Innovation

Why is Lung Function Testing useful?

Over the past decade, pulmonary lung function testing (PFT) has gained increasing importance in veterinary patients, due to its ability both  to characterize and quantify the patient’s lung dysfunction using non-invasive techniques. This is particularly important during the early diagnosis of respiratory disease and the evaluation of treatment responses. The Cummings School of Veterinary Medicine has pioneered the development of non-invasive lung function testing in animals, including horses, dogs, llamas and alpacas.

Our Lung Function Laboratory, under the leadership of Dr. Andrew Hoffman and operation by Drs. Melissa Mazan and Daniela Bedenice, is a nationally recognized Continue reading

Clinical Case Review

Windy’s Cough: Causes and Characteristics

For the past 4 years, Windy, a 12-year old Hanoverian mare, has had a mild cough whenever her barn was closed up against the cold in the winter. Last year, the cough did not go away – and even seemed to be worse during the hot, humid weather in the late spring and summer. The cough was now interfering with the horse’s work as a third-level dressage horse. Windy’s veterinarian had recommended treatment with dexamethasone, a corticosteroid. The medication seemed to help, but the cough came back as soon as the treatment was discontinued.

Windy came to the Hospital for Large Animals at Tufts University’s Cummings School of Veterinary Medicine for a more in-depth evaluation. On physical examination, Windy’s breathing rate was slightly higher than usual (about 20 breaths per minute). There was also a small trickle of white discharge from both nostrils. When we listened to the air moving through her trachea, or windpipe, we could hear a rattling noise–which suggested the presence of mucus in her airways.

We examined Windy further at the Tufts Lung Function Laboratory, the only one of its kind in the Northeast. Here, we were able to test the ability of Windy’s lungs to move air effectively through her airways (see lung function testing, in our “Innovation” section), and found that her baseline resistance was only slightly elevated, an indicator of mild airway narrowing. This was good news, as it suggested a lower level of lung dysfunction. To determine if Windy’s lungs were “twitchy,” or more responsive to stimuli as often seen in horses with inflammatory airway disease, we performed a histamine bronchoprovocation test. These results showed that Windy narrowed her airways when exposed to very low levels of histamine, a substance that may be released in the horse’s lung when it is irritated by a dusty environment or cold temperatures.

Cytology of a bronchoalveolar lavage

This image shows the cytology of a bronchoalveolar lavage (BAL or lung wash) from a horse with inflammatory airway disease (IAD). This horse has many mast cells, as well as neutrophils and particulates from exposure to barn dust.

To further characterize the degree and type of inflammation in Windy’s airways, we performed a bronchoalveolar lavage, or BAL, using a thin, 2.3-meter videoscope. After examining the larger airways, we infused sterile saline into the lower lung and quickly suctioned it back. This gave us a sample of the abnormal inflammatory cells and mucus that were causing Windy’s cough. Microscopic examination of the lung secretions showed a large amount of mucus and inflammatory cells, called neutrophils. Windy also had an elevated number of mast cells, another type of inflammatory cell that contributes to airway reactivity, or twitchiness (see image).

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Innovation

Achieving Excellence in Equine Podiatry

Dr. Carl Kirker-Head

Equine podiatry requires collaboration between farriers and veterinarians, says Tufts' Dr. Carl Kirker-Head

If there’s ever a disease that requires the veterinarian’s medical and surgical expertise and the farrier’s anatomical and functional knowledge of the hoof for a successful outcome, it is laminitis. In years past, the two professions often worked in a vacuum, neither one fully engaging the other in the interest of the patient. That situation is now very different, in no small way due to the sustained efforts of a few dedicated educators and practitioners from both professions, along with the gentle encouragement of academic institutions like Tufts University‘s Cummings School of Veterinary Medicine.

Since the early 1990’s Dr. Kirker-Head and the Hospital for Large Animals have hosted annual continuing education podiatry forums, frequently in conjunction with the Southern New England Farriers Association. The subject matter is always interesting. Tufts can lay claim to the only comprehensive forum addressing the farriery needs of the draft horse (2004). Most recently (2010), Dr. Ric Redden – a recognized leader in evolving podiatry techniques for managing laminitis – presented a day seminar on shoeing modalities for problem cases. And like any entity exploring the boundaries of knowledge, one should expect topics to sometimes be controversial Continue reading

Clinical Case Review

Laminitis and Metabolic Syndrome

Image 1, Hospital for Large Animals at Tufts University

Image 1: View of the Hoof Wall and Coffin Bone. Image Copyright Tufts University.

