Equine neonatal septicaemia: 24 cases

Equine neonatal septicaemia was confirmed in 24 foals hospitalised at the Rural Veterinary Centre between 1989 and 1992 with suspected septicaemia. Septicaemia was confirmed by culture of bacteria from blood of live foals and tissues obtained at necropsy of foals that died or were euthanased. Pathogenic bacteria isolated were predominantly Enterobacteriaceae (including Escherichia coli and Salmonella serovars) and Actinobacillus equuli. Clinical manifestations of septicaemia included signs of depression, dehydration, abnormalities in body temperature and manifestations of localised infection including diarrhoea, pneumonia, and septic arthritis. Most common haemato-logical abnormalities were neutropenia and increase of circulating band neutrophils. Survival rate of foals with confirmed septicaemia was 70.8%. Survival was found to be less likely in the presence of pneumonia, severe signs of depression, marked haematological changes or septic arthritis at the time of admission. Seven foals were confirmed to have septic arthritis without concurrent septicaemia. Of these, 4 had multiple joint involvement. Bacteria isolated from infected joints were predominantly Salmonella serovars. Four foals with septic arthritis failed to survive, due to multiple joint infection, which was unresponsive to treatment. The clinical and haematological abnormalities present in foals with confirmed septicaemia and septic arthritis were consistent with those observed in other studies. The bacterial isolates from foals with confirmed septicaemia were similar to those isolated in other studies. In contrast, the bacteria isolated from foals with septic arthritis without concurrent septicaemia were different from other studies.     

Successful treatment of infectious (Salmonella type III: 44) polyarthritis and osteomyelitis in a 4‐week‐old foal

This article describes the acute onset of infectious polyarthritis and osteomyelitis in a 4‐week‐old foal. Analysis of synovial fluid obtained from the left femoropatellar and right tarsocrural joints combined with clinical signs consisting of joint effusion and lameness yielded a diagnosis of septic arthritis. Bacterial culture of synovial fluid from the left stifle revealed Salmonella type III: 44. Rapid, sustained clinical improvement was noted following discontinuation of empirical antimicrobial therapy (potassium penicillin and amikacin sulphate) and initiation of treatment with ceftiofur and ampicillin. The importance of combining knowledge of veterinary pharmacology and microbiology so that appropriate antimicrobials may be selected with regard to the local environment in which they are to eradicate infection is emphasised. Despite frequent reference to amikacin sulphate as an effective antimicrobial for treating infections in foals caused by Salmonella, factors are discussed that explain why amikacin may not be clinically effective for treating infectious arthritis caused by Salmonella.     

Spontaneous oesophageal perforation secondary to idiopathic muscular hypertrophy of the oesophagus

Idiopathic muscular hypertrophy of the oesophagus (IMHO) is reported in equids as an incidental post mortem finding, infrequently associated with clinical signs of oesophageal dysfunction or additional oesophageal abnormalities. Clinicopathological and post mortem findings are presented from a 15‐year‐old gelding that developed a spontaneous perforation of the distal, intrathoracic oesophagus, in association with IMHO. The majority of oesophageal perforations documented in the equine literature have been related to external or iatrogenic trauma resulting in rupture of the cervical portion of the oesophagus. In this case, the early presenting features included pyrexia and inappetance, and progressed over a 4 day period to include signs of tachypnoea, tachycardia and endotoxaemia due to the development of a fatal septic pleuritis and pleural effusion. Oesophageal obstruction was not a presenting feature. Diagnostic investigation in cases of unexplained septic pleural effusion should include oesophageal endoscopic evaluation to rule out perforation of the intrathoracic oesophagus. IMHO may represent a clinically significant, primary disease entity with the potential to lead to oesophageal perforation.     

