Spring 2010 Santé De Cheval
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Horse Health Vol. 3, Spring 2010 Santé De Cheval The News Magazine of the LSU Equine Health Studies Program In this Issue: An Emerging Pathogen in Weanling Foals Breeding for Early Foals Foal Diarrhea and Pneumonia FROM THE DIRECTOR’S DESK Greetings from the Equine Health Studies Program (EHSP) • Enhancing and at Louisiana State University School of Veterinary Medicine. upgrading the equine As many of you know, the EHSP was established in 2003 hospital facilities and and had the broad-based support of the Louisiana Racing maintain accreditation Commission, Louisiana Thoroughbred Breeders Association, • Attracting and equine veterinarians and horse owners. The program was keeping high quality initiated to specialized faculty and • Support the $2.4 Billion horse industry in Louisiana staff • Improve the quality of the horse industry and horse racing • Providing timely and in the state state-of-the-art services • Increase the number of critically ill and injured horses for Louisiana’s referring referred to the School veterinarians and horse owners • Provide the highest quality in veterinary medical support services We feel well supported • Support cutting-edge equine research to benefit by our alumni, friends, Louisiana horses and horse owners, and this was evident at this year’s American Association of Equine • Improve diagnostic capabilities and facilities within the Practitioners’ Convention in Las Vegas, where we had over equine hospital 60 alumni and friends at the LSU reception. A hearty thanks to all of you who attended and donated money to defray the Since its inception, the EHSP has provided value-added cost of the reception. A good time was had by all! Again, we support for Louisiana’s horse industry and 100% of the thank you for your continued support of our program and the allocated funds (Figure 1) have been spent to support the best of luck in 2010. vital Louisiana horse industry, which generates $120 million annually in slot machine revenues from the four racetracks. Allocated funds have provided value-added programs and 7% services to over 18,000 ill and injured horses and facilities. Since our last newsletter, we put in new flooring throughout 14% 27% the large animal hospital and installed a new Echelon High Field 1.5 Tesla MRI Unit for advanced diagnostics. The program provides in-house veterinary specialists and a clinical 7% equine ambulatory specialist (Dr. Ann Chapman) to improve 45% the health of the horses in Louisiana and surrounding states. Our continuing mission is to further support Louisiana’s $2.4 billion horse industry and horse racing by: • Maintaining a competitive national and international recognized research program Figure 1: 100% of the allocated funds are used to support the EHSP, which in turn supports Louisiana’s horse industry. • Maintaining and adding new and innovative diagnostic and therapeutic technologies (Hyperbaric Oxygen Therapy, Frank M. Andrews, DVM, MS, DACVIM Laser, Laparoscopy, Acupuncture, Rehabilitation Medicine) to Louisiana Veterinary Medical Association Professor, Section improve the health and wellbeing of Louisiana’s horses Chief, and EHSP Director LSU SCHOOL OF VETERINARY MEDICINE EQUINE HEALTH STUDIES PROGRAM Peter F. Haynes, DVM, MS, DACVS, Dean School of Veterinary Medicine Louisiana State University Frank Andrews, DVM, MS, DACVIM, Director, EHSP Baton Rouge, Louisiana 70803 Ky Mortensen, MBA, CFRE, Director of Advancement, EHSP Administration 225-578-9900 Ginger Guttner, MMC, Editor Large Animal Clinic 225-578-9500 Small Animal Clinic 225-578-9600 Michelle Reed, Administrative Specialist www.vetmed.lsu.edu ON THE COVER Spring Means birth and growth With spring, come foals, and this issue includes articles about foal breeding and health. The LSU Veterinary Teaching Hospital provides a full range of services for our equine, farrm, and small animal patients. http://www.vetmed.lsu.edu/vth&c/default.htm Page 6 TABLE OF CONTENTS Lawsonia intracellularis .................................................. 2 Grant to Study Equine Adult Stem Cells ................ 4 Facility Update .......................................................................... 5 Page 16 Breeding For Early Foals.................................................... 