Double-outlet right ventricle in a 10-month-old Friesian filly

A 10-month-old Friesian filly had a presentation that was consistent with chronic left- and right-sided congestive heart failure. Clinical pathology findings included abnormal haematological and biochemical variables, abnormal blood gas values and increased serum concentration of cardiac troponin I. Echocardiography revealed cardiac chamber dilation and dextropositioning of the aorta. Radiography revealed a generally enlarged heart and pulmonary interstitial infiltration. These findings were supported at necropsy and the diagnosis of double-outlet right ventricle was confirmed. The pathological changes and physiological responses subsequent to double-outlet right ventricle have not previously been described in detail in horses. Clinical progression closely resembles that seen in humans, in whom antemortem diagnosis relies on echocardiography. In horses, complex cardiac disease presents a diagnostic challenge to the clinician. Appropriate therapy must be based on an accurate diagnosis.     

Double-outlet right ventricle with an intact interventricular septum and concurrent hypoplastic left ventricle in a calf

A 3-day-old Hereford heifer calf presented for evaluation of lethargy and dyspnea, with persistent hypoxia despite supplemental oxygen therapy. A grade III/VI right apical systolic murmur was noted during cardiac auscultation. Echocardiography revealed a double-outlet right ventricle with an intact interventricular septum and concurrent hypoplastic left ventricle and tricuspid valve dysplasia. Post-mortem examination revealed additional congenital anomalies of ductus arteriosus, patent foramen ovale, and persistent left cranial vena cava. This report illustrates the use of echocardiographic images to diagnose a double-outlet right ventricle with an intact interventricular septum and a hypoplastic left ventricle in a calf.     

Double aortic arch in a Siamese cat.

A double aortic arch is described in an 8-week-old female Siamese cat. In this case a vascular ring anomaly consistent with a double aortic arch is described in a cat. Stridor and dysphagia were noted in the cat. Radiography showed an esophageal dilation, with constriction at the fifth intercostal space. At necropsy, the esophagus and trachea were constricted at the base of the heart. The cause of the constriction of both the esophagus and trachea was a vascular ring formed by well-developed right and left aortic arches. The ascending aorta divided into two asymmetrical arches. The right aortic arch was larger than the left. The origin of the major arteries from the aortic arches were anomalous.     

Hypoplastic left ventricular syndrome in a foal

A necropsy diagnosis of hypoplastic left ventricular syndrome was made in a day-old foal. The cardiac abnormalities included mitral and aortic valve atresia, patent ductus arteriosus, and a secundum atrial septal defect. The left ventricle was hypoplastic and nonfunctional. The brief survival of the foal was a consequence of left-to-right shunting through the atrial septal defect and right-to-left shunting through the patent ductus. The information is presented to demonstrate the existence of the syndrome as a congenital defect in the horse and to clarify the necropsy findings for the practitioner to diagnose if seen.     

Double aortic arch in a dog

Vascular ring anomalies are developmental anomalies of the thoracic great vessels resulting in complete or partial encircling of the esophagus and the trachea by a vascular ring formation. Persistent right aortic arch with left ligamentum arteriosum accounts for 95% of vascular ring anomalies in dogs. The dog in this report had a double aortic arch, which is a type 4 vascular ring anomaly. Double aortic arch is a rare congenital heart defect resulting from the improper development of the embryonic arches. The prognosis for dogs that have undergone surgery for correction of double aortic arches is generally regarded as poor. The dog in this report underwent surgery for correction of double aortic arches and recovered without dilation or motility disorders of the esophagus. Results indicate that small animals that undergo early surgical correction of double aortic arches with relief of esophageal constriction can have a good prognosis. To the authors' knowledge, there have been no previous reports of dogs that have survived long enough to be discharged from the hospital after surgical correction of double aortic arches.     

Symmetrical double aortic arch in a beagle puppy

Double aortic arch denotes the persistence of both fourth aortic arches and has been reported as 'very rare' in the dog. Most reported cases have been seen in German shepherd dogs. An eight-week-old, male, 1.5-kg beagle presented with a three-week history of regurgitation and dyspnoea. A barium oesophagram showed severe oesophageal constriction cranial to the base of the heart, and a provisional diagnosis of a persistent right aortic arch was made. A left-sided fourth intercostal thoracotomy was performed. The ligamentum arteriosum was ligated and divided. The oesophagus was seen lying on the right-hand side of the aorta. Postoperatively, the puppy deteriorated and was euthanized. Postmortem revealed a double aortic arch entrapping both the oesophagus and trachea. The inexperienced surgeon could consider computed tomography or angiography to determine the exact vascular ring, and other possible concurrent vascular anomalies present, before surgery.     

