Blood Vessel Topography of the Feet in Selected Species of Birds of Prey and Owls

Birds of prey and owls are susceptible to diseases of and traumatic injuries to their feet, which regularly require surgical intervention. A precise knowledge of the blood vessel topography is essential for a targeted therapy. Therefore, the metatarsal and digital vasculature was examined in eight species of birds of prey and owls. The study included contrast micro-computed tomography scans and anatomical dissections after intravascular injection of colored latex. In all examined species, the dorsal metatarsal arteries provided the main supply to the foot and their branching pattern and number differed between species. They continued distally as digital arteries. All examined species showed a basic pattern of four collaterally located digital blood vessels per toe: a prominent artery and small vein on one side and a small artery and prominent vein on the other side. Digital veins united to form common digital veins, most of which joined into a superficial, medially located metatarsal vein. This vein provided the main drainage of the foot. The detailed visualization of the topography of pedal blood vessels will help veterinary surgeons during surgical procedures. In addition, differences in the plantar arterial arch between hawks and falcons were discussed regarding their possible influence on the prevalence of pododermatitis (bumblefoot).

Ectoparasites of European hedgehogs (Erinaceus europaeus) in Germany and their health impact

BACKGROUND

The European hedgehog (Erinaceus europaeus) is known for high levels of ectoparasitism that not only represents a health risk for the animals themselves, but also for pet animals and humans as hedgehogs are frequently taken into human care. In the present study, patterns of ectoparasite infestation were assessed in hedgehogs taken into care at northern German animal rehabilitation centres.

METHODS

Ectoparasites (ticks, fleas and mites) of 498 hedgehogs were collected over a period of 3 years from July 2018 to May 2021. Species were identified based on morphological characteristics and also via amplification and sequencing of the partial cytochrome c oxidase subunit 2 (COX-2) gene for fleas of the family Ceratophyllidae. Seasonal changes in infestation patterns as well as correlations with animal age, body weight and health status were assessed using generalised linear models.

RESULTS

Infestation with ticks, fleas and mites occurred throughout the year. Overall, 86.5% (431/498) of the examined hedgehogs were infested with ticks, 91.4% (455/498) with fleas and 17.7% (88/498) with mites. Ixodes ricinus and Ixodes hexagonus/Ixodes canisuga were the most common tick species detected, with the additional occurrence of one Ixodes frontalis. Significant seasonal changes were observed for I. ricinus, but not for I. hexagonus/I. canisuga. Additionally, I. ricinus nymph prevalence declined significantly as of 2020, probably as a consequence of the climate change-related drought as of 2018. In hedgehogs with flea infestations, Archaeopsylla erinacei, Ceratophyllus sciurorum, Nosopsyllus fasciatus and Ctenocephalides felis were identified. In all cases of mite infestation, Caparinia tripilis was detected, in addition to specimens of the family Macronyssidae and free-living mites of the family Acaridae. Statistical analyses showed correlations regarding the factors month, year, body weight and age, but no correlation was evident regarding the health status of the animals.

CONCLUSIONS

With a detected infestation rate of 98.6%, almost all of the examined hedgehogs were infested with at least one ectoparasite species. The seasonal activity patterns of the different ectoparasite species together with the complex annual cycle of hedgehogs lead to different seasonal patterns in ectoparasite prevalence and infestation intensities. Due to the risk of transmission of zoonotic pathogens as well as the possible negative impact on the host itself, hedgehogs should be treated against ectoparasites when taken into care facilities.

Surgical removal of an atypical histiocytic cell proliferation in a bearded dragon (Pogona vitticeps)

A 4-year-old female bearded dragon (Pogona vitticeps) was referred to the Clinic for Small Mammals, Reptiles and Birds of the University of Veterinary Medicine, Hannover, Germany for diagnostics and treatment of a growing mass in the right cervical region. The owner reported that the mass had grown over the past 4 weeks with only little alteration in the lizard´s behavior when the animal started rubbing its neck against the cage equipment. Physical examination as well as ultrasonographic and computed tomographic diagnostics revealed a highly vascularized mass, which allowed for the hypothesis of an aneurysm or a neoplasia. Complete surgical resection of the mass could be performed uneventfully. The bearded dragon recovered well from anesthesia and the surgical procedure. The microbiological sample of the excised mass revealed Group F-67 Salmonella. Histopathological examination of the excised mass revealed a histiocytic cell proliferation with centrally located blood filled cavities, hemorrhages and granulation tissue resembling features of a pseudoaneurysm. This report describes the diagnosis of an atypical growing mass in a bearded dragon and its successful removal.

Surgical Stabilisation of a Coxofemoral Luxation in a Northern Goshawk (Accipter gentilis) with Transarticular Pinning

A 3-year-old male northern goshawk (Accipiter gentilis) used in falconry for hunting was diagnosed with a craniodorsal coxofemoral luxation of the left leg after an unsuccessful hunting flight. Closed reduction in the dislocation was unsuccessful and the hip joint reluxed again with slight abduction of the limb. An open surgical reduction with a transarticular stabilization using a normogradely inserted Kirschner wire was performed. The implant was removed surgically after five weeks. After about seven weeks, the owner saw no abnormalities in the loading of the limbs, and the goshawk was successfully used for hunting after nine months in the next hunting season.

Treatment options, complications and long-term outcomes for limb fractures in pet rabbits

BACKGROUND

Limb fractures represent the most common orthopaedic disease in pet rabbits. However, only a few studies have evaluated therapeutic details of limb fractures. There are no data available for long-term outcomes of limb fracture treatment.

METHODS

The medical records of six institutions were reviewed retrospectively to identify cases of traumatic limb bone fractures in pet rabbits between 1999 and 2020. The medical records (n = 387) were analysed for details of fracture prevalence, aetiology, therapy protocols, treatment complications, outcome and long-term effects. In addition to the retrospective data evaluation, 13 rabbits were re-evaluated in person in recent clinical analyses, including orthopaedic examination, radiography and computed-tomographic imaging. Details of long-term effects of fracture treatment were requested over the telephone for a further 232 animals using a standardised questionnaire.

RESULTS

Long bone fractures accounted for the majority of all fractures (296/387; 76.5%). Hindlimb fractures (301/387; 77.7%) were more common than forelimb fractures (86/387; 22.2%), and tibial fractures and combined fractures of the tibia and fibula (119/387; 30.8%) were observed most frequently. Most fracture treatments were based on osteosynthesis procedures (243/328; 74.1%). Treatment complications occurred in 130 out of 328 (39.6%) cases. A high bodyweight (p = 0.047) and an older age (p = 0.01) were found to be significant risk factors for the emergence of therapy complications. Overall, 75.4% of animals (175/232) had a satisfactory long-term outcome. Limb posture anomalies were evaluated in 61 cases (26.3%).

LIMITATIONS

The multi-centre approach led to the inclusion of various institutions, veterinarians, treatment protocols and rabbit populations that might have influenced the results. The medical records were reviewed retrospectively, so there were some data that were lacking or could not be collected in a standardised manner. Furthermore, rabbit owners' evaluation of long-term outcomes might be prone to error, despite the use of a standardised interview questionnaire.

CONCLUSION

Limb fractures are a common orthopaedic issue in pet rabbits. The patient's bodyweight and age are significant risk factors for the emergence of complications during the fracture treatment process. Long-term orthopaedic effects, such as abnormal limb posture and permanent lameness of the affected limb, were observed regularly.

