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.

Histological evidence of fibrosis affecting the outer layer of the large intestinal tunica muscularis was identified in five of 32 horses affected by colic. In three cases, foci of pale eosinophilia and vacuolation of myocytes were observed. These findings are suggestive of a degenerative and fibrotic abnormality in the outer layer of the tunica muscularis of the large intestinal smooth muscle of some horses with colic.

REASONS FOR PERFORMING STUDY:The most prevalent type of equine dental pulpitis due to apical infection is not associated with coronal fractures or periodontal disease. The pathogenesis of this type of pulpitis is not fully understood. Computed tomography (CT) is increasingly used to investigate equine dental disorders. However, gross, tomographic and histopathological changes in equine dental pulpitis have not been compared previously.OBJECTIVES:To compare gross, CT and histological appearances of sectioned mandibular cheek teeth extracted from horses with clinical signs of pulpitis without coronal fractures or periodontal disease. To contribute to understanding the pathogenesis of equine dental pulpitis.STUDY DESIGN:Descriptive study using diseased and healthy teeth.METHODS:Mandibular cheek teeth extracted from horses with clinical signs of pulpitis (cases), and from cadavers with no history of dental disease (controls), were compared using CT in the transverse plane at 1 mm intervals. Teeth were then sectioned transversely, photographed and processed for histopathological examination. Tomographs were compared with corresponding gross and histological sections.RESULTS:Cement, dentine and bone had similar ranges of attenuation (550-2000 Hounsfield Units, HU) in tomographs but could be differentiated from pulp (-400 to 500 HU) and enamel (> 2500 HU). Twelve discrete dental lesions were identified grossly, 10 of which were characterised histologically. Reactive and reparative dentinogenesis and extensive pulpar mineralisation, previously undescribed, were identified. Pulpar oedema, neutrophilic inflammation, cement and enamel defects, and reactive cemental deposition were also observed. The CT and pathological findings corresponded well where there was mineralised tissue deposited, defects in mineralised tissue, or food material in the pulpar area. Pulpar and dentinal necrosis and cement destruction, evident grossly and histologically, did not correspond to CT changes.CONCLUSIONS:Computed tomography is useful for identifying deposition and defects of mineralised material but less useful for identifying inflammation and tissue destruction. The equine dentine-pulp complex responds to insult with reactive and reparative changes.

REASONS FOR PERFORMING STUDY:Survey data on equine tumours are sparse compared with other species and may have changed over time.OBJECTIVES:To describe the most frequently diagnosed equine tumours recorded by a diagnostic pathology laboratory over 29 years, to identify background factors associated with tumour type, and to identify any changes in the tumours diagnosed or the background of cases submitted during the study period.STUDY DESIGN:Observational; cross-sectional analysis of records of a diagnostic pathology laboratory.METHODS:The records of all neoplastic equine histology submissions to the University of Bristol (January 1982-December 2010) were accessed from a database, and a list of diagnoses compiled. The 6 most commonly diagnosed tumour types were analysed using logistic regression to identify background factors associated with tumour type. The overall population of equine tumour submissions and the relative frequency of diagnosis of the most common tumour types were compared between decades.RESULTS:There were 964 cases included. The most frequently diagnosed tumours were: sarcoid (24% cases), squamous cell carcinoma (SCC) (19%), lymphoma (14%), melanoma (6%), gonadal stromal tumour (6%) and mast cell tumour (MCT) (4%). With sarcoid, Thoroughbred/Thoroughbred cross and gelding as reference categories: increasing age was significantly associated with the odds of each of the other tumour types, mares were at reduced risk of SCC, Arab/Arab cross had a higher risk of MCT, Cob/Cob cross had an increased risk of SCC and MCT, and ponies had an increased risk of melanoma. The mean age of submissions increased in each successive decade and the breed composition became broader. Sarcoids and lymphoma formed a smaller proportion of diagnoses in later decades.CONCLUSIONS:The types of tumours submitted to this laboratory have changed over the last 3 decades. Current data inform clinicians and researchers and further studies are warranted to follow trends.

