Development of equine post anaesthetic myelopathy: Thirty cases (1979–2010)

Post anaesthetic myelopathy is a rare but devastating complication of equine anaesthesia and there is a need for better understanding of the condition and to raise veterinary awareness. The aim of this study was to collect data on unreported cases and combine those with reported cases to better identify possible risk factors and early clinical signs and outcomes of horses developing post anaesthetic myelopathy (PAM). A survey was conducted to identify cases of equine PAM. Records were also requested via the American College of Veterinary Anaesthesiologists listserve. Additional cases of PAM were located through review of the literature. Eighteen new cases and 12 published cases were identified. Large‐framed breeds between 6–24 months of age were more commonly affected (23/30). The majority of horses were positioned in dorsal recumbency during anaesthesia. Lack of movement and deep pain of the rear limbs, loss of anal tone and lack of panniculus response from the mid to caudal thorax distally were the most common clinical findings. Reported treatments resulted in no improvement of clinical signs and all horses died or were subjected to euthanasia from a few hours to 8 days post operatively. Poliomyelomalacia of the caudal spinal cord is the most common histopathological finding. Although a rare complication it is a catastrophic risk that can be eliminated by performing a standing operation. Hopefully in the future better understanding of this condition will lead to prevention and treatment strategies.     

Chronic lymphocytic leukaemia in the cat: 18 cases (2000–2010)

There is little information regarding the presentation, biologic behaviour, treatment and prognosis in cats with chronic lymphocytic leukaemia (CLL), and further investigation is needed to characterize this disease in cats. The goal of this study was to describe the clinical presentation, response to treatment and prognosis of feline CLL. A multi‐institutional retrospective study of 18 cats diagnosed with CLL between 2000 and 2010 was performed. CLL was defined as the presence of a mature lymphocytosis (> 9000 lymphocytes µL^?1) and confirmation of an immunophenotypically monomorphic or clonal lymphoid population. Each patient was required to also have at least one of the two following criteria: (1) concurrent cytopenia of at least one cell line and/or (2) >15% mature lymphocytes in the bone marrow. Data on signalment, history, clinical signs, clinicopathologic features and response to treatment were reviewed. Median age of the cats at initial presentation was 12.5 years (range: 5–20 years). The most common presenting complaint was chronic weight loss, which was present in 8/18 (44%) cats. Sixteen of 18 (89%) cats were treated with chlorambucil and prednisolone; four of these cats also received vincristine. Two (11%) cats were treated with multi‐agent injectable chemotherapy (L‐CHOP, l ‐asparaginase, cyclophosphamide, doxorubicin, vincristine, prednisolone). Eighty‐eight percent of cats evaluable for response achieved a complete (nine cats) or partial (six cats) remission. Median overall remission was 15.7 months (range: 1.3–22.8 months). The median overall survival in the 17 cats with follow‐up data was 14.4 months (range: 0.9–25.3 months). Results of this study suggest that CLL affects older‐aged cats and responds favourably to treatment with oral chlorambucil and prednisolone.     

A review of 14 cases of hypertrophic osteopathy (Marie's disease) in horses in the Republic of Ireland

There are few reports describing hypertrophic osteopathy (HO) in horses and no reports describing this in the Irish equine population. This case series outlines the clinical, radiological and pathological features of HO in horses in Ireland and compares and contrasts the findings to previous reports. Overall, the prevalence of HO in Irish horses was found to be low with clinical signs similar to previous reports. Diagnosis of the primary lesion was low, largely due to the limited diagnostic evaluation in a large proportion of the horses evaluated. The horses had a low average age and a high prevalence (35.5%) of mandibular and facial involvement.     

Primary gastric impaction in horses: A retrospective study of 20 cases (2005–2008)

Primary gastric impaction is an uncommon condition. Furthermore, the factors associated with gastric impaction and the optimal method of treatment are not clear. The aim of this article is to describe the clinical findings, treatment and outcome of horses with a primary gastric impaction. Medical records of horses that presented with a primary gastric impaction between 2005 and 2008 were reviewed and 20 horses with a primary gastric impaction identified. Diagnosis of a primary gastric impaction was made if the horse had been fasted for a minimum of 16 h, a concretion of ingesta precluded visualisation of the margo plicatus and there was no evidence of concurrent intestinal pathology. Thirteen of 20 (65%) horses were presented on an emergency basis. The most common complaint was inappetence (50%) followed by acute colic (35%) and recurrent colic (35%). On initial examination for colic, all horses had a normal heart rate and 7 of 20 (35%) had decreased gastrointestinal borborygmi. All horses were treated with enteral fluid therapy. The median dose of fluids administered per day was 5 doses (range 1–8 doses) of 2–10 l of isotonic electrolyte solution. The median length of treatment until resolution was 2 days (range 1–5 days). Eighteen of 20 (90%) horses survived to discharge. Primary gastric impaction appears to be a condition with clinical signs of inappetence and mild abdominal discomfort. This is the largest group of horses reported that were treated with enteral fluid therapy for a gastric impaction and it was concluded that enteral fluid therapy was of value in this study.     

