lower the heels as far back as the widest part of the frog. The frog and bars were not trimmed. The authors have photographs and diagrams to show the changes in the hooves and X-rays to show the alignment of the hooves and the increase in the heel angle. The authors considered that palmar migration of the heels, which increased the heel angle and support length, as well as the solar angle and collation of the third phalanx, were potentially beneficial to the health of the horses’ feet. Small animals A study of mixed mammary tumours in dogs reports the expression of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER-2) using immunohistochemistry, as is performed for determining the prognosis of human breast cancers.7 Benign mixed tumours have a complex histopathology and undergo malignant transformation to form carcinomas. HER-2 protein overexpression may correlate with poor prognosis and is a useful marker for therapeutic decision-making in human patients. There are conflicting results on the overexpression of epidermal growth factor and the role of this factor may differ between cancer subtypes. There are also conflicting reports of the expression of
Australian Veterinary Journal Volume 89, No 8, August 2011
279
EDITORIAL
EDITORIAL
HER-2 and EGFR in canine mammary glands. This study included 70 cases of canine mammary gland tumours that were stained using immunohistochemistry. Results showed that there was no relationship between HER-2 expression and the histological component of these tumours. EGFR was overexpressed in one-third of tumours studied. Epithelial cells in the malignant invasive component were more frequently positive than either the benign component or benign mammary tumours. Further work is needed to assess the value of epidermal growth factor as a predictive marker in these neoplasms. Stud dogs that are to be used as semen donors are required to be in good health and their semen needs to be suitable for freezing. Bacteriological analysis may not be performed routinely although previous studies suggest that samples cannot be free of bacterial contamination and criteria for distinguishing between physiological and pathological flora are unknown. This study looked at fractionated ejaculates to see which would have the lowest bacterial load, in relation to samples that had normospermia, teratozoospermia and azoospermia.8 There were no differences between the three groups of ejaculates in the frequency of positive and negative semen samples. There were significant differences in bacterial growth between the three fractions, with bacteriological findings much higher in the pre-sperm fraction that comes from the prepuce and posterior urethra. The authors conclude that separation of the pre-sperm fraction may reduce the risk of contaminating the sperm-rich fraction with bacteria and suggests that fractionated semen collection may be the preferred option if semen is to be processed for artificial insemination.
LETTER TO THE EDITOR
avj_814
1. Caple IW. A short history of veterinary education in Australia: the 120-year transition from education for a trade to education for a profession. Aust Vet J 2011;89:282–288. 2. Kessell AE, Finnie JW, Windsor PA. Neurological diseases of ruminant livestock in Australia. III: bacterial and protozoal infections Aust Vet J 2011;89:289–296. 3. Finnie JW, Windsor PA, Kessell AE. Neurological diseases of ruminant livestock in Australia. I: general neurological examination, necropsy procedures and neurological manifestations of systemic disease, trauma and neoplasia. Aust Vet J 2011;89:243–246. 4. Finnie JW, Windsor PA, Kessell AE. Neurological diseases of ruminant livestock in Australia. II: toxic disorders and nutritional deficiencies. Aust Vet J 2011;89:247– 253. 5. Colditz IG, Paull DR, Hervault G, Aubriot D, Lee C. Development of a lameness model in sheep for assessing efficacy of analgesics. Aust Vet J 2011;89:297–304. 6. Clayton HM, Gray S, Kaiser LJ, Bowker RM. Effects of barefoot trimming on hoof morphology. Aust Vet J 2011;89:305–311. 7. Bertagnolli AC, Ferreira E, Dias EJ, Cassali GD. Canine mammary mixed tumours: immunohistochemical expressions of EGFR and HER-2. Aust Vet J 2011;89:312– 317. 8. Goericke-Pesch S, Weiss R, Wehrend A. Bacteriological findings in different fractions of canine ejaculates showing normospermia, teratozoospermia or azoospermia. Aust Vet J 2011;89:318–322.
