Defects In Dogs Research Articles

Evaluation of the effect of PRF on bone healing in diabetic animals after periradicular surgery

Objective: was directed to evaluate platelet rich fibrin alone and in combination with xenograft as an alternative to bone substitute in treatment of critical sized bone defects in dogs. Material and methods:8 dogs were selected for this study in which diabetes mellitus was induced. Root canal treatment was done in the 2nd and 4th premolar teeth of both sides then 4 critical sized bone defects were created in relation to the distal root of the selected teeth. According to the bone cavity filling materials there was 4 groups xenograft, xenograft and PRF, PRF and blood clot groups. Dogs were sacrificed at 4 days,2,5and 9 weeks the mandibles were harvested for DEXA evaluation. Results: bone density measurement at 9 weeks was significant with Xenograft and PRF group than Xenograft, PRF and blood clot groups, and at the same time there was no significance between Xenograft and PRF groups. Conclusion: PRF is a valuable material that can be used as a sole grafting material in periradicular surgery to improve bone regeneration.

Evaluation of the Use of Platelet-Rich Fibrin Xenologous Membranes Derived from Bubaline Blood in Canine Periodontal Defects.

Periodontal disease is the most common oral disease in dogs. Platelet-rich fibrin (PRF) is widely utilized to facilitate soft and hard tissue healing and has been proposed in periodontal healing in small animal treatment. However, the quality and amount of autologous PRF is compromised in animals with systemic diseases. The present study aimed to evaluate the efficacy of xenologous bubaline blood-derived PRF (bPRF) on periodontal tissue healing in canine periodontal defects. Split-mouth design was employed in twenty dogs diagnosed with periodontal disease. The defects were divided randomly into two groups: the open-flap debridement (OFD)-treated group and the OFD with bPRF (OFD+bPRF) application group. Results demonstrated that gingival index and periodontal probing depth decreased significantly in the OFD+bPRF group compared with those treated with OFD alone. Application of bPRF in periodontal defects also promoted fibrous tissue formation, as confirmed by the marked increase in fibrosis score. bPRF application significantly increased COL1A1 and PDGFB mRNA levels at day 14 compared with the baseline. Taking this evidence together, bPRF provided a favorable therapeutic modality in canine periodontal defects. bPRF could be an alternative biomaterial for the treatment of periodontal defects in dogs.

A defect in the NOG gene increases susceptibility to spontaneous superficial chronic corneal epithelial defects (SCCED) in boxer dogs

BackgroundSuperficial chronic corneal epithelial defects (SCCEDs) are spontaneous corneal defects in dogs that share many clinical and pathologic characteristics to recurrent corneal erosions (RCE) in humans. Boxer dogs are predisposed to SCCEDs, therefore a search for a genetic defect was performed to explain this susceptibility. DNA was extracted from blood collected from Boxer dogs with and without SCCEDs followed by whole genome sequencing (WGS). RNA sequencing of corneal tissue and immunostaining of corneal sections from affected SCCED Boxer dogs with a deletion in the NOG gene and affected non-Boxer dogs without the deletion were performed.ResultsA 30 base pair deletion at a splice site in Noggin (NOG) (Chr 9:31453999) was identified by WGS and was significantly associated (P < 0.0001) with Boxer SCCEDs compared to unaffected non-Boxer dogs. NOG, BMP4, MMP13, and NCAM1 all had significant fold reductions in expression and SHH was significantly increased in Boxers with the NOG deletion as identified by RNA-Seq. Corneal IHC from NOG deletion dogs with SCCEDs had lower NOG and significantly higher scores of BMP2.ConclusionsMany Boxer dogs with SCCED have a genetic defect in NOG. NOG is a constitutive protein in the cornea which is a potent inhibitor of BMP, which likely regulate limbal epithelial progenitor cells (LEPC). Dysregulation of LEPC may play a role in the pathogenesis of RCE.

Superficial temporal axial pattern flap for facial reconstruction of skin defects in dogs and cats.

