Multicentric Hemangiosarcoma in the Horse: A Case Report

The present article reports a case of multicentric hemangiosarcoma in a 22-year-old Warmblood mare presented for recurrent fever and weight loss. Thoracic ultrasonography showed multiple small areas of pulmonary consolidation. Ultrasonography in the region of the right liver lobe showed the presence of a rounded mass, approximately 24 × 19 cm² in size, extending from the 9th to 14th rib of the right side, characterized by multiple fluid-filled cavities and hypo- and hyperechoic rounded areas. On the left side, several hyperechoic rounded areas were detected in the spleen. Because of sudden onset of hemoperitoneum and worsening of the clinical conditions, the mare was humanely destroyed. Necroscopy confirmed the presence of hepatic, splenic, and pulmonary lesions, and showed further nodules on the stomach wall. The microscopic appearance of the lesions was consistent with hemangiosarcoma with multiple visceral metastases. Because the reported prevalence of equine hemangiosarcoma is as low as 0% to 0.7%, this case report may provide further information and describe one of the possible ultrasonographic patterns of multicentric hemangiosarcoma in horses.     

Dyspnea Caused by an Obstructive Tracheal Leiomyoma in a Horse: A Rare Case

Tracheal leiomyoma is a rare neoplasm of the respiratory tract in animals. This primary benign tumor arises from smooth muscle cells of the trachea. We report a 13-year-old female horse with clinical signs of severe airways obstruction. It had dyspnea, exercise intolerance, chronic progressive respiratory noises, and cyanosis in mucosa membranes. Radiography revealed a foreign body obliterating the luminal trachea. Endoscopic biopsy showed a 3 × 3-cm ovoid mass attached to the dorsal aspect of the trachea. Hematoxylin and eosin and Masson's trichrome stains showed dense spindle cells forming irregular bundles disposed in short interlacing fascicles. Nuclei were elongated with blunt ends, eosinophilic cytoplasm with indistinguishable cell borders, and low mitotic activity. This study is considered the first reported case of an obstructive intratracheal leiomyoma in the horse.     

Cholangiocarcinoma and Squamous Cell Carcinoma of the Stratified Epithelial Portion of the Stomach in a Horse: A Case Report

Both cholangiocarcinoma and squamous cell carcinoma of the stomach stratified squamous epithelial portion are rarely found in equine medicine despite being more common in human beings, dogs, and cats. The objective of the present article was to report the simultaneous occurrences of these two types of neoplasias in an 11-year-old mare. Numerous firm, whitish nodules were distributed throughout the liver parenchyma and those protruding over its surface were umbilicated in their appearance. It was verified that the nodules adhered to the peritoneum and omentum, diaphragm, spleen, and stomach serosa compressed the adjacent structures. The stomach stratified squamous epithelial portion, particularly originating in the margo plicatus toward the cardia, was covered by numerous smooth, whitish spherules. Microscopic examination allowed the liver, tumor, and the abdominal implants to be identified as a cholangiocarcinoma, and the stomach neoplasia as a carcinoma of its stratified squamous epithelial portion. Considering this as an uncommon finding, although when considered individually, the presence of a cholangiocarcinoma and a squamous cell carcinoma of the stratified squamous epithelial portion of the equine stomach in the same specimen is worthy of reporting.     

A Retrospective Analysis of Renal Carcinoma in the Horse

Background: Renal carcinoma is a rare tumor of horses.
Hypothesis: Presenting complaints and clinical signs of this disease are vague and early diagnosis increases survival time.
Animals: Data were collected from the medical records of 4 horses presented to Washington State University as well as the 23 previously published case reports of horses with renal carcinoma.
Methods: Retrospective study.
Results: Renal carcinoma affects horses of all ages with most cases observed in geldings and Thoroughbreds. The most common presenting complaints are nonspecific and usually do not occur until late in the course of the disease. Routine laboratory results generally are unremarkable with no evidence of renal dysfunction. Urine and peritoneal fluid analyses are consistently abnormal, but the changes usually are nonspecific. Rectal palpation often allows detection of an abnormal kidney or a mass in the area of the kidney. Renal ultrasound examination is the most rewarding imaging procedure, and when combined with renal biopsy, antemortem diagnosis can be achieved. Renal carcinoma is both locally invasive and metastatic, necessitating careful staging for metastasis using thoracic radiography and abdominal ultrasound examination. If the tumor is localized to 1 kidney, nephrectomy is the treatment of choice. No chemotherapy or radiation treatment for renal carcinoma has been reported in the horse. Median survival for this series of cases was 11 days (0 days–1 year).
Conclusions and Clinical Importance: Prognosis is poor to grave.     