Summary Identification of regional and/or distant metastasis following treatment and local resolution of primary ocular squamous cell carcinoma (SCC) was observed in 5 horses. In all cases, identification of metastasis occurred at least 18 months following treatment of the primary ocular lesions. In 3 cases, invasion of blood or lymphatic vessels by neoplastic cells was identified in the excisional biopsies of the primary tumour. Two horses developed SCC at 2 or more separate sites. At the time metastases were identified, there was no evidence of local recurrence of the ocular tumour in any of the horses. These cases confirm the importance of long‐term monitoring of horses for metastatic disease following treatment of ocular SCC even in the absence of local recurrence.

REASONS FOR PERFORMING STUDY:Gastric impaction in the horse is poorly described in the veterinary literature.OBJECTIVES:To review the clinical and pathological features of gastric impaction.METHODS:The clinical details of horses presenting with colic over a 7-year period and cases in which gastric impaction was considered to determine the outcome were reviewed. Clinical and clinicopathological data were recorded.RESULTS:Twelve cases of gastric impaction were recorded (1.4% of 857 horses hospitalised for colic). Diagnosis was achieved by ultrasonographic examination, gastroscopy, exploratory celiotomy and/or post mortem examination. Five out of 12 horses were successfully treated, 5/12 were subjected to euthanasia (3 at celiotomy and 2 due to recurrence of impaction) and 2/12 died. Three out of 12 horses had spontaneous gastric rupture despite attempted treatment (one was subjected to euthanasia at celiotomy and 2 died). Post mortem examination (7 horses) revealed gross muscular thickening of the stomach wall in 6/7 horses. Histological examination revealed focal fibrosis of the stomach wall in 4/6 and focal myositis in 1/6 horses. CONCLUSIONS AND PRACTICAL SIGNIFICANCE: Gastric impaction is a rare cause of colic and affected horses can present with acute, chronic or recurrent colic in the presence or absence of other gastrointestinal disease. Spontaneous gastric rupture may occur. A proportion of affected horses have gross thickening of the muscular layers of the stomach wall.

Exophiala dermatitidis is a dematiaceous fungal pathogen that exists in nature as a mould, but can grow in a yeast-like manner in mammalian tissues in certain circumstances. It can cause superficial infections of the skin and subcutis following a penetrating injury, and visceral or disseminated

Three mature horses presented with progressive weight loss, inappetence, ventral abdominal oedema and lethargy. Two of the animals had intermittent signs of low grade abdominal pain. At presentation, all 3 had hypoalbuminaemia; 2 had hyperfibrinogenaemia and the other had neutrophilia. An oral glucose tolerance test was performed in 2 cases, both of which demonstrated impaired glucose absorption. One pony treated with corticosteroids failed to improve and developed peritonitis and was subjected to euthanasia after 2 weeks. One pony had small intestinal biopsies obtained via a standing flank laparotomy, which revealed a mainly mononuclear cell infiltrate of the mucosa. It failed to respond to treatment with antibiotics and corticosteroids and, after 2 months, developed sternal oedema in addition to the ventral abdominal oedema and peritonitis and was subjected to euthanasia. The remaining pony deteriorated despite symptomatic therapy and was subjected to euthanasia after one week. At post mortem examination, all 3 animals had multifocal lesions of small intestinal wall thickening, mucosal ulceration, pseudodiverticula and enlarged mesenteric lymph nodes. One pony also had a multinodular mass at the root of the mesentery, a mediastinal mass and a lung mass. Histological examination confirmed the presence of lymphoma of the intestinal wall at post mortem examination in each case and immunohistochemistry (including retrospective evaluation of the intestinal biopsies obtained from the pony that underwent a flank laparotomy) indicated that the lymphomas were of T cell origin.