Aortic rupture and aorto‐pulmonary fistulation in the Friesian horse: Characterisation of the clinical and gross post mortem findings in 24 cases

Reasons for performing study: In horses, aortic sinus of Valsalva aneurysms or tears in the aortic root are well‐recognised conditions in breeding stallions, often leading to sudden death. A more uncommon form of aortic rupture, located proximal to the ligamentum arteriosum has been reported in 3 Friesian horses. Objectives: The purpose of this study was to phenotypically characterise aortic rupture and aorto‐pulmonary fistulation in Friesian horses in terms of clinical and post mortem data based on 24 cases. Methods: Friesian horses that were diagnosed with aortic rupture and aorto‐pulmonary fistulation over a period of 13 years (1997–2010) at the Department of Equine Sciences of Utrecht University (n = 15) and Wolvega Equine Hospital (n = 9), were included in this study. Case history, results of clinical examination and gross post mortem findings were screened and analysed. Results: Some cases were found dead without prior symptoms, but in several cases signs such as recurrent colic, peripheral oedema and sustained tachycardia were present for several weeks prior to cardiac failure. Clinical examination during hospitalisation revealed increased rectal temperature, peripheral oedema and increased jugular pulse with a bounding arterial pulse. In the majority of horses an aortic rupture of the aortic arch near the ligamentum arteriosum, concurrent with a circumferential cuff of perivascular haemorrhage and aorto‐pulmonary fistulation, was found at post mortem examination. Conclusions: Aorto‐pulmonary fistulation in conjunction with aortic rupture is more common in Friesians than previously estimated. In some cases findings demonstrate a progressive pathology rather than acute cardiac failure and sudden death. An appropriate approach is necessary during post mortem examination of the heart in order not to overlook the diagnosis. Potential relevance: Equine practitioners should realise that in Friesian horses presented with a history of recurrent false colic, coughing, sustained tachycardia and/or peripheral oedema, aortic rupture and aorto‐pulmonary fistulation should be included in the differential diagnosis.     

Septic fibrinous pericarditis in a cocker spaniel

A four-year-old cocker spaniel presented with cardiac tamponade due to a pericardial effusion, in addition to pyrexia and peripheral neutrophilia and a recent history of chest trauma. Cytological examination of the pericardial effusion revealed a predominant neutrophilia. The echocardiographic findings were of numerous hyperechoic densities in the pericardial space, due to fibrin, with concurrent thickening and distortion of the pericardium. Postmortem examination, including microbiology, revealed the presence of organising septic fibrinous pericarditis associated with a mixed infection of Streptococcus canis, Citrobacter species, Pseudomonas species and alpha-haemolytic streptococci.     

Septic arthritis of the first and second cervical vertebral articulations with vertebral osteomyelitis in a foal caused by Salmonella

A case of infectious arthritis of a cervical vertebral articulation and vertebral osteomyelitis in a foal caused by Salmonella is described. Ultrasound images of the cervical facet joints were suggestive of septic arthritis and ultrasound facilitated needle placement for arthrocentesis and joint lavage. Due to the uncommon location of the infection, diagnosis of septic arthritis was not immediate and, despite aggressive intra‐articular lavage and instillation of appropriate intra‐articular antibiotics after hospitalisation, we were unable to resolve the infection in this foal. Radiographs did not show evidence of osseous involvement until later in the course of the infection. Septic arthritis should be suspected in cases with similar clinical and laboratory findings and radiographic changes may not be present early in the course of infection. Ultrasound imaging provided the most useful diagnostic information regarding infection of the cervical joints, facilitating both diagnosis and treatment.     

Common variable immunodeficiency in a horse with chronic peritonitis

This report describes the clinical progression of a Quarter Horse filly with common variable immunodeficiency (CVID). Equine CVID is a primary immunodeficiency in which affected animals are unable to mount an appropriate antibody response and suffer recurrent bacterial infections. The filly in this report had a history of chronic respiratory tract infections but presented for assessment of poor weight gain and was diagnosed with Actinobacillus equuli peritonitis.     

Recurrent colics in a 9‐year‐old Arabian stallion due to several congenital anomalies

A 9‐year‐old Arabian stallion was presented for evaluation of recurrent colic problems of 2 years' duration. These colic episodes were associated with a right sided abdominal distension. An exploratory laparotomy revealed a colonic diverticulum that was resected en bloc. Two days later, following signs of acute colic, a second laparotomy showed incarceration of the distal jejunum into a mesodiverticular band combined with haemorrhage of a mesenteric arterial branch. In addition, an abnormally short jejunum (10 m) was also observed. An end‐to‐end jejunojejunostomy was performed. Following surgery the horse developed septic peritonitis, ptyalism and became dysphagic. Ten days after the second surgery, an infected oesophageal diverticulum causing regional inflammation was diagnosed endoscopically and euthanasia was performed. Post mortem examination showed a 40 cm long diverticulum lateral to the oesophagus. Histology suggested a congenital nature of the colonic and oesophageal diverticuli.     