Intra-articular Infection by Scedosporium prolificans in a Horse

Two months following the surgical repair of an acute, open, comminuted, and articular fracture of the left olecranon, a 15-year-old American Saddlebred gelding presented with nonweight-bearing lameness. A fungus cultured from the cubital joint was identified as Scedosporium prolificans by sequencing of the D2 large subunit ribosomal DNA region and subsequently confirmed by phenotypic methods. Therapy with systemic fluconazole, terbinafine and intra-articular voriconazole was attempted, but was unsuccessful.     

Bladder Eversion Caused by Chronic Cystitis in an Arabian Racehorse: A Case Report

Bladder eversion is a rare condition and may occur in mares as a result of excessive straining during pregnancy or in the postpartum period. In the present case, bladder eversion was caused by chronic cystitis in a nonpregnant mare. An Arabian racehorse (mare, 3 years old) was admitted to The Racehorse Hospital of the Turkish Jockey Club with a history of lumbar pain, excessive straining, and frequently assuming the urination position. Physical examination revealed the presence of tenesmus, stranguria, passing of small amounts of urine, and a visible mucosal structure at the ventral vulvar commissure during tenesmus. Laboratory findings revealed leucocytosis, increased urine pH, proteinuria, pyuria, and hematuria. Streptococcus equi subsp. zooepidemicus and Escherichia coli were isolated and identified in urine culture. Transrectal ultrasonography revealed thickening of the bladder wall and prolapse of the bladder corpus into the bladder. In the cystoscopic examination, performed following bladder reduction, severe hyperemia, erosion, and ulcers were determined in the bladder mucosa. Chronic cystitis was treated using antibiotics, based on urine culture test results, together with steroids and non-steroidal anti-inflammatory drugs. Twenty-four hours after the start of treatment, the severity of straining was observed to have decreased, ceasing completely on Day 4, and the bladder returned to its normal position.     

Management of Chronic Diarrhea in an Adult Horse

Chronic diarrhea could be a challenge from both the diagnostic and therapeutic point of view. This case report will discuss the clinical approach to the evaluation of chronic diarrhea with the production of free fecal water in an adult horse. The discussion of this case report may provide further information and describe a possible therapeutic option with sulfasalzine, focusing on the nutritional management of chronic diarrhea in adult horses. Nutritional management could be of higher importance for horses that suffer from this problem because it improves the well-being of the hindgut environment. In the present case report, motility abnormalities were identified without other physiological disturbances of colonic function or a decrease in body weight, and the priority was the following: (1) rebalancing of the diet to the real nutritional requirements of the patient, (2) avoiding excess carbohydrate from both forage and concentrate, (3) selecting the right proportion between good quality first-cut meadow hay and grounded and pelleted meadow hay that helps to reduce mechanical and physical load of the colon and could help in the formation of more homogeneous digesta, (4) reducing the stress with adequate feed consumption time, meal size, and time spent in a overgrazed paddock, and (5) increasing the proportion of omega-3 fatty acids in the diet. With the nutritional plan and management and the initial use of sulfasalazine, the horse maintained a good quality of the feces with a reduced or absent production of the free fecal water.     

Persistent Bilateral Mydriasis Associated With a Pituitary Adenoma in a Horse

Severe bilateral mydriasis and bilaterally decreased vision were observed in a 23-year-old crossbred warmblood gelding with a history of pituitary pars intermedia dysfunction. Ten years after the onset of clinical signs, it was killed humanely because of worsening of clinical signs and loss of therapeutic responsiveness. Postmortem examination of the head was performed to confirm the suspected pituitary neoplasm and to investigate secondary oculomotor lesions. Pathomorphologic examination revealed an expansile space-occupying pituitary adenoma and degenerative changes in the preganglionic oculomotor nerve, ciliary ganglion, and optic chiasm. The ocular clinical findings share features of a cavernous sinus syndrome.     

