Diagnosis and treatment of a primary splenic lymphoma in a mule

The case reported here describes a transthoracic approach for removal of a splenic lymphoma from a 5‐year‐old mule. Nine months prior to presentation at Iowa State University College of Veterinary Medicine (ISUCVM), abdominal ultrasound was performed as part of a work‐up to investigate the cause of lethargy, anorexia and anaemia. Ultrasound examination identified a haemoabdomen and multiple splenic masses. Transabdominal biopsies were collected for histopathological evaluation and lymphoma diagnosed. Based on a number of clinical and laboratory examinations there was a lack of support for multicentric involvement and all results suggested solitary splenic involvement. Surgical removal of the spleen was accomplished via a transthoracic approach without complications. Histopathology of the splenic masses revealed a B cell lymphoma. Bone marrow was collected during surgery and submitted for cytology and was found to contain a normal lymphoid population with no evidence of neoplastic cells. The mule was discharged from the hospital 11 days after surgery.     

B cell lymphoma and secondary leukaemia in a mule

A 20‐year‐old mule was evaluated for anorexia and fever. Haematological evaluation revealed a population of large, immature lymphoid cells and significant anaemia. Bone marrow aspiration was unsuccessful, and abdominal ultrasonographic evaluation was unremarkable. The mule was subjected to euthanasia due to poor prognosis, and necropsy and histological evaluation revealed multicentric B cell lymphoma. The leukaemic phase of lymphoma is rarely documented in equids, and is regarded as an indication of advanced or aggressive disease. To the authors' knowledge, lymphoma in a mule has been reported only once previously.     

Locally invasive melanoma in the internal laminae of the hoof of a bay mule

An 8-year-old bay mule was presented with moderate right forelimb lameness and dark discolouration of the white line. Histopathology of the dark material indicated a melanoma. Extensive resection and debridement were not curative and the mule was subjected to euthanasia 70 days after presentation.     

Sudden death in racing Thoroughbred horses: an international multicentre study of post mortem findings

Reasons for performing study: To improve the understanding of exercise related sudden death in Thoroughbred racehorses. Objectives: To describe the post mortem findings in cases of sudden death associated with exercise in 268 Thoroughbred racehorses. Methods: Gross and histological post mortem findings of 268 cases of sudden death were collated and reviewed. Cases originated from 6 racing jurisdictions around the world. Sudden death was defined as acute collapse and death in a closely observed and previously apparently healthy Thoroughbred racehorse, during, or within one hour after, exercise. Cause of death as determined by the attending pathologist was categorised as definitive, presumptive or unexplained and compared between the different populations. Cardiopulmonary lesions recorded at post mortem examination were compared between different populations. Results: Pathologists recorded a definitive cause of death in 53% (143/268) of cases. Major definitive causes of sudden death included cardiac failure, apparent pulmonary failure, pulmonary haemorrhage, haemorrhage associated with pelvic fractures or with idiopathic blood vessel rupture, and spinal cord injury. A presumptive cause of death was made in 25% (67/268) of cases and death remained unexplained in 22% (58/268) of cases. There were several statistically significant inter‐population differences in the cause of death and in reporting of cardiopulmonary lesions. Conclusions: Sudden death can be attributed to a variety of causes. Causes of sudden death and the lesions found in cases of exercise‐related sudden death are similar in different racing jurisdictions. However, the lesions are often not specific for the cause of death and determination of the cause of death is therefore affected by interpretation by the individual pathologist.     

Suspected ivermectin toxicosis in a miniature mule foal causing blindness

A 9-week-old miniature mule foal presented to the Veterinary Medical Teaching Hospital for acute blindness, ataxia, and depression following an overdose of an over-the-counter ivermectin-based de-worming medication. Ophthalmic examination and electrodiagnostic evaluation eliminated outer retinal abnormalities as the primary cause of the bilateral blindness, implicating instead a central neurologic effect of the drug. With symptomatic and supportive care, the foal recovered fully and regained its vision.     

Post mortem survey of dental disorders in 349 donkeys from an aged population (2005-2006). Part 1: prevalence of specific dental disorders

REASON FOR PERFORMING STUDY: Donkey dental disorders are being recognised with increased frequency worldwide and have important welfare implications; however, no detailed investigations of dental disorders in donkeys appear to have been published. OBJECTIVES: To determine the prevalence of specified dental disorders in donkeys by performing a prospective post mortem study on donkeys that were subjected to euthanasia or died for other reasons at the Donkey Sanctuary, UK. METHODS: Post mortem examinations were performed on 349 donkeys over an 18 month period, 2005-2006. The presence and extent of specified dental disorders were recorded and these data analysed to determine their prevalence and common locations. RESULTS: A high prevalence (93%) of disorders was noted in the population with a median age of 31 years. In particular, cheek teeth diastemata (85% prevalence) were very common, often associated with advanced periodontal disease. Other disorders observed included missing teeth (in 55.6% of donkeys), displaced teeth (43%), worn teeth (34%), local overgrowths (15%), focal sharp overgrowths (3%) and dental-related soft tissue injuries (8%). CONCLUSIONS AND POTENTIAL RELEVANCE: Aged donkeys have a high prevalence of significant dental disease, especially cheek teeth diastemata. These findings highlight the importance of routine dental examinations and prophylactic dental treatments to improve the dental health and welfare of donkeys.     

