Biomedical subjects

R M Kirberger

Publications and source records attributed to R M Kirberger.

At least 19 recordsLinked to original sources

PubMed2006

Aortic foreign body (airgun pellet) embolism in a cat.

A five-year-old female domestic shorthair cat presented with clinical signs typical of an aortic saddle thromboembolism. An echocardiogram and thoracic radiographs excluded cardiac disease as a source of the thrombus. Two heavy metal opacity, pellet-like objects were seen in the thoracic and abdominal radiographs. Abdominal ultrasound demonstrated occlusion of aortic blood flow by the abdominal pellet but could not indicate whether this was due to a penetrating aortic wound or pellet embolisation. A necropsy confirmed a penetrating left ventricular cardiac wound with subsequent embolisation of the pellet to the abdominal aorta.

Abdomen↗

PubMed2005

Doppler ultrasonographic changes in the canine kidney during normovolaemic anaemia.

The haemodynamics of the canine left renal artery (LRA) and interlobar artery (ILA) were evaluated in eleven fasted, healthy, conscious beagles with severe acute (haematocrit [Hct] 16%), moderate chronic (Hct 26%) and mild chronic (Hct 34%) normovolaemic anaemia using Doppler ultrasound. Heart rate, peak systolic velocity (PSV), end diastolic velocity (EDV), time-averaged mean velocity (TAVmean), pulsatility index (PI) and resistive index (RI) were recorded. Doppler values in the dogs following the induction of anaemia states were compared with corresponding values in the same dogs prior to the induction of anaemia. Left renal artery mean PSV, mean PI and mean RI were significantly higher and the mean EDV was significantly lower in severe acute anaemia. No significant change was seen in mean values of the same parameters in moderate or mild chronic anaemia. There was no significant change in TAVmean of the LRA or mean PI and mean RI of the ILA in any grade of anaemia. Acute, severe normovolaemic anaemia significantly altered LRA Doppler parameters in resting dogs without influencing those of the ILA. Moderate or mild chronic anaemia had no effect on any renal Doppler parameter.

Anemia↗

PubMed2005

Effect of various thoracic radiographic projections on the appearance of selected thoracic viscera.

OBJECTIVES: To assess the effect of different radiographic projections on thoracic width, as well as position and visibility of the trachea, principal bronchi, cardiac silhouette, aorta, caudal vena cava (CVC) and oesophagus. METHODS: Right lateral recumbency (RLR), left lateral recumbency (LLR), dorsoventral (DV) and ventrodorsal (VD) thoracic radiographs of 42 dogs were reviewed retrospectively. RESULTS: In 78 per cent of cases the thoracic width was significantly larger on the VD projection than on the DV projection. The angle of divergence formed by the principal bronchi was significantly larger on the VD projection than on the DV projection in 80 per cent of dogs. A cardiac silhouette bulge at 1 to 2 o'clock was apparent on the VD projection in 22 per cent of dogs but was never seen on DV projections. The descending aorta was more visible at the 4 to 5 o'clock cardiac silhouette level on the DV projection and laterally at the T8 level on LLR projections. The CVC was better seen on VD and LLR projections. The oesophagus was visible as a soft tissue opacity in LLR in large dogs with normal thoracic conformation in 35 per cent of cases. CLINICAL SIGNIFICANCE: The DV projection appears to be more reliable for assessing the cardiac silhouette, the descending aorta and the angle of divergence of the principal bronchi. The VD projection should be considered for evaluating the CVC. LLR should be used for assessing the descending aorta and CVC.

Animals↗

PubMed2005

Diagnosis of suspected hypovitaminosis A using magnetic resonance imaging in African lions (Panthera leo).

Vitamin A deficiency is described in captive lions. Ante mortem diagnosis can either be made by serum analysis or liver biopsy, both of which may be problematic. This study utilised magnetic resonance imaging to identify vitamin A deficiency in lions with relatively mild clinical signs, which could otherwise be attributed to numerous other neurological conditions. Magnetic resonance imaging is a non-invasive, reliable diagnostic tool to demonstrate pathology typically associated with this condition. To accommodate varying lion ages and sizes, a number of cranium and brain measurements were compared with that of the maximum diameter of the occular vitreous humor. Occular ratios of the tentorium cerebelli osseum and occipital bone were most reliable in diagnosing the thickened osseous structures characteristic of hypovitaminosis A. The ratio of maximum:minimum dorsoventral diameter of the C1 spinal cord was also of value.

Animal Feed↗

PubMed2005

Comparison of effects of uncomplicated canine babesiosis and canine normovolaemic anaemia on abdominal splanchnic Doppler characteristics--a preliminary investigation.