A Case of Bronchioloalveolar Carcinoma in a Mare

A case of pulmonary carcinoma in a 23-year-old Quarterhorse mare is described. On physical examination, depression, poor body condition, tachypnea, bilateral serosanguineous nasal discharge and a wide area of reduced breath sounds in association with the right hemithorax were detected. Laboratory evaluation showed leukocytosis with neutrophilia and lymphopenia, hyperfibrinogenemia, hyperprotidemia, hypoalbuminemia, increased beta 2 and gamma globulin fractions, hypoxemia, and normocapnia. Radiography and thoracic ultrasonography revealed a large rounded mass extending from the 9th to the 14th right intercostal space, where neither bronchial nor vascular structures were detectable. Endoscopy showed a large amount of serosanguineous fluid within the tracheal lumen and a mass of reddish soft tissue completely obliterating the right caudal lobar bronchus. Histopathology of the endobronchial mass and of the transthoracic ultrasound-guided biopsy samples was consistent with a primary pulmonary epithelial tumor. Due to worsening of the clinical condition, the mare was euthanized. Postmortem examination confirmed the presence of a large 30-cm mass located in the right caudal pulmonary lobe, characterized by epithelial cells arranged in papillary projections and alveolar structures, findings consistent with bronchioloalveolar carcinoma.     

The Impact of Horse Age,Sex, and Number of Riders on Horse Performance in British Eventing Horse Trials

Limited research has been undertaken to determine the impact of horse age, sex, and number of riders on horse performance in British Eventing (BE) horse trials. Improved understanding of this can aid professionals in planning a competition horse’s career. To investigate the impact of age, sex, and number of riders on the peak performance of horses at each of the main levels of BE competitions. The best score from each horse competing in BE horse trials in the years 2008–2018 was recorded, and principal component and hierarchical cluster analysis was performed. Basic data analysis was used to identify variables associated with particular better-performing clusters of horses. The interplay of the combinatory variables was then used to map out the trends in career trajectory for horses competing at each level of competition in the best-performing and worst-performing clusters. The peak performance of mares was worse than geldings and stallions at all levels. At Novice to Advanced, stallions did not perform as consistently with multiple riders as geldings. The age at which the best-performing groups peaked was similar for mares and geldings in all classes, although stallions peaked at an older age than mares and geldings at Novice and Intermediate level. All horses were a minimum of 4-years-old at the time of competition, as per BE rules.     

Evaluation of Horse Fitness for Exercise: The Use of a Logit-Log Function to Model Horse Postexercise Heart Rate Recovery

The aim of this study was to test the adjustment of the logistic-log model with postexercise heart rate (HR) recovery data in horses and introduce the logit-log model as a parsimonious model, with the half recovery time as a measure of horse fitness. Postexercise HR (bpm) measurements at different timings were obtained from 32 polo ponies in two different exercise regimes: n = 16 “full chukker” and n = 16 in “half chukker.” Measurements were taken at rest, immediately after exercise and then 2, 4, 6, 10, and 20 minutes after exercise. The HR variable was transformed into a logit (HR) variable, and time was transformed into log (time). Means of logit (HR) at the different log (times) were obtained, creating two time series of transformed variables that were then adjusted by simple linear regression. The degree of adjustment of the model is high with values of r² = 0.989 for the full chukker and r² = 0.998 for the half chukker. Full chukker ponies have a half recovery time of 5.7 minutes and half chukker ponies of 11.2 minutes, with the former showing to be fitter than the latter, which is why they are chosen to play for longer periods. The logit-log model is parsimonious, and the half recovery time can be easily determined. The half recovery time has potential to be used as a measure of fitness degree, allowing comparison between horses.     