[Limb fractures in pet rabbits (Oryctolagus cuniculus f. domestica) - A case series of orthopedic long-term effects in fracture patients]

OBJECTIVE

Limb fractures account for a large proportion of all orthopedic diseases in pet rabbits and are a common reason for presentation. The fracture etiologies and characteristics vary considerably in comparison to trauma of the extremities in cats and dogs. For this reason, conservative and surgical treatment options need to be adapted. To our knowledge, long-term effects of limb fracture therapies in pet rabbits have not been described scientifically.

MATERIALS AND METHODS

This article features a case series of 13 pet rabbits with limb fractures. Their medical records were analyzed retrospectively and all patients were presented for a follow-up examination including clinical and orthopedic examination.

RESULTS

Orthopedic anomalies (abducted limb postures) were identified in four patients. Arthrotic ossification was found in twelve of thirteen animals - in six cases to a high extent. Measurement of the fractured bones revealed a shortening in ten of thirteen cases.

CONCLUSION AND CLINICAL RELEVANCE

Orthopedic long-term complications following fracture treatments were commonly detected in the patient population of this study. Permanent issues may result in anomalies of limb posture or postural control which are not noticed by the rabbit owners in every case. Ultimately, the patients should be examined routinely after the conclusion of fracture therapy in order to detect and adequately treat possible orthopedic complications.

Performing a Three-Dimensional Finite Element Analysis (FEA) to Simulate and Quantify the Contact Pressure in the Canine Elbow Joint: A Pilot Study

OBJECTIVE

 The aim of this study was to measure surface pressures and force distribution on radius and ulna in healthy and dysplastic elbow joints in different positions using the finite element analysis (FEA).

STUDY DESIGN

 FEA was performed on computed tomographic data of healthy and fragmented coronoid process diseased elbow joints of Labrador Retrievers. It considered the articular cartilage, collateral ligaments, triceps and biceps muscle. The analysis of each joint was performed in four positions (standing position: 145 degrees and three positions of the stance phase of gait: beginning: 115 degrees, middle: 110 degrees, end: 145 degrees joint angle) in consideration of different ground reaction forces (standing: 88.3 N; stance phase of gait: 182.5 N).

RESULTS

 Mean values of total force of 317.5 N (standing), 590.7 N (beginning), 330.9 N (middle) and 730.9 N (end) were measured. The percentual force distribution resulted in a total of 49.56 ± 26.58% on the ulna with a very inhomogeneous distribution. A significant difference was detected between the positions 'standing' and 'end' (p = 0.0497) regardless of the joint condition. In some FEA results, visual assessment of the surface pressures indicated an increase in pressure in the region of the medial compartment without a uniform pattern. An increase in pressure resulted in an area increase in the pressure marks on the joint surface and measurable pressure was increased at a larger joint angle.

CLINICAL SIGNIFICANCE

 FEA can provide information about the transmission of force in the joint. Prior to the use of FEA in scientific clinical research for the simulation of force, further model improvements are necessary.

Ex Vivo Evaluation of the Cranial Tibial Artery and Its Compression through Fragment Rotation during Tibia Plateau Levelling Osteotomy: An Angiographic Three-Dimensional Reconstruction

OBJECTIVE

 To illustrate the arterial vascularity of the proximal tibia three-dimensionally and to evaluate the impact of fragment rotation on the cranial tibial artery by tibia plateau levelling osteotomy (TPLO).

METHOD

 Radiographic angiography and computed tomography (CT) were performed on 12 pelvic limbs from six large-breed canine cadavers before and after TPLO. Three-dimensional (3D) models of the stifle, including osseous and vascular structures, were obtained, and the integrity of the cranial tibial artery was assessed. Post-TPLO CT images were used to analyze compression of the cranial tibial artery by the rotated fragment.

RESULTS

 The uncompressed cranial tibial artery caliber, measured proximally and distally to the osteotomy, was 9.52 mm² (6.07-18.90 mm²). In all adequately rotated fragments, the mean caliber of the artery on the level of the osteotomy was 1.57 mm² (0.89-2.93 mm²) after TPLO. This represented a significant decrease of approximately 81%. Only slight cross-sectional area decrease (8.8%) was seen in one limb, which was revealed to have insufficient fragment rotation (2.83 mm). Another limb only showed signs of stretching of the artery (31.51%), which was under-rotated and medially displaced. Pre-TPLO 3D reconstructions were mainly consistent with previous anatomic studies except for the distance between tibial cortex and cranial tibial artery, which appeared closer.

CONCLUSION

 Sufficient fragment rotation leads to compression of the cranial tibial artery. Intraoperative hemorrhage can be caused by laceration of the main cranial tibial artery or by multiple small branches reaching craniolaterally.

[Studies on the use of iodine-containing contrast agent diatrizoate in rabbits (Oryctolagus cuniculus)]

OBJECTIVE

The use of the iodine-containing contrast agent diatrizoate was investigated in healthy rabbits and in rabbits with gastric dilatation and intestinal obstruction. For this purpose, transit times through the gastrointestinal tract and clinical use were investigated during a one year period. In addition, a possible influence on thyroid hormone levels was evaluated.

MATERIAL AND METHODS

Transit times of contrast agent through the different intestinal sections were examined radiographically in 14 healthy rabbits. For this purpose, 7 ml/kg of a 300 mg iodine/ml and 600 mg diatrizoate/ml containing solution were administered. Radiographs were obtained at different time intervals. Three different doses (D1 2 ml/kg, D2 7 ml/kg, D3 10 ml/kg) were administered, and blood samples were collected at two time points (60 min, 24 h) to analyze thyroid hormone levels (TT4, fT4, TSH). In addition, 70 rabbits that had received the contrast agent diatrizoate because of gastric dilatation and suspected intestinal obstruction were retrospectively evaluated during a period of one year. Focus was placed on arrival of the contrast agent in the cecum, laboratory changes, and mortalities.

RESULTS

In all healthy rabbits, contrast medium was detectable in the cecum after a mean of 45-60 min. In the animals suffering from gastrointestinal obstruction, this was delayed to a mean of 121.2 min. These animals showed hypothermia in 92.4 % and hyperglycemia in 45.9 %. 56.1 % exhibited an increase in urea and 33.9 % an increase in creatinine. In 71.4 % of cases, medical treatment was possible, however 12 % of these individuals succumbed to the disease. 28.6 % of the cases were managed surgically which was associated with a mortality of 50 %. TT4, fT4, and TSH levels displayed significant alterations among the three contrast agent doses (p < 0.05). These changes were found to be transient when follow-up was performed two weeks later.

CONCLUSION AND CLINICAL RELEVANCE

When ileus is suspected in rabbits, diatrizoate may be helpful in evaluating the progression of the disease in addition to the use of native radiographs. Sufficient hydration and monitoring of renal function are advisable. Transient changes in thyroid hormones were evident but lacked clinical relevance.

Influence of anesthesia with isoflurane on myocardial velocities of racing pigeons (Columba livia f. domestica)

OBJECTIVE

Tissue Doppler imaging (TDI) is a new technique to measure the myocardial velocities of the avian heart. Using this technique, the present study investigated the influence of isoflurane anesthesia on the systolic and diastolic longitudinal myocardial velocities in racing pigeons.