6 Foal Diarrhea and Pneumonia .....................................10 Call for Foals with Infectious Arthritis .............14 Forman Foundation Scholarships Continue Strong Support ......................................................................15 Fresh Horses .............................................................................16 Publications & Presentations ........................................19 Page 16 The EHSP newsletter is published by the Louisiana State University, School of Veterinary Medicine, Office of Public Relations. Communications should be addressed to Editor, EHSP Magazine, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, or sent via e-mail to [email protected]. Research Figure 1: Ultrasound image of small intestinal thickening in a foal with Lawsonia intracellaris infection. Lawsonia intracellularis: An emerging pathogen in weanling foals Ann M. Chapman, DVM, MS, DACVIM Assistant Professor of Equine Medicine awsonia intracellularis is the causative agent enteropathy in foals and the importance of this disease to of equine proliferative enteropathy (EPE), an equine breeders. intestinal disease of weanlings and yearlings. LProliferative enteropathy (or PE) caused by Lawsonia intracellularis is a gram-negative bacteria that Lawsonia intracellularis has been an important disease in the lives inside mammalian cells. The bacteria has a worldwide commercial swine industry for many decades, but it was not distribution in pigs, and in horses it has been identified in identified in foals with intestinal disease (enteropathy) until North America (U.S and Canada), Europe (Switzerland, 1996. Recently, veterinarians in Louisiana and other areas Great Britain, Belgium), Africa (South Africa), and Australia. of the U.S. have observed an increased number of foals Affected foals generally show signs of the disease between infected with Lawsonia. This article will discuss proliferative 4 to 7 months of age, shortly after the weaning period. 2 However, the disease has also been identified in yearlings. Abdominal ultrasound is a useful tool in Transmission occurs either by fecal-oral or environmental- identifying intestinal thickening in affected oral routes, although the exact source of infection in foals (Figure 1). horses is unknown. Researchers have identified Lawsonia intracellularis sporadically in indigenous wildlife on farms However, a normal abdominal ultrasound does not rule out with endemic EPE. However, a definitive link between the Lawsonia intracellularis infection. Lawsonia intracellularis identified in these animals (including pigs) and infected horses has not been established. The Definitive diagnosis of EPE due to Lawsonia intracellularis stresses associated with weaning and the weaknesses in the in a live foal can be challenging. The gold standard test immune system may be fundamental to the development of for confirming the disease is to identify the organism on the disease in foals. intestinal tissue using immunohistochemistry or special stains, such as Warthin Starry stain. This requires either surgical Once ingested, Lawsonia intracellaris preferentially biopsy or necropsy to obtain tissue samples. However, invades the epithelial crypt cells of the small intestine. The testing antemortem using immunoperoxidase monolayer organism causes these surface cells to proliferate resulting assay (IPMA) can be used to detect the presence of serum in severe intestinal thickening, thus the name, “proliferative antibodies to Lawsonia intracellularis. Serum antibody titers enteropathy.” After initial infection, affected foals may > 1:60 are considered significant and suggestive of recent demonstrate few symptoms, and the disease may be missed. infection or exposure to the organism. However, studies But as the intestinal thickening progresses, clinical signs have found clinically normal horses with a positive IPMA include: test. Also, colostral antibodies may be detected in foals younger than three months of age; therefore, this test should • diarrhea be interpreted in conjunction with clinical signs of disease. • weight loss Fecal samples can be tested for presence of the organism by using polymerase chain reaction (PCR). PCR testing is very • poor growth sensitive and can detect very small numbers of bacteria in • severe edema feces. Unfortunately, false negative results can occur since the bacteria is not shed constantly in infected animals, and • reduced appetite fecal shedding may stop quickly after treatment is initiated. • lethargy A presumptive diagnosis of Lawsonia • intermittent fever intracellularis infection can be made based on the presence of clinical signs in • colic. conjunction with low blood albumin, low The most common bloodwork abnormalities found in affected blood protein, a positive serum IPMA test foals are low blood protein and albumin concentrations. This (>1:60), and/or a positive fecal PCR. may occur because the affected intestinal tissue becomes inflamed in response to infection, which allows blood proteins Treatment of EPE includes both antibiotics to eliminate to escape into the bowel. With severe diarrhea, the protein the bacteria and supportive care. Doxycyline, tetracycline, losses can be considerable. Also, thickened intestinal tissue