A preliminary study was conducted to compare uncomplicated canine babesiosis (CB) and experimentally induced normovolaemic anaemia (EA) using Doppler ultrasonography of abdominal splanchnic vessels. Fourteen dogs with uncomplicated CB were investigated together with 11 healthy Beagles during severe EA, moderate EA and the physiological state as a control group. Canine babesiosis was compared with severe EA, moderate EA and the physiological state using Doppler variables of the abdominal aorta, cranial mesenteric artery (CMA), coeliac, left renal and interlobar, and hilar splenic arteries, and the main portal vein. Patterns of haemodynamic changes during CB and EA were broadly similar and were characterised by elevations in velocities and reductions in resistance indices in all vessels except the renal arteries when compared with the physiological state. Aortic and CMA peak systolic velocities and CMA end diastolic and time-averaged mean velocities in CB were significantly lower (P < 0.023) than those in severe EA. Patterns of renal haemodynamic changes during CB and EA were similar. However, the renal patterns differed from those of aortic and gastrointestinal arteries, having elevations in vascular resistance indices, a reduction in end diastolic velocity and unchanged time-averaged mean velocity. The left renal artery resistive index in CB was significantly higher (P < 0.025) than those in EA and the physiological state. Renal interlobar artery resistive and pulsatility indices in CB were significantly higher (P < 0.016) than those of moderate EA and the physiological state. The similar haemodynamic patterns in CB and EA are attributable to anaemia, while significant differences may additionally be attributed to pathophysiological factors peculiar to CB.

Anemia↗

PubMed2005

A canine model of normovolaemic acute anaemia.

The objective was to develop a non-terminal, acute normovolaemic anaemia model in dogs that has minimal effects on patient well-being. Eleven normal Beagle dogs were used. About 20% of the circulating blood volume was removed from the jugular vein 1-3 times per day over a 3-4 day period until a haematocrit (Ht) of 13-17% was obtained. Normovolaemia was maintained by replacing the volume deficit of the red blood cells with Ringer's lactate and re-infusing the plasma. Full blood count and Ht were monitored twice daily. The 13-17% Ht was reached within 3-4 days with the number of phlebotomies ranging from four to seven. The model was primarily developed to determine echocardiographic values as well as Doppler abdominal splanchnic blood flow parameters in anaemic dogs as part of a study that will compare these results to similar studies in babesiosis-induced anaemia. The model may also be useful in the evaluation of the pathophysiology of anaemia in dogs or as a model for anaemia in humans.

Acute Disease↗

PubMed2004

Nutritional secondary hyperparathyroidism in a white lion cub (Panthera leo), with concomitant radiographic double cortical line.

A captive-bred white lion cub was presented with hindquarter pain, lameness and reluctance to move. Radiographs revealed generalised osteoapenia, multiple fractures, a severely collapsed pelvic girdle, bilateral lateral bowing of the scapulae and mild kyphosis of the caudal vertebrae. A double cortical line, a distinct sign of osteopaenia, was repeatedly seen on the pelvic limbs, most strikingly along both femurs. Based on radiographic findings and a history of an exclusive meat diet since weaning, a diagnosis of nutritional secondary hyperparathyroidism was made. The diet was changed to a commercial kitten food and the cub was given cage rest for 6 weeks. Signs of pain abated and the cub became more active. A guarded prognosis was given for full recovery, as changes to the pelvis were considered potentially irreversible.

Animal Feed↗

PubMed2003

Cervical spondylomyelopathy (wobbler syndrome) in the Boerboel.

The Boerboel is a South African large-breed dog resembling a Bullmastiff. The records of Onderstepoort Veterinary Academic Hospital were searched for dogs that had presented, between 1998 and 2003, with symptoms indicative of wobbler syndrome and had undergone survey radiographic and myelographic studies. Ten cases fitted the inclusion criteria. Dogs presented within the first 2 years of life, often with acute onset of symptoms. All presented with pelvic limb and 6 with concomitant thoracic limb ataxia or paresis. Treatment varied and included none (4), prednisolone (2), and dorsal laminectomy (2). Two dogs were euthanased at the time of diagnosis. The breed appears to be affected with a form of spondylomyelopathy that comprises bony malformation of cervical and/or thoracic vertebrae. In 8 dogs, malformations were evident on survey radiographs and were characterised by enlarged, irregular articular facets and associated medial deviation of the pedicles. These changes resulted in axial compression of the spinal cord best seen on ventrodorsal or dorsoventral myelographic studies. Multiple vertebrae were affected in some dogs and lesions were not confined to the caudal area of the cervical spine. Three dogs were alive and without symptoms at follow-up. Four were euthanased as a result of the disease and 1 died as a result of post-operative complications. Two additional dogs presenting with wobbler clinical signs are also described. One had medial deviation of the T5 and T6 caudal pedicles and 1 dog suffered from multiple cervical articular facet synovial cysts.