MATERIAL AND METHODS

Racing pigeons (n = 40) were anesthetized with isoflurane with a semi-open anesthesia system with an anesthetic mask and spontaneous breath. The echocardiographic examination was performed during the stage of surgical anesthesia with the failure of the toe pinch and wing twitch reflexes and with deep regular breaths. Echocardiographic measurements were taken in conscious and anesthetized pigeons in the right parasternal longitudinal horizontal heart view.

RESULTS

The results demonstrated a significant decrease in heart rate, systolic and diastolic A' wave myocardial velocities. The diastolic E' wave velocities were less influenced by anesthesia and significantly decreased only for some heart wall segments. The systolic myocardial velocities were significantly negatively correlated with the heart rate. Using the TDI curve, the isovolumic contraction (IVC) and relaxation time (IVR) and the time of atrioventricular delay during anesthesia could be determined. There is a significant increase in IVR and atrioventricular delay during anesthesia CONCLUSION AND CLINICAL RELEVANCEN: A higher heart rate in anesthesia should be interpreted as a compensation for reduced heart performance. The results of the present study indicate the necessity for establishing normal heart values in conscious and anesthetized pigeons.

Analysis of the B-Type Natriuretic Peptide and the Aminoterminal-Pro-B-Type Natriuretic Peptide in Different Parrot, Raptor and Owl Species

The B-type natriuretic peptide (BNP), a member of the natriuretic peptide family and a cardiac hormone, is produced mainly in the ventricular myocytes and released into the circulation due to mechanical stimuli during an increasing cardiac wall stretch. BNP has a significant role in the regulation of the cardiovascular system and body fluid. The concentration of this hormone and of the biologically inactive amino-terminal-prohormone in the blood plasma is a helpful diagnostic tool for detecting cardiovascular diseases in human medicine and can be used as a prognostic marker for the risk of mortality, whilst such a tool does not exist for avian medicine. To date, the amino acid sequence of BNP is not known for many of the species commonly presented in avian consultation. In this study, the amino acid sequence of BNP and the prepropeptide was described for 12 parrot species as well as 3 raptor and 3 owl species by polymerase chain reaction (PCR) after RNA isolation from the heart. The results showed a high similarity between the amino acid sequences in the mature peptide region of the BNP. The prepropeptide showed several differences between the examined species, some of them shared by closely related species.

The prevalence of Leucocytozoon spp. in nestlings of three wild raptor species including implications on haematological and blood chemistry values

Leucocytozoonosis is a vector-borne infection of birds, caused by members of the haemosporidian genus Leucocytozoon. The clinical presentation may range from asymptomatic to severe disease. Consequences of Leucocytozoon infection on blood profiles remain to be described, especially for different host species in the wild. In the current study, the prevalence of Leucocytozoon infection was determined in wild nestlings of three European raptor species, the common buzzard (Buteo buteo, n = 464), red kite (Milvus milvus, n = 46) and northern goshawk (Accipiter gentilis, n = 18). Among 528 nestlings, 51.9% (n = 274) were infected with Leucocytozoon spp., whereby the highest prevalence was found in common buzzards (54.9%), followed by red kites (32.6%) and northern goshawks (22.2%). For a subset of 87 individuals (50 common buzzards, 29 red kites, 8 northern goshawks), a detailed analysis of differential leukocyte counts and several blood chemistry parameters in response to infection was conducted: AP (alkaline phosphatase), AST (aspartate aminotransferase), GLDH (glutamate dehydrogenase), LDH (lactate dehydrogenase), GGT (gamma glutamyl transferase), CK (creatine kinase), BuChE (butyrylcholinesterase), BA (bile acids), ALB (albumin) and TP (total protein). Even though in the physiological range, infected nestlings displayed significantly increased levels of heterophils, aspartate aminotransferase, lactate dehydrogenase, bile acids and butyrylcholinesterase, but decreased lymphocyte and monocyte values compared to uninfected ones. Furthermore, significant species differences with regard to blood parameters, but no sex differences were found. Overall, obtained results show a high prevalence, but a low pathogenicity of Leucocytozoon spp. in wild raptor chicks, presumably resulting from coevolutionary adaptation, but show signatures of infection in the haematological and blood chemistry profiles.

•

Leucocytozoon prevalence in nestlings of three wild raptor species was 52%.

•

Common buzzards (Buteo buteo) showed the highest prevalence (55%).

•

Examined blood parameter values varied with species, age and infection status.

•

Leucocytozoon infections were associated with increased AST and BuChE.

•

Leucocytozoon infections in Accipitridae nestlings seem to be of minor pathogenicity.

[Extraction of diseased mandibular incisors in the guinea pig (Cavia porcellus) via ventral mandibular trepanation]

OBJECTIVE

This retrospective study describes the use of ventral mandibular trepanation for extraction of diseased mandibular incisors in guinea pigs and evaluates the clinical outcome.

MATERIAL AND METHODS

In 40 guinea pigs with abnormal feed intake, at least one mandibular incisor was extracted via ventral mandibular trepanation. The diagnosis of primary mandibular incisor disease was based on the findings of the clinical general examination and intraoral and radiographic examination under general anesthesia. Following the procedure radiographs were taken and the patients were monitored and cared for as inpatients until discharge. Regular re-examinations were undertaken in order to assess and treat the surgical sites.

RESULTS

A total of 42 altered mandibular incisors were extracted via ventral mandibular trepanation. Macrodonts (25/42) and periapical and alveolar changes (8/42) were the main reasons for extraction. Tooth residuals of unknown etiology (4/42) as well as such resulting from failed conventional extraction attempt using luxators (3/42) and traumatically loosened incisors (2/42) were also extracted. Tooth-associated jaw abscesses were found in 40 % of the guinea pigs. In addition, 40 % of the animals presented secondary elongation of the molars requiring occlusal equilibration. In all patients, it was possible to completely remove the altered incisors or residuals. On average, independent feed intake was observed 2 days after surgery and the animals were discharged. Complete healing of the surgical site was observed on average after 39 days (minimum 9 days, maximum 98 days). A total of 22 animals were evaluated 6 months following surgery and showed no further tooth-associated complaints.

CONCLUSION AND CLINICAL RELEVANCE

Ventral mandibular trepanation allows diseased mandibular incisors in guinea pigs to be removed entirely within one surgery and thus represents a curative procedure. Unlike the conventional extraction with luxators, it does not bear the risk of tooth fractures resulting in tooth fragments remaining in the alveolus.

Experimental evidence for proarrhythmic effects of nonsteroidal anti-inflammatory drugs in a sensitive whole-heart model

BACKGROUND

Previous studies have raised serious concerns on cardiovascular safety of widely prescribed nonsteroidal anti-inflammatory drugs (NSAIDs). Therefore, the aim of this study was to characterize the electrophysiological effects of certain NSAIDs in an established whole heart model of proarrhythmia.

METHODS AND RESULTS

Thirty-eight hearts of New Zealand White rabbits were harvested and retrogradely perfused employing a Langendorff setup, and electrophysiology studies were performed to investigate action potential duration at 90% of repolarization (APD₉₀ ), QT intervals, and effective refractory period (ERP). After generating baseline data, hearts were perfused with ibuprofen (Group 1, n = 12; 10 and 30 μM), indomethacin (Group 2, n = 13; 10 and 20 μM) and diclofenac (Group 3, n = 13; 10 and 20 μM), respectively, and the pacing protocols were repeated for each concentration. In all groups, perfusion with the NSAIDs resulted in a significant and reproducible shortening of APD₉₀ and QT interval. In all groups, the arrhythmia susceptibility was significantly raised as occurrence of monomorphic ventricular tachycardia under programmed ventricular stimulation was significantly increased under perfusion with ibuprofen, indomethacin and diclofenac in all concentrations.

