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Abstract
Equine dysautonomia (ED; also known as equine grass sickness) is a neurological disease of unknown cause, which primarily affects grazing adult horses. The clinical signs reflect degeneration of specific neuronal populations, predominantly within the autonomic and enteric nervous systems, with disease severity and prognosis determined by the extent of neuronal loss. This review is primarily focused on the major clinical decision-making processes in relation to ED, namely, (1) clinical diagnosis, (2) selection of appropriate ancillary diagnostic tests, (3) obtaining diagnostic confirmation, (4) selection of treatment candidates, and (5) identifying appropriate criteria for euthanasia.
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Affiliation(s)
- Bruce C McGorum
- The Dick Vet Equine Hospital, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Easter Bush, Roslin, Midlothian EH25 9RG, GBR.
| | - R Scott Pirie
- The Dick Vet Equine Hospital, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Easter Bush, Roslin, Midlothian EH25 9RG, GBR
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Jago RC, Scholes S, Mair TS, Pearson GR, Pirie RS, Handel I, Milne EM, Coyle F, Mcgorum BC. Histological assessment of β-amyloid precursor protein immunolabelled rectal biopsies aids diagnosis of equine grass sickness. Equine Vet J 2017. [PMID: 28621903 DOI: 10.1111/evj.12710] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND An accurate, minimally invasive, ante-mortem diagnostic test for equine grass sickness (EGS) is currently lacking. Although histological examination of haematoxylin and eosin-stained rectal biopsies for chromatolytic neurons is insensitive as a diagnostic test for EGS, we hypothesised that its diagnostic accuracy could be improved by immunolabelling for β-amyloid precursor protein (β-APP), which has increased expression in cranial cervical ganglia (CCG) neuronal perikarya in EGS. OBJECTIVES To develop a grading scheme for assessing the distribution and intensity of β-APP immunoreactivity within individual rectal submucosal neurons and subsequently to determine the value of the distribution of different grades of neurons in EGS diagnosis. STUDY DESIGN Retrospective case-control diagnostic accuracy study. METHODS Initially, a standardised grading scheme was developed and β-APP immunoreactivity in individual neuronal perikarya and axons was compared in sections of CCG and ileum from EGS and control horses. The grading scheme was then refined before being blindly applied to submucosal neurons in rectal biopsies derived from 21 EGS and 23 control horses. RESULTS β-APP immunoreactivity was increased in neuronal perikarya and axons in sections of CCG, ileum and rectum from EGS horses compared with controls. For rectal biopsies, a mean immunoreactivity grade exceeding 1.1 was 100% specific and sensitive for EGS, and the presence of at least one neuron with diffuse labelling of the entire cytoplasm (grade 3) was 95% sensitive and 100% specific for EGS. MAIN LIMITATIONS Although the diagnostic criteria facilitated the discrimination of the EGS and control biopsies evaluated in this study, further prospective validation using a larger sample set is required. CONCLUSIONS Histological assessment of β-APP immunolabelled rectal biopsies is more sensitive than conventional histological examination in EGS diagnosis. Further validation is required before this technique can be advocated for use in clinical decision making.
