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Regenerative bone implants promote new bone formation and ideally degrade simultaneously to osteogenesis. Although clinically established calcium phosphate bone grafts provide excellent osseointegration and osteoconductive efficacy, they are limited in terms of bioresorption. Magnesium phosphate (MP) based ceramics are a promising alternative, because they are biocompatible, mechanically extremely stable, and degrade much faster than calcium phosphates under physiological conditions. Bioresorption of an implant material can include both chemical dissolution as well as cellular resorption. We investigated the bioresorption of 3D powder printed struvite and newberyite based MP ceramics in vitro by a direct human osteoclast culture approach. The osteoclast response and cellular resorption was evaluated by means of fluorescence and TRAP staining, determination of osteoclast activities (CA II and TRAP), SEM imaging as well as by quantification of the ion release during cell culture. Furthermore, the bioactivity of the materials was investigated via SBF immersion, whereas hydroxyapatite precipitates were analyzed by SEM and EDX measurements. This bioactive coating was resorbed by osteoclasts. In contrast, only chemical dissolution contributed to bioresorption of MP, while no cellular resorption of the materials was observed. Based on our results, we expect an increased bone regeneration effect of MP compared to calcium phosphate based bone grafts and complete chemical degradation within a maximum of 1.5–3.1 years.

Objectives: The objectives of the study were to investigate the association between change in postoperative (post-op) tibial plateau angle (TPA) in dogs and cranial cruciate ligament disease (CCLD) after tibial plateau leveling osteotomy (TPLO) during 6 months on the post-op outcome. Methods: The inclusion criteria included 60 dogs with CCLD treated with TPLO fulfilled. TPA measurements were taken immediately post-op and 6 months post-op by three observers, and change in TPA was calculated. The outcome was evaluated using lameness score, owner questionnaire, and gait analysis performed preoperatively and 6 months post-op. Results: The mean change in TPA was 0.22 ± 0.75°. The interobserver reliability for TPA measurements was excellent. No differences in TPA measurements between observers were found (p = 0.07–0.105). No association between the change in TPA and outcome was found. The multivariate linear regression model for the symmetry index of peak vertical force (SIPVF) 6 months post-op was significant (R 2 = 0.210; p = 0.031), and the TPA at 6 months post-op was the only significant factor (ß = 0.459; 95% CI: 0.41–1.44; p < 0.001), indicating that a lower TPA 6 months post-op results in lower SIPVF values. Conclusion: The study indicated that lower TPAs 6 months post-op lead to a more symmetrical gait in hindlimbs 6 months post-op. No other significant factor between post-op changes in TPA and outcome after TPLO was found. Our results showed little post-op TPA change up to 6 months. This indicates that change in TPA is not present as reported. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate whether the wearing of hearing protection has a positive influence on stress levels during an MRI examination in dogs under anaesthesia. To this end, the stress hormones cortisol and arginine vasopressin (AVP) were measured in the saliva of patients wearing hearing protection during an MRI scan, as well as in the control group without hearing protection, before and after the scan. Pulse rate and noise level were also measured during the MRI. It was shown that salivary cortisol concentrations in dogs without hearing protection increased during the MRI examination, while those in the control group with hearing protection remained the same (p<0.05). The pulse range was greater in the control group without hearing protection, although not statistically significant. The maximum loudness during the MRI examination, measured at 200 cm from the gantry, was 87 dB(A). The results on the loudness during mri scan highlight that hearing protection should always be used to minimise hearing damage and possibly the stress level for dogs. [ABSTRACT FROM AUTHOR]