CONCLUSION

The perfusion with ibuprofen, indomethacin and diclofenac in commonly used doses raised the arrhythmia susceptibility in an established rabbit whole-heart model while APD shortening and shortened ERP seem to be crucial for arrhythmogenesis.

The B-type natriuretic peptide of the Congo and Timneh grey parrot

In captivity, cardiovascular diseases are common in grey parrots. The diagnosis of these diseases in living birds is difficult, and new diagnostic possibilities would be desirable. The heart is an important endocrine organ in which cardiomyocytes synthetise B-type natriuretic peptide (BNP) and release it into the bloodstream. This hormone has a significant role in cardiovascular and body fluid regulation. The blood concentration of BNP is used in human medicine and small animal medicine as a diagnostic tool in the identification of heart diseases and as a prognostic marker for the risk of mortality. The nucleotide and amino acid sequence of BNP was described in Congo (n = 4) and Timneh (n = 3) grey parrots by PCR after RNA isolation from the atria and ventricles. The results showed a high similarity between the nucleotide sequences of the grey parrots’ BNP and the already known sequence of this hormone in chickens. The amino acid sequence of the mature peptide region is consistent in these three species. BNP plasma concentration could be a possible blood parameter for identifying clinically manifest cardiovascular diseases in grey parrots as it is in other species.

Proarrhythmic potential of metoclopramide in a sensitive whole-heart model

BACKGROUND

Metoclopramide (MCP) is a dopamine D₂ -receptor antagonist, mainly used to treat post-operative or chemotherapy-induced nausea. While it is very effective in the cure of gastric symptoms, MCP can cause severe neurologic side effects. Furthermore, there is growing evidence for severe arrhythmic side effects resulting from inhibitory effects on cardiac sodium and potassium channels.

METHODS AND RESULTS

Thirteen hearts of New Zealand white rabbits were retrogradely perfused, and electrophysiology studies were performed to obtain action potential duration (APD₉₀ ) and effective refractory period (ERP). After generating baseline data, the hearts were perfused with increasing concentrations of metoclopramide (MCP 10 µM, MCP 50 µM, MCP 100 µM) and the standardized protocol was repeated for each concentration. Perfusion with MCP resulted in a significant prolongation of APD₉₀ and QT interval. In parallel, the incidence of ventricular tachycardias was significantly increased by high doses of MCP.

CONCLUSION

This is the first experimental study that investigated the effect of increasing doses of metoclopramide on a sensitive whole-heart model of proarrhythmia. MCP led to a significant increase in action potential duration and QT interval; meanwhile, the number of ventricular tachycardias was significantly increased.

Diastolic and Systolic Longitudinal Myocardial Velocities of Healthy Racing Pigeons (Columba livia f. domestica) Measured by Tissue Doppler Imaging

Tissue Doppler imaging (TDI) is a noninvasive sonographic method of acquiring and quantifying myocardial velocities. This technique is used in human and small animal medicine to diagnose cardiac diseases. Using this technique, we evaluated the longitudinal myocardial peak velocities of the interventricular septum, and the left and right ventricular free walls in the systole and diastole in 40 racing pigeons. The TDI examinations confirmed the movement of the heart base toward the apex in the systole and away from the apex in the diastole. Inhomogeneous distribution of the myocardial velocities with a statistically significant velocity gradient from the basal to the apical myocardial segments was found. The left and right free walls have significantly higher myocardial velocities than the myocardium of the septum. The myocardial velocities during active ventricular filling were significantly higher in the right ventricular free wall than in the left one. The validation of the method resulted in coefficients of variation between 3% and 33% for the systolic and 3% and 75% for the diastolic individual myocardial velocities. Weekly repeated measurements resulted in variation coefficients between 3% and 45% for systolic and diastolic myocardial velocities, respectively.

Clinical characteristics and outcome of patients over 60 years with Hodgkin lymphoma treated in Switzerland

Hodgkin lymphoma (HL) in older patients appears to be a different disease compared with younger patients with historically lower survival rates. This is related to a variety of factors, including increased treatment-related toxicity, the presence of comorbidities, and biologic differences. In order to better assess the clinical characteristics, treatment strategies, and outcome of this particular population, we conducted a population-based, retrospective analysis including 269 patients with HL older than 60 years (median age 71 years, range 60-94), treated between 2000 and 2017 in 15 referral centers across Switzerland. Primary endpoints were overall survival (OS), progression-free survival (PFS), and cause-specific survival (CSS). The vast majority of patients were treated with curative intent, either with a combined modality approach (chemotherapy followed by radiation therapy) or with systemic therapy. At a median follow-up of 6.6 years (95% confidence interval [CI], 6.0-7.6), 5-year PFS was 52.2% (95% CI, 46.0-59.2), 5-year OS was 62.5% (95% CI, 56.4-69.2), and 5-year CSS was 85.1.8% (95% CI, 80.3-90.1) for the entire cohort. A significant difference in terms of CSS was observed for patients older than 71 years in comparison to patients aged 60-70 years (hazard ratio 2.6, 1.3-5.0, p = 0.005). Bleomycin-induced lung toxicity (BLT) was documented in 26 patients (17.7%) out of the 147 patients exposed to this compound and was more frequent in patients older than 71 years (15/60, 25%). Outcome of HL pts older than 71 years appeared to decrease substantially in comparison to the younger counterpart. Treatment-related toxicities appeared to be relevant, in particular, BLT. New, potentially less toxic strategies need to be investigated in prospective clinical trials in this particular frail population.

Treatment of the Clinical Symptoms of Osteoarthritis in the Elbow Joints of Dogs Using Nuclear Magnetic Resonance Therapy: A Randomized, Double-Blinded Trial

Objectives: To evaluate the effects of nuclear magnetic resonance therapy (MBST®) on the clinical symptoms of osteoarthritis (OA) in the elbow joints of dogs.

Methods: In this double-blind study, 28 dogs with lameness caused by OA in the elbow joint were randomly allocated to two groups: 14 dogs received nuclear magnetic resonance (NMR) therapy [treatment group (TG)], and 14 dogs received a placebo [placebo group (PG)] over a period of 7 consecutive days. Visual and objective gait analyses were performed before treatment (M1) and at 3 (M2) and 6 months (M3) after treatment. At M2 and M3 Symmetry indices (SI) of the peak vertical force (PVFz) and the vertical impulse (IFz), lameness scores, and pain scores were compared with their values at M1 to calculate the overall treatment effectiveness (OTE) score. We also documented additional pain medication and medical physiotherapy during the time of study. Finally, we measured the range of motion (ROM) in order to evaluate the functional development of the joint.

Results: The median OTE score of dogs in the TG indicates no change after 3 month and was improved after 6 months of treatment. There was an improvement of the median OTE score of dogs in the PG after 3 months of treatment. Further, the OTE scores of dogs in the PG were actually worse after 6 months.

Nevertheless, there were no significance differences in SIPVFz, SIIFz, ROM, and lameness- and pain scores between the TG and PG at M1, M2, and M3. When considering all collected parameters (excluding the ROM) to calculate the OTE, no significant difference between groups was measurable for the OTE.

Conclusion: There was a positive effect of NMR therapy (MBST®) on the treatment of OA in dogs. However, future studies should investigate the mechanisms underlying NMR therapy and the pathophysiology of OA to provide optimal treatments for patients.