AE Jackson Editor in Chief doi: 10.1111/j.1751-0813.2011.00813.x
280..282
The epidemiology of ILT in Australia – insufficient data to support the conclusions. ‘Epidemiology of recent outbreaks of infectious laryngotracheitis in poultry in Australia’1 – a useful work, is marred by inaccuracies but mostly by conclusions beyond what the data can support. Several inaccuracies are apparent, including the species of birds identified with infectious laryngotrcheitis (ILT) virus in New South Wales (NSW) and Queensland. The birds reported as game birds were actually small backyard flocks of chickens and not game birds that only on rare occasions have been reported to be susceptible to ILT. Some of the suggestions and hypotheses as a result of this are also questionable. However, the main issue is whether the data or the references cited can support the prime conclusion that class 8/9 were not present in Australia prior to the introduction of the Serva vaccine strain. The sole reference used to support this hypothesis is Kirkpatrick et al.2 This paper examined only 17 field ILT virus isolates over a period of 8 years. Since the March 2011 paper also stated that class 8 and 9 ILT viruses were predominantly present in NSW and that the outbreaks in different jurisdictions were epidemiologically unrelated, the comparison of the 2007–2009 ILT virus isolates with previous years should have been predominantly with isolates from NSW before 2007.
280
References
Australian Veterinary Journal Volume 89, No 8, August 2011
Only four ILT virus isolates were examined from NSW prior to 2007.2 Even if all the 17 Australian field isolates analysed2 prior to the introduction of Serva ILT vaccine are considered, the entire historical comparative data is based on fewer than two isolates per year over a period of 8 years. The AVJ paper1 acknowledges that cluster analysis is considered a crude technique of establishing the relationship between ILT virus strains and that the results obtained by this technique should be confirmed by analysis of the entire genomic sequence of the ILT virus strains in order to further confirm the relatedness of the classes of ILT viruses in their study. Despite this and the meagre comparative historical data, the paper concludes that it seems unlikely that these ILT virus classes are true field isolates which by chance show molecular similarity to class 7 ILTV particularly ‘because these genotypes were not detected in Australia before the introduction of the Serva vaccine strain’. Reversion to virulence and the presence of quasispecies of ILT vaccines are recognised phenomena that may explain the pathogenicity of ILT vaccines in some cases. In this context, the paper should have noted that in Australia, the Serva vaccine strain has been used extensively contrary to the registration and label advice. This may have had some impact on the reversion to virulence and the possible emergence of a virulent sub-population. © 2011 The Author Australian Veterinary Journal © 2011 Australian Veterinary Association
·
History of veterinary education in Australia Neurological diseases following bacterial and protozoal infections Lameness model in sheep Effects of barefoot trimming EGFR and HER-2 as prognostic makers in mammary tumours Bacteria in semen fractions in dogs
·
History Knowledge about managing the husbandry and health of domesticated animals arrived with the first shipment of convicts and officers to the Australian colony. With a favourable climate and no infectious diseases, the introduced animals were able to multiply with little input from qualified veterinarians for the first 100 years of European settlement. Because of the economic and social conditions in Britain in the 19th century, a few young, qualified veterinarians migrated to Australia because they anticipated better opportunities. Graham Mitchell was one of these, arriving in Melbourne in 1855 and he was responsible for establishing veterinary education in Australia. The model he developed, which is still followed by Australian veterinarians, was upgrading his qualifications as needed, conducting research to improve his knowledge, and writing and contributing to community organisations. William Tyson Kendall, the acknowledged founder of veterinary education and the profession in Australia, and John Anderson Gilruth, who was instrumental in fostering original research at The University of Melbourne Veterinary School and the Veterinary Research Institute, are other influential figures in the fascinating history of the transition from education for a trade to education for a profession.1 Production animals This review2 is the third of a series for veterinary practitioners who deal with neurological diseases in ruminants.3,4 After a general introduction to infectious disease, the authors describe the clinicopathological presentations of infectious diseases of the central nervous system. These depend on the neuroanatomical site of infection, the agent involved and the nature of the inflammatory response. The effects of bacterial infections, including chlamydia, and protozoal infections are described. A study