Diagnosis of right coronary artery to right atrial fistula in a dog using two-dimensional echocardiography

A five-year-old boxer dog developed cardiac murmurs, complete heart block and car-diomegaly associated with vegetative bacterial endocarditis. Using two-dimensional echocardiography, vegetative lesions of the aortic valves and extension of the vegetations into the proximal right coronary artery and adjacent atrial septum were identified. The vegetation within the atrial septum appeared as a cavitated mass which protruded into the right atrium. Fistulae within the atrial septal vegetation permitting communication between the coronary artery and right atrium were observed with colour Doppler echocardiography. The dog died despite medical treatment. Post mortem examination confirmed the echo-cardiographic findings. Vegetative endocarditis with invasion into the right coronary artery and atrial septum producing fistulae and communication with the right atrium has not been reported previously in dogs. Doppler echocardiography proved useful in demonstrating the abnormal anatomy, intraluminal fistular blood flow and its communication with the right atrium.     

Echocardiographic diagnosis of an anomaly of the tricuspid valve in a male pygmy goat.

A 3-year-old male pygmy goat was evaluated because of a grade III/V plateau pansystolic murmur that was auscultated over the tricuspid valve area and a grade II/V plateau pansystolic murmur that was auscultated over the left heart base. Echocardiography revealed a large right atrium and ventricle, an atrial septal defect, and a dysplastic tricuspid valve displaced apically into the right ventricle. Contrast echocardiography and color-flow Doppler echocardiography revealed flow from right to left through the atrial septal defect and severe tricuspid regurgitation. A diagnosis of tricuspid valve dysplasia and severe tricuspid regurgitation was made. This anomaly (Ebstein's anomaly) of the tricuspid valve should be considered in goats that have systolic, with or without diastolic, murmurs over the tricuspic valve. Two-dimensional echocardiography can confirm the diagnosis of the anomaly. The associated tricuspid regurgitation and interatrial right-to-left shunt flow can be detected and semiquantitated by use of contrast, continuous wave, and color-flow Doppler echocardiography.     

TWO-DIMENSIONAL ECHOCARDIOGRAPHY IN THE NORMAL CAT

Two-dimensional echocardiography (2DE) and M-mode echocardiography were used to image the heart of 13 clinically healthy cats. Seven awake cats and six cats tranquilized with a combination of acetylpromazine and ketamine were studied. Six cats were studied by 2DE on 3 consecutive days to assess repeatability of the study. Long-axis and short-axis echocardiographic tomograms were obtained from the right parasternal location, and these images were used to determine internal cardiac dimensions, ventricular and septal wall thicknesses, repeatability of the study, and interobserver variability. Some but not all parameters were significantly (P < 0.05) related to body weight. Significant correlations (P <0.05) were found between measurements obtained by long-axis and by short-axis image planes. Comparison of parameters measured by 2DE and M-mode echocardiography demonstrated minimal differences between mean values. Repeatability of the 2DE study was good with 14 of 16 parameters having a mean percent error less than 10%. Interobserver variability was acceptable for some but not all parameters. The study indicates that repeatable 2DE tomograms can be obtained in the cat and that quantitation of cardiac anatomy is possible with this imaging technique.     

Use of tissue Doppler imaging to confirm the diagnosis of dilated cardiomyopathy in a dog with equivocal echocardiographic findings

A 1-year-old healthy female Great Dane was referred for an echocardiographic examination prior to anesthesia and surgical correction of prolapse of the right third eyelid gland. Findings of a physical examination were normal. Conventional 2-dimensional and M-mode echocardiography revealed equivocal findings of dilated cardiomyopathy (DCM). Conversely, tissue Doppler imaging revealed a dramatic decrease in systolic and early diastolic radial myocardial velocity gradients, which were related to a decrease in endocardial velocities. Four months later, the diagnosis of DCM was confirmed via conventional echocardiography. In dogs with equivocal conventional echocardiographic findings of DCM, severe myocardial alterations may be detected via tissue Doppler imaging and this technique may enable early diagnosis of radial myocardial dysfunction.     