Report the use, complications and outcome of the superficial temporal axial pattern flap (STA) when used for closure of skin defects localised to the maxillofacial region in dogs and cats. Multi-centre retrospective cohort study. Medical records of dogs and cats treated with a STA flap for closure of skin defects were reviewed. Information regarding signalment, reason for axial pattern flap use, flap size, flap healing, postoperative complications including need for surgical revision and overall outcome were collected. Nineteen patients were included: nine dogs and 10 cats. Indications for the STA flap included closure of defects following excision of tumours (18/19, 94.7%) and fungal granuloma resection (1/19, 5.2%). 100% flap survival occurred in 17 of 19 flaps (89.4%). Postoperative complications occurred in eight of 19 flaps (42.1%). A major complication of full thickness partial necrosis of the flap occurred in one of 19 cases (5.2%), where the flap length exceeded recommended guidelines. Minor complications related to the flap were seen in four of 19 cases (21%). This included partial thickness flap necrosis, flap oedema and wound discharge. Complications related to the location of surgery (5/19, 26.3%) included mild ectropion, mild exposure of the eye, reduced ability to blink and subcutaneous emphysema. The STA flap is a good option for closure of a skin defect localised to the maxillofacial region. STA flaps were associated with a high percentage of survival and a low incidence of major complications.

Reconstruction of a large nasal–facial defect using an augmented temporal myocutaneous tube flap in a dog

The muzzle region of dogs contains various composite tissues, which are challenging to recreate during reconstruction. Small or moderate facial/nasal defects can be closed primarily or left for second‐intention healing. However, larger defects require the application of composite tissue or labial advancement flaps. Axial pattern flaps based on the caudal auricular artery, superficial temporal artery (STA), angularis oris artery, and other cutaneous arteries have been reported. In our case, we aim to report the reconstruction of a large composite defect of the rostral and dorsal nasal regions in a dog using an augmented, axial myocutaneous flap based on bilateral STAs. This is a clinical report on a spayed female mixed‐breed dog (age, 7 years; weight, 15 kg), in which a large‐scale nasal–facial composite tissue defect was surgically reconstructed using an axial myocutaneous flap based on bilateral STA branches. A delay technique was applied to prefabricate the flap to enrich the blood supply. New nostrils were created on a folded, rostral hard palate. As a result, the axial tube rotational flap was successfully transferred. The use of delay technique for prefabricating the tube flap optimized its size and survival. In addition to the folded rostral hard palate, the flap fully closed the defects on the face and nose. Functional and cosmetic outcomes were satisfactory, with minimal donor‐site morbidity. In, conclusion, a large‐scale nasal–facial defect in a dog was successfully reconstructed using an augmented tube pedicle flap based on the bilateral STAs, which may, thus, be used to repair very large facial‐nasal defects in dogs.

Dynamics of biochemical bone and endothelial parameters during the replacement of bone defects in dogs with hydroxyapatite ceramic doped with silicon

Metal structures for osteosynthesis available in veterinary orthopedics are not able to compensate for the lost elements of bone tissue in complex splinter fractures. It is prompt the use of hydroxyappatite materials that replaced bone defects for maintenance of osteoconductive function, and ideally would combine osteointegration and osteoinductive properties. However, their influence on the biological processes of fracture consolidation which go through a number of successive stages and end with the formation of bone tissue in the fracture zone identical to the maternal, is insufficiently substantiated according to the criteria of the molecular biological phase of reparative osteogenesis. The aim of the study was to investigate the dynamics of biochemical osteotropic parameters and the level of NO using silicon-doped ceramics for fractures heeling in dogs. Materials and methods. The animals suffering of fractures that were admitted to the faculty clinic were divided into control (n=7) and experimental (n=7) groups. In both groups, extracortical osteosynthesis was performed with a support plate from an unalloyed titanium alloy. In the control group, bone defects were left to heal under spontaneous blood clot, and in the experimental group, they were replaced with ceramic based on hydroxyapatite with β-tricalciumphosphate doped with silicon (HA/β-TCP/l-Si–3).Blood samples were taken after the injury no later than the 48th day, and on the 3th, 12th, 21th, 42th and 60th days after osteosynthesis. To increase the objectivity of the biochemical analysis, we additionally formed a group of clinically healthy dogs that were admitted to the clinic for routine vaccination (n=10). It included the spectrophotometric determination of the content of NO, BALP, TRACP, Ca, P, Mg, total protein in blood serum, and fibrinogen in blood plasma. Research results. A clinical study showed that in the case of using HA/β-TCP/l-Si–3for splinter fractures, the stages of reparative osteogenesis are more optimized in time, and their consolidation occurs on average 19 days earlier than in the control group. The results of the biochemical study showed that when using HA/β-TCP/l-Si–3, it is accompanied by a peak NO value already on the third day, which is significantly higher than in the control group and indicates early angiogenesis in the research group. In terms of TRACP, the period of osteoresorption in the control group was permanent with little expressed peaks of activity. However, in the research group, the peak of TRACP activity is limited to 12 and 21 days, which is evidence of an optimized inflammatoryresorptive phase. In parallel with this, the activity of BALP increases, which indicates the consistency of the stages of reparative osteogenesis and provides an optimized and accelerated consolidation of fractures in the research group. Conclusion. The dynamics of NO, BALP and TRACP pathochemically substantiates the optimized reparative osteogenesis when using HA/β-TCP/l-Si–3 for bone defects replacement in cases of splinter fractures of tubular bones. Key words: bone markers, bone isoenzyme of alkaline phosphatase, NO, tartrate-resistant acid phosphatase, fibrinogen, calcium, phosphorus.