Veterinary RecordVolume 168, Issue 10 p. 266-266 Research Spinal osteolytic osteosarcoma in a pet rabbit A. T. A. Weiss DVM, PhD, A. T. A. Weiss DVM, PhD Department of Veterinary Pathology, College of Veterinary Medicine, Freie Universität Berlin, Robert-von-Ostertag-Strasse 15, 14163 Berlin, GermanySearch for more papers by this authorK. Müller DrMedVet, DipECZM, Corresponding Author K. Müller DrMedVet, DipECZM [email protected] Small Animal Clinic, College of Veterinary Medicine, Freie Universität Berlin, Oertzenweg 19b, 14163 Berlin, GermanyCorrespondence to Dr Müller, e-mail: [email protected]Search for more papers by this author A. T. A. Weiss DVM, PhD, A. T. A. Weiss DVM, PhD Department of Veterinary Pathology, College of Veterinary Medicine, Freie Universität Berlin, Robert-von-Ostertag-Strasse 15, 14163 Berlin, GermanySearch for more papers by this authorK. Müller DrMedVet, DipECZM, Corresponding Author K. Müller DrMedVet, DipECZM [email protected] Small Animal Clinic, College of Veterinary Medicine, Freie Universität Berlin, Oertzenweg 19b, 14163 Berlin, GermanyCorrespondence to Dr Müller, e-mail: [email protected]Search for more papers by this author First published: 12 March 2011 https://doi.org/10.1136/vr.c6159Citations: 8Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References 1Amand W. B. Riser W. H. Biery D. N. (1973) Spontaneous osteosarcoma with widespread metastasis in a belted Dutch rabbit. Journal of the American Animal Hospital Association 9, 577 –581 2Bahr A. (2007) The vertebrae. In Textbook of Veterinary Diagnostic Radiology. Ed Thrall D.. Saunders Elsevier. pp 179 –193 3Dom P. Ducatelle R. Deherdt P. (1992) Osteosarcoma in a juvenile rabbit. Vlaams Diergeneeskundig Tijdschrift 61, 50 –52 4Hoover J. P. Paulsen D. B. Qualls C. W. Bahr R. J. (1986) Osteogenic sarcoma with subcutaneous involvement in a rabbit. Journal of the American Veterinary Medical Association 189, 1156 –1158 5Jacobson S. A. (1971) The Comparative Pathology of the Tumors of Bone. Charles C. Thomas 6Kondo H. Ishikawa M. Maeda H. Onuma M. Masuda M. Shibuya H. Koie H. Sato T. (2007) Spontaneous osteosarcoma in a rabbit (Oryctolagus cuniculus). Veterinary Pathology 44, 691 –694 7Liptak J. M. Erhart N. (2005) Bone and joint tumors. In Veterinary Internal Medicine. Eds Ettinger S. J. Feldman E. C.. Elsevier Saunders. pp 761 –773 8Mazzullo G. Russo M. Niutta P. P. de Vico G. (2004) Osteosarcoma with multiple metastases and subcutaneous involvement in a rabbit (Oryctolagus cuniculus). Veterinary Clinical Pathology 33, 102 –104 9Özsoy S. Özyildiz Z. (2008) Osteosarcoma in a rabbit. Journal of the Dental Faculty of Ankara University 55, 211 –212 10Salm R. Field J. (1965) Osteosarcoma in a rabbit. Journal of Pathology and Bacteriology 89, 400 –402 11Slayter M. V. Boosinger T. R. Pool R. R. Dämmrich K. Misdorp W. Larsen S. (1994) Histological Classification of Bone and Joint Tumors of Domestic Animals. Armed Forces Institute of Pathology 12Thompson K. (2007) Bones and joints. In Jubb, Kennedy, and Palmer's Pathology of Domestic Animals. 5th edn. Ed Maxie M. G.. Saunders Elsevier. pp 1 –184 13Walberg J. A. (1981) Osteogenic sarcoma with metastasis in a rabbit (Oryctolagus cuniculus). Laboratory Animal Science 31, 407 –408 14Wappler O. Harder A. (2000) Osteosarkom des Oberkiefers bei einem Kaninchen (Oryctolagus cuniculus). Kleintierpraxis 45, 707 –712 15Weisbroth S. H. (1974) Neoplastic diseases. In The Biology of the Laboratory Rabbit. Eds Weisbroth S. H. Flatt R. E. Kraus A. L.. Academic Press. pp 332 –375 16Weisbroth S. H. Hurvitz A. (1969) Spontaneous osteogenic sarcoma in Oryctolagus cuniculus with elevated serum alkaline phosphatase. Laboratory Animal Care 19, 263 –265 Citing Literature Volume168, Issue10March 2011Pages 266-266 ReferencesRelatedInformation