Clinical Significance: Our results demonstrated that the response to NMR treatment was individualized for each dog. As an integral way of treating dogs with chronic OA, NMR therapy may be an alternative therapeutic approach to support traditional medications.

Divergent Electrophysiological Effects of Loperamide and Naloxone in a Sensitive Whole-Heart Model

Several case reports suggest QT prolongation leading to ventricular arrhythmias with fatal outcome after intoxication with the μ-opioid receptor agonist and anti-diarrheal agent loperamide. The number of cases of loperamide misuse are growing due to its potential stimulating effects. Loperamide intoxications can be treated by naloxone. However, previous reports described a further QT prolongation associated with naloxone administration. Therefore, the aim of this study was to investigate the effects of loperamide and naloxone on the cardiac electrophysiology in a sensitive whole-heart model. Twenty-six hearts of New Zealand White rabbits were retrogradely perfused in a modified Langendorff apparatus. Monophasic action potentials were recorded by endo- and epicardially positioned catheters. Hearts were stimulated at different cycle lengths, thereby obtaining action potential duration at 90% of repolarization (APD₉₀) and QT intervals. Programmed ventricular stimulation was used to assess ventricular vulnerability. Fourteen hearts were perfused with ascending concentrations of loperamide (0.2 μM, 0.35 μM, and 0.5 μM) after obtaining baseline data. Another 12 hearts were treated with naloxone (0.1 μM, 0.5 μM, 2 μM). Loperamide led to a significant increase in QT interval, APD₉₀, and ventricular tachycardia (VT) episodes. In contrast, naloxone led to a decrease in QT interval and APD₉₀. Accordingly, the number of VT episodes was unaltered. To the best of our knowledge, this is the first experimental study that investigated the effects of loperamide and naloxone in a whole-heart model. Loperamide led to a significant increase in action potential duration and QT interval. Simultaneously, the number of ventricular tachycardias was significantly increased. In contrast, naloxone led to a shortening of the action potential duration without altering arrhythmia susceptibility.

SARS-CoV-2-derived peptides define heterologous and COVID-19-induced T cell recognition

T cell immunity is central for the control of viral infections. To characterize T cell immunity, but also for the development of vaccines, identification of exact viral T cell epitopes is fundamental. Here we identify and characterize multiple dominant and subdominant SARS-CoV-2 HLA class I and HLA-DR peptides as potential T cell epitopes in COVID-19 convalescent and unexposed individuals. SARS-CoV-2-specific peptides enabled detection of post-infectious T cell immunity, even in seronegative convalescent individuals. Cross-reactive SARS-CoV-2 peptides revealed pre-existing T cell responses in 81% of unexposed individuals and validated similarity with common cold coronaviruses, providing a functional basis for heterologous immunity in SARS-CoV-2 infection. Diversity of SARS-CoV-2 T cell responses was associated with mild symptoms of COVID-19, providing evidence that immunity requires recognition of multiple epitopes. Together, the proposed SARS-CoV-2 T cell epitopes enable identification of heterologous and post-infectious T cell immunity and facilitate development of diagnostic, preventive and therapeutic measures for COVID-19.

Comparative assessment of left atrial volume in healthy cats by two-dimensional and three-dimensional echocardiography

Background

The left atrium (LA) is an important prognostic parameter in cardiac pathologies of cats. Its size is currently measured in one-dimensional methods, while human medicine considers two- and three-dimensional echocardiography as standard. The objectives of this study were to compare monoplane, biplane, triplane and real-time three dimensional echocardiography for volumetric measurement of the left atrium in healthy cats and establish a reference interval for further studies on cats with heart disease. Additionally, the influence of age, sex and weight on left atrial volume (LAV) was tested.

Results

One dimensional monoplane Simpson method of discs (SMOD) in the right parasternal four chamber view (r4) and the left apical 2 chamber view (l2) as well as biplane SMOD had no significant difference for left atrial maximum volume (LAMax). They can be used as equivalent in future studies and one common reference range was set up (1.96 ± 0.54 ml). Those three methods produced significantly higher volumes than triplane echocardiography (RTTPE) and real time three dimensional echocardiography (RT3DE) using TomTec® software. LA volumetry with RTTPE and RT3DE-TomTec™ was more feasible than expected, but low RT3DE image quality was the main reason for excluding patients. Neither age nor weight had an influence on LA volume in healthy cats. Male LAV results were only slightly, but in 2D and RTTPE significantly higher than those of female cats with a range of + 10.46% to + 19.58%.

Conclusions

Monoplane, biplane, triplane and real-time three dimensional echocardiography were feasible for LA volumetry in healthy cats and showed acceptable intra- and interobserver variability. One common LAMax reference range for monoplane r4, l2 and biplane SMOD was set up. Raw data can be used for LA volumes and does not need to be correlated with the cat’s weight or age. Male cats have only slightly but significantly larger atria than females in 2D and RTTPE. Therefore, under reservation, also sex related limit values were defined.

A structural UGDH variant associated with standard Munchkin cats

Background

Munchkin cats were founded on a naturally occurring mutation segregating into long-legged and short-legged types. Short-legged cats showed disproportionate dwarfism (chondrodysplasia) in which all four legs are short and are referred as standard Munchkin cats. Long-legged animals are referred as non-standard Munchkin cats. A previous study using genome-wide single nucleotide polymorphisms (SNPs) for genome-wide association analysis identified a significantly associated region at 168–184 Mb on feline chromosome (FCA) B1.

Results

In this study, we validated the critical region on FCA B1 using a case-control study with 89 cats and 14 FCA B1-SNPs. A structural variant within UGDH (NC_018726.2:g.173294289_173297592delins108, Felis catus 8.0, equivalent to NC_018726.3:g.174882895_174886198delins108, Felis catus 9.0) on FCA B1 was perfectly associated with the phenotype of short-legged standard Munchkin cats.

Conclusion

This UGDH structural variant very likely causes the chondrodysplastic (standard) phenotype in Munchkin cats. The lack of homozygous mutant phenotypes and reduced litter sizes in standard Munchkin cats suggest an autosomal recessive lethal trait in the homozygote state. We propose an autosomal dominant mode of inheritance for the chondrodysplastic condition in Munchkin cats.

Concomitant Treatment with Proton Pump Inhibitors and Cephalosporins Does Not Enhance QT-Associated Proarrhythmia in Isolated Rabbit Hearts

Recent results from data mining analyses and reports of adverse drug events suggest a QT-prolonging drug-drug interaction resulting from the combination of distinct proton pump inhibitors and cephalosporins. Therefore, this study aimed at investigating the effect of the suspected QT-prolonging combinations of lansoprazole + ceftriaxone and esomeprazole + cefazolin, respectively. 26 hearts of New Zealand White rabbits were retrogradely perfused and paced at different cycle lengths. After generating baseline data, the hearts were assigned to two groups: In group 1, hearts were treated with 5 µM lansoprazole. Thereafter, 200 µM ceftriaxone was infused additionally. Group 2 was perfused with 10 µM esomeprazole followed by 250 µM cefazolin. In group 1, lansoprazole did not significantly alter QT intervals and APD₉₀. Additional treatment with ceftriaxone significantly shortened QT interval, APD₉₀ and slightly reduced dispersion of repolarization compared to sole lansoprazole infusion. In group 2, esomeprazole led to a significant shortening of the QT interval without altering APD₉₀ or dispersion. Additional treatment with the antibiotic cefazolin further shortened QT interval, APD₉₀ and reduced the dispersion of repolarization. Incidence of ventricular arrhythmias was not significantly altered in both groups. This is the first experimental whole-heart study that investigated the impact of a concomitant treatment with proton pump inhibitors and cephalosporins. In contrast to previous reports, the combination of both agents did not cause QT prolongation but instead shortened QT interval and action potential duration. As a consequence, no triggered activity occurred in the presence of a stable dispersion of repolarization.