Treatment of cranial cruciate ligament injuries in dogs using a combination of tibial tuberosity advancement procedure and autologous mesenchymal stem cells/multipotent mesenchymal stromal cells - A pilot study.

In the present pilot study, we evaluated different supplemental therapies using autologous multipotent mesenchymal stromal cells (MMSCs) for the treatment of cranial cruciate ligament defects in dogs. We used tibial tuberosity advancement (TTA) and augmented it by supportive therapy with MMSCs in three patient groups. In the first patient group, the dogs were injected with MMSCs directly into the treated stifle one month after surgery. In the second group, MMSCs were delivered in a silk fibroin scaffold which was placed in the osteotomy gap during surgery. In the third group, MMSCs were first mixed with bone tissue and blood from the patient and delivered into the osteotomy gap during surgery. In the control group, patients underwent the TTA procedure but did not receive MMSC treatment. In the group of patients who received cells in the silk fibroin scaffold during surgery, the osteotomy gap did not heal, presumably due to the low absorption of silk fibroin. Patients who received MMSCs mixed with bone tissue and blood during surgery into the osteotomy gap recovered clinically faster and had better healing of the osteotomy gap than dogs from the other two treated groups and from the control group, as assessed by clinical examination and quantification of radiographs. In conclusion, dogs that received stem cells directly into the osteotomy gap (Group 3) recovered faster compared to dogs from Groups 1 (MMSCs injected into the joint one month after surgery), 2 (cells implanted into the osteotomy gap in a silk fibroin scaffold), and the control group that did not receive additional MMSCs treatment.

Evaluation of Wound Healing Following Wide Surgical Resection and Subdermal Skin Flap Reconstruction for Management of Soft Tissue Tumours in 20 Dogs

Background: Tumours in dogs are increasing day by day and the mainstay of treatment is surgery. Wide surgical resection of soft tissue tumour in dogs is mandatory to prevent recurrence but it leads to the formation of a large skin defect requiring skin reconstruction. Among the various skin reconstruction techniques, subdermal skin flap is a simple reconstruction technique which can be performed by harvesting full-thickness skin from the surrounding skin without using special instruments. The current study was aimed to evaluate the healing and recurrence of tumours in dogs after wide surgical resection of tumour and subdermal skin flap reconstruction.Methods: 20 dogs with soft tissue tumours presented to MSVH, GADVASU, Ludhiana, Punjab, during the period 2019-2020 were treated by wide surgical resection and subdermal skin flap technique. Routine clinico-physical, Hematobiochemical, Radiographic examinations, Fine Needle Aspiration Cytology, Histopathology and Culture Sensitivity Test were performed. Different types of flap were created according to the location of tumour and availability of the loose skin and wound healing was evaluated and complications recorded. Result: Healing of subdermal flap was seen in 15 dogs (75%) while necrosis of subdermal flap was recorded in 5 dogs (25 %) of the cases of which 4 of them had mobility of flap base and were located in ventral abdomen (n=4) and limb (n=1). Overall tumour recurrence was recorded in 3 dogs (15%) which were located in limbs of which 2 dogs had lung metastasis and the tumours were malignant. It can be concluded that single pedicle advancement flaps for thoracic region; bipedicle advancement flap for thoracic and abdominal regions; rotational flaps for lateral thoracic region and transposition flap for proximal limb region are feasible skin reconstruction techniques for the repair of large skin defects in dogs.

Periodontal wound healing/regeneration of two-wall intrabony defects following reconstructive surgery with cross-linked hyaluronic acid-gel with or without a collagen matrix: a preclinical study in dogs.