Veterinary RecordVolume 168, Issue 10 p. 266-266 Research Comparison of ileal and rectal biopsies in the diagnosis of equine grass sickness T. S. Mair BVSc, PhD, DEIM, DESTS, DipECEIM, MRCVS, Corresponding Author T. S. Mair BVSc, PhD, DEIM, DESTS, DipECEIM, MRCVS tim.mair@btinternet.com Bell Equine Veterinary Clinic, Mereworth, Maidstone, Kent, ME18 5GSE-mail for correspondence tim.mair@btinternet.comSearch for more papers by this authorA. M. Kelley BVetMed, MRCVS, A. M. Kelley BVetMed, MRCVS Bell Equine Veterinary Clinic, Mereworth, Maidstone, Kent, ME18 5GSSearch for more papers by this authorG. R. Pearson BVMS, PhD, FRCPath, FRCVS, G. R. Pearson BVMS, PhD, FRCPath, FRCVS School of Clinical Veterinary Science, University of Bristol, Langford, North Somerset, BS40 5DUSearch for more papers by this author T. S. Mair BVSc, PhD, DEIM, DESTS, DipECEIM, MRCVS, Corresponding Author T. S. Mair BVSc, PhD, DEIM, DESTS, DipECEIM, MRCVS tim.mair@btinternet.com Bell Equine Veterinary Clinic, Mereworth, Maidstone, Kent, ME18 5GSE-mail for correspondence tim.mair@btinternet.comSearch for more papers by this authorA. M. Kelley BVetMed, MRCVS, A. M. Kelley BVetMed, MRCVS Bell Equine Veterinary Clinic, Mereworth, Maidstone, Kent, ME18 5GSSearch for more papers by this authorG. R. Pearson BVMS, PhD, FRCPath, FRCVS, G. R. Pearson BVMS, PhD, FRCPath, FRCVS School of Clinical Veterinary Science, University of Bristol, Langford, North Somerset, BS40 5DUSearch for more papers by this author First published: 12 March 2011 https://doi.org/10.1136/vr.c6349Citations: 8 Ms Kelley's present address is Pet Doctors, 125/129 Chertsey Road, Woking, Surrey GU61 5BP Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume168, Issue10March 2011Pages 266-266 RelatedInformation

This paper describes three cases of liver lobe torsion in rabbits presenting with anorexia, lethargy, jaundice and abdominal pain. This condition was associated with anaemia and elevation of alanine aminotransferase, aspartate aminotransferase and gamma-glutamyl transferase. Abnormal radiological findings included hepatomegaly, gas-filled intestinal loops consistent with gastrointestinal ileus and ascites. Ultrasonographic findings included heterogeneous liver parenchyma, free abdominal fluid and reduced bowel motility. Diagnosis was confirmed by histopathological examination of the liver in all three cases.

SummaryThis Case Report describes a weanling filly with protein‐losing enteropathy associated withLawsonia intracellularisinfection. This was diagnosed on the basis of a significant antibody response and a positive faecal PCR result. The histopathological lesion observed in proliferative enteropathy is mucosal hyperplasia, commonly affecting the ileum and colon in foals. Duodenal biopsies obtained from this filly revealed a lymphocytic plasmacytic infiltrate. The filly recovered completely following treatment with erythromycin and no additional medication was administered to treat the lymphocytic plasmacytic infiltrate. This Case Report suggests that lymphocytic plasmacytic infiltrates observed on duodenal biopsies may represent a nonspecific intestinal immune response.