from the CSIRO describes the development of a model of lameness in sheep for assessing the efficacy of analgesics.5 A range of analgesic and local anaesthetics can alleviate some of the pain and discomfort caused by castration and surgical mulesing in sheep. However, none of the non-steroidal antiinflammatory drugs (NSAIDs) are currently registered for sheep in Australia or the European Union. This study aimed to develop a model that was reproducible and involved both local and systemic inflammation, as well as short-term pain, for eventual use in quantifying the ability of NSAIDs to reduce pain and inflammation. The response to a subcutaneous injection of 0.10 mL turpentine into a pastern was examined © 2011 The Author Australian Veterinary Journal © 2011 Australian Veterinary Association
· ·
·
avj_813
EDITORIAL
In this issue – August 2011
279..281
with and without the NSAID meloxicam. The weight borne on the turpentine-treated limb and sensitivity at the injection site was lowest 2 h after treatment and recovered to be similar to controls at 24 h, although local tissue inflammation was still present at 72 h. Results showed that meloxicam provided some alleviation of pain but local tissue inflammation was not significantly affected. The authors conclude that this model could be suitable for more detailed studies comparing the efficacy of analgesics for indications in sheep. Equine Many studies have investigated the effect of shoeing on horse feet under static and dynamic conditions and the effect of different ground surfaces. There is some suggestion that keeping horses barefooted and using trimming may promote the health of the undershot hoof, but few studies have investigated barefoot trimming techniques under modern management conditions. This study included seven adult Arabian horses that had been barefooted for 3–4 years.6 The hooves had been allowed to grow naturally with minimal farrier interventions for the previous year. All four feet had a barefoot trim, which involved lowering the heels to allow the frog and bars to contact the ground, and the dorsal hoof wall was aligned with the pastern axis. The goal was to trim the wall and lower the heels as far back as the widest part of the frog. The frog and bars were not trimmed. The authors have photographs and diagrams to show the changes in the hooves and X-rays to show the alignment of the hooves and the increase in the heel angle. The authors considered that palmar migration of the heels, which increased the heel angle and support length, as well as the solar angle and collation of the third phalanx, were potentially beneficial to the health of the horses’ feet. Small animals A study of mixed mammary tumours in dogs reports the expression of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER-2) using immunohistochemistry, as is performed for determining the prognosis of human breast cancers.7 Benign mixed tumours have a complex histopathology and undergo malignant transformation to form carcinomas. HER-2 protein overexpression may correlate with poor prognosis and is a useful marker for therapeutic decision-making in human patients. There are conflicting results on the overexpression of epidermal growth factor and the role of this factor may differ between cancer subtypes. There are also conflicting reports of the expression of
Australian Veterinary Journal Volume 89, No 8, August 2011
279
EDITORIAL
EDITORIAL
HER-2 and EGFR in canine mammary glands. This study included 70 cases of canine mammary gland tumours that were stained using immunohistochemistry. Results showed that there was no relationship between HER-2 expression and the histological component of these tumours. EGFR was overexpressed in one-third of tumours studied. Epithelial cells in the malignant invasive component were more frequently positive than either the benign component or benign mammary tumours. Further work is needed to assess the value of epidermal growth factor as a predictive marker in these neoplasms. Stud dogs that are to be used as semen donors are required to be in good health and their semen needs to be suitable for freezing. Bacteriological analysis may not be performed routinely although previous studies suggest that samples cannot be free of bacterial contamination and criteria for distinguishing between physiological and pathological flora are unknown. This study looked at fractionated ejaculates to see which would have the lowest bacterial load, in relation to samples that had normospermia, teratozoospermia and azoospermia.8 There were no differences between the three groups of ejaculates in the frequency of positive and negative semen samples. There were significant differences in bacterial growth between the three fractions, with bacteriological findings much higher in the pre-sperm fraction that comes from the prepuce and posterior urethra. The authors conclude that separation of the pre-sperm fraction may reduce the risk of contaminating the sperm-rich fraction with bacteria and suggests that fractionated semen collection may be the preferred option if semen is to be processed for artificial insemination.