Microsurgical reconstruction affects the outcome in a translational mouse model for Achilles tendon healing

Background

Animal models are one of the first steps in translation of basic science findings to clinical practice. For tendon healing research, transgenic mouse models are important to advance therapeutic strategies. However, the small size of the structures complicates surgical approaches, histological assessment, and biomechanical testing. In addition, available models are not standardized and difficult to compare. How surgery itself affects the healing outcome has not been investigated yet. The focus of the study was to develop a procedure that includes a transection and microsurgical reconstruction of the Achilles tendon but, unlike other models, preserves the sciatic nerve. We wanted to examine how distinct parts of the technique influenced healing.

Methods

For this animal model study, we used 96 wild-type male C57BL/6 mice aged 8–12 weeks. We evaluated different suture techniques and macroscopically confirmed the optimal combination of suture material and technique to minimize tendon gap formation. A key element is the detailed, step-by-step illustration of the surgery. In addition, we assessed histological (Herovici and Alcian blue staining) outcome parameters at 1–16 weeks postoperatively. Microcomputed tomography (micro-CT) was performed to measure the bone volume of heterotopic ossifications (HOs). Biomechanical analyses were carried out using a viscoelastic protocol on the biomechanical testing machine LM1.

Results

A modified 4-strand suture combined with a cerclage for immobilization without transection of the sciatic nerve reliably eliminated gap formation. The maximal dorsal extension of the hindlimb at the upper ankle joint from the equinus position (limited by the immobilization cerclage) increased over time postoperatively (operation: 28.8 ± 2.2°; 1 week: 54 ± 36°; 6 weeks: 80 ± 11.7°; 16 weeks: 96 ± 15.8°, p > 0.05). Histological staining revealed a maturation of collagen fibres within 6 weeks, whereas masses of cartilage were visible throughout the healing period. Micro-CT scans detected the development of HOs starting at 4 weeks and further progression at 6 and 16 weeks (bone volume, 4 weeks: 0.07604 ± 0.05286 mm³; 6 weeks: 0.50682 ± 0.68841 mm³; 16 weeks: 2.36027 ± 0.85202 mm³, p > 0.001). In-depth micro-CT analysis of the different surgical elements revealed that an injury of the tendon is a key factor for the development of HOs. Immobilization alone does not trigger HOs. Biomechanical properties of repaired tendons were greatly altered and remained inferior 6 weeks after surgery.

Conclusion

With this study, we demonstrated that the microsurgical technique greatly influences the short- and longer-term healing outcome. When the sciatic nerve is preserved, the best surgical reconstruction of the tendon defect is achieved by a 4-strand core suture in combination with a tibiofibular cerclage for postoperative immobilization. The cerclage promotes a gradual increase in the range of motion of the upper ankle joint, comparable with an early mobilization rehabilitation protocol. HO, as a key mechanism for poor tendon healing, is progressive and can be monitored early in the model.

The translational potential of this article

The study enhances the understanding of model dependent factors of healing. The described reconstruction technique provides a reproducible and translational rodent model for future Achilles tendon healing research. In combination with transgenic strains, it can be facilitated to advance therapeutic strategies to improve the clinical results of tendon injuries.

Color Flow Doppler Echocardiography in Healthy Racing Pigeons (Columba livia f. domestica) and the Evidence of Physiological Blood Flow Vortex Formations

In avian medicine, Doppler sonographic techniques are used to visualize and estimate blood flow in the heart. In the literature there is a lack of standardized studies of the use of color Doppler flow on healthy avian species. For this purpose, we examined blood flow in the heart in the four-chamber view of clinically healthy awake racing pigeons (n = 43) by color flow Doppler sonography. With this technique the diastolic and systolic blood flow in the heart chambers and the heart valve regions were well visualized. However, the pulse repetition frequency must be adapted to the specific blood flow velocities of the heart region to be measured to reduce aliasing in higher velocities and to visualize blood flow of lower velocities. With the help of color Doppler imaging in the four-chamber view, typical physiological atrial and ventricular blood flow vortex formations were visualized in the avian heart for the first time. In the left ventricle an asymmetric vortex ring in the passive and active ventricular filling, in the right ventricle a great counter-clockwise blood vortex in the active ventricular filling, in the left atrium a vortex clockwise, and in the right atrium counter-clockwise were observed. The knowledge of these physiological blood flow vortices is important to identify pathological blood flow.

Lenalidomide added to standard intensive treatment for older patients with AML and high-risk MDS

More effective treatment modalities are urgently needed in patients with acute myeloid leukemia (AML) of older age. We hypothesized that adding lenalidomide to intensive standard chemotherapy might improve their outcome. After establishing a safe lenalidomide, dose elderly patients with AML were randomly assigned in this randomized Phase 2 study (n = 222) to receive standard chemotherapy ("3 + 7") with or without lenalidomide at a dose of 20 mg/day 1-21. In the second cycle, patients received cytarabine 1000 mg/m² twice daily on days 1-6 with or without lenalidomide (20 mg/day 1-21). The CR/CRi rates in the two arms were not different (69 vs. 66%). Event-free survival (EFS) at 36 months was 19% for the standard arm versus 21% for the lenalidomide arm and overall survival (OS) 35% vs. 30%, respectively. The frequencies and grade of adverse events were not significantly different between the treatment arms. Cardiovascular toxicities were rare and equally distributed between the arms. The results of the present study show that the addition of lenalidomide to standard remission induction chemotherapy does not improve the therapeutic outcome of older AML patients. This trial is registered as number NTR2294 in The NederlandsTrial Register (www.trialregister.nl).

[Blood gas analysis in rabbits during a completely antagonizable anesthesia with special focus on oxygen management]

OBJECTIVE

The aim of this study was to evaluate the consequences of different oxygen supplementation methods on arterial blood gas analysis during an injectable anesthesia.

MATERIAL AND METHODS

A total of 29 rabbits with dental diseases (tooth elongation) were sampled before, during and after coronal reduction. Oxygen was provided either via the flow-by method or with a nasal oxygen tube; the control group breathed room air.

RESULTS

All patients receiving oxygen developed respiratory acidosis that intensified during the course of anesthesia. Furthermore, these groups experienced reduced respiratory rates intraoperatively, nevertheless they showed elevated oxygen parameters (hyperoxemia) in the arterial blood gas analysis. No significant differences could be demonstrated between the 2 oxygen providing methods. In the control group, pH remained stable, the oxygen parameters however decreased to less than 80 mmHg (hypoxemia).

CONCLUSIONS

Although there were no clinical consequences of hypoxemia or hyperoxemia, moderate oxygen support during an injectable anesthesia is recommended due to the development of hypoxemia. A balance between oxygen supply and oversupply needs to be established to aid in avoiding oxygen toxicity.

