Clinical Case Review

Septic arthritis and osteomyelitis in a neonatal foal
Mary Rose Paradis, DVM, MS, Diplomate ACVIM(LAIM)

’11 Royal Reign, a 10-day old crossbred filly was referred to the internal medicine service at Tufts Cummings School of Veterinary Medicine, Hospital for Large Animals, with a one day history of sudden hind limb lameness. On her physical examination, the filly was bright and alert but had a rapid heart rate of 120 beats/minute and a fever of 103.5. She exhibited left hind limb lameness at the walk; however, no joint or limb swelling was noted. Physical examination of the left hip and sacroiliac (lower back) region elicited a painful response. The filly’s initial blood work was within normal limits with the exception of a low IgG (antibody level) of 400 mg/dl, indicating that she had not had sufficient transfer of antibodies from her dam.

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Clinical Case Review

CURRENT STEM CELL RESEARCH

Andy Hoffman, D.V.M., D.V.Sc., D.A.C.V.I.M., Professor, Director, Lung Stem Cell Laboratory and Jose Garcia-Lopez, DVM, DACVS, Associate Professor.

The clinical scenario:

Charger, a 9-year-old Oldenburg gelding, presented to clinicians at the Hospital for Large Animals at the Cummings School of Veterinary Medicine at Tufts University for non-resolving hind limb lameness. During evaluation, Charger displayed excessive toe dragging of the rear limbs and abduction (outward swinging) of the right hind. When trotting, Charger exhibited a 2 out of 5 (0= sound; 5= non-weight bearing) right hind limb lameness, with a positive upper limb flexion test (indicating pain in the upper portion of the leg). Continue reading

Clinical Case Review

The Case of a “Street Nail”

The contrast material fills the navicular bursa.

Nagel, a four year old Quarter Horse gelding, presented to the Tufts Hospital for Large Animals at the Cummings School of Veterinary Medicine after stepping on a nail, which entered the outer aspect of his right hind sole. Initial home treatments included daily foot soaks, phenylbutazone (an anti-inflammatory) and a course of antibiotics. Unfortunately, Nagel’s lameness returned despite his owner’s supportive and diligent home care. Radiographs taken by the referring veterinarian showed a penetrating wound that was tracking to the navicular bursa, with a small volume of gas observed within the bursa. Contrast injection into the site of nail puncture confirmed a communication of the wound with the navicular bursa. At that time, Nagel was referred to Tufts for exploratory arthroscopy. 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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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