Simple Summary: Osteoarthritis is a degenerative joint disease. Chronic joint inflammation leads to a loss of joint cartilage. Osteoarthritis is the most common joint disease in dogs and usually develops secondarily as a result of joint incongruence or trauma. Dogs with advanced osteoarthritis often suffer from chronic pain, reduced quality of life and restricted mobility despite pain medication. Conventional treatment options for OA can alleviate the symptoms, but cartilage regeneration is not achieved. Regenerative medicine is increasingly becoming the focus of osteoarthritis research because regenerative cells contribute to tissue healing. The aim of this study was to measure the treatment success of regenerative cell therapy in dogs with chronic osteoarthritis that were no longer responding to pain therapy. The regenerative cells were obtained from the dogs' fatty tissue, processed and applied to the affected joints. Based on the veterinary lameness examination, gait analysis and owner questionnaires, it was assessed whether the regenerative cell therapy led to an improvement in the dogs' lameness and pain. In addition, the animals were X-rayed to measure the progression of osteoarthritis. Some patients showed a therapy-related improvement in lameness and pain. However, the therapy did not have an effect on all patients. This study aimed to assess the efficacy of a single intra-articular injection of autologous stromal vascular fraction (SVF) in dogs with chronic lameness due to advanced elbow osteoarthritis (OA) that were unresponsive to conventional drug therapy. In this clinical, prospective, non-blinded, single-center study, twenty-three dogs received autologous SVF derived from falciform adipose tissue. Primary outcome measures over the six-month study period included clinical-orthopedic and radiographic examinations, objective gait analysis and validated owner questionnaires. In 19 of 23 joints, no progression of OA was visible radiographically. Peak vertical force improved significantly at three months and vertical impulse at six months after the injection compared to baseline. Over 33% of dogs demonstrated treatment-related improvements in lameness based on objective gait analysis. Owner questionnaires indicated significant improvement in clinical signs throughout the study period and 26% of dogs showed treatment-related improvements in pain scores according to the Canine Brief Pain Inventory. No side effects were reported. These findings suggest that autologous regenerative cell therapy may provide a promising treatment option for dogs with advanced OA that do not respond to conventional drug therapy. However, the treatment did not improve the clinical symptoms in all dogs, so it cannot be recommended for all patients. [ABSTRACT FROM AUTHOR]

Objective: Osteoarthritis (OA) is the most common joint disorder in humans and dogs. Due to its chronic progressive nature, the predominant clinical signs after a certain point are pain and immobility. The similar pathogenesis allows conclusions to be drawn from canine to human OA. Current treatments are limited and often attempt to treat OA symptoms rather than improve joint structure and function. Collagen hydrolysates as oral supplements are a promising therapeutic option to achieve this advanced therapeutic aim in both species. The effects of oral supplementation were therefore investigated in canine OA patients. Method: In a systematic, placebo-controlled, double-blind interventional study in 31 dogs with naturally occurring OA, the efficacy of oral supplementation of specific bioactive collagen peptides (BCP) was tested in comparison to the approved combination of the active substances omega-3 fatty acids and vitamin E. The dogs were examined on a horizontal treadmill with 4 integrated piezoelectric force plates at the beginning and end of a twelve-week test period. At both points, the owners completed a specific questionnaire containing the validated Canine Brief Pain Inventory (CBPI) and the dogs were fitted with accelerometers to record total daily activity data. Results: Only the oral supplementation of BCP resulted in a significant improvement of several kinetic parameters measured using a force-plate fitted treadmill, and the quality of life assessed by CBPI, while accelerometry was unaffected by the intervention. Conclusion: The results of this three-month BCP supplementation study using objective measurement parameters in dogs with naturally occurring OA demonstrate an efficacy, suggesting the therapeutic use of BCP in canine OA patients and demonstrating the relevance of this collagen hydrolysate formulation for the treatment of OA in human patients as well. [ABSTRACT FROM AUTHOR]

Simple Summary: The diagnostic value of anti-Müllerian hormone (AMH) is well established but less is known about physiological concentrations in young individuals. The aim of this study was to determine AMH levels in small animals before and around puberty and to correlate these levels with testosterone in males entering puberty. Blood samples were collected between 2 and 48 weeks after birth for AMH and testosterone measured using a chemiluminescence immune assay. AMH concentrations were higher in males than in females, with no significant differences among male individuals. However, queens had significantly higher AMH concentrations compared to bitches. A significant decreased in AMH was observed in the males beginning 24 weeks after birth, which correlated only in dogs with an increase in testosterone. In bitches, AMH remained below the detection limit until 16 weeks after birth after which it increased slightly. In queens, AMH was detectable from week 2 with a significant increase starting at week 8, even approaching the chemiluminescence immune assay's upper limit. In conclusion, queens secreted AMH much earlier and in significantly higher amounts than bitches. The decrease of AMH in male species entering puberty was observed in both dogs and tomcats, but a negative correlation with testosterone was derived only for male dogs. In recent years several studies established the diagnostic value of anti-Müllerian hormone (AMH) in companion animals. However, less is known about physiological AMH concentrations in young individuals highlighting the necessity to apply the diagnostic findings to this group. The aim of this study was to determine the AMH values of healthy male and female dogs between the age of 8 and 48 weeks, tomcats under 8 weeks and up to 48 weeks of age and queens between 2 to 12 weeks of age. In total, 96 blood samples were collected. Anti-Müllerian hormone was measured in all samples and testosterone was measured in the oldest age group of the males in both species. The hormones were analyzed using a human based chemiluminescence immune assay. Overall, AMH concentrations were higher in males than in females (p < 0.001). According to the AMH concentration there was no difference in males, but queens had significant higher AMH concentrations than bitches (p < 0.001). AMH remained high in males up to week 24 and decreased significantly thereafter (tomcats: p = 0.015; male dogs: p = 0.013), which correlated with an increase in testosterone levels for male dogs only. In bitches, AMH remained below the detection limit until the week 16 and slightly increased subsequently. In queens, AMH was detectable from the beginning with a significant increase in the older age group (p = 0.003). Half of the cats in the older age group even approached the chemiluminescence immune assay's upper limit. The results show that female cats secrete AMH much earlier than female dogs in which AMH secretion begins just shortly before the start of the puberty. In the male animals, the decrease in AMH concentration around puberty was similar in dogs and cats, but a correlation with the increase of testosterone was only observed in dogs. Further research is required to determine the origin of the high AMH concentrations in female kittens and the lack of correlation between testosterone and AMH concentrations in male kittens. [ABSTRACT FROM AUTHOR]