Specific anatomy and radiographic illustration of the digestive tract and transit time of two orally administered contrast media in Inland bearded dragons (Pogona vitticeps)

The aim of this study was to describe the specific gross and radiographic anatomy of the digestive tract of inland bearded dragons (Pogona vitticeps). Eleven bearded dragon cadavers of both sexes (6 females, 5 males) were dissected to examine, measure, and document the specific gross anatomy of the alimentary canal. Measurements collected from the cadavers included snout-vent length, total length of the alimentary canal, and the lengths of the individual sections of the gastrointestinal tract, including the esophagus, stomach, small intestine, ampulla coli, isthmus coli, rectum, and the distance from the coprodeum to the vent opening. Twenty-two healthy adult bearded dragons (13 females, 9 males) maintained under standardized husbandry conditions underwent a physical examination, blood collection, and whole-body dorsoventral and lateral survey radiographs; these animals were used to provide the radiographic images of the complete digestive tract. For the subsequent contrast passage studies, two different contrast media, barium sulfate (BaSO₄, Barilux suspension) and an iodinated ionic radiocontrast agent (Sodium meglumine amidotrizoate [SMAT], Gastrografin), were used. Water-diluted Barilux suspension (dose 9 ml/kg) was administered orally to 5 bearded dragons, while Gastrografin (dose 5ml/kg) was administered orally to 21 bearded dragons. Four animals were used for both contrast media studies, but received a break of four weeks in between. Dorsoventral and laterolateral radiographs were collected at 0 (baseline), 15, 30, and 45 minutes and 1, 2, 3, 4, 5, 6, 8, 10, 12, 24, 30, and 36 hours after each contrast medium was administered. Both contrast media were found to illustrate the alimentary tracts in the adult bearded dragons. Transit time was substantially faster with SMAT, and SMAT illustrated the entire gastrointestinal tract within 36 hours; BaSO₄ did not fully illustrate the gastrointestinal tract in 36 hours. These results might serve as a guideline for the interpretation of subsequent contrast studies in this lizard species.

Antiarrhythmic effect of antazoline in experimental models of acquired short- and long-QT-syndromes

Aims

Antazoline is a first-generation antihistamine with antiarrhythmic properties. This study examines potential electrophysiological effects of antazoline in short-QT-syndrome (SQTS) and long-QT-syndrome (LQTS).

Methods and results

Sixty-five rabbit hearts were Langendorff-perfused. Action potential duration at 90% of repolarization (APD90), QT-interval, spatial dispersion (DISP), and effective refractory period (ERP) were measured. The IK, ATP-opener pinacidil (1 µM, n = 14) reduced APD90 (-14 ms, P < 0.01), QT-interval (-14 ms, P < 0.01), and ERP (-11 ms, P < 0.01), thus simulating acquired SQTS. Additional infusion of 20 µM antazoline prolonged repolarization. Under baseline conditions, ventricular fibrillation (VF) was inducible in 5 of 14 hearts (10 episodes) and in 5 of 14 pinacidil-treated hearts (21 episodes, P = ns). Antazoline significantly reduced induction of VF (0 episodes, P < 0.05 each). Further 17 hearts were perfused with 100 µM sotalol and 17 hearts with 300 µM erythromycin to induce acquired LQTS2. In both groups, prolongation of APD90, QT-interval, and ERP was observed. Spatial dispersion was increased (sotalol: +26 ms, P < 0.01; erythromycin: +31 ms, P < 0.01). Additional infusion of antazoline reduced DISP (sotalol: -22 ms, P < 0.01; erythromycin: -26 ms, P < 0.01). Torsade de pointes (TdP) occurred in 6 of 17 sotalol-treated (22 episodes, P < 0.05 each) and in 8 of 17 erythromycin-treated hearts (96 episodes P < 0.05 each). Additional infusion of antazoline completely suppressed TdP in both groups (P < 0.05 each). Acquired LQTS3 was induced by veratridine (0.5 µM, n = 17) and similar results were obtained (APD90: +24 ms, P < 0.01, QT-interval: +58 ms, P < 0.01, DISP: +38 ms, P < 0.01). Torsade de pointes occurred in 10 of 17 hearts (41 episodes, P < 0.05 each). Antazoline significantly reduced TdP (2 of 17 hearts, 4 episodes, P < 0.05 each).

Conclusion

Antazoline significantly reduced induction of VF in an experimental model of acquired SQTS. In three experimental models of acquired LQTS, antazoline effectively suppressed TdP.

Diminished apoptosis in hypoxic porcine retina explant cultures through hypothermia

Simulation of hypoxic processes in vitro can be achieved through cobalt chloride (CoCl2), which induces strong neurodegeneration. Hypoxia plays an important role in the progression of several retinal diseases. Thus, we investigated whether hypoxia can be reduced by hypothermia. Porcine retinal explants were cultivated for four and eight days and hypoxia was mimicked by adding 300 µM CoCl2 from day one to day three. Hypothermia treatment (30 °C) was applied simultaneously. Retinal ganglion, bipolar and amacrine cells, as well as microglia were evaluated via immunohistological and western blot analysis. Furthermore, quantitative real-time PCR was performed to analyze cellular stress and apoptosis. In addition, the expression of specific marker for the previously described cell types were investigated. A reduction of ROS and stress markers HSP70, iNOS, HIF-1α was achieved via hypothermia. In accordance, an inhibition of apoptotic proteins (caspase 3, caspase 8) and the cell cycle arrest gene p21 was found in hypothermia treated retinae. Furthermore, neurons of the inner retina were protected by hypothermia. In this study, we demonstrate that hypothermia lowers hypoxic processes and cellular stress. Additionally, hypothermia inhibits apoptosis and protects neurons. Hence, this seems to be a promising treatment for retinal neurodegeneration.

Validation of whole-body radiographs for examining uterine disorders in sexually intact female rabbits

OBJECTIVE

The present study evaluated whole-body radiographs of female rabbits regarding uterine disorders.

MATERIAL AND METHODS

Based on radiographs of 143 rabbits, visibility, size, shape and density of the uterus, nutritional status of the animal and possible metastasis in other organs were examined. A suspected diagnosis was deduced. The radiological findings were compared with the results of the histopathological examination.

RESULTS

Especially the nutritional status was important regarding the visibility of the genital tract. In 99 of the 130 visible uteri (76.2 %), a pathological alteration was detected. Thereof, endometrial hyperplasia was most frequently seen (63.6 %), followed by neoplasia (altogether 42.4 %, 39.4 % of these with adenocarcinoma), endometritis (35.4 %) and other diseases (18.2 %). Forty-six rabbits showed only one disease, 42 rabbits had two, 10 rabbits three and one rabbit four different diseases. Among 13 of the 143 uteri that were not visible in the radiograph four were altered pathologically. In 31 of the 130 rabbits with a visible uterine region (21.7 %) the uterus was unaltered. Visualising the uterus proved impossible in two of four skinny rabbits (2.8 %), whereas in all 39 obese rabbits the uterus was visible. Only in one of the four skinny rabbits was the uterus without pathological findings and six of the 39 obese rabbits showed no pathological alteration, visibility notwithstanding. Calcification indicated a tumourous occurrence in 23 of 53 cases. Except for one rabbit, the mineralised neoplasia was an adenocarcinoma (n = 22). Five animals with calcification in the uterine region showed no abnormalities. Of these, the calcification of four animals was no longer existent in the radiograph after ovariohysterectomy. Neoplastic changes in the uterus did not always show calcification. In 20 of the 44 patients with uterine neoplasia no calcification was seen. Changes in uterine size occurred in 118 of the 143 rabbits (82.5 %) and alteration of the uterine shape in 109 of the 143 rabbits (67.1 %).