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Affiliation(s)
- R C Jago
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - S Scholes
- SAC Consulting Veterinary Services, Penicuik, UK
| | - T S Mair
- Bell Equine Veterinary Clinic, Maidstone, UK
| | - G R Pearson
- School of Clinical Veterinary Science, University of Bristol, Bristol, UK
| | - R S Pirie
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - I Handel
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - E M Milne
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - F Coyle
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - B C Mcgorum
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Edinburgh, UK
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Pirie RS, McGorum BC. Equine grass sickness: Benefits of a multifaceted research approach. Equine Vet J 2016; 48:770-772. [DOI: 10.1111/evj.12628] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R. S. Pirie
- Royal (Dick) School of Veterinary Studies and Roslin Institute; University of Edinburgh; Midlothian UK
| | - B. C. McGorum
- Royal (Dick) School of Veterinary Studies and Roslin Institute; University of Edinburgh; Midlothian UK
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Jago RC, Handel I, Hahn CN, Pirie RS, Keen JA, Waggett BE, McGorum BC. Bodyweight change aids prediction of survival in chronic equine grass sickness. Equine Vet J 2016; 48:792-797. [PMID: 26701780 DOI: 10.1111/evj.12551] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 12/11/2015] [Indexed: 11/30/2022]
Abstract
REASONS FOR PERFORMING STUDY Objective criteria for predicting survival of chronic grass sickness cases are currently lacking. OBJECTIVES To determine whether the rate and/or magnitude of bodyweight change during hospitalisation of chronic grass sickness cases can provide an objective predictor of survival to discharge from hospital. Clinicians' recorded indication(s) for euthanasia were also reviewed. STUDY DESIGN Single centre retrospective observational study. METHODS Case records of all horses admitted for management of chronic grass sickness to The Dick Vet Equine Hospital between 1998 and 2013 were analysed. Case background, survival to hospital discharge, indication(s) for euthanasia, disease duration at admission and bodyweight changes during the hospitalisation period were analysed, and data for survivors and nonsurvivors compared. Percentage weight change was calculated for 7 day intervals up to 28 days (0-7, 7-14, 14-21, 21-28 days) and for entire periods from the first weight recorded (0-7, 0-14, 0-21, 0-28 days). These results were used to estimate survival probability conditional on weight change. RESULTS The study sample comprised 213 horses, with 114 survivors (53.5%) and 99 (46.5%) nonsurvivors. Compared with nonsurvivors, survivors had significantly lower median maximum bodyweight loss as a percentage of first weight (survivors 5.9%, interquartile range 1.8-13.5; nonsurvivors 12.7%, 6.4-17.3). Throughout all time periods analysed, survivors had significantly lower median bodyweight loss than nonsurvivors, but no specific time period was more predictive of survival. Highest percentages of total bodyweight loss for individual horses were comparable for survivors (36%) and nonsurvivors (37%). Survival prediction curves reporting percentage survival rates for all time periods analysed provided data to aid prediction of chronic grass sickness survival. CONCLUSIONS Overall, nonsurvivors had greater bodyweight loss than survivors. Rapidity and magnitude of bodyweight loss were equally predictive of outcome. Percentage survival prediction curves provide objective data to aid discussion of prognosis, but greater predictive specificity with associated sensitivity is required for clinical decision making in individual cases.
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Affiliation(s)
- R C Jago
- The Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh Easter Bush Campus, Midlothian, UK.
| | - I Handel
- The Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh Easter Bush Campus, Midlothian, UK
| | - C N Hahn
- The Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh Easter Bush Campus, Midlothian, UK
| | - R S Pirie
- The Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh Easter Bush Campus, Midlothian, UK
| | - J A Keen
- The Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh Easter Bush Campus, Midlothian, UK
| | - B E Waggett
- The Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh Easter Bush Campus, Midlothian, UK
| | - B C McGorum
- The Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh Easter Bush Campus, Midlothian, UK
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Pirie RS, Jago RC, Hudson NPH. Equine grass sickness. Equine Vet J 2014; 46:545-53. [PMID: 24580639 DOI: 10.1111/evj.12254] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 02/18/2014] [Indexed: 11/30/2022]
Abstract
Equine grass sickness (EGS; equine dysautonomia) is a polyneuronopathy affecting both the central and the peripheral nervous systems of horses. As the name implies, EGS almost exclusively affects grazing horses, resulting in the development of a characteristic array of clinical signs, most of which can be attributed to neuronal degeneration in the autonomic and enteric nervous systems. Varying disease severities occur, largely determined by the extent of neuronal degeneration in the myenteric and submucous plexuses of the enteric nervous system. Extensive neuronal degeneration, as seen in acute and subacute forms of EGS, results in intestinal dysmotility, the severity of which is incompatible with survival. In comparison, a proportion of chronic forms of EGS, characterised by less severe neuronal degeneration, will survive. Despite extensive research efforts since EGS was first reported over 100 years ago, the precise aetiology remains elusive. This article reviews much of the scientific literature on EGS, covering epidemiology, pathology, diagnosis, treatment and aetiological hypotheses.