In-vitro data have shown that cross-linked hyaluronic acid (HA) enhances the proliferative and migratory properties of cells involved in periodontal wound healing/regeneration, stabilizes the blood clot, reduces the inflammatory response, and facilitates angiogenesis. The aim of this study was to histologically evaluate the effects of cross-linked HA alone or combined with a collagen matrix (CM) on the periodontal wound healing/regeneration in intrabony defects. Two-wall intrabony defects (5 mm wide, 5 mm deep) were surgically created at the distal and mesial aspects of mandibular premolars in six beagle dogs. The 24 defects were randomly treated as follows: open flap debridement (OFD) + HA, OFD + CM, OFD + HA + CM (HA/CM), and OFD alone (control). At 2 months, the animals were euthanized for histologic evaluation. The HA (2.43 ± 1.25 mm) and HA/CM (2.60 ± 0.99 mm) groups yielded statistically significantly (P &lt; .05) greater formation of new attachment (ie, linear length of new cementum adjacent to newly formed bone, with inserting collagen fibers) compared with the OFD (0.55 ± 0.99 mm) group. Among the four treatment groups, the HA/CM group demonstrated the highest amount of regenerated tissues, although no statistically significant differences in any of the histometric parameters were observed between the HA and HA/CM groups. Within their limits, it can be concluded that cross-linked HA alone or combined with CM promotes periodontal wound healing/regeneration in two-wall intrabony defects in dogs.

Efficacy of Nano Composite Porous 3D Scaffold of Crab Shell and Al-Kharit Histological and Radiological for Bone Repair in Vivo

The present study was conducted to evaluate the effect of scaffold fabricated from Nano crab shell and Al-kharit (Papyrus Vaccine) for enhancing the healing of the experimentally induced bone defect in dogs. For this purpose, twenty healthy adult mongrel dogs were used in this study which divided randomly into two equal groups, under general anesthesia, 1 cm bone gap was created in the distal part of the tibia, that fixed by bone plate and screws. Nano crab shell scaffold was implanted. All experimental animals showed normal situation without any infection at the site of operation, while the radiography showed a periosteal and endosteal reaction. Moreover, the gaps were bridged faster in the treated group as compared with the control group. Treated animals showed new bone formation which represented by obvious lamellar bone, haversian canal and osteocyte cells in 90 days. In conclusion, the Nano crab shell scaffold gave better acceleration in the bone healing process, also this scaffolds may provide insight into the clinical repair of large bone defects

The Use of Biphasic Calcium Phosphate Substitute (BCP) in Mandibular Defects in Dogs: Use of CBCT to Evaluate Bone Healing.

This study aimed to assess the use of cone beam computed tomography (CBCT) to follow-up bone healing of mandibular bone defects in dogs, filled with a combination of autologous blood and millimetric BCP granules. CBCT was performed ≥4 weeks postoperatively. CBCT gray-scale values were measured from multiplanar reconstructions of the defects and compared to that of normal contralateral mandibular bone and to pure BCP/blood composite time 0 (T0) value. Other parameters, determined by affecting grades according to specific criteria included: bone ridge margin restoration; biomaterial homogeneity; bone-biomaterial interface. Results: 8 dogs with 14 defects were included. Median age was 7.2 years (1-15 years). Follow-up CBCT was performed 1 to 7.5 months postoperatively (mean 3.3 months). Defect CBCT gray-scale values at follow-up were significantly greater than T0 (p < 0.05). Ratios of maximum and minimum densities of the defects to contralateral mandibular bone followed a linear correlation with time (p < 0.05). The bone ridge margin was adequately restored in all the defects and significantly correlated with time (p = 0.03). Biomaterial homogeneity was fair to good in 11 defects and significantly correlated with the bone ridge margin parameter (p = 0.05) and time (p = 0.006). There was no significant correlation with the bone-material interface. The latter was satisfactory in 12 defects and significantly correlated with time (p = 0.01) but not with the other parameters. The biomaterial was more homogeneous in smaller defects and with increasing time. CBCT allowed effective assessment of bone healing via the measurement of CBCT gray-scale values and assessment of multiple radiological variables.