Veterinary RecordVolume 162, Issue 10 p. 318-320 Short Communication Naturally occurring intestinal lesions in three alpacas (Vicugna pacos) caused by attaching and effacing Escherichia coli A. P. Foster BSc, BVSc, PhD, DipACVD, MRCVS, A. P. Foster BSc, BVSc, PhD, DipACVD, MRCVS Veterinary Laboratories Agency (VLA) — Shrewsbury, Kendal Road, Harlescott, Shrewsbury, SY1 4HDSearch for more papers by this authorA. Otter MA, VetMB, PhD, MRCVS, A. Otter MA, VetMB, PhD, MRCVS Veterinary Laboratories Agency (VLA) — Shrewsbury, Kendal Road, Harlescott, Shrewsbury, SY1 4HDSearch for more papers by this authorA. M. Barlow BVSc, MSc, MRCVS, A. M. Barlow BVSc, MSc, MRCVS VLA — Langford, Langford House, Bristol, BS40 5DXSearch for more papers by this authorG. R. Pearson BVMS, PhD, FRCPath, MRCVS, G. R. Pearson BVMS, PhD, FRCPath, MRCVS Department of Clinical Veterinary Science, Division of Veterinary Pathology, Infection and Immunology, School of Veterinary Science, University of Bristol, Langford, Bristol, BS40 5DUSearch for more papers by this authorM. J. Woodward BSc, PhD, M. J. Woodward BSc, PhD VLA — Weybridge, New Haw, Addlestone, Surrey, KT15 3NBSearch for more papers by this authorR. J. Higgins BVMS, MSc, MRCVS, R. J. Higgins BVMS, MSc, MRCVS VLA — Lasswade, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, EH26 0PZSearch for more papers by this author A. P. Foster BSc, BVSc, PhD, DipACVD, MRCVS, A. P. Foster BSc, BVSc, PhD, DipACVD, MRCVS Veterinary Laboratories Agency (VLA) — Shrewsbury, Kendal Road, Harlescott, Shrewsbury, SY1 4HDSearch for more papers by this authorA. Otter MA, VetMB, PhD, MRCVS, A. Otter MA, VetMB, PhD, MRCVS Veterinary Laboratories Agency (VLA) — Shrewsbury, Kendal Road, Harlescott, Shrewsbury, SY1 4HDSearch for more papers by this authorA. M. Barlow BVSc, MSc, MRCVS, A. M. Barlow BVSc, MSc, MRCVS VLA — Langford, Langford House, Bristol, BS40 5DXSearch for more papers by this authorG. R. Pearson BVMS, PhD, FRCPath, MRCVS, G. R. Pearson BVMS, PhD, FRCPath, MRCVS Department of Clinical Veterinary Science, Division of Veterinary Pathology, Infection and Immunology, School of Veterinary Science, University of Bristol, Langford, Bristol, BS40 5DUSearch for more papers by this authorM. J. Woodward BSc, PhD, M. J. Woodward BSc, PhD VLA — Weybridge, New Haw, Addlestone, Surrey, KT15 3NBSearch for more papers by this authorR. J. Higgins BVMS, MSc, MRCVS, R. J. Higgins BVMS, MSc, MRCVS VLA — Lasswade, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, EH26 0PZSearch for more papers by this author First published: 08 March 2008 https://doi.org/10.1136/vr.162.10.318Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume162, Issue10March 2008Pages 318-320 RelatedInformation

Ollulanus tricuspis is a small nematode of the family Ollulanidae, found in the stomach of domestic cats and other felids. Of 131 gastric biopsy samples collected at endoscopic examination, four were shown to contain the parasite. Vomiting was the main presenting sign in three cats and weight loss in the fourth. The stomachs were grossly normal on endoscopic examination. Chronic gastritis was observed histologically in two cases, while the remaining cases were microscopically normal. The significance of the parasite remained undetermined. To our knowledge, this is the first report of O. tricuspis infection in domestic cats in which the diagnosis was made by examining routine endoscopic biopsy samples.

OBJECTIVES:To evaluate the clinical, clinical pathology, diagnostic imaging, microbiological and pathological features of cholangitis/cholangiohepatitis in the dog.METHODS:The study design was a retrospective review of cases of bacterial cholangitis/cholangiohepatitis presented to the University of Bristol during the period 1995 to 2000. The diagnosis was made based on hepatic histopathological findings and positive bile culture results.RESULTS:Four dogs met the inclusion criteria. Common presenting signs included anorexia (n=4), jaundice (n=4), vomiting (n=4) and pyrexia (n=2). All four dogs had a leucocytosis or neutrophilia reported at some time in their history along with serum bilirubin elevation. In addition, serum alkaline phosphatase and alanine transaminase activity was increased in all of the dogs in which it was measured both before and at the time of referral. In general, the diagnostic imaging findings were non-specific. Organisms cultured from bile aspirates were Escherichia coli (n=3), Clostridium species (n=2) and a faecal Streptococcus species (n=1). Two cases resolved with medical treatment alone; two with concurrent cholecystitis required cholecystectomy. Following surgery, both of these cases showed a resolution of clinical signs.CLINICAL SIGNIFICANCE:This report highlights the fact that bacterial cholangitis/cholangiohepatitis with or without concurrent cholecystitis should be considered as a potential differential in dogs presenting with signs referable to biliary tract disease.