Setaria digitata was the main cause of equine neurological ataxia in Korea: 50 cases (2015–2016)

This study was performed to examine and clarify the cause of hindlimb ataxia and neuropathy seen in the South Korean horse population. Fifty horses diagnosed with hindlimb ataxia and neuropathy were referred for this study. Neurological examination was performed on 47 horses while necropsy was performed in all 50 animals. The occurrence of neurological diseases increased rapidly in the summer and 47 out of 50 horses were referred after the end of July. The incidence of neurological diseases started from the southern part of Korea in July and proceeded northward in August and September. Although there was no correlation with age, Thoroughbred and Warmblood horses showed a higher incidence rate than Halla and Jeju horses. The incidence rate was 5 times higher in geldings than in mares and stallions. Of the 20 cases, 16 were diagnosed with eosinophilic meningoencephalomyelitis in 2015. The most common lesions observed in 2016 were parasitic meningoencephalomyelitis (10 cases, 33%) and eosinophilic meningomyelitis (7 cases, 23%). Histopathological analysis of the brain and spinal cord revealed nematodes of approximately 100–200 µm in diameter, microcavitation and infiltrates of eosinophils, and brown pigmented macrophage infiltrates. The nematodes were identified as Setaria digitata via DNA sequencing, performed subsequent to polymerase chain reaction using DNA isolated from formalin-fixed paraffin-embedded tissue sections of the spinal cord. These results show that aberrant migration of Setaria digitata larva in the brain and spinal cord was a major cause for neurological signs in horses.     

Diagnostic utility of computed tomography imaging in foals: 10 cases (2008–2010)

Despite an increasing number of case reports published using computed tomography (CT) in foals only limited data on its diagnostic utility are available. Medical and imaging records of 10 foals that had a CT examination between May 2008 and December 2010 were retrieved and studied. Three out of 10 cases were examined for orthopaedic problems, 3 were referred for medical disorders, 3 for both orthopaedic and medical problems, and one case was presented for a follow‐up of an abdominal mass. In this series CT was an accurate diagnostic tool in identifying abscesses, osteomyelitis, arthritis, physitis and fractures, bone ossification defects, intracranial haematomas and sinusitis. An indication for the best medical and/or surgical approach was obtained.     

Outcome and long‐term follow‐up of 20 horses undergoing surgery for caecal impaction: A retrospective study (2000–2008)

Reasons for performing study: If untreated, caecal impaction may progress to rupture of the caecum and reports of long‐term outcome for horses undergoing surgery for caecal impaction are required. Objectives: To describe short‐ and long‐term complication rates for horses undergoing surgery for caecal impaction in an otherwise life‐threatening gastrointestinal condition. Methods: Case records were reviewed for horses undergoing surgery for caecal impaction. Horses were included in the study if an abnormally large, fluid‐distended or feed‐impacted caecum was the primary diagnosis at surgery and excluded if the caecum had already ruptured upon opening the abdomen, necessitating euthanasia. Short‐term follow‐up data were obtained from clinical records; and included complications, repeat celiotomy and survival to discharge. Long‐term survival was defined as survival for >1 year post operatively. Long‐term follow‐up data were obtained through telephone interviews with owners and referring veterinary surgeons. Survival, occurrence of post operative colic and subsequent use of the horse were recorded. Results: Twenty horses underwent surgery for caecal impaction: 16 horses underwent caecal bypass (typhlotomy and removal of caecal contents, ileal transection followed by ileocolostomy); 3 underwent typhlotomy alone; and one horse underwent typhlotomy followed by a second procedure where caecal bypass was performed. Five horses (25%) were admitted for colic evaluation with primary caecal impactions, in 10/20 (50%) of cases the impaction was secondary to previous orthopaedic surgery and in 5/20 (25%) caecal impaction was identified at repeat celiotomy following a previous colic surgery. Sixty‐five percent (13/20) of horses survived to discharge; 11/13 (85%) of horses discharged survived long term; 100% (3/3) horses that received typhlotomy alone were discharged and survived long term. Conclusions: The prognosis following caecal impaction surgery is fair, if the horse survives to discharge then prognosis for long‐term survival is good. Potential relevance: Surgery for caecal impaction carries a fair prognosis for a potentially life threatening disease, in particular where caecal dysfunction is suspected.     

Long‐term prognosis of gastrojejunostomy in foals with gastric outflow obstruction: 16 cases (2001–2006)

Reasons for performing study: It has been suggested that the success of gastric bypass surgery in foals for the treatment of gastric outflow obstruction is poor. However, few reports exist evaluating the long‐term prognosis of these cases. Objectives: To determine the long‐term success of foals, including racing records, surgically treated for gastric outflow obstruction secondary to gastroduodenal ulceration. Methods: Medical records of foals undergoing surgical treatment of gastric outflow obstruction secondary to gastroduodenal ulceration were evaluated for clinical information. Owners, trainers and race records were evaluated regarding long‐term survival and racing success. Results and conclusions: Sixteen foals were included in the study, all treated with a gastrojejunostomy. All foals survived to immediate discharge from the hospital; 8 survived to racing age, with 7 of those entering training and 3 actually racing. Foals that did not survive to racing age had various post operative complications. The success rate for these foals appears somewhat better than that previously reported. Potential relevance: Gastrojejunostomy for the treatment of gastric outflow obstruction, secondary to gastric ulceration, is a valid treatment option for foals.     

Canine,feline, and equine corneal vascular neoplasia: A retrospective study (2007‐2015)

Corneal vascular neoplasms (hemangioma and hemangiosarcoma) are rare in all species. Reported cases are single case reports in a single species. Archived cases of corneal hemangioma and hemangiosarcoma from dogs, cats, and horses were obtained from the Comparative Ocular Pathology Lab of Wisconsin (COPLOW, Madison, WI), tabulated, and examined. This retrospective study describes the breeds, ages, tumor types, and characteristics of vascular neoplasms that appeared to be primarily corneal in location, in feline, canine, and equine patients, with gross and histologic images. There is a discussion of predisposing factors and speculated association with chronic ocular surface disease.