CONCLUSION AND CLINICAL RELEVANCE

Thus, the above presented parameters - especially size, shape and mineralisation - are very important regarding uterine diseases.

[Gastric dilatation-volvulus syndrome in guinea pigs (Cavia porcellus)]

AIM

The aim of this study was to present an overview of the gastric dilatation-volvulus syndrome in guinea pigs.

MATERIAL AND METHODS

Four cases of gastric dilatation-volvulus syndrome in guinea pigs were evaluated. Its clinical presentation, diagnostic options, therapeutical approach and possible alternatives thereof were discussed. Furthermore, risk factors for the disease as well as pathophysiology and etiology were discussed and compared to the situation in other species.

RESULTS

The presented cases indicate that in addition to anamnesis and clinical examination, radiography is the means of choice to diagnose a gastric dilatation-volvulus syndrome in guinea pigs. All four patients underwent surgery. One animal was euthanized during surgery, the other three guinea pigs died postoperatively.

CONCLUSION AND CLINICAL RELEVANCE

Gastric dilatation-volvulus syndrome in guinea pigs is considered to be an emergency and, therefore, immediate stabilization is necessary, as well as surgery in almost all cases. The prognosis of this disease is guarded to poor.

The influence of anesthesia with isoflurane on the pulmonary and aortic blood flow of Racing Pigeons (Columba livia f. domestica) measured by pulsed wave Doppler echocardiography

Doppler echocardiographic examinations are an important technique for evaluating the blood flow also in avian cardiology. The influence of anesthesia on the blood flow in the heart is in detail unknown for the most avian species. The present study investigated the influence of an isoflurane anesthesia on the systolic blood flow of the aorta and the pulmonary artery in the area of the heart valves examined by pulsed wave Doppler sonography in Racing Pigeons (Columba livia f. domestica, n = 43). Measurements were taken in conscious and anaesthetized birds in the left (aorta) and right (pulmonary artery) parasternal longitudinal horizontal heart view. The results demonstrated a significant decrease in heart rate and systolic peak flow velocities as well as prolonged ejection times during anesthesia. A positive correlation of systolic peak flow velocity and heart rate could be demonstrated, especially for the pulmonary artery in conscious pigeons. The aortic systolic peak flow velocity and heart rate showed a significantly negative correlation in anaesthetized pigeons. These correlations should be borne in mind in the echocardiographic examination, especially of conscious birds. A higher incidence of second degree atrioventricular block (30.23%) was induced by anesthesia in the Racing Pigeons. These results of the present study indicate the necessity for establishing normal heart values in conscious and anaesthetized individuals.

Additive Proarrhythmic Effect of Combined Treatment with QT-Prolonging Agents

Drug combinations may elevate the risk of proarrhythmia. The aim of the present study was to investigate whether combinations of non-cardiovascular agents induce an additive increase in the proarrhythmic risk. In 12 female rabbit hearts, a drug combination of cotrimoxazole (300 µM), ondansetron (5 µM) and domperidone (1 µM) was infused after obtaining baseline data. In another 13 hearts, a combination of cotrimoxazole (300 µM), ondansetron (5 µM) and erythromycin (300 µM) was infused. Monophasic action potentials and ECG displayed a significant QT prolongation in all groups. This was accompanied by a significant increase in action potential duration. Of note, addition of each drug resulted in a further increase in the QT interval. Furthermore, a significant elevation of spatial dispersion of repolarization was observed. Lowering of potassium concentration in bradycardic AV-blocked hearts provoked early afterdepolarizations and torsade de pointes (TDP) in both study groups. Under baseline conditions, no episodes of TDP recorded. After administration of the first agent, TDP occurred in 5 of 12 hearts (37 episodes) and 5 of 13 hearts (26 episodes), respectively. After additional infusion of the second drug, TDP were recorded in 7 of 12 hearts (55 episodes) and 8 of 13 hearts (111 episodes). After additional infusion of the third drug, TDP occurred in 11 of 12 hearts (118 episodes) and 9 of 13 hearts (88 episodes). Combined treatment with several non-cardiovascular QT-prolonging agents resulted in a remarkable occurrence of proarrhythmia. An additive and significant prolongation of cardiac repolarization combined with an increased spatial dispersion of repolarization represents the underlying electrophysiological mechanism.

Intervertebral disc herniation in two coatis (Nasua nasua) and postoperative laminectomy membrane formation

Magnetic resonance imaging revealed spinal cord compression due to intervertebral disc herniation of Hansen type I and II in the thoracolumbar vertebral column in two middle-aged coatis (Nasua nasua) with chronic progressive paraparesis. Surgical treatment included hemilaminectomy and partial corpectomy in one and dorsal laminectomy in the other coati. Both coatis recovered well after surgery. One showed unremarkable gait 6 and 15 months post surgery, while the other one suffered from recurrence of paraparesis leading to euthanasia because of deterioration of neurological signs 20 months after the first surgery. Necropsy revealed formation of a laminectomy membrane compressing the spinal cord. Histopathological signs of spinal cord injury and findings of degenerative processes in the intervertebral disc were comparable to those described in dogs. In conclusion, this case report shows for the first time that surgical intervention seems to be a useful and safe treatment in chronic intervertebral disc herniation in coatis, but relapses are possible.

Severe Proarrhythmic Potential of the Antiemetic Agents Ondansetron and Domperidone

The potential of ondansetron and domperidone, both clinically established antiemetic agents, to increase the QT-interval has been described in several case reports. Therefore, the aim of the present study was to investigate whether these drugs may provoke polymorphic ventricular tachycardia in a sensitive experimental model of drug-induced proarrhythmia. In 10 female rabbits, ondansetron (1, 5 and 10 µM, n = 10) or domperidone (0.5, 1 and 2 µM, n = 8) was infused after obtaining baseline data. Eight endo- and epicardial monophasic action potentials and a simultaneously recorded 12-lead ECG reproduced the clinically observed QT-prolongation (ondansetron: 1 µM:+17 ms, 5 µM:+41 ms, 10 µM:+78 ms, p < 0.01; domperidone: 0.5 µM:+57 ms, 1 µM:+79 ms, 2 µM:+99 ms, p < 0.01). This was accompanied by a significant increase in action potential duration at 90% of repolarization. Administration of both agents also increased dispersion of repolarization (ondansetron: 1 µM:+12 ms, 5 µM:+17 ms; 10 µM:+18 ms, p < 0.05; domperidone: 0.5 µM:+19 ms, 1 µM:+27 ms; 2 µM:+23 ms p < 0.05). Lowering of potassium concentration in bradycardic AV-blocked hearts provoked early afterdepolarizations (EADs) in 9 of 10 ondansetron-treated hearts and induced polymorphic ventricular tachycardia (VT) resembling torsade de pointes in 7 of 10 ondansetron-treated hearts (86 episodes). Under the influence of domperidone, EAD and polymorphic VT occurred in 7 of 8 hearts (131 episodes). In the present study, both ondansetron and domperidone demonstrated a severe proarrhythmic potential. A significant prolongation of cardiac repolarization as well as a marked increase in spatial dispersion of repolarization represents the underlying electrophysiologic mechanisms. These results imply that application of ondansetron should be handled carefully. For regular administration, ECG monitoring should be mandatory.