Cerebral haemorrhage in a pregnant Standardbred mare with Evan's syndrome

A 3‐year‐old pregnant Standardbred mare was treated at the University of Helsinki Equine Teaching Hospital for severe idiopathic immune‐mediated thrombocytopenia and haemolytic anaemia (Evan's syndrome). Despite initial improvement with supportive care and immunosuppressive doses of corticosteroids and azathioprine, the mare died from a fatal cerebral haemorrhage on Day 21 of treatment.     

不同维生素E水平对骡鸭肝脏L-FABP mRNA表达量的影响

试验旨在研究不同维生素E水平对骡鸭肝脏L-FABP mRNA表达量的影响。试验选用600只70日龄公骡鸭,随机分为4组:Ⅰ为对照组,Ⅱ、Ⅲ、Ⅳ为试验组,分别在填饲日粮基础上分别添加0、40、90、140 mg/kg的维生素E。预饲期25 d,填饲期13 d。结果表明:填饲结束后,与填饲前相比,肝脏中L-FABP mRNA的相对表达量显著升高(P<0.05);填饲结束后,与对照组相比,Ⅱ、Ⅲ、Ⅳ组肝脏组织中L-FABP mRNA相对表达量显著升高(P<0.05),且Ⅱ组最高。     

Pathological features of hepatic portal venous gas in a cat

An 8-year 8-month-old castrated male Munchkin presented with vomiting, anorexia and hypoactivity. Computed tomography revealed excessive gas accumulation within the intestinal lumen and gas bubbles in the liver, spleen, and portal venous system, indicating hepatic portal venous gas. The cat died without any significant improvement, and mild splenomegaly was found at necropsy. Histologically, multiple gas vacuoles were diffusely observed in the liver and spleen. In the stomach, multiple gas vacuoles and scattered focal ulcers were detected within the mucosa. Multifocal hemorrhage was noted in the small and large intestines, whereas gas vacuoles were not present. Based on these findings, a gastric ulcer under high gas pressure may have provided an entry point for gas into the portal venous system.     

A tumour of vascular origin in a horse

Tumours of vascular origin are uncommon in horses. This report describes the surgical treatment of a large subcutaneous tumour in a Quarter Horse colt. The histopathological appearance of the mass was most consistent with a haemangioma. While these neoplasms of vascular origin are often difficult to characterise, it has been suggested that there is a continuum of types with some cases falling between the categories. Further classification of vascular tumours requires special stains and immunohistochemical techniques.     

Metabolic acidosis in healthy mules under general anaesthesia with halothane

ObjectiveTo report the severe metabolic acidosis identified in a group of 11 healthy mules anaesthetized with halothane for castration.Study designData generated from a prospective study.AnimalsEleven mules aged 2.5–8 years, weighing 230–315 kg and 11 horses aged 1.5–3.5 years, weighing 315–480 kg.MethodsAnimals were anaesthetized for castration as part of an electroencephalographic study. Preanaesthetic medication was acepromazine (0.03 mg kg^?1) administered through a preplaced jugular venous catheter. Anaesthesia was induced 30–90 minutes later with intravenous thiopental (10 mg kg^?1). After orotracheal intubation, anaesthesia was maintained with halothane vaporised in oxygen. The animals’ lungs were ventilated to maintain the end-tidal CO₂ concentration between 3.9 and 4.5 kPa (29–34 mmHg). Anaesthetic monitoring included invasive blood pressure measurement via the auricular artery (mules) and submandibular branch of the facial artery (horses). Arterial blood gas samples were drawn from these catheters at three time points during surgery and pH, PaCO₂, base excess (ecf) and HCO₃^? were measured. Values were compared between groups using a Mann–Whitney test. p was taken as <0.05. Results are reported as median (range).ResultsPaCO₂ did not differ between groups but pH was significantly lower in mules [7.178 (7.00–7.29)] compared to horses [7.367 (7.24–7.43)] (p = 0.0002). HCO₃^? values were significantly lower in the mules [16.6 (13.0–22.3) mM] compared to horses [23.7 (20.9–23.7) mM] (p = 0.0001), whilst base excess (ecf) was significantly more negative in the mules [?11.4 (?1.27 to ?16) mM] compared to horses [?1.3 (?5.8 to +2.4) mM] (p = 0.0004).Conclusion and clinical relevanceThis study demonstrated severe metabolic acidosis in healthy mules, which may have prompted intervention with drug therapies in a clinical arena. It is probable that the acidosis existed prior to anaesthesia and caused by diet, but other possible causes are considered.     