Animals↗

PubMed2002

An investigation into the usefulness of a rostrocaudal nasal radiographic view in the dog.

A rostrocaudal (RCd) nasal view was developed in large breed mesaticephalic dogs using a complete, subsequently sectioned, skull and cadaver specimens to optimise the radiographic technique and evaluate normal anatomic features. Gelatin was placed in one nasal passage of the cadaver specimens to mimic the effects of nasal pathology. The latter specimens and 18 clinical cases with suspected nasal disease were evaluated to determine the usefulness of the RCd view compared to standard nasal views. An optimal RCd view was obtained with the dog in dorsal recumbency and the head symmetrically positioned with the hard palate perpendicular to the table using a table top technique with 8:1 grid, collimating to the nasal region and centring the primary beam on the philtrum. The dorsolateral aspects of the maxillary bone, the nasal bones, septal sulcus of the vomer, mucosa lined nasal septum and conchae could be seen. A centrodorsal more radiolucent area representing the ethmoid bone region was also visible. Gelatin soft tissue opacification of the nasal passage could be seen more clearly in RCd nasal view than in occlusal dorsoventral view. In clinical cases the RCd view was useful to build up a 3-dimensional image of nasal passage pathology as well as to detect nasal septum and osseous nasal border pathology not visible in other views. This view is particularly useful in cases where cross-sectional imaging modalities are not available or where the nasal investigation is limited by cost considerations.

Animals↗

PubMed2001

Radiographic anatomy of the thoraco-abdominal cavity of the ostrich (Struthio camelus).

This study provides a reference for the radiographic anatomy of the thoraco-abdominal cavity of female ostriches as a representative of ratites. One ostrich cadaver, 2 adult and 2 growing ostriches were used. Right lateral radiographs produced by a 6-frame technique and 2 dorsoventral radiographs produced by an adapted 3-frame technique were selected and schematic illustrations of these were labelled to illustrate normal radiographic anatomy. Differences from other avian species and unique features of the ostrich are briefly discussed.

Abdomen↗

PubMed2000

Arrhythmogenic right ventricular cardiomyopathy in a dog.

An 8-month-old Labrador retriever bitch was evaluated for sudden-onset, progressive abdominal distension. Physical examination revealed an exaggerated inspiratory effort, severe ascites, bilateral jugular vein distension, and hypokinetic femoral arterial pulses. Thoracic auscultation detected tachycardia with muffled heart sounds, without audible cardiac murmurs. Thoracic radiographs identified severe right ventricular enlargement and pleural effusion. The electrocardiogram was consistent with incomplete right bundle branch block or right ventricular enlargement. Echocardiography demonstrated severe right ventricular and atrial dilation, secondary tricuspid regurgitation, and thinning and hypocontractility of the right ventricular myocardium. Left heart chamber sizes were slightly decreased, with normal left ventricular contractility. A diagnosis of arrhythmogenic right ventricular cardiomyopathy was reached, based on the characteristic clinical, electrocardiographic, radiographic and echocardiographic findings, and the exclusion of other causes of isolated right ventricular failure. Treatment effected good control of clinical signs, until acutely decompensated congestive right heart failure led to euthanasia after 4 months. Arrhythmogenic right ventricular cardiomyopathy is a well-described clinical entity in humans, and has previously been documented in 3 male dogs. The condition is characterised by progressive fibro-adipose replacement of right ventricular myocardium, while the left ventricle usually remains unaffected. It should be considered a differential diagnosis in any young dog presented with isolated right heart failure, syncope, or unexplained ventricular tachyarrhythmias. This article reports the 1st case of arrhythmogenic right ventricular cardiomyopathy in a female dog, and highlights its echocardiographic features.

Animals↗

PubMed1999

Vacuum phenomenon in equine carpal, metacarpophalangeal and metatarsophalangeal joints.

In order to establish the incidence of vacuum phenomenon in horses' carpal, metacarpophalangeal and metatarsophalangeal joints, stress-flexed radiographs were made of normal joints, joints with known pathology and in anaesthetised horses with joints under traction. Focal intra-articular radiolucencies were identified in normal stress-flexed carpal, metacarpophalangeal and metatarsophalangeal joints. These radiolucencies can be confused with those associated with pathological conditions.

Animals↗

PubMed1998

Elbow dysplasia in the dog: pathophysiology, diagnosis and control.