Reversible pulmonary hypertension presenting simultaneously with an atrial septal defect and angiostrongylosis in a dog

A one-year-old female neutered beagle was presented with marked abdominal effusion. Echocardiography showed marked dilatation of the right cardiac chambers, an atrial septal defect and severe tricuspid insufficiency. Systolic pulmonary arterial pressure (sPAP), evaluated by continuous wave Doppler echocardiography, was very high (80 mmHg), with a right to left interatrial shunt. The radiographic images were compatible with widespread pneumonitis. Numerous larvae of Angiostrongylus vasorum were visible on direct faecal examination. The animal was given fenbendazole for 15 days, combined with diuretics, an antibiotic and a vasodilator. Two weeks later, the dog showed a marked improvement. The treatment, except the anthelmintic, was continued for seven weeks and then stopped. At that stage, Doppler echocardiography revealed that the sPAP had returned to normal (20 mmHg) and the interatrial shunt had reversed (left to right). Eighteen months later, clinical and Doppler echocardiographic examinations were normal.     

Paratuberculosis in a large goat herd

Paratuberculosis was studied for three years in a large goat herd. Post mortem lesions were seen mainly in the ileum and mesenteric lymph nodes where caseation was often present. In three successive years the annual faecal excretor rate was 15, 9 and 13 per cent despite removal of positives. Faecal culture and an agar gel immunodiffusion test proved useful for detecting the disease in live goats, but complement fixation and tuberculin tests were of less value. The prospects of controlling the disease are discussed.     

Noninvasive assessment of systolic left ventricular torsion by 2-dimensional speckle tracking imaging in the awake dog: repeatability, reproducibility, and comparison with tissue Doppler imaging variables

BACKGROUND: Left ventricular (LV) torsional deformation plays an important role in myocardial function. However, it has never been assessed in the awake dog, because magnetic resonance imaging and sonomicrometry have been the only methods available so far. HYPOTHESIS: Two dimensional speckle tracking echocardiography (STE), a new ultrasound imaging technique, provides a repeatable and reproducible noninvasive assessment of systolic LV wringing motion in the awake dog. ANIMALS: Six healthy dogs were used to determine the repeatability and reproducibility of STE variables (study 1). These variables also were prospectively assessed in a population of 35 healthy dogs (study 2). METHODS: Peak LV basal and apical systolic rotations were measured by STE from right parasternal short-axis views using automatic frame-to-frame tracking of gray-scale speckle patterns. Systolic LV torsion (LVtor, degrees ) was defined as apical rotation relative to the base. RESULTS: All within-day and between-day coefficients of variation were <20% (6.8-18.0%). Amplitude of apical systolic rotation was significantly higher (P < .001) than the basal value (5.4 +/- 3.2 degrees and -3.1 +/- 1.3 degrees , respectively). Global LVtor was significantly correlated with systolic longitudinal LV myocardial velocity gradient assessed by tissue Doppler (P < .05), but not with either systolic radial LV myocardial velocity gradient or the ratio of early mitral inflow velocity to early mitral annular velocity (Em/Ea). CONCLUSIONS AND CLINICAL IMPORTANCE: Speckle tracking echocardiography is a repeatable and reproducible method for assessing systolic LV torsional deformation. The combination of these new STE indices with tissue Doppler variables could provide a new approach for quantifying canine LV systolic function.     

Quantitative Analysis of Stress Echocardiograms in Healthy Horses with 2‐Dimensional (2D) Echocardiography,Anatomical M‐Mode,Tissue Doppler Imaging,and 2D Speckle Tracking