Introduction: Brachycephalic obstructive airway syndrome (BOAS) is a common condition in brachycephalic dogs, with Pugs (PG) and French Bulldogs (FB) appearing to be particularly typically affected. Objective and easy-to-perform tests are necessary to detect the disease at an early stage and to exclude dogs affected by BOAS from breeding. Methods: The present study investigated the extent to which vital signs and salivary cortisol concentrations can be used to distinguish between healthy and BOAS-affected dogs in a standardized fitness test. A total of 57 PG, 56 FB and 27 meso- and dolichocephalic dogs were studied as control group (CG). In addition to vital signs, salivary cortisol concentrations were measured before and after the exercise test. Results: It emerged that non-brachycephalic dogs showed a higher fitness level than brachycephalic dogs. The PG recovered significantly slower than the FB after the exercise test. In unaffected PG, cortisol levels rose significantly after the test and then fell again, in unaffected FB they fell significantly during the test. Unexpectedly, cortisol levels remained constant in BOAS affected dogs of both breeds. Discussion: A possible explanation could be a disturbance of the pituitary--hypothalamic--adrenal axis, which could be due to the chronic stress of affected animals. This would have to be clarified in further studies. In conclusion, a submaximal fitness test may be a useful method to identify dogs suffering from BOAS as it is imperative to prevent the breeding and reproduction of affected dogs. [ABSTRACT FROM AUTHOR]

Background: Mammary adenocarcinomas are one of the most common tumour diseases in bitches. The relationship between oxidative stress and the degree of malignancy of the tumour has not been sufficiently researched in veterinary medicine. Objectives: The main objective was to investigate the potential role of MDA as a practice‐relevant biomarker for the assessment of systemic oxidative stress and to determine whether this parameter can indicate the malignancy grade of a mammary adenocarcinoma. Methods: In the present pilot study, MDA plasma concentrations were analysed in 55 bitches with (n = 28) and without (n027) malignant adenocarcinomas of the mammary gland using two different measurement methods and the relationship to tumour size was investigated. Results: The mean MDA concentration measured by enzyme‐linked immunosorbent assay (ELISA) was 289 ng/mL (range 365–634 ng/mL) in dogs with grade 1 adenocarcinoma (n = 13), 288.5 ng/mL (range 85–752 ng/mL) in dogs with grade 2 adenocarcinoma (n = 10), 332 ng/mL (range 239–947 ng/mL) in dogs with grade 3 (n = 5) adenocarcinoma and 293 ng/mL (range 175–549 ng/mL) in dogs without a mammary tumour (n = 27). When MDA was measured by HPLC, the average MDA concentration in the study group (n = 11) was 0.24 µmol/L (range 0.16–0.37) and that of the control group (n = 15) was 0.27 µmol/L (range 0.16–1.62). Thus, there were no significant differences between the study group with malignant adenocarcinomas and the control group in both examination methods (p > 0.05). Furthermore, there was no correlation between the MDA concentrations and the approximate volume of the mammary tumour. Conclusion: The results highlight the challenges of providing a prognosis for the malignancy of a mammary adenocarcinoma based on MDA concentrations in plasma using ELISA or HPLC. As a result, histopathological examination remains the gold standard for diagnosing and differentiating adenocarcinomas of the mammary gland. [ABSTRACT FROM AUTHOR]