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Affiliation(s)
- R S Pirie
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Veterinary Campus, Midlothian, UK
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Affiliation(s)
- R. S. Pirie
- Royal (Dick) School of Veterinary Studies and Roslin Institute; University of Edinburgh; Midlothian UK
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Mellor NE, Bladon B, Foote AK, O'Meara B. Successful treatment of chronic grass sickness in a donkey. EQUINE VET EDUC 2013. [DOI: 10.1111/eve.12067] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- N. E. Mellor
- Baskerville Horgan and Partners; Buckinghamshire
| | - B. Bladon
- Donnington Grove Veterinary Surgery; Berkshire UK
| | | | - B. O'Meara
- Donnington Grove Veterinary Surgery; Berkshire UK
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Wylie CE, Shaw DJ, Fordyce FM, Lilly A, McGorum BC. Equine grass sickness in Scotland: A case-control study of signalment- and meteorology-related risk factors. Equine Vet J 2013; 46:64-71. [DOI: 10.1111/evj.12077] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 02/22/2013] [Indexed: 11/29/2022]
Affiliation(s)
- C. E. Wylie
- Royal (Dick) School of Veterinary Studies & Roslin Institute; Easter Bush Veterinary Centre; University of Edinburgh; UK
| | - D. J. Shaw
- Royal (Dick) School of Veterinary Studies & Roslin Institute; Easter Bush Veterinary Centre; University of Edinburgh; UK
| | | | - A. Lilly
- James Hutton Institute; Aberdeen UK
| | - B. C. McGorum
- Royal (Dick) School of Veterinary Studies & Roslin Institute; Easter Bush Veterinary Centre; University of Edinburgh; UK
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Wylie CE, Proudman CJ, McGorum BC, Newton JR. A nationwide surveillance scheme for equine grass sickness in Great Britain: results for the period 2000-2009. Equine Vet J 2011; 43:571-9. [PMID: 21649713 DOI: 10.1111/j.2042-3306.2011.00364.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
REASONS FOR PERFORMING STUDY Equine grass sickness (EGS) remains a frequently fatal disease of equids in Great Britain (GB). The first nationwide surveillance scheme for EGS was developed to obtain information on the occurrence of EGS and to help facilitate future proposed intervention studies, such as vaccine trials. OBJECTIVES To collect both retrospective and prospective data on cases of EGS occurring in GB since 2000 and to assess potential risk factors for categories of EGS and survival after chronic EGS. METHODS Prospective data were collected using a nationwide surveillance scheme for EGS that was developed and initiated in 2007. Data were collected by means of postal and online questionnaires documenting both retrospective premises-level and prospective case-level information. Data on outcomes of EGS category and survival after chronic grass sickness (CGS) were analysed using univariable logistic regression. RESULTS Descriptive data for 1410 EGS cases occurring in GB in the decade between the beginning of 2000 and the end of 2009 are presented. Univariable logistic regression analyses identified that CGS cases in Scotland were significantly more likely to survive than those occurring elsewhere in GB. There was no relationship between case details and the category of EGS or the outcome among CGS cases. CONCLUSIONS EGS affected equids throughout England, Scotland and Wales. Although an overall average of 141 cases were reported to the nationwide surveillance scheme annually, this number of cases was not consistent between years. Around 50% of CGS cases survived, although regional differences in survival rates existed, probably due to variation in expertise of care and/or disease severity. POTENTIAL RELEVANCE This study provides information on the spatiotemporal occurrence of EGS in GB during the last decade. Data from the nationwide surveillance scheme can be used in developing protocols for future intervention studies such as Clostridium botulinum vaccine trials.
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Affiliation(s)
- C E Wylie
- Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, UK.