Background: Stress echocardiography is used to diagnose myocardial dysfunction in horses, but current methods are not well standardized. The influence of heart rate (HR) on measurements is largely unknown. Objectives: To investigate the use of 2‐dimensional echocardiography (2DE), anatomical M‐mode (AMM), tissue Doppler imaging (TDI), and 2D speckle tracking (2DST) at rest and after exercise for quantification of regional and global left‐ventricular (LV) function. Animals: Five athletic Warmblood horses; 11.6 ± 3.6 years; 529 ± 48 kg. Methods: Prospective study. Three separate echocardiographic examinations were performed before (baseline) and over 5 minutes after treadmill exercise with 2DE (1st, short‐axis view; 2nd, long‐axis view) and pulsed‐wave TDI (3rd examination). Offline analyses were performed at baseline and after exercise at HR 120, 110, 100, 90, and 80 minute^?1. Global and segmental measurements were compared by analysis of variance. Results: Quantitative analyses of stress echocardiograms were feasible in all horses. None of the AMM indices changed significantly after exercise. Stroke volume and ejection fraction by 2DE and strain by 2DST decreased, whereas strain rate by 2DST increased significantly at HR > 100 minute^?1. TDI analyses were technically difficult and provided little additional information. Conclusions and Clinical Importance: Volumetric indices by 2DE and strain and strain rate by 2DST are applicable for quantitative assessment of stress echocardiograms. In healthy horses, they are significantly altered at a HR > 100 minute^?1 and need to be evaluated in view of the instantaneous HR. Further investigations are needed to define the clinical value of stress echocardiography in horses with cardiac disease.     

Clinical, echocardiographic, and Doppler imaging characteristics of mitral valve stenosis in two dogs.

Mitral stenosis was diagnosed noninvasively by echocardiography and Doppler imaging in 2 Bull Terriers. Two-dimensional echocardiography revealed severe atrial and moderate left ventricular dilatation; severely reduced mitral valve opening excursion; doming of the cranial mitral valve leaflet into the left ventricle during diastole; thickened, nodular cranial mitral valve leaflets; and reduced mitral valve orifice. M-mode echocardiographic findings additionally indicated greatly diminished mitral valve E to F slope and abnormal caudal mitral valve leaflet motion. Color flow Doppler imaging revealed bright bursts of color with aliasing originating from the stenotic mitral valve orifice, extending into the left atrium during systole, and into the left atrium during diastole. Spectral Doppler recordings revealed transvalvular mitral valve gradients and prolonged pressure half-times. Necropsy performed on 1 dog revealed extremely thickened, nodular, and stiff mitral valves with short, thickened, and fused chordae tendineae. The diagnosis of mitral valve stenosis was easily facilitated with diagnostic ultrasonography.     

Echocardiographic evaluation including tissue Doppler imaging in New Zealand white rabbits sedated with ketamine and midazolam

Limited data are available on the use of more recent echocardiographic parameters in the rabbit. Echocardiographic examination, including conventional echocardiography and tissue Doppler imaging (TDI), was performed on 26 male New Zealand white rabbits under ketamine–midazolam sedation. Particular emphasis was placed on the more recent systolic and diastolic parameters, such as myocardial performance index (Tei index) and mitral annular motion (from septal and lateral sides of the left ventricle) obtained using pulsed TDI.Parameters that assessed systolic and diastolic function (fractional shortening, Tei index, and maximal mitral E- and A-wave velocities) were comparable to those reported in the literature for rabbits in the awake state. The less cardiodepressive anaesthetic protocol could offer a good alternative in performing echocardiographic evaluation whenever such caution is necessary. TDI is feasible in healthy rabbits and potentially suitable for the investigation of left ventricle systolic and diastolic function.     