LETTER TO THE EDITOR
avj_814
1. Caple IW. A short history of veterinary education in Australia: the 120-year transition from education for a trade to education for a profession. Aust Vet J 2011;89:282–288. 2. Kessell AE, Finnie JW, Windsor PA. Neurological diseases of ruminant livestock in Australia. III: bacterial and protozoal infections Aust Vet J 2011;89:289–296. 3. Finnie JW, Windsor PA, Kessell AE. Neurological diseases of ruminant livestock in Australia. I: general neurological examination, necropsy procedures and neurological manifestations of systemic disease, trauma and neoplasia. Aust Vet J 2011;89:243–246. 4. Finnie JW, Windsor PA, Kessell AE. Neurological diseases of ruminant livestock in Australia. II: toxic disorders and nutritional deficiencies. Aust Vet J 2011;89:247– 253. 5. Colditz IG, Paull DR, Hervault G, Aubriot D, Lee C. Development of a lameness model in sheep for assessing efficacy of analgesics. Aust Vet J 2011;89:297–304. 6. Clayton HM, Gray S, Kaiser LJ, Bowker RM. Effects of barefoot trimming on hoof morphology. Aust Vet J 2011;89:305–311. 7. Bertagnolli AC, Ferreira E, Dias EJ, Cassali GD. Canine mammary mixed tumours: immunohistochemical expressions of EGFR and HER-2. Aust Vet J 2011;89:312– 317. 8. Goericke-Pesch S, Weiss R, Wehrend A. Bacteriological findings in different fractions of canine ejaculates showing normospermia, teratozoospermia or azoospermia. Aust Vet J 2011;89:318–322.
AE Jackson Editor in Chief doi: 10.1111/j.1751-0813.2011.00813.x
280..282
The epidemiology of ILT in Australia – insufficient data to support the conclusions. ‘Epidemiology of recent outbreaks of infectious laryngotracheitis in poultry in Australia’1 – a useful work, is marred by inaccuracies but mostly by conclusions beyond what the data can support. Several inaccuracies are apparent, including the species of birds identified with infectious laryngotrcheitis (ILT) virus in New South Wales (NSW) and Queensland. The birds reported as game birds were actually small backyard flocks of chickens and not game birds that only on rare occasions have been reported to be susceptible to ILT. Some of the suggestions and hypotheses as a result of this are also questionable. However, the main issue is whether the data or the references cited can support the prime conclusion that class 8/9 were not present in Australia prior to the introduction of the Serva vaccine strain. The sole reference used to support this hypothesis is Kirkpatrick et al.2 This paper examined only 17 field ILT virus isolates over a period of 8 years. Since the March 2011 paper also stated that class 8 and 9 ILT viruses were predominantly present in NSW and that the outbreaks in different jurisdictions were epidemiologically unrelated, the comparison of the 2007–2009 ILT virus isolates with previous years should have been predominantly with isolates from NSW before 2007.
280
References
Australian Veterinary Journal Volume 89, No 8, August 2011
Only four ILT virus isolates were examined from NSW prior to 2007.2 Even if all the 17 Australian field isolates analysed2 prior to the introduction of Serva ILT vaccine are considered, the entire historical comparative data is based on fewer than two isolates per year over a period of 8 years. The AVJ paper1 acknowledges that cluster analysis is considered a crude technique of establishing the relationship between ILT virus strains and that the results obtained by this technique should be confirmed by analysis of the entire genomic sequence of the ILT virus strains in order to further confirm the relatedness of the classes of ILT viruses in their study. Despite this and the meagre comparative historical data, the paper concludes that it seems unlikely that these ILT virus classes are true field isolates which by chance show molecular similarity to class 7 ILTV particularly ‘because these genotypes were not detected in Australia before the introduction of the Serva vaccine strain’. Reversion to virulence and the presence of quasispecies of ILT vaccines are recognised phenomena that may explain the pathogenicity of ILT vaccines in some cases. In this context, the paper should have noted that in Australia, the Serva vaccine strain has been used extensively contrary to the registration and label advice. This may have had some impact on the reversion to virulence and the possible emergence of a virulent sub-population. © 2011 The Author Australian Veterinary Journal © 2011 Australian Veterinary Association