羊脑包虫病CT、MRI影像特征

本研究旨在观察羊脑包虫病CT、MRI的特征性影像学表现。选择3只表现出脑包虫病典型症状的新疆细毛羊进行神经学检查及血常规、血清生化检查。对其中2只羊头部进行CT和MRI扫查。最后进行病理剖检,观察病理解剖变化。动物神经学检查发现动物出现眼球震颤,双侧眼睑反射、角膜反射减弱,动物的翻正反应、双侧独轮车反应存在异常;血常规和血清生化检查结果无明显异常;CT影像可见颅内数量不等囊性低密度影,内部CT值与脑脊液相近,边界清晰,有占位效应,囊壁分布大量点状中等到高密度的原头节影像,其余脑组织未见明显异常密度影像。MRI影像可见颅内数量不等囊性病灶,T1WI低信号,T2WI高信号,与脑脊液信号相近,可见沿囊壁分布大量点状T1等信号,T2低信号的原头节影像,病灶周围未见明显异常信号。病理剖检可见充满澄清囊液的寄生虫包囊,内含有数量不等的原头节。寄生虫包囊位置与影像学检查结果一致。结果说明羊脑包虫病具有特征性的CT和MRI影像学表现,影像学诊断方法可准确定位寄生虫包囊数量和位置,显示病灶累及周围组织的情况,有助于手术治疗计划的制定。     

TWO-DIMENSIONAL ECHOCARDIOGRAPHIC ANATOMY OF THE SNAKE HEART (PYTHON MOLURUS BIVITTATUS)

Two-dimensional echocardiography was performed on Burmese pythons (Python molurus bivittatus) to determine an optimal echocardiographic imaging technique for snakes and to describe the echocardiographic anatomy of the snake heart. Five snakes immobilized with tiletamine/zolazepam and maintained on isoflurane in oxygen were imaged in dorsal recumbency. The portion of the snake's body containing the heart was submerged in warm water to reduce the artifact created by air trapped between and under the scales. Imaging in sagittal planes demonstrated the caudal vena cava, sinus venous valve, right atrium, various portions of the ventricle, horizontal septum, the left aortic arch, and pulmonary artery. Transverse imaging depicted the spatial relationship of the left and right aortic arches and pulmonary artery and the horizontal septum. Basic knowledge of cardiac blood flow in the reptile was necessary to understand the echocardiographic anatomy.     

Echocardiographic evaluation of equine aortic insufficiency

Echocardiographic evaluation of 23 horses with aortic insufficiency was performed, using M-mode (n = 23) and 2-dimensional real-time echocardiography (n = 14 of 23). Echocardiograms were evaluated for abnormalities of aortic and mitral valves and alterations in motion of these valves. Changes in left ventricular chamber size and function, as well as aortic root size, were evaluated. The presence of other cardiac disease was also evaluated. Horses with aortic insufficiency had significant increases (P less than 0.01) in mean values of left ventricular chamber size, aortic root diameter, and shortening fraction. Left ventricular free wall thickness also was significantly decreased (P less than 0.01). Valvular abnormalities were seen echocardiographically in all 23 horses. Eighteen horses with aortic insufficiency had thickened valves, whereas two horses had lesions associated with vegetative endocarditis. High-frequency vibrations of the septal leaflet of the mitral valve were noticed in all horses, whereas similar vibrations of the aortic valve were seen in six horses. The presence of a bounding arterial pulse correlated significantly (P less than 0.05) with increased left ventricular chamber size at end diastole and shortening fraction, indicating a marked left ventricular volume overload. A reliable diagnosis of aortic insufficiency can be made with the detection of bounding arterial pulses in concert with a holodiastolic decrescendo grade II to V/V murmur with maximal intensity over the aortic valve area, radiating toward the left cardiac apex.     

Vascular Ring Anomalies: Case Report and Brief Review

During early fetal life six pair of aortic arches surround the esophagus and trachea. Normal maturation and selective regression of these structures form the adult vasculature. Abnormal location or development of the aortic arches may result in pressure on adjacent organs.Vascular ring anomalies must be considered with any patient with a history of regurgitating food shortly after eating. Physical examination, test feedings, survey and contrast radiographs may give an accurate impression of the problem but a final diagnosis can only be made following surgical exploration. In the case presented, the dog had all the clinical and diagnostic signs suggestive of a vascular ring anomaly. Thoracotomy and elimination of the vascular constriction around the esophagus was both diagnostic and therapeutic for the condition. It is important that owners be made aware that surgical correction of the stenosis does not guarantee a successful conclusion to the case. If the dilation of the esophagus cranial to the stenosis is severe, accumulation of food with subsequent regurgitation may persist. A dilation of the esophagus caudal to the stenosis is present in a large percentage of cases and this also may result in an unrelenting problem. Unfortunately, the probability of these complications cannot be accurately evaluated prior to treatment.The hereditary potential for this defect must also be considered. Congenital vascular anomalies such as patent ductus arteriosus would seem to have a hereditary basis. Therefore, it is probably correct to advise against breeding affected animals. Further, the inbreeding of nonaffected animals which come from litters containing affected animals should be avoided.     