Escherichia coli O157 : H7 and Cryptosporidium parvum infections of man have been associated with direct contact with small ruminants. Colostrum protects neonates against gastrointestinal pathogens, and orphan lambs, which are common on petting farms, may be deprived of this protection. In a recent study, it was demonstrated that high shedding of E. coli O157 : H7 by an 8-week-old goat kid was associated with coincidental C. parvum infection. Furthermore, both pathogens were co-located in the distal gastrointestinal tract. It was hypothesized that colostrum deprivation and pre-infection with C. parvum predisposed young ruminants to colonization and increased shedding of E. coli O157 : H7. To test this, 21 lambs 5 weeks of age were divided into four groups as follows: (A) colostrum-deprived and inoculated with E. coli O157 : H7, (B) colostrum-deprived and inoculated with C. parvum and then E. coli O157 : H7, (C) conventionally reared and inoculated with E. coli O157 : H7, (D) conventionally reared and inoculated with C. parvum and then E. coli O157 : H7. C. parvum was detected between 8 and 12 days post-inoculation in most of the infected lambs. At 24 h post-inoculation with E. coli O157 : H7, all lambs were shedding between 5 x 10(4) and 5 x 10(7) c.f.u. E. coli O157 : H7 per gram of faeces. E. coli O157 : H7 was shed in higher numbers in the groups pre-inoculated with C. parvum, whether conventionally reared or colostrum-deprived. Interestingly, for the colostrum-deprived lambs on day 3, a significant difference in shedding of E. coli O157 : H7 was observed (P = 0.038), with the lambs inoculated with E. coli alone yielding higher counts than those pre-inoculated with C. parvum. From day 15 onwards, shedding of E. coli O157 : H7 was highest from the colostrum-deprived C. parvum-infected lambs, then (in descending order of shedding) the colostrum-deprived lambs, the conventionally reared lambs infected with C. parvum, and the conventionally reared animals. In total, four animals were euthanized, two at 24 h and two at 96 h post inoculation with E. coli O157 : H7 (two conventionally reared and two colostrum-deprived). All animals euthanized were from groups pre-inoculated with C. parvum prior to challenge with E. coli O157 : H7. On examination of tissues, in three of the four animals examined, multifocal attaching and effacing lesions were observed in the caecum, colon, rectum and at the recto-anal junction, and were confirmed by immunohistochemistry to be associated with E. coli O157 : H7.