Suture exostosis with concurrent nasal septum chondrosarcoma in a horse

A 15‐year‐old Hanoverian mare presented with a 10‐day history of facial swelling in the right maxillary and frontal regions, left epiphora and intermittent right epistaxis. Radiographs revealed suture exostosis of both nasofrontal sutures and a deviated and thickened nasal septum. Computed tomography (CT) of the skull revealed exostosis of the nasolacrimal sutures and ducts bilaterally of both nasofrontal sutures and of the right zygomatocomaxillary and lacrimomaxillary sutures. The mid‐to‐caudal aspect of the nasal septum was thickened and had multiple well demarcated hypoattenuated regions within the septum. Histological examination of biopsies taken from the right nasofrontal suture and the nasal septal mass revealed suture exostosis and nasal septum chondrosarcoma. The horse was treated with rest and anti‐inflammatories. The facial swelling and left epiphora were improved at 7 months telephone follow‐up. This report is the first to describe a nasal septum chondrosarcoma in a horse. Additionally, we suggest that the suture exostosis may have developed due to an alteration of the biomechanics of the skull sutures secondary to the septal tumour.     

Surgical treatment of a mandibular ameloblastic carcinoma with metastases to the mandibular lymph nodes in a pony

A 4-year-old Connemara filly was presented with a rapidly growing oral mass on the right rostrolateral mandible and a right mandibular lymphadenopathy. Radiographs of the rostral mandible revealed a lytic, infiltrative mass consistent with soft tissue and mineralised material, and displacement of tooth 403. A biopsy showed characteristic histopathological features of an ameloblastic carcinoma. Subsequent FNA of the right abnormally firm and enlarged mandibular lymph node confirmed the metastatic spread. Computed tomography of the head was performed for surgical planning, including sentinel lymph node mapping to rule out other lymph node involvement. An aggressive lesion, consistent with soft tissue of the rostral right mandible was identified with intralesional contrast injection showing drainage of contrast within the right mandibular lymph nodes (Sentinel node). Based on the infiltrative and destructive nature reported in ameloblastic carcinoma in humans, a rostral mandibulectomy was performed, along with complete mandibular lymphadenectomy. The horse recovered uneventfully from surgery. In the early post-operative period marked lymphoedema of the ventral mandibular region was observed, which resolved 4–5 days post-operatively. Optimal cosmesis was maintained post-operatively, and no recurrence has been observed to date – 12 months post-surgery.     

The clinical presentation of a mid‐tail melanocytoma with sudden malignant transformation in a bay Irish Draught gelding

Equine melanocytic tumours may be either a benign or malignant skin disease. They commonly involve the skin of grey horses. There are no reports of mid‐tail melanocytoma with sudden malignant transformation. Partial tail amputation was used to resect a melanocytic tumour mass from the mid‐tail of a 16‐year‐old bay Irish Draught (ID) horse. There was no evidence of significant re‐growth or complications at a 6‐month post operative examination.     

Surgical resection of a dysgerminoma in a mare

A mare was referred for further evaluation of a mass found in the left caudal abdomen during a routine postpartum reproductive palpation. The mare was clinically normal with no history of health problems. Ultrasonographic examination of the mass confirmed its presence, but the origin of the mass could not be accurately determined. Routine haematology and serum biochemistry results were within normal limits. The mare was initially treated conservatively with antibiotics, but the mass continued to increase in size, so it was surgically excised. The mass involved the left ovary. The mare showed transient abdominal pain after surgery, but developed no other complications and was in foal 7 months later. On histology, the mass was diagnosed as a dysgerminoma, a rare ovarian tumour of germ cell origin.     

Fibromatous epulis in a Campolina horse

An 11-year-old Campolina horse was referred to the Veterinary Hospital due to the presence of an exophytic mass located in the rostral region of the mandible. Radiographic evaluation showed no evidence of tumour infiltration in the underlying mandibular bone, and the histopathology and immunohistochemical evaluations confirmed the diagnosis of fibromatous epulis. The treatment included surgical excision of the mass, followed by extensive curettage of the underlying mandibular bone. Complete healing of the wound was evidenced 60 days after the procedure; however, relapse was reported by the owner between 1 and 3 years after surgery.     

Dysautonomia in a six‐year‐old mule in the United States

Equine dysautonomia, also known as equine grass sickness (EGS), is a well documented disease in several countries. To the authors’ knowledge, EGS has not been reported previously in North America. This report describes EGS in a 6‐year‐old female mule in the USA. Failure initially to consider EGS resulted in a delayed diagnosis. EGS should be considered as a differential diagnosis and appropriate diagnostic tests performed in similar cases in North America.