Double aortic arch in a dog (Canis familiaris): a case report

We herein report a case of a double aortic arch in a 10-week-old male dog of no defined race, which presented episodes of regurgitation at the time of weaning. This vascular malformation was characterized by the persistence of two aortic arches, right and left, of varying dimensions. The right aortic arch was observed to be larger. During post mortem examination the vessels of the animal were injected with coloured latex bi-centrifuged CIS 1-4 polisopreno which revealed the patency of the two aortic arches. Concomitantly, dilation of the cranial oesophagus causing constriction was observed, indicating megaesophagus. Apart from the constriction, the oesophagus presented normal morphometric parameters in relation to its dimensions.     

Experimental transmission of abnormal prion protein (PrPsc) in the small intestinal epithelial cells of neonatal mice

Using an immunohistochemical method, we attempted to detect the transmission of abnormal prion protein (PrPsc) to the enterocytes of the small intestine of neonatal mice by oral exposure with sheep brain affected by scrapie. Five 1-day-old neonatal mice were exposed by oral inoculation to the homogenized brain of a scrapie-affected sheep. In the small intestine of all mice 1 hour after inoculation, immunoreactivity with antinormal prion protein (PrPc) antibody was seen in the cytoplasm of villus enterocytes. This finding suggests transmission of abnormal PrPsc into the cytoplasm of enterocytes. In control mice treated with normal sheep brain, no PrPc signal was seen in enterocytes of the small intestine. Immunopositivity for neurofilament protein and glial fibrillary acidic protein was seen in the cytoplasm of enterocytes of mice inoculated with scrapie and normal sheep brain. This suggests that the enterocytes of neonatal mice can absorb PrPsc and other macromolecular proteins of the sheep brain affected by scrapie and may be more important than previously thought as a pathway for PrPsc transmission in neonatal animals.     

Review paper: a review of the pathology of abnormal placentae of somatic cell nuclear transfer clone pregnancies in cattle, sheep, and mice

Cloning of cattle, sheep, and mice by somatic cell nuclear transfer (SCNT) can result in apparently healthy offspring, but the probability of a successful and complete pregnancy is less than 5%. Failures of SCNT pregnancy are associated with placental abnormalities, such as placentomegaly, reduced vascularisation, hypoplasia of trophoblastic epithelium, and altered basement membrane. The pathogenesis of these changes is poorly understood, but current evidence implicates aberrant reprogramming of donor nuclei by the recipient oocyte cytoplast, resulting in epigenetic modifications of key regulatory genes essential for normal placental development. The purpose of this review is to provide an overview of the anatomic pathology of abnormal placentae of SCNT clones and to summarize current knowledge concerning underlying pathogenetic mechanisms.     

Specific features of echocardiographic examination in ophidians

Echocardiography in ophidians shows several particularities, directly due to the anatomical features of their cardiovascular system: two aortic arches (instead of one in mammals), one single ventricle (instead of two), two cranial venae cavae (instead of one), and also one supplementary tubular cavity called sinus venosus, which proceeds into the right atrium at the sino-atrial opening. Ultrasound examination using a ventral and an intercostal approach allows a good visualisation of these cardiac structures in short and long axis. The main purpose of this technique is to establish the ante-mortem diagnosis of heart diseases, such as endocarditis and myocarditis.     

以山羊痘疫苗免疫绵羊防制绵羊痘的报告

1988年3～8月间,在张家口地区进行了以山羊痘疫苗免疫绵羊,防制绵羊痘的实际应用。对109个疫点及其受威胁区的337061只绵羊,注射了山羊痘疫苗,取得了良好效果。对改良细毛羊、纯种细毛羊及哺乳羔羊,都很安全,无不良反应;注苗羊获得保护,免疫效果确实,疫情于注苗后5～10日被控制。     