Two-dimensional echocardiographically guided pericardiocentesis in a horse with traumatic pericarditis

Two-dimensional echocardiographic (2DE) examination was performed on a horse with clinical signs of pericardial effusion. Thickening of the pericardium, excess amount of pericardial fluid, elevation of the cardiac apex, and right ventricular compression, characteristic of cardiac tamponade, could be seen on 2DE recordings. Fibrinous pericarditis was suspected by observation of fibrinous strands in the pericardial fluid and epicardial fibrin deposits. Echocardiographically guided pericardiocentesis was performed, and 4 L of fluid was removed from the pericardial sac. Streptococcus zooepidemicus was isolated from the fluid. Pericardiocentesis was repeated for 3 days, and medication was administered. Despite temporary improvement in cardiac function, the horse's condition deteriorated gradually, and euthanasia was performed on the ninth day of hospitalization. Necropsy revealed chronic serofibrinous pericarditis of traumatic origin, attributable to an intercostal stab wound entering the pericardium and the apical portion of the myocardium.     

Carcinoma of an accessory genital gland in a 23‐year‐old Camargue gelding

This report describes the case management, histopathological and post mortem findings in a 23‐year‐old gelding with a peri‐rectal mass. The mass was debulked surgically and submitted samples revealed it to be a poorly differentiated carcinoma. In the post operative period the horse developed signs of abdominal pain and dysuria and was subjected to euthanasia. Post mortem examination revealed a large infiltrative mass located between the rectum and urethra, consistent with a carcinoma of an accessory genital gland, most likely the seminal vesicle.     

An unusual cause of colic in a neonatal foal

A case of a neonatal foal with acute colic and respiratory distress is described. The foal presented with signs of acute colic and was treated medically. The foal did not respond to treatment and 2 h after admission the foal began to demonstrate signs of respiratory distress. Thoracic and abdominal radiographs were obtained and a diagnosis of a diaphragmatic hernia was made. Surgical repair of the hernia was recommended but the owner declined and the foal was subjected to euthanasia. Post mortem findings confirmed the diagnosis and revealed that the defect was of congenital origin. Congenital diaphragmatic hernia is an unusual cause of colic in a neonatal foal.     

Treatment of cardiovascular disease in cattle.

Cardiac diseases of cattle may involve valvular structures, myocardium, pericardium, or blood vessels and are manifested by the clinical signs of cardiac dysrhythmias, cardiac murmurs, generalized edema, muffled heart sounds, jugular venous distention, jugular venous pulsations, pulmonary edema, pleural effusion, or ascites. Digoxin, quinidine, and furosemide can be used effectively to control signs of CHF and cardiac arrhythmias. Combination antimicrobial therapy can be successful for cows with infective endocarditis and thrombophlebitis. Pericardial fluid drainage may temporarily improve cattle with traumatic pericarditis or lymphosarcoma so that short-term goals may be reached.     

Idiopathic pericarditis and cardiac tamponade in two cows

Idiopathic pericarditis is an uncommon diagnosis in cattle with cardiac tamponade. Two cows were examined for clinical signs of right-sided congestive heart failure, including tachycardia, venous distention, and peripheral edema. Muffled heart sounds were detected in one of the cows. Echocardiography in both cows revealed voluminous anechoic pericardial effusion and compression of the right atrium and right ventricle. Cytologic analysis of the pericardial fluid revealed hemorrhagic inflammation but no evidence of a septic or neoplastic condition such as traumatic reticulopericarditis or lymphoma, respectively. Pericardial drainage and lavage accompanied by treatment with anti-inflammatory drugs were curative in both cows. It is important to differentiate cows with idiopathic pericarditis from cows with more common septic pericarditis because the prognosis for the former disease appears to be good with appropriate treatment.     

Cervical vertebral osteomyelitis in a 4‐month‐old foal

Vertebral body osteomyelitis in the cervical spine secondary to Rhodococcus equi has been treated both medically and surgically. This Case Report describes a 4‐month‐old foal exhibiting severe neurological signs from R. equi vertebral body osteomyelitis. Rapid, significant resolvement of neurological signs was noted in this case with surgical debridement and use of synthetic bone filler. The outcome suggests that aggressive surgical therapy in conjunction with synthetic allograft may be indicated in treatment of cervical vertebral body osteomyelitis.     