Advances in echocardiography

Before the development of echocardiography, cardiac disease in the horse was diagnosed if a loud heart murmur (grade III-IV/VI or louder) and clinical signs of congestive heart failure (coughing, edema, venous distention, jugular pulsations) were detected on physical examination. Arrhythmias that persisted during and after exercise also indicated cardiac disease, which could be characterized electrocardiographically. Electrocardiography, thoracic radiography, angiography, cardiac catheterization, and oximetry could add only small pieces of information about the heart. M-mode echocardiography provided the first "window" with which to evaluate the heart and its intracardiac structures, albeit an ice-pick one-dimensional view. With M-mode echocardiography, the diameter of the aorta at the valves, the left ventricle, right ventricle, and left atrial appendage, as well as the thickness of the interventricular septum and left ventricular free wall, could be measured. Motion and thickness of the tricuspid, mitral, and aortic valves could be assessed, but only in a one-dimensional plane. Two-dimensional echocardiography provided an added dimension, resulting in visualization of all the intracardiac structures, aorta, and pulmonary artery. Two-dimensional echocardiography became the diagnostic technique of choice for the evaluation and characterization of congenital cardiac disease in critically ill neonates, as well as in adult horses. Two-dimensional echocardiography also improved the ability to diagnose valvular regurgitations, characterize valvular lesions (bacterial endocarditis, ruptured chorda tendineae), myocardial function (segmental wall motion abnormalities), atrial size, mass lesions (endocarditis, neoplasia, and thrombi), and pericardial effusion. Information about blood flow was obtained using contrast echocardiography but was limited to certain cardiac abnormalities (congenital cardiac defects and tricuspid regurgitation). This information about blood flow was limited to the detection of positive or negative contrast jets. Comprehensive information about blood flow was lacking until the application of Doppler echocardiography to equine cardiology. Pulsed-wave and color flow Doppler echocardiography resulted in precise localization of the abnormal blood flow and semiquantitation of the shunt flow or regurgitant jet. Color flow Doppler echocardiography sped up the localization and semiquantitation of the jet in many instances and provided some information about blood flow velocity in the enhanced and variance modes. The peak velocity of jets can be determined using continuous-wave Doppler echocardiography. This value then can be used to estimate pressure difference between cardiac chambers or to calculate cardiac output noninvasively if angles parallel to flow can be obtained. Thus, information about cardiac size, function, and blood flow can be combined to diagnose cardiac disease in horses and to formulate a prognosis for life and performance.     

Anatomical validation of two-dimensional echocardiography in the horse

This study was performed on 15 horses to validate the cardiac anatomy as imaged with two dimensional echocardiography (2DE) and to determine the accuracy of intracardiac measurements. 2DE images were recorded in five horses in life with a Diasonics DRF100 ultrasound system and a 3.5 MHz transducer in different tomographic planes. After slaughter, the hearts were fixed in 10 per cent formalin. To compare in vivo and in vitro results, the specimens were suspended in a water-filled tank and 2DE images were made using the same transducer positions as in life. In vitro 2DE and autopsy measurements of the same planes and parameters were also taken on a further 10 hearts, and the results were statistically compared. The in vivo 2DE images corresponded well with both in vitro 2DE recordings and anatomical sections. Repeatable imaging of each tomographic plane was possible on the post mortem hearts using intracardiac reference points. Comparison of parameters measured during in vitro 2DE and autopsy demonstrated a significant correlation between all 2DE and autopsy data (r: 0.879 to 0.926; P less than 0.001). Repeated 2DE measurements of each parameter showed a good reproducibility with coefficients of variation (CV%) varying between 4.6 to 10.6 per cent. The results suggest that 2DE is a reliable method for accurate anatomical evaluation of the equine heart and show the potential application of quantitative two dimensional echocardiography in the living horse.     

Echocardiographic evidence of left atrial mechanical dysfunction after conversion of atrial fibrillation to sinus rhythm in 5 horses

BACKGROUND: Atrial contractile dysfunction occurs in some species after conversion of atrial fibrillation (AF) to normal sinus rhythm (NSR) but has not been reported in horses with naturally occurring AF. HYPOTHESIS: Transthoracic echocardiography allows detection of left atrial (LA) mechanical dysfunction in horses after conversion of AF to NSR. ANIMALS: Five Standardbreds with AF and 6 healthy Standardbreds of similar age, weight, and athletic condition were included in this study. METHODS: Four horses were treated pharmacologically (quinidine), and 1 horse was treated by means of transvenous electrical cardioversion. Echocardiographic examinations were performed in normal horses (once) and in AF horses (24 hours and 72 hours after conversion to NSR) by means of 2-dimensional echocardiography (2DE), transmitral flow Doppler, and tissue Doppler imaging (TDI) techniques. Echocardiographic indices of LA mechanical function were compared between normal horses and AF horses. RESULTS: Two-dimensional echocardiography and TDI indices of LA mechanical function revealed significant decreases in LA contractile function and LA reservoir function 24 hours after cardioversion. This decrease was no longer statistically significant 72 hours after cardioversion, but changes in echocardiographic variables between 24 and 72 hours varied among horses. CONCLUSIONS AND CLINICAL IMPORTANCE: LA contractile dysfunction can be evaluated in horses by use of 2DE, transmitral Doppler flow velocity profiles, and analyses of LA wall motion by TDI. The results of this study are consistent with AF-induced atrial remodeling, although residual treatment effects or influence of underlying primary myopathy cannot be excluded.     