 

While veterinary investigators from around the world improve our understanding of the causes of laminitis and its effective  management, the disease remains one of the most debilitating for horses as well as the most frustrating for clients, attending veterinarians and farriers alike. In a USDA study (pdf) specifically looking at laminitis in the U.S. horse population, 46% of owners perceived that their horses became laminitis because of introduction to lush pasture. Another 27% felt that the laminitis was secondary to feed problems, obesity pregnancy or injury. Less-common causes included diarrhea, grain overload and retained placenta.
The most common theme is thus related to feed management and body condition of the animals involved.  

The following two cases, presented to Tufts’ Hospital for Large Animals, represent one of the underlying conditions we see that predispose horses to laminitis, Equine Metabolic Syndrome. They also illustrate the strategies we use and the principles we follow to optimize long-term outcome. Continue reading

Clinicians and Staff

This Month’s Guest Editors

Dr. Carl Kirker-Head
Carl Kirker-Head

Dr. Carl Kirker-Head, Associate Professor of Clinical Sciences

Dr. Kirker-Head is the Marilyn M. Simpson Professor and Associate Professor of Surgery at Tufts Cummings School of Veterinary Medicine. He is also Director of the Orthopaedic Research Laboratory and an Adjunct Associate Professor in Tufts Department of Bio-Engineering. He is a Faculty Fellow at Tufts Center for Animals and Public Policy.  Dr. Kirker-Head graduated from the University of Cambridge, England in 1983 and completed his surgery residency at Tufts University in 1987, since which time he has been on faculty.  He is a Diplomate of the American and European Colleges of Veterinary Surgeons and he sits on the Academic Council and Board of Trustees of the AO Foundation. He and his wife own and operate an equine rehabilitation facility at their horse farm in Sturbridge, Massachusetts.

Dr. Nicholas Frank

Dr. Nicholas Frank, Chair of the Department of Clinical Sciences

Dr. Nicholas Frank

Dr. Nicholas Frank recently joined the faculty at Tufts University as Professor of Large Animal Internal Medicine and Chair of the Department of Clinical Sciences. Dr. Frank is a recognized expert in the areas of equine endocrine disorders, laminitis, geriatric medicine, nutrition, and internal medicine.  He comes to us from the University of Tennessee where he was a clinician and researcher, as well as Section Chief of Large Animal Medicine and Director of the Center for Equine Veterinary Research.  Research performed by Dr. Frank and his group helped to describe Equine Metabolic Syndrome and to assess medical treatments for this condition in horses. Dr. Frank will provide medicine consultations for the equine podiatry center and referring veterinarians.

Topics of Discussion

Cover of the Journal of Veterinary Internal Medicine

Equine Metabolic Syndrome (EMS), is explained in this Concensus Statement in the Journal of Veterinary Internal Medicine. Tufts' Dr. Nick Frank is the lead author.

 Equine Metabolic Syndrome, In Depth

While the two cases in this month’s Clinical Case Review are quite different in terms of severity of lameness at the time of presentation, as well as their current prognosis for soundness (good for case 1; poor-to-fair for case 2), they share common themes. First, both horses display the hallmarks of Equine Metabolic Syndrome (EMS) as a predisposing feature. They are both overweight; have crested necks; their body condition scores are higher than expected considering the low dietary intake being fed prior to laminitis; and they both lose weight reluctantly in spite of being fed meager rations. Additionally, both horses have elevated blood insulin but normal to high normal glucose. This is the case for most insulin resistant horses because pancreatic insulin secretion increases to normalize blood glucose levels.       

Equine Metabolic Syndrome                       

Equine Metabolic Syndrome, described by Dr. Nicholas Frank in this Concensus  Statement in the Journal of Veterinary Internal Medicine, should be suspected in any horse or pony that is predisposed to obesity. These animals are often described as “easy keepers” because weight gain occurs with pasture grazing and obesity persists after caloric restriction. Genetics are likely to play an important role Continue reading