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Hudson NPH, Pirie RS. Four cases of equine grass sickness: acute, subacute, chronic and surviving chronic grass sickness. EQUINE VET EDUC 2010. [DOI: 10.1111/j.2042-3292.2005.tb00329.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Wylie CE, Proudman CJ. Equine Grass Sickness: Epidemiology, Diagnosis, and Global Distribution. Vet Clin North Am Equine Pract 2009; 25:381-99. [DOI: 10.1016/j.cveq.2009.04.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Lewis CA, Bozynski CC, Johnson GC, Harral CM, Williams F, Tyler JW. Colonic impaction due to dysautonomia in an alpaca. J Vet Intern Med 2009; 23:1117-22. [PMID: 19627474 DOI: 10.1111/j.1939-1676.2009.0351.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- C A Lewis
- Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO 65211, USA
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Naylor JM, Poirier KL, Hamilton DL, Dowling PM. The Effects of Feeding and Fasting on Gastrointestinal Sounds in Adult Horses. J Vet Intern Med 2006. [DOI: 10.1111/j.1939-1676.2006.tb00759.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Milne EM, Fintl C, Hudson NPH, Pearson GT, Mayhew IG, Hahn CN. Observations on the Interstitial Cells of Cajal and Neurons in a Recovered Case of Equine Dysautonomia (Grass Sickness). J Comp Pathol 2005; 133:33-40. [PMID: 15904924 DOI: 10.1016/j.jcpa.2005.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2004] [Accepted: 01/17/2005] [Indexed: 10/25/2022]
Abstract
This paper describes the histopathological and immunohistochemical changes in the central, autonomic and enteric nervous systems in a well-documented case of equine dysautonomia (ED), after the animal had recovered without significant residual clinical signs. Evidence of neuronal degeneration, such as neuronal chromatolysis, glial scars or a decrease in density of neurons, was not observed in the midbrain, pons, medulla oblongata or spinal cord, including the nuclei of cranial nerves III, V, VII, X and XII. In addition, no evidence of muscle denervation or re-innervation, such as group atrophy of clusters of cells or grouping of cells of similar size in the triceps muscle, was observed. These findings support the hypothesis that the chromatolytic motor neurons may not progress to cell death in ED. The autonomic ganglia showed evidence of previous neuronal loss. In the myenteric and submucosal plexuses of the ileum there was significant loss of enteric neurons. However, in the ileum, a continuous network of interstitial cells of Cajal (ICC) was observed by means of immunohistochemical techniques. It is possible that recovery without significant residual clinical signs was associated with lack of damage to, or more likely recovery of, the ICC, which have a pacemaker function in the intestinal tract.
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Affiliation(s)
- E M Milne
- Veterinary Pathology Unit, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Veterinary Centre, Roslin, Midlothian EH25 9RG, UK
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Owen RAR, Kelly DF. Complete clinical recovery of a pony with histologically confirmed chronic grass sickness. Vet Rec 2003; 153:597-8. [PMID: 14640328 DOI: 10.1136/vr.153.19.597] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Rh ap Rh Owen
- Clinigau Ceffylau Fyrnwy, Llanymynech, Powys SY22 6LG
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Fintl C, McGorum BC. Evaluation of three ancillary treatments in the management of equine grass sickness. Vet Rec 2002; 151:381-3. [PMID: 12403518 DOI: 10.1136/vr.151.13.381] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Brotizolam, acetylcysteine and aloe vera gel were evaluated as ancillary treatments for 29 cases of equine grass sickness. None of the treatments had any significant beneficial effect on the survival of the horses. However, 11 of 13 horses with mild chronic grass sickness survived solely with intensive nursing care.
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Affiliation(s)
- C Fintl
- Department of Veterinary Clinical Studies, Easter Bush Veterinary Centre, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian
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Hunter LC, Poxton IR. Systemic antibodies to Clostridium botulinum type C: do they protect horses from grass sickness (dysautonomia)? Equine Vet J 2001; 33:547-53. [PMID: 11720025 DOI: 10.2746/042516401776563418] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The aetiology of equine grass sickness (EGS) is still unknown. There is increasing evidence that toxicoinfection with Clostridium botulinum type C is involved. Epidemiological evidence shows that resistance to EGS can occur in older horses and those that have been on a particular pasture for longer or have been in prior contact with the disease. This resistance may be in the form of an immune response to the aetiological agent. Levels of systemic antibodies to the surface antigens of C. botulinum type C (using the closely related and safe C. novyi type A as a phenotypic marker) and to the botulinum type C neurotoxin (BoNT/C) were investigated in horses with and without EGS. Horses with grass sickness were found to have significantly lower levels of systemic IgG to both surface antigens and BoNT/C. Horses with low levels of systemic immunity to these antigens may be more susceptible to developing EGS. There were no significant differences in antibody levels between the different categories of EGS, suggesting systemic immunity to C. botulinum type C does not play a significant role in influencing the severity of the disease. However, horses that had been in contact with EGS or that were grazing land where it had occurred frequently in the past had significantly higher antibody levels to these antigens. These horses may have been exposed to subclinical doses of C. botulinum type C and BoNT/C, resulting in the production of a protective immune response against the putative aetiological agent. This finding is of potential significance for the prospect of prevention of EGS by vaccination against C. botulinum type C.