THERE have been few reports of attaching and effacing Escherichia coli (AEEC) infections in goats. A severe outbreak was recorded by Drolet and others (1994) affecting neonatal goat kids, of which 21 of 34 born alive died after having diarrhoea. A further case (Duhamel and others 1992) involved a goat approximately two months old, with severe diarrhoea of three weeks’ duration. This animal was part of a drug toxicity trial, which may have been an exacerbating factor. This short communication describes a naturally occurring infection with AEEC in an adult goat with diarrhoea. Nine adult diary goats out of a herd of 300 had died over the course of a month with a history of milk drop, anorexia and weakness followed by death within a few days. The 10th animal, a three-year-old Saanen cross nanny which showed similar clinical signs, was submitted to the Veterinary Laboratories Agency (VLA) – Langford for examination. The animal was depressed, remained recumbent during clinical examination and had mild diarrhoea. Blood samples were collected for routine haematological and biochemical analysis. Haematological examination indicated dehydration, with a packed-cell volume of 0·53 litre/litre (reference range 0·24 to 0·39 litre/litre). The blood urea level was 94·7 mmol/litre (reference range 4·0 to 8·6 mmol/litre) and there was a raised blood creatine kinase level of 1083 U/litre at 37°C (reference range 0 to 100 U/litre), consistent with muscle damage due to recumbency. The remaining parameters were within normal limits. The goat was euthanased by intravenous pentobarbitone injection and a postmortem examination was performed immediately. At postmortem examination the carcase weighed 77 kg and had a large amount of abdominal fat. No gross lesions were identified in the gastrointestinal tract. The rumen contained a large volume of pale straw-coloured fluid and a little roughage. The contents of the abomasum were fluid. The small and large intestines contained a moderate amount of yellow, watery fluid and the mucosa appeared normal. The rectal contents were semisolid. The kidneys appeared slightly enlarged, and the uterus contained excess clear fluid consistent with pseudopregnancy. No other abnormalities were detected. Samples of the small and large intestinal contents, liver, heart blood and brain were collected for routine bacteriological examination. Smears of small intestinal mucosa were stained using Gram’s stain. Ten colonies of E coli selected at random from sweeps of the contents taken from the large and small intestines were subcultured onto Dorset’s egg slopes for preliminary typing as described by Pearson and others (1999). Samples of the duodenum, jejunum, ileum and colon were fixed immediately in 10 per cent neutral-buffered formalin; the tissues were processed routinely to paraffin wax, and 4 μm sections were stained with haematoxylin and eosin. For peroxidase-antiperoxidase (PAP) immunostaining, additional 4 μm sections of the ileum and colon were mounted on organosilane-coated slides and incubated at room temperature with commercially available rabbit anti-O45, anti-O71 and anti-O145 antisera (Prolabs) at a dilution of 1/1000. These antisera were selected after preliminary analysis of the E coli isolates recovered from the goats. Goat anti-rabbit antiserum (Sigma), rabbit PAP (Dako) and diaminobenzidine were then applied sequentially. Sections incubated with normal rabbit serum (diluted 1/500 and 1/1000) and rabbit anti-O157 and anti-O26 antisera were used as controls. For electron microscopic studies, a small area of the ileum was cut from the paraffin wax block and processed as described by Pearson and others (1989). Bacteriological culture of the small and large intestinal contents produced a heavy, pure growth of coliforms. Salmonella species were not isolated using specific culture techniques. The 10 randomly selected coliform colonies were tested using the multiplex PCR described by Meng and others (1997). Seven isolates possessed the eae gene, encoding the 94 kDa outer membrane protein intimin, but none was positive for stx or stx2, the genes encoding Shiga-like toxins. Five of the seven eae-positive isolates were identified as E coli O145, one as E coli O45 and one as E coli O71. Following immunostaining, the five E coli O145 isolates were analysed further by the genetic methods of Cookson and others (2002) and each was found to possess genes encoding the β-intimin subtype and CNF1 and CNF2 cytotoxins. There were no significant isolates following culture of heart blood, liver or brain. Clostridia-like organisms were not identified in Gram-stained smears of the small intestinal contents. Histological examination of the duodenum and jejunum revealed moderate separation of the villous epithelium from the lamina propria, associated with early autolytic changes, but the villi were otherwise normal. In the ileum, severe stunting and fusion of villi, with flattening of the mucosa and an irregular epithelial surface, was observed (Fig 1). Adherent bacteria were present as multifocal colonies of variable size on the mucosal surface. In the colon, a few areas of focal, irregular surface epithelium were seen, some of which were associated with adherent bacteria similar to those observed in the ileum. Examination of the kidneys revealed a marked ectasia of the distal convoluted tubules, with many of them containing oxalate casts. Sparse neutrophil foci were present in a few tubules. Immunostained ileum and colon sections demonstrated bacterial expression of E coli O145 antigen (Fig 2), but E coli O45 and O71 staining was not identified. Electron microscopy of the ileum confirmed that these bacteria were associated with attachingeffacing (AE) lesions (Fig 3). Veterinary Record (2004) 155, 807-808