Surgical treatment of a double aortic arch in a dog

An 8-month-old spayed female Labrador retriever dog was evaluated for regurgitation 6 months after surgery for a suspected vascular ring anomaly. The dog had a history of regurgitation and slow development as a puppy. An initial left-sided exploratory thoracotomy was unsuccessful in identifying and treating a vascular ring anomaly. The dog was subsequently presented to the PennVet Emergency Service for regurgitation. Thoracic radiography showed cranial thoracic esophageal dilation and an esophageal foreign body that was then removed endoscopically. Subsequent computed tomographic (CT) angiography revealed a double aortic arch. A left 4th intercostal space thoracotomy was performed. The smaller left aortic arch and a left ligamentum arteriosum were ligated and transected. The dog recovered uneventfully and was healthy at the 1-month follow-up visit. This is the 5th reported successful surgical correction of a double aortic arch in a dog. Computed tomographic angiography was essential in diagnosis and surgical planning.Key clinical message:Although uncommon, double aortic arches can occur and present a diagnostic and surgical challenge when a persistent right aortic arch is suspected. Computed tomographic angiography provides an accurate preoperative diagnosis and allows for surgical planning.     

Double-outlet right ventricle associated with discordant atrioventricular connection and dextrocardia in a cat

The prevalence of congenital cardiac disease in cats varies from 0.2 to 1 per cent, with males being more affected than females. This is probably an underestimate due to the fact that not all affected kittens are presented. Discordant atrioventricular connection (where the morphological right atrium connects to the morphological left ventricle, and the morphological left atrium connects to the morphological right ventricle) is an uncommon condition in humans and, to the authors' knowledge, has not to date been described in animals. The association between this anomaly and the double-outlet right ventricle (where both great arteries arise entirely or partially from the morphological right ventricle) is extremely rare in children. This report describes a case of a cat which presented with this association of cardiac defects.     

Lobar holoprosencephaly in a Miniature Schnauzer with hypodipsic hypernatremia

A 9-month-old male Miniature Schnauzer was examined because of a lifelong history of behavioral abnormalities, including hypodipsia. Diagnostic evaluation revealed marked hypernatremia and a single forebrain ventricle. The behavioral abnormalities did not resolve with correction of the hypernatremia, and the dog was euthanatized. At necropsy, midline forebrain structures were absent or reduced in size, and normally paired forebrain structures were incompletely separated. Findings were diagnostic for holoprosencephaly, a potentially genetic disorder and the likely cause of the hypodipsia. Similar evaluation of affected Miniature Schnauzer dogs may reveal whether holoprosencephaly routinely underlies the thirst deficiency that may be seen in dogs of this breed.     

Echocardiographic parameters in 14 healthy English Bull Terriers

OBJECTIVE: To determine the range of various cardiac parameters using echocardiography in apparently normal, healthy English Bull Terriers. DESIGN: Fourteen English Bull Terriers were selected for study. Cardiac auscultation of the parents of these dogs was normal. Echocardiographic examination of one parent of each animal showed: no mitral or aortic valve abnormalities; no myocardial lesions; no two dimensional evidence of fixed or dynamic left ventricular outflow tract obstruction; and no systolic aortic or left ventricular outflow tract turbulence on colour flow Doppler examination. The 14 selected dogs did not have arrhythmias or murmurs, and on echocardiographic examination had similar findings to their parents. Systolic blood pressure was measured in all dogs and they had no clinical evidence of Bull Terrier polycystic kidney disease or Bull Terrier hereditary nephritis. PROCEDURE: All dogs were auscultated and subjected to a sequential global echocardiographic assessment of the heart, including two dimensional long and short axis, and colour flow Doppler interrogation of the mitral and aortic valves. Dimensional measurements, including those from the left atrium, aortic annulus and left ventricle, were taken from a right parasternal window, and derived values such as fractional shortening, stroke volume and left atrial to aortic annulus ratio were calculated. Peak systolic aortic velocity was measured from the left parasternal window using two dimensional-guided pulsed wave Doppler with angle correction. Systolic blood pressure was measured using a Doppler monitor. The absence of Bull Terrier polycystic kidney disease was determined using renal ultrasonography, and of Bull Terrier hereditary nephritis using urinary protein to creatinine ratio. RESULTS: These 14 dogs had greater left ventricular wall thickness and smaller aortic root diameters than those reported as normal for other breeds of comparable body size. Left atrial dimensions were also larger, however this may have been due to the "maximising" method of measurement. These apparently normal English Bull Terriers also had higher aortic velocities than those reported for other breeds, possibly due to a smaller aortic root diameter or other anatomic substrate of the left ventricular outflow tract, lower systemic vascular resistance, or breed-specific "normal" left ventricular hypertrophy. While these dogs were selected to be as close to normal as possible, the breed may have a particular anatomy that produces abnormal left ventricular echocardiographic parameters. CONCLUSION: These echocardiographic parameters may be used to diagnose left ventricular outflow tract obstruction and left ventricular hypertrophy, and inaccurate diagnoses may result if breed-specific values are not used.