Elbow dysplasia is a non-specific term denoting abnormal development of the elbow. Elbow dysplasia encompasses the clinical and radiographic manifestation of ununited anconeal process, fragmented medical coronoid process, osteochondritis dissecans, erosive cartilage lesions and elbow incongruity. The net result is elbow arthrosis, which may be clinically inapparent or result in marked lameness. These conditions may be diagnosed by means of routine or special radiographic views and other imaging modalities, or the precise cause of the arthrosis or lameness may remain undetermined. Breeds most commonly affected are the rottweiler, Bernese mountain dog, Labrador and golden retriever and the German shepherd dog. Certain breeds are more susceptible to a particular form of elbow dysplasia and more than 1 component may occur simultaneously. The various conditions are thought to result from osteochondrosis of the articular or physeal cartilage that results in disparate growth of the radius and ulna. Heritability has been proven for this polygenic condition and screening programmes to select suitable breeding stock have been initiated in several countries and have decreased the incidence of elbow dysplasia.

Age Factors↗

PubMed1997

Right atrial myxosarcoma in a dog.

A case of right atrial myxosarcoma is described in a Staffordshire bull terrier with a history of weight loss, exercise intolerance and collapse. The diagnosis of an intracavitary cardiac tumour was made on echocardiography. The dog was euthanased. Secondary spread to the lungs and lymph nodes was present. Myxoma is one of the rare intracavitary cardiac tumours and this case is believed to be the 1st report of its more malignant form in the dog.

Animals↗

PubMed1996

Radiological appearance of air introduced during equine regional limb anaesthesia.

Twelve horses were injected intra-articularly into the metacarpophalangeal joint and extra-articularly in the region of the lateral palmar digital nerve with 1 ml air and local anaesthetic to simulate gas accidentally introduced during regional anaesthesia. Half the horses underwent limited exercise after which all horses were radiographed at 15 and 45 min and then every 24 h until all evidence of gas had disappeared. Intra-articular gas appeared as gas capped radiolucencies (GCR) in the proximal aspect of the joint. Extra-articular gas appeared as linear radiolucencies (LR) which initially tended to migrate proximally. There was no significant difference in gas resorption in exercised and nonexercised horses. All gas was resorbed within 96 h with most of the gas already gone at 48 h.

Air↗

PubMed1995

Radiographic artifacts.

Radiographic artifacts commonly occur, particularly with hand processing. The artifacts may originate between the X-ray tube and the cassette as extraneous material on the patient or contamination of positioning aids, or result from debris within the cassette, or damage to, or staining of the screens. These artifacts are white to grey, may have a constant or different position on follow-up radiographs, and their size and shape are reflective of the inciting cause. A number of artifacts may occur in the darkroom during handling, developing, fixing and drying of the film. White to shiny artifacts are caused by the contamination of films with fixer, inability of developer to reach parts of the film or loss of emulsion from the developed film. Black artifacts result from improper handling or storage of films, resulting in exposure to light, or from pressure marks or static electricity discharges. Dropped levels of hand-processing chemicals may result in a variety of tide-marks on films. Most radiographic artifacts can be prevented by proper storage and handling of films and by optimal darkroom technique.

Animals↗

PubMed1993

Pulsed wave Doppler echocardiographic evaluation of intracardiac blood flow in normal sheep.

The blood flow velocities and flow patterns were evaluated in normal sheep across the four cardiac valves using pulsed wave spectral Doppler echocardiography. Merino ewes (n = 20) aged between 16 and 61 months with bodyweights ranging between 51 to 72 kg were evaluated. The sheep were fully conscious and required no sedation. The mean peak velocities for the left atrioventricular, right atrioventricular, aortic and pulmonary valves were 68.4, 51.9, 99.1 and 92.7 cm s-1, respectively. Additionally the wave forms were described and mean velocities and a variety of flow variables determined for each of these flow areas. The mean left atrioventricular valve E:A ratio was under 1 which differs from humans and dogs. Aortic and pulmonary flow variables were compared to each other.

Animals↗

PubMed1992

Atrial septal defect in a dog: the value of Doppler echocardiography.

A four-month-old German Shepherd Dog was presented with an atrial septal defect. An estimated pulmonary to systemic blood flow ratio in the range of 2,5 to 2,9:1 was determined by means of Doppler echocardiography. This technique allows for the non-invasive determination of the Qp:Qs ratio by calculating aortic versus pulmonary artery cardiac output or by determining mean trans-atrial septal velocities. In addition, the flow patterns across the valves are characterised and the direction of the shunt determined. Atrial septal defect is reviewed with special reference to the value of Doppler echocardiography.

Animals↗