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Affiliation(s)
- L C Hunter
- Medical Microbiology, University of Edinburgh Medical School, UK
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Doxey DL, Milne EM, Gwilliam R, Sandland J. Prediction of long-term outcome following grass sickness (equine dysautonomia). Vet Rec 1999; 144:386-7. [PMID: 10327542 DOI: 10.1136/vr.144.14.386] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- D L Doxey
- Easter Bush Veterinary Centre, Roslin, Midlothian
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Doxey DL, Milne EM, Ellison J, Curry PJ. Long-term prospects for horses with grass sickness (dysautonomia). Vet Rec 1998; 142:207-9. [PMID: 9533290 DOI: 10.1136/vr.142.9.207] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Responses to questionnaires were received from 31 owners of horses or ponies treated for chronic grass sickness (dysautonomia). Contrary to previous opinions the respondents indicated that the majority of the animals were capable of strenuous work, had regained the weight they had lost and, apart from a few residual problems such as difficulty in coping with dry fibrous food, had returned to a normal life. They had recovered slowly and had involved the owners in considerable extra work, but all the owners indicated that they considered the effort to have been worthwhile.
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Affiliation(s)
- D L Doxey
- Department of Veterinary Clinical Studies, University of Edinburgh, Easter Bush Veterinary Centre, Roslin, Midlothian
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Milne EM, Doxey DL, Woodman MP, Cuddeford D, Pearson RA. An evaluation of the use of cisapride in horses with chronic grass sickness (equine dysautonomia). THE BRITISH VETERINARY JOURNAL 1996; 152:537-49. [PMID: 8885464 DOI: 10.1016/s0007-1935(96)80006-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A clinical trial was carried out to determine the effect of cisapride on rate of passage of digesta and clinical parameters in horses with chronic grass sickness. Sixteen horses were given intramuscular cisapride (0.1 mg kg-1 three times daily) (group I), and 15 received oral cisapride (0.8 mg kg-1 three times daily) (group O). A liquid-phase marker (cobalt-EDTA) and a solid-phase marker (polystyrene pellets) were given by stomach tube at the beginning of each of three consecutive 7 day periods, i.e., before, during and after cisapride therapy. Seven horses in each group completed the rate of passage trial; the remainder provided clinical data only. The rate of passage was found to be significantly faster after cisapride therapy than before. Comparison with data from 20 normal animals showed a trend towards normal rates of passage after therapy. In cases that died during the trial, the caecum and large colon were the main sites of pellet retention. Dry matter intake was significantly higher after therapy than before in group O and dry matter output was higher after treatment than before in both groups. Gut auscultation score increased in both groups in the periods during and after cisapride administration but heart rate was unaffected. Diarrhoea and colic occurred in each group but its occurrence was not associated with cisapride therapy. The results suggest that by increasing gut motility, cisapride is of benefit in the management of selected cases of chronic grass sickness.
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Affiliation(s)
- E M Milne
- Department of Veterinary Clinical Studies, Royal (Dick) School of Veterinary Studies, Veterinary Field Station, Roslin, Midlothian, UK
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Murphy D, Love S. Diagnostic aids and prognostic indicators for chronic grass sickness: possibilities for the future. THE BRITISH VETERINARY JOURNAL 1996; 152:497-9. [PMID: 8885461 DOI: 10.1016/s0007-1935(96)80003-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Clinical Quiz - Part IV. EQUINE VET EDUC 1994. [DOI: 10.1111/j.2042-3292.1994.tb01137.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Murray A, Cottrell DF, Woodman MP. Cholinergic activity of intestinal muscle in vitro taken from horses with and without equine grass sickness. Vet Res Commun 1994; 18:199-207. [PMID: 7985382 DOI: 10.1007/bf01839269] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Equine grass sickness (EGS) is a pan-dysautonomia of horses that involves central and peripheral neuronal degeneration and ultimately depletion. This is the first reported functional study on the motility of equine intestine taken immediately post mortem from horses with EGS. Strips of smooth muscle from the small intestine of healthy and EGS-affected horses were suspended in an organ bath and their motility was measured isometrically. The activity of the cholinergic system was studied. Physostigmine enhanced the motility of all muscle strips. Tissues taken from horses suffering from acute grass sickness (AGS) had the longest latency before a measurable response could be obtained (p < 0.05). The ileum appeared to be damaged by EGS to a greater extent than the duodenum. For the duodenal strips the enhanced rate of spontaneous contractions was significant (p < 0.05) for both normal tissue and that affected by grass sickness but this was not the case for the ileal strips. Muscarinic receptor sensitivity investigation using bethanecol suggested a hypersensitivity of receptors with AGS material.
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