Bullous emphysema with haemorrhage in a premature foal

A Warmblood foal was admitted at one day of age because of prematurity and seizures. Clinical and clinical pathology abnormalities were consistent with prematurity and suspected hypoxic seizures that responded to anti‐convulsive therapy. The foal stabilised after several days of intensive care but then developed an airway infection. Thoracic radiographs showed multiple cavitary lesions and ultrasound examination suggested intra‐cavital haemorrhage. The foal went on to develop septicaemia and was subjected to euthanasia. Post mortem examination revealed multiple bullous emphysema with haemorrhage. This disorder should be considered in the differential diagnosis of foals having air‐fluid filled cavities on thoracic radiographs.     

Cervical vertebral anomaly and ventricular septal defect in an Arabian foal

A male Arabian foal born with a cervical mass and no apparent clinical signs presented with a cervical vertebral anomaly and ventricular septal defect. Both congenital anomalies were diagnosed at age 3 weeks and rechecked at age 6 months with radiographs and ultrasonographic studies respectively. At 11 months, in addition to radiographs and Doppler ultrasonographic studies, a contrast ultrasonographic study and post mortem myelographic and computed tomographic studies of the cervical vertebral column revealed the appearance of this rare cervical vertebral anomaly and the severity of the ventricular septal defect. To the authors' knowledge, in the Arabian foal, both conditions have not been reported simultaneously in the same patient.     

Severe hyperkalaemia associated with renal dysplasia in a 2-day-old foal

A 2-day-old filly foal presented with signs of depression, recumbency and inappetence. Blood analyses revealed hypoalbuminaemia, hyperfibrinogenaemia, hyperglycaemia and hyperkalaemia. The foal deteriorated despite intensive treatment and was subjected to euthanasia. At post mortem examination, the urinary bladder, ureters and kidneys appeared normal grossly. Histologically both kidneys showed disorganised development with the presence of structures inappropriate for a foal of this age, including primitive glomeruli, immature renal tubules and persistent metanephric ducts. Based on these findings a diagnosis of bilateral renal dysplasia was made.     

Equine laryngeal dysplasia as a cause of acute respiratory distress in a neonatal foal

Equine laryngeal dysplasia (ELD) is a congenital disorder caused by hypoplasia or aplasia of the structures derived from the fourth and possibly sixth branchial arches. The severity of the clinical signs varies widely, and depends on which structures are involved and the extent of the defect. In most cases, affected horses present with abnormal respiratory noise during exercise and poor performance. Manifestation of the disease in foals is very rare. This case report describes an unusual presentation of ELD in a neonatal foal. The foal presented with severe respiratory distress and weakness. Equine laryngeal dysplasia was suspected on endoscopy and later confirmed on post mortem examination of the larynx. To the best of our knowledge, this is the first report describing ELD as a cause of respiratory distress in a neonatal foal.     

Case Report: Sequelae of traumatic reticuloperitonitis in a Friesian dairy cow

Abstract

CASE HISTORY: A 10-year-old Friesian dairy cow presented with a history of weight loss, decreased milk production and fluid splashing on auscultation of the heart. Previous antibiotic therapy included oxytetracycline, marbofloxacin and penicillin.

CLINICAL AND PATHOLOGICAL FINDINGS: Following a failure to respond to treatment, prescribed by the referring veterinarian for respiratory infection and septic arthritis, the cow was referred to Massey University Veterinary Teaching Hospital with suspected pericarditis. Clinical examination identified a predominantly left sided holodiastolic heart murmur with tachycardia and cording of the jugular veins. Cardiac ultrasound showed an enlarged aortic valve with turbulent blood flow and regurgitation, consistent with bacterial endocarditis. Blood culture demonstrated Paenibacillus spp. Due to the severity of the clinical signs and poor prognosis, euthanasia was performed and a post-mortem examination carried out.

DIAGNOSIS: Traumatic reticuloperitonitis with abscessation of the reticulum and rumen wall, which progressed to a bacteraemia and presumptively caused endocarditis, endometritis, septic arthritis, and renal and myocardial infarcts due to emboli from the endocarditis lesions.

CLINICAL RELEVANCE: New Zealand dairy cattle are at risk of traumatic reticuloperitonitis and due to varying presentations diagnosis can be complicated. Subsequent bacteraemia is common and in this case the novel bacterial species Paenibacillus was implicated as a potential pathogen.