Isolation of a virus serologically related to the bluetongue group from an outbreak of haemorrhagic disease among exotic deer in Saudi Arabia.

In February 1991 a severe haemorrhagic disease affected exotic deer aged over six months in the Al-Hofuf area of the eastern region of Saudi Arabia. The morbidity rate was 40 per cent and the case fatality rate was 60 per cent. The clinical signs were high temperature (up to 41.5 degrees C), nasal discharge, slight salivation and lacrimation, congestion of the conjunctivae, torticollis, tremors when trying to stand, recumbency and coma leading to death. Post mortem examination revealed a severe haemorrhagic disease. A virus, serologically related to the bluetongue serogroup, was isolated from the deer. Sheep and goats kept on the same farm did not show any clinical signs. The epidemiology of the outbreak is discussed.     

TWO-DIMENSIONAL, REAL-TIME ECHOCARDIOGRAPHY IN THE DOG Technique and Anatomic Validation

Two-dimensional, real-time echocardiography (2DE), studied extensively in humans, has only recently been utilized in veterinary medicine. To develop standardized transducer locations and examination technique and to validate cardiac anatomy as imaged from these locations, 2DE was performed in 12 normal, anesthetized dogs. Anatomic structures were identified by shape, position and motion, selective microbubble-laden saline injections, and percutaneous pin insertion followed by necropsy dissection. Consistent echotomographic images were obtained from right intercostal and left intercostal transducer locations. From the right, long-axis and short-axis views of the heart were obtained. From the left, several long-axis views were possible. One or more views of all four cardiac chambers, atrioventricular and semilunar valves, and the proximal portions of the great vessels were obtained by systematic examination from both sides of the thorax. It was concluded that complete anatomic evaluation of the canine heart by 2DE was possible using a standardized, systematic examination technique.     

Brucellae through the food chain: the role of sheep, goats and springbok (Antidorcus marsupialis) as sources of human infections in Namibia

A confirmed case of human brucellosis motivated an investigation into the potential source of infection in Namibia. Since domestic animals are principal sources of Brucella infection in humans, 1692 serum samples were screened from sheep, goats and cattle from 4 presumably at-risk farms and 900 springbok (Antidorcas marsupialis) serum samples from 29 mixed farming units for Brucella antibodies by the Rose-Bengal test (RBT) and positive cases confirmed by complement fixation test (CFT). To assess the prevalence of human brucellosis, 137 abattoir employees were tested for Brucella antibodies using the standard tube agglutination test (STAT) and by enzyme linked immunosorbent assay (ELISA). Cattle and sheep from all 4 farms were negative by RBT and CFT but 2 of the 4 farms (Ba and C) had 26/42 and 12/285 seropositive goats, respectively. Post mortem examination of seropositive goats revealed no gross pathological lesions typical of brucellosis except enlarged mesenteric and iliac lymph nodes seen in a single buck. Culture for brucellae from organs of seropositive animals was negative. None of the wildlife sera tested positive by either RBT or CFT. Interviews revealed that besides the case that prompted the investigation, a family and another person from other farms with confirmed brucellosis shared a common history of consumption of unpasteurised goat milk, home-made goat cheese and coffee with raw milk and prior contact with goats, suggesting goats as the likely source of infection. All 137 abattoir employees tested negative by STAT, but 3 were positive by ELISA. The 3 abattoir workers were clinically normal and lacked historical connections with clinical cases. Although goats are often associated with B. melitensis, these studies could not explicitly implicate this species owing to cross-reactivity with B. abortus, which can also infect goats. Nevertheless, these data reinforce the need for a better National Control Programme for brucellosis in Namibia.     