Veterinary RecordVolume 157, Issue 26 p. 847-849 Short Communication Malignant peripheral nerve sheath tumour of the heart in a horse G. C. Quinn BVSc, CertES(Soft Tissue), DipECVS, MRCVS, G. C. Quinn BVSc, CertES(Soft Tissue), DipECVS, MRCVS Department of Veterinary Clinical Science, School of Clinical Veterinary Science, Langford, Bristol, BS40 5DU Mr Quinn’s present address is Ashbrook Equine Hospital, Middlewich Road, Allostock, Knutsford, Cheshire WA16 9JQSearch for more papers by this authorD. Fews BVM&S, BSc, CertVA, DipRCPath, MRCVS, D. Fews BVM&S, BSc, CertVA, DipRCPath, MRCVS Department of Veterinary Pathology, School of Clinical Veterinary Science, Langford, Bristol, BS40 5DUSearch for more papers by this authorT. J. Scase BSc, BVM&S, PhD, DipACVP, MRCVS, T. J. Scase BSc, BVM&S, PhD, DipACVP, MRCVS Animal Health Trust, Lanwades Park, Newmarket, Suffolk, CB8 7UUSearch for more papers by this authorG. R. Pearson BVMS, PhD, FRCPath, MRCVS, G. R. Pearson BVMS, PhD, FRCPath, MRCVS Department of Veterinary Pathology, School of Clinical Veterinary Science, Langford, Bristol, BS40 5DUSearch for more papers by this author G. C. Quinn BVSc, CertES(Soft Tissue), DipECVS, MRCVS, G. C. Quinn BVSc, CertES(Soft Tissue), DipECVS, MRCVS Department of Veterinary Clinical Science, School of Clinical Veterinary Science, Langford, Bristol, BS40 5DU Mr Quinn’s present address is Ashbrook Equine Hospital, Middlewich Road, Allostock, Knutsford, Cheshire WA16 9JQSearch for more papers by this authorD. Fews BVM&S, BSc, CertVA, DipRCPath, MRCVS, D. Fews BVM&S, BSc, CertVA, DipRCPath, MRCVS Department of Veterinary Pathology, School of Clinical Veterinary Science, Langford, Bristol, BS40 5DUSearch for more papers by this authorT. J. Scase BSc, BVM&S, PhD, DipACVP, MRCVS, T. J. Scase BSc, BVM&S, PhD, DipACVP, MRCVS Animal Health Trust, Lanwades Park, Newmarket, Suffolk, CB8 7UUSearch for more papers by this authorG. R. Pearson BVMS, PhD, FRCPath, MRCVS, G. R. Pearson BVMS, PhD, FRCPath, MRCVS Department of Veterinary Pathology, School of Clinical Veterinary Science, Langford, Bristol, BS40 5DUSearch for more papers by this author First published: 24 December 2005 https://doi.org/10.1136/vr.157.26.847Citations: 4 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume157, Issue26December 2005Pages 847-849 RelatedInformation

In a series of experiments involving the inoculation of sheep with Escherichia coli O157:H7, and subsequent detailed histopathological examination of the intestinal mucosa, attaching–effacing (AE) lesions formed by elements of the natural flora were observed in 18% of animals. These incidental AE lesions typically were small and sparse, and were not associated with clinical disease. It was possible to identify further some of the lesional bacteria, revealing that E. coli O115 had formed lesions in one of the seven affected animals, and similarly E. coli O26 had formed some of the lesions in another. As AE strains, source flocks, housing and feed sources were diverse, a common source of lesion-forming bacteria appears to be unlikely. It is postulated that subclinical AE lesions are a mechanism of persistence of AE bacteria in sheep.

Enteric bacteria with a demonstrable or potential ability to form attaching-effacing lesions, so-called attaching-effacing (AE) bacteria, have been found in the intestinal tracts of a wide variety of warm-blooded animal species, including man. In some host species, for example cattle, pigs, rabbits and human beings, attaching-effacing Escherichia coli (AEEC) have an established role as enteropathogens. In other host species, AE bacteria are of less certain significance. With continuing advances in the detection and typing of AE strains, the importance of these bacteria for many hosts is likely to become clearer. The pathogenic effects of AE bacteria result from adhesion to the intestinal mucosa by a variety of mechanisms, culminating in the formation of the characteristic intimate adhesion of the AE lesion. The ability to induce AE lesions is mediated by the co-ordinated expression of some 40 bacterial genes organized within a so-called pathogenicity island, known as the "Locus for Enterocyte Effacement". It is also believed that the production of bacterial toxins, principally Vero toxins, is a significant virulence factor for some AEEC strains. Recent areas of research into AE bacteria include: the use of Citrobacter rodentium to model human AEEC disease; quorum-sensing mechanisms used by AEEC to modulate virulence gene expression; and the potential role of adhesion in the persistent colonization of the intestine by AE bacteria. This review of AE bacteria covers their molecular biology, their occurrence in various animal species, and the diagnosis, pathology and clinical aspects of animal diseases with which they are associated. Reference is made to human pathogens where appropriate. The focus is mainly on natural colonization and disease, but complementary experimental data are also included.