Aging Equines: Understanding the Experience of Caring for a Geriatric Horse with a Chronic Condition

This study evaluated the experience of 1,448 people in the United States who currently care for or had previously cared for a geriatric horse and how that experience was qualified by the presence or absence of a chronic condition in the horse. An anonymous, online questionnaire was distributed to a cross-country sample to investigate the burden of caregivers from the perspective of owners of geriatric horses. Traumatic events and veterinary care decisions were also explored. Findings from the study supported the hypothesis that owners of geriatric horses with a chronic condition experienced higher levels of physical and emotional care burden, regardless of the age of the geriatric horse. Attachment levels reported by participants were high, regardless of the health status of the horse. This exploratory study provides the equine practitioner a greater understanding of the care burden experienced by owners of geriatric horses, particularly of owners of geriatric horses with a chronic condition, who rely on their veterinarian to guide their management and health care decisions. Veterinarians can help prepare and support clients as they navigate the complexities of caring for an older horse with a chronic condition.     

Equine Performance and Autonomic Nervous System Improvement After Joint Manipulation: A Case Study

A nine-year-old gelding quarter horse, whose discipline is barrel racing, was experiencing difficulty performing tight turns around the barrels for 8 months prior to treatment. He demonstrated tail swishing as if aggravated when under the saddle, which would escalate to bucking for 3 weeks prior to treatment. This gelding had no previous history of bucking under the saddle. Static and motion palpation findings indicated multiple segmental joint fixations located throughout the spine and extremities. High-velocity low-amplitude adjustments were performed to address the joint fixations found during examination. A comparison of pre and post-treatment thermographic images showed a temperature change indicative of autonomic nervous system improvement caused by joint manipulation. A follow-up at two weeks revealed subjective long term improvements. Subjective, objective, and thermographic evidence indicated that segmental joint dysfunction was causing increased nociception and autonomic dysregulation, most notably over the sacroiliac joints, lateral front left cannon bone and right carpus. Previous research has indicated causative effects of joint manipulation on the autonomic nervous system and nociceptive processes. This case shows the positive thermographic effects post-adjustment on the nervous system, and a two week follow-up indicated that the gelding no longer showed signs or symptoms of pain. This case demonstrates how joint manipulation can affect the autonomic and nociceptive nervous systems in the equine patient.     

Scapular Sequestrum in a Horse A Case Report

A 15-year-old Morgan mare presented with a draining tract associated with osteomyelitis and sequestration of the medullary cancellous bone of the right scapula. Moderate lameness and muscle atrophy were present. Partial resection of the lateral cortex allowed exploration and debridement of the medullary cavity of the scapula. The mare returned to soundness, the muscle mass returned, but a small discharging sinus persisted.     

Cryptococcal Pneumonia and Meningitis in a Horse

Gross and microscopic evidence of Cryptococcus neoformans in the lungs and central nervous system of a mature Thoroughbred horse presenting with granulomatous pneumonia and meningitis has been described in this article.     

Long-Term and Immediate Effects of Whole Body Vibration on Chronic Lameness in the Horse: A Pilot Study

The effects of whole body vibration (WBV) in horses with chronic lameness were evaluated in an experimental, single subject, repeated measure design. To assess the long-term effect of WBV, eight horses not previously exposed to WBV were subject to WBV, 30 minutes twice daily, five days a week, for 60 days in addition to their regular exercise routine. Lameness was assessed subjectively and objectively 30 days before the start, at the start and 30 and 60 days after the start of the treatment (WBV). The immediate effect of WBV was assessed in four horses accustomed to WBV, by comparing lameness before and within 30 minutes of a single 30-minute WBV session at four different time intervals. Change in lameness was sought using paired t tests on the kinematic data. A P-value of <.05 was considered statistically significant. Intraindividual change was sought using a subjective and objective scoring system. No statistically significant change in lameness was seen after 30 or 60 days of WBV, respectively, in the chronically lame horses not previously exposed to WBV. However, a trend toward improvement was observed after the first 30 days of WBV, but this improvement appeared to be lost during the second 30 days of WBV. Although a statistically significant worsening of front limb lameness was seen immediately after a single 30-minute WBV session in the chronically lame horses accustomed to WBV, this result was largely attributed to a very significant worsening of the front limb lameness in one horse within that group.