Effects of sedation on echocardiographic variables of left atrial and left ventricular function in healthy cats

Although sedation is frequently used to facilitate patient compliance in feline echocardiography, the effects of sedative drugs on echocardiographic variables have been poorly documented. This study investigated the effects of two sedation protocols on echocardiographic indices in healthy cats, with special emphasis on the assessment of left atrial size and function, as well as left ventricular diastolic performance. Seven cats underwent echocardiography (transthoracic two-dimensional, spectral Doppler, color flow Doppler and tissue Doppler imaging) before and after sedation with both acepromazine (0.1 mg/kg IM) and butorphanol (0.25 mg/kg IM), or acepromazine (0.1 mg/kg IM), butorphanol (0.25 mg/kg IM) and ketamine (1.5 mg/kg IV). Heart rate increased significantly following acepromazine/butorphanol/ketamine (mean ± SD of increase, 40 ± 26 beats/min) and non-invasive systolic blood pressure decreased significantly following acepromazine/butorphanol (mean ± SD of decrease, 12 ± 19 mmHg). The majority of echocardiographic variables were not significantly different after sedation compared with baseline values. Both sedation protocols resulted in mildly decreased left ventricular end-diastolic dimension and mildly increased left ventricular end-diastolic wall thickness. This study therefore failed to demonstrate clinically meaningful effects of these sedation protocols on echocardiographic measurements, suggesting that sedation with acepromazine, butorphanol and/or ketamine can be used to facilitate echocardiography in healthy cats.     

Systemic histiocytosis in a Bernese mountain dog

Systemic histiocytosis was diagnosed at post mortem examination in a three-year-old Bernese mountain dog born in the United Kingdom. The dog presented with a progressive nodular skin disease, chemosis and periocular swelling occurring over six months. It was unresponsive to topical corticosteroids, antibiotics and oral azathioprine. Elective euthanasia was performed. Post mortem examination revealed extensive histiocytic infiltration of the skin, subcutis and skeletal muscles, particularly of the head.     

Assessment of pain associated with degenerative hip disorders in adult male turkeys

The extent to which degenerative hip disorders in adult male turkeys result in pain was investigated in a two-period crossover experiment. The birds in six pens received daily injections of an anti-inflammatory steroid (betamethasone) during week 1 and control injections of physiological saline in week 3. The turkeys in the other six pens received saline in week 1 and steroid in week 3. Behavioural observations of the birds during weeks 1 and 3 revealed that the steroid treatment resulted in more spontaneous activity. The steroid-treated birds also showed speedier movement in a sexual activity test in weeks 1 and 3. Post mortem examination revealed that all the turkeys were suffering from degenerative hip disorders. It is concluded that degenerative hip disorders in adult male turkeys result in a state of chronic pain which inhibits spontaneous activity and sexual activity.     

Control of paratuberculosis (Johne's disease) in goats by vaccination

After several years of unsuccessful efforts to eradicate paratuberculosis in goats in Norway by conventional methods such as general hygienic precautions and the isolation and slaughtering of clinically affected and serologically positive animals, a vaccination programme was initiated in 1967. The vaccine used consists of two live attenuated strains of Mycobacterium paratuberculosis suspended in a mixture of liquid paraffin, olive oil and pumice powder. The vaccine may be stored at 4 degrees C for two weeks, the dose is 1 ml and the goat kids are vaccinated at the age of two to four weeks. The efficacy of the vaccine has been judged mainly by post mortem examination of vaccinated and unvaccinated goats in the period 1967-82. During this period about 131,000 goats were vaccinated and, based on the post mortem examination of 15,219 goats, the infection rate was reduced from 53 to 1 per cent. Moreover, infection occurred almost exclusively in goats which for some reason or other had not been vaccinated or which had been too old when vaccinated. The results of these examinations showed that the adjuvanted vaccine with live M paratuberculosis bacteria offers a high degree of protection against paratuberculosis in goats.