Autologous corneal graft for the treatment of deep corneal defects in dogs: 15 cases (2014‐2017)

To describe the use of corneal autografts for repair of deep corneal defects in dogs. Retrospective analysis of clinical records of dogs that received autologous corneal grafts. Fifteen dogs (16 eyes) of different breed, age and gender were included. Brachycephalic breeds were overrepresented (10/15 dogs). Defects were unilateral in 14 dogs and bilateral in one dog, extended to at least 80% of the stromal thickness in all eyes, with descemetoceles in four eyes and corneal perforations in five eyes. Most ulcers (13/16 eyes) were located centrally. Corneal autografts were harvested from healthy peripheral cornea of the ipsilateral eye. The thickness of the autograft was limited to a set depth of 0.3 mm. The autograft was sutured into a previously debrided ulcer bed with a continuous or simple interrupted suture pattern using absorbable or non-absorbable suture material. Additional interventions included a partial temporary tarsorrhaphy and bandage contact lenses. Postoperatively patients received topical antibiotics and systemic anti-inflammatory drugs, and 12/15 dogs also received systemic antibiotics. Mean follow-up time was 54 days (2 to 462). In all eyes the donor site healed uneventfully with mild, persistent corneal fibrosis. Postoperative complications included autograft keratomalacia, graft dehiscence and corneal pigmentation. No patient required additional surgery. Good structural and functional outcome was accomplished in 14 of 16 eyes. Autologous corneal grafts provide tectonic support and result in good corneal transparency in selected cases of dogs with deep to perforated corneal ulcerations.

Palliative combined cutting and high-pressure balloon valvuloplasty in six dogs with severe, symptomatic subaortic stenosis

Introduction/ObjectivesSevere subaortic stenosis (SAS) is a congenital heart defect in dogs that often results in clinical signs and reduced survival. The objective of this study was to describe characteristics of dogs with severe, symptomatic SAS who underwent combined cutting and high-pressure balloon valvuloplasty (CB/HPBV). Animals, materials, and methodsRetrospective description of the clinical characteristics, CB/HPBV procedural deviations from reported methodology and outcomes in a series of six client-owned dogs with severe, symptomatic SAS. ResultsBreeds included two each of Newfoundland, Golden retriever, and German shepherd. Median age was 10.1 months (range: 5–72.3 months), and median weight was 25.5 kg (range: 21.8–36.4 kg). Before CB/HPBV, clinical signs were present in all dogs; four were managed for congestive heart failure (CHF). Three dogs had concurrent congenital heart disease. Median Doppler-estimated left ventricular outflow tract pressure gradient was pre-operatively 149.7 mmHg (range: 89.9–254.7 mmHg) and post-operatively 134.1 mmHg (range: 83.9–181.2 mmHg). Median aortoseptal angle was steep at 136° (range: 109–143°). Clinical improvement was documented in all dogs, based on temporary discontinuation of diuretics and/or owner-perceived reduction in clinical signs. At the time of writing, three dogs had died suddenly, one was euthanized because of recurrence of clinical signs, and one died in CHF. Median survival time was 26.4 months after procedure (range: 6.3–45.8 months). One dog remained alive at 44 months after procedure. ConclusionsPalliative CB/HPBV is a potential therapeutic option for dogs with severe, symptomatic SAS complicated by concurrent congenital heart disease, arrhythmias, or CHF.

Use of four-layer porcine small intestinal submucosa alone as a scaffold for the treatment of deep corneal defects in dogs and cats: preliminary results.

To describe the efficacy of four-layer porcine small intestinal submucosa (Vetrix BioSIS plus+) as single scaffold for the treatment of deep corneal lesions in dogs and cats. 10 dogs and 3 cats with deep or full thickness corneal defects were treated surgically with BioSIS plus graft. Corneal transparency scores and vision were evaluated. Lesions in dogs were four perforations, three descemetoceles, two limbal melanocytomas and one deep corneal ulcer. In cats, there were one limbal melanocytoma and two perforations. The average length of the follow-up was 86 days. In all, 12 out of 13 eyes treated were visual at last recheck (92.3 per cent). The scars were mild eight cases (66.7 per cent), but denser in four cases (33.4 per cent). Complication were partial collagenolysis in three cases (25 per cent), which resolved with medical therapy, mild corneal pigmentation in one case (8.4 per cent) and anterior synechia in one case (8.4 per cent). One case experienced severe collagenolysis and was enucleated 21 days postoperatively. Four-layer porcine SIS graft was successfully used for surgical treatment of deep corneal lesions in selected corneal diseases in a small series of dogs and cats, with good results in terms of mechanic support and corneal transparency.