Bone substitutes are ideally biocompatible, osteoconductive, degradable and defect-specific and provide mechanical stability. Magnesium phosphate cements (MPCs) offer high initial stability and faster degradation compared to the well-researched calcium phosphate cements (CPCs). Calcium magnesium phosphate cements (CMPCs) should combine the properties of both and have so far shown promising results. The present study aimed to investigate and compare the degradation and osseointegration behavior of 3D powder-printed wedges of CMPC and MPC in vivo. The wedges were post-treated with phosphoric acid (CMPC) and diammonium hydrogen phosphate (MPC) and implanted in a partially loaded defect model in the proximal rabbit tibia. The evaluation included clinical, in vivo µ-CT and X-ray examinations, histology, energy dispersive X-ray analysis (EDX) and scanning electron microscopy (SEM) for up to 30 weeks. SEM analysis revealed a zone of unreacted material in the MPC, indicating the need to optimize the manufacturing and post-treatment process. However, all materials showed excellent biocompatibility and mechanical stability. After 24 weeks, they were almost completely degraded. The slower degradation rate of the CMPC corresponded more favorably to the bone growth rate compared to the MPC. Due to the promising results of the CMPC in this study, it should be further investigated, for example in defect models with higher load. [ABSTRACT FROM AUTHOR]

Joint effusion is diagnostically important. The canine carpal joint effusion, which is sometimes difficult to detect clinically, has received less attention in diagnostic ultrasound (US) studies. The aim of the present study was to provide a description of the morphological appearance of the canine carpal joint cavities and recesses using US, radiography, helical computed tomography (CT) and three‐dimensional volume rendering technique (3D‐VRT) images and to prove the applicability of musculoskeletal US for the detection of artificial carpal joint effusion in dogs. The understanding of the characteristics of these structures in normal patients is essential in the diagnosis. Twenty‐eight clinically and radiologically unremarkable canine carpal cadavers of different breeds were examined, representative images were selected and anatomical structures were labelled. The canine carpal joint cavities and in particular its recesses had a complex appearance with a basic structure found in all dogs: Antebrachiocarpal joint: dorsoproximal antebrachiocarpal recess, dorsodistal antebrachiocarpal recess, medial antebrachiocarpal recess, lateral antebrachiocarpal recess and five palmar antebrachiocarpal recesses. Middle carpal joint: two dorsal middle carpal recesses, medial common middle carpal and carpometacarpal recess, lateral common middle carpal and carpometacarpal recess, four palmar middle carpal recesses. The carpometacarpal joint had dorsal and palmar funnel‐shaped and irregular, finely tubular extensions, the most prominent ran dorsal to metacarpal III, the maximum distal end represented the proximal metacarpal diaphysis. All recesses presented ultrasonographically as a generalized anechogenic to hypoechoic filled continuation of the articular capsule with an indistinct peripheral hypoechogenic to isoechogenic fine capsule, the synovial‐connective tissue interface was difficult to identify. The novel results of this study provide the first morphological description of the ultrasonographic, radiographic and computed tomographic arthrographic appearance of the canine carpal joint cavities and recesses with different injection volumes. The canine carpal joint cavities and in particular its recesses had a complex appearance with a basic structure found in all dogs. The applicability of musculoskeletal US to visualize an artificial carpal effusion has been demonstrated. The results of this study, and in particular US, give the practitioner an advantage in visualizing joint effusion and assist in the decision to perform arthrocentesis. [ABSTRACT FROM AUTHOR]

The documented increase in the occurrence of dental diseases in captive big cats over the past decades has necessitated the need to target dental medical research accordingly. The aim of this study was the systematic evaluation of dental and oral pathologies of lions and tigers which included intraoral dental radiography. Thirty-six animals of both sexes, ranging in age from nine months to 18 years, predominantly in circus husbandry, served as the basis of the present study, and their dental health status was investigated. The preliminary report and history, adspection of the awake animal, and examination under anesthesia provided important information. Eight animals were specifically presented for oral examination because of known dental disease. The remaining 28 animals were anesthetized for other medically necessary procedures, and each animal's oral and dental health status was also evaluated while under anesthesia. In the 28 animals that underwent routine oral cavity examination, pathological changes that had not previously been noticed were found in two-thirds of the animals (19/28). One-quarter of all the animals (9/36) had no abnormal oral cavity findings. Dentoalveolar trauma such as tooth fractures and abrasion (24/36) were diagnosed most frequently. The results highlight the importance of regular oral examinations in big cats. Furthermore, the results suggest that there is a relationship between husbandry conditions and the incidence of dentoalveolar trauma in captive big cats. [ABSTRACT FROM AUTHOR]