CATTLE MEDICINE. Philip R Scott BVM&S, MPhil, DVM&S, DSHP, FRCVS, DipECBHM, DipECSRHM FHEA Reader, Division of Veterinary Clinical Sciences

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2 CATTLE MEDICINE Philip R Scott BVM&S, MPhil, DVM&S, DSHP, FRCVS, DipECBHM, DipECSRHM FHEA Reader, Division of Veterinary Clinical Sciences Colin D Penny BVM&S, CertCHP, DBR, DipECBHM, MRCVS Senior Lecturer, Farm Animal Practice Alastair I Macrae BVM&S, PhD, CertSHP, CertCHP, MRCVS Dairy Herd Health and Productivity Service Division of Veterinary Clinical Sciences Royal (Dick) School of Veterinary Studies University of Edinburgh Easter Bush Veterinary Centre Roslin, Midlothian, UK Manson Publishing/The Veterinary Press

3 Copyright 2011 Manson Publishing Ltd ISBN: All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means without the written permission of the copyright holder or in accordance with the provisions of the Copyright Act 1956 (as amended), or under the terms of any licence permitting limited copying issued by the Copyright Licensing Agency, Alfred Place, London WC1E 7DP, UK. Any person who does any unauthorized act in relation to this publication may be liable to criminal prosecution and civil claims for damages. A CIP catalogue record for this book is available from the British Library. For full details of all Manson Publishing Ltd titles please write to: Manson Publishing Ltd, 73 Corringham Road, London NW11 7DL, UK. Tel: +44(0) Fax: +44(0) manson@mansonpublishing.com Website: Commissioning editor: Jill Northcott Project manager: Julie Bennett Copy editor: Peter Beynon Design and layout: Cathy Martin Colour reproduction: Tenon & Polert Colour Scanning Ltd, HK Printed by: Grafos SA, Barcelona, Spain

4 CONTENTS PREFACE 4 ABBREVIATIONS 5 CHAPTER 1 REPRODUCTIVE SYSTEM 7 Part 1: Male reproductive tract diseases 7 Part 2: Female reproductive tract diseases 17 Part 3: Causes of fetal loss/abortion 27 CHAPTER 2 OBSTETRICS AND PARTURIENT DISEASES 39 CHAPTER 3 DIGESTIVE TRACT AND ABDOMEN 59 Part 1: Diseases of the digestive tract and abdomen 59 Part 2: Infectious diseases of the digestive tract 94 CHAPTER 4 RESPIRATORY DISEASES 115 CHAPTER 5 CARDIOVASCULAR DISEASES 133 CHAPTER 6 NERVOUS SYSTEM DISEASES 143 CHAPTER 7 MUSCULOSKELETAL DISEASES 163 CHAPTER 8 URINARY TRACT DISEASES 195 CHAPTER 9 SKIN DISEASES 201 CHAPTER 10 EYE DISEASES 211 CHAPTER 11 MASTITIS AND TEAT DISEASES 216 CHAPTER 12 PARASITIC DISEASES 236 CHAPTER 13 CLOSTRIDIAL DISEASES 242 CHAPTER 14 METABOLIC DISEASES 247 CHAPTER 15 TRACE ELEMENT AND VITAMIN DEFICIENCIES 258 CHAPTER 16 MISCELLANEOUS INFECTIOUS AND EXOTIC DISEASES 266 CHAPTER 17 POISONS 272 CHAPTER 18 ANAESTHESIA 276 FURTHER READING 283 INDEX 284

5 4 PREFACE The major objective of this book is to describe, with the aid of a large number of high-quality images, the important diseases of cattle encountered by veterinary surgeons in general practice and their diagnosis, treatment, prognosis and control. Wherever possible, the sequential images take the reader through all stages of the disease process, highlighting clinical features important in the diagnosis. The book is specifically aimed at fulfilling the need for a practical, concise text that will be of use to veterinary undergraduate students in their clinical years and later in farm practice. The book is not intended to be a fully referenced text covering bovine medicine in detail, as there are already such texts available. The book is divided into chapters based on body system. Where appropriate, chapters open with a suggested approach to clinical examination of that body system rather than simply listing the disorders and diseases affecting that system. Such a systematic approach is more applicable to certain sections, such as the nervous, digestive and respiratory systems. The book is based on the authors experience of bovine medicine and surgery both in general practice and in a referral University hospital in the United Kingdom. While management and husbandry systems vary worldwide, the clinical signs, diagnosis, treatment and prevention of the major diseases do not. For example, the clinical signs of metabolic acidosis in 8 21-day-old calves are described with the important differential diagnoses, followed by discussion of the estimation of base deficit on the farm with a detailed description of the authors treatment regimen. Several different methods are employed by veterinary surgeons in the UK, and many others worldwide, for spiking the intravenous solution with bicarbonate, but the principle is the same to correct the estimated base deficit. It is not possible to describe every method used worldwide; rather, the authors have chosen the method they believe to work best based on a review of the literature and their clinical experience. Control by vaccination will depend on isolation of potential enteropathogens and the availability and cost of a suitable vaccine in that particular country. Surgical correction of a left displaced abomasum is another good example where many different treatment options are used worldwide. The authors have described the two most commonly used surgical methods and discuss why these have been chosen; it is not possible to describe every method. Similarly, it is not possible within the limited text to detail the availability of all antibiotics and other drugs in individual countries worldwide, therefore treatments described are most relevant to UK veterinary practice. However, what the book does do is to give practical instruction, using sequential high-quality images, on how to recognize, treat and control the common conditions encountered in bovine practice, which, in most cases, cross national and international boundaries. Philip Scott Colin Penny Alastair Macrae

6 5 ABBREVIATIONS ADH AGID AI AST BAL BCS BHB BHV BLV BMSCC BPS BRSV BSE BTV BVD BVDV CCN CFT CJD CJLD CL CMT CN CNS CpBVDV COD CSF CSPD DCAB DCM DJD DM EBL EBVs ELISA epg ETEC FAT FMD FSH GGT GLDH GnRH antidiuretic hormone agar gel immunodiffusion (test) artificial insemination aspartate aminotransferase bronchoalveolar lavage body condition score b-hydroxybutyrate bovine herpesvirus bovine leukaemia virus bulk milk somatic cell count bovine papular stomatitis bovine respiratory syncytial virus bovine spongiform encephalopathy bluetongue virus bovine virus diarrhoea bovine viral diarrhoea virus cerebrocortical necrosis complement fixation test Creutzfeldt Jakob disease congenital joint laxity and dwarfism corpus luteum California mastitis test cranial nerve central nervous system cytopathic bovine viral disease virus cystic ovarian disease cerebrospinal fluid chronic suppurative pulmonary disease dietary cation anion balance dilated cardiomyopthy degenerative joint disease dry matter enzootic bovine leucosis estimated breeding values enzyme-linked immunosorbent assay eggs per gram enterotoxigenic Escherichia coli fluorescent antibody test foot and mouth disease follicle-stimulating hormone gamma glutamyltransferase glutamate dehydrogenase gonadotropin-releasing hormone GSHPx glutathione peroxidase hcg human chorionic gonadotropin IBK infectious bovine keratoconjunctivitis IBR infectious bovine rhinotracheitis ICSCC individual cow somatic cell count IPV infectious pustular vulvovaginitis IVRA intravenous regional anaesthesia LDA left displaced abomasum LH luteinizing hormone MAP Mycobacterium avium subsp. paratuberculosis MAT microscopic agglutination test MCF malignant catarrhal fever MD mucosal disease MIC minimum inhibitory concentration MOET multiple ovulation/embryo transfer (programme) NcpBVDV non-cytopathic bovine viral disease virus NEFA non-esterified fatty acid NMR National Milk Records NSAID non-steroidal anti-inflammatory drug OCD osteochondritis dissecans PCV packed cell volume PEM polioencephalomalacia PAGE polyacrylamide gel electrophoresis (test) PDA patent ductus arteriosus PGE parasitic gastroenteritis PGF2oc prostaglandin F2oc PI parainfluenza PLR pupillary light reflex PMSG pregnant mare serum gonadotropin PTH parathyroid hormone PUFA polyunsaturated fatty acids RDA right-sided displacement of the abomasum RFM retained fetal membranes SBL sporadic bovine leucosis SCC somatic cell count TBC total bacteria count TEME thromboembolic meningoencephalitis vcjd variant Creutzfeldt Jakob disease VSD ventricular septal defect

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8 Chapter 1 Reproductive system 7 Part 1: Male reproductive tract diseases INTRODUCTION Fully fertile bulls are critical in herd fertility management, especially where farmers are trying to achieve high pregnancy rates in restricted breeding periods. A sensible working definition of a fully fertile bull is a bull that can achieve a 90% pregnancy rate in a group of 50 normal cyclic females in a nine-week mating period. Various surveys worldwide have shown that 20 30% of bulls are found to be subfertile or infertile in routine breeding soundness examinations. Although subfertile bulls will achieve pregnancies, they contribute to fertility inefficiency in herds and thus should be identified and replaced or treated. Bull breeding soundness examinations carried out prior to breeding will help identify most subfertile and infertile bulls and should be a routine part of herd management. A full breeding soundness examination should consist of the following parts: Physical examination: General health and body condition (1). Musculoskeletal system limbs and feet (2) A bull in good working condition. Very thin or obese bulls will have depressed fertility. 2 A post-hocked young bull. This conformation is associated with upper limb lameness problems.

9 8 Reproductive system Reproductive system examination: Measure scrotal circumference (3). The minimum recommended standards (Society of Theriogenology) for Bos taurus bulls are: months, 30 cm; >15 18 months, 31 cm; >18 21 months, 32 cm; >21 24 months, 33 cm; >24 months, 34 cm. Palpate testicles and epididymides carefully. Palpate internal accessory sex glands. Palpate sheath and penis. Semen evaluation. Collect semen by electroejaculation (4) or artificial vagina and assess motility: should be >60% progressive motility, and percentage normal sperm morphology should be >70% (5). Handling of semen is critical after collection in order to avoid cold shock and a heated stage should be used when doing motility assessment (6). Serving assessment. Need to observe bull mating an oestrous female in order to ensure good libido and normal intromission. A full breeding soundness evaluation should include all four components, but even doing just a physical examination and a reproductive system examination will help to ensure unsound bulls are not used. For bulls to be examined safely and properly it is essential that farmers provide adequate handling facilities (7). Some of the more common conditions that may be encountered during bull breeding soundness investigations are discussed in this section Scrotal circumference being measured using a properly designed tape to ensure accuracy and consistency. 4 A modern electroejaculator for collection of semen from bulls The field laboratory shown here includes a warming box and heated stage to keep semen at body temperature during examination for motility. 5 Seventy percent or more of sperm should be morphologically normal, as in this field.

10 Part 1: Male reproductive tract diseases 9 7 TRANSMISSIBLE VIRAL FIBROPAPILLOMATOSIS (WARTS) DEFINITION/OVERVIEW Transmissible viral fibropapillomatosis occurs quite commonly in young bulls and is only of clinical significance in bulls destined for breeding, when penile lesions can interfere with the ability to serve. 7 Safe handling facilities are essential for proper bull breeding soundness examination. 8 AETIOLOGY Transmissible viral fibropapillomatosis is caused by bovine papillomavirus. It is normally only seen in young bulls (<3 years old), but it can be transmitted venereally to females (8). CLINICAL PRESENTATION The condition can present as a single pedunculated mass or as large broad-based cauliflower-like lesions on the glans penis and prepuce (9, 10). Both presentations may prevent intromission. Secondary superficial bacterial infection of papillomas is common and may lead to bleeding and/or discharge from the prepuce. DIAGNOSIS Diagnosis is based on history and clinical examination of the penis. MANAGEMENT There is no treatment except in severe cases, when autogenous vaccines and/or debulking the lesions with surgery are options. Care must be taken when attempting surgery to ensure that the dorsal nerve of the penis or the urethral opening is not damaged (11). Spontaneous regression occurs in most cases. 8 Viral papillomatosis, which has been transmitted venereally, is shown in this cow. 9, 10 Penile papillomas. Large broad-based cauliflowerlike lesions on the glans penis are shown. 11 Care must be taken to avoid damage to the dorsal nerve of the penis and the urethal opening when attempting surgery to remove a penile papilloma

11 10 Reproductive system PERSISTENT PENILE FRENULUM DEFINITION/OVERVIEW Persistent penile frenulum is a rare congenital problem identified in young bulls. AETIOLOGY The condition is due to a failure of complete separation of the fused penis and prepuce at puberty. CLINICAL PRESENTATION A band of tissue extends from the prepuce to the tip of the penis, causing deviation of the tip of the penis during attempted service (12, 13). DIAGNOSIS Clinical examination during attempted service or when stimulated with an electroejaculator will demonstrate the lesion. MANAGEMENT Simple surgical excision of the band of tissue is successful, but as the condition can be inherited, treated bulls should not be used for pedigree breeding. 12 CORKSCREW/SPIRAL DEVIATION OF THE PENIS DEFINITION/OVERVIEW Corkscrew or spiral deviation is the most common penile deviation seen in the bull; however, ventral deviation may also occasionally be observed. AETIOLOGY The aetiology is unknown. There is possibly some heritable component, but this has not been proven. Corkscrew of the penis occurs during erection, when the dorsal apical ligament slips laterally from its normal position. CLINICAL PRESENTATION Corkscrew or spiral deviation of the penis is normally an acquired condition seen in their second or third breeding season in mature bulls. While spiral deviation is normal within the vagina after intromission, bulls that develop this problem start to corkscrew while searching for the vulva and therefore fail to achieve normal intromission. From a distance bulls will be seen to repeatedly mount but fail to thrust. The problem can be sporadic at first, then gradually worsen to cause total infertility. (Note: Some bulls will corkscrew during electroejaculation but not during natural service.) DIFFERENTIAL DIAGNOSIS Other penile deviations or conditions causing pain and failure to thrust (e.g. lumbar pain, penile fibropapilloma, venous shunts causing erection failure). DIAGNOSIS Careful close-up inspection during attempted service will confirm the condition and rule out most differentials (14) , 13 Persistent penile frenulum. (12) The band of tissue extending from the prepuce to the ventral tip of the penis is causing deviation of the tip of the penis during attempted service. (13) The tissue band has been isolated and can then be surgically excised to cure the condition. (Courtesy E. Taylor) 14 Premature spiral deviation of the penis preventing normal intromission. (Courtesy E. Taylor)

12 Part 1: Male reproductive tract diseases 11 MANAGEMENT Surgical correction is possible, involving suturing the dorsal apical ligament to the penile body; however, recurrence is likely so treatment is rarely considered and culling is recommended. RUPTURED PENIS (PENILE HAEMATOMA) DEFINITION/OVERVIEW Ruptured penis is a sporadic problem in stock bulls. It normally occurs during the mating period. AETIOLOGY Rupture of the tunica albuginea commonly occurs around the dorsal aspect of the sigmoid flexure, leading to haematoma formation. This may be caused by sudden movement of the cow during intromission or when young bulls are mounting each other. CLINICAL PRESENTATION The condition presents as a sudden onset of cessation of service activity, with a variably sized painful swelling at the base of the sheath anterior to the scrotum (15). The prepuce and/or tip of penis may be prolapsed. DIAGNOSIS Diagnosis is based on palpation of a painful firm swelling in the area of the sigmoid flexure of the penis. Ultrasonography will confirm a diagnosis of haematoma. Chronic cases may have progressed to abscess formation. MANAGEMENT In acute cases, surgery to drain very large haematomas can be attempted within seven days of occurrence. In more chronic cases or with smaller haematomas, medical treatment is more common and should include hydrotherapy, systemic antibiotics and at least two months of sexual rest. Complications are common and include recurrence of rupture, abscessation with adhesion formation, and development of venous shunts. PENILE HAIR RINGS DEFINITION/OVERVIEW Penile hair rings are a sporadic problem in bulls. They can lead to ischaemic necrosis of the tip of the penis. AETIOLOGY Hairs from the tip of the sheath encircle the tip of the penis, leading to strangulation and ischaemia if neglected (16). CLINICAL PRESENTATION This condition may be missed unless close inspection of bulls is carried out on a regular basis. Bulls will stop serving cows because of discomfort and an inability to extrude the penis. In neglected cases, urethral obstruction may develop due to swelling. DIAGNOSIS Careful inspection, under sedation if required, will confirm the diagnosis. MANAGEMENT Under standing sedation the offending hair ring can be cut carefully, avoiding further damage to the penis. Neglected cases may require culling because of necrosis of the tip of the penis Hairs from the tip of the sheath can encircle the tip of the penis and cause necrosis, as shown Haematoma formation, with swelling at the base of the sheath anterior to the scrotum, due to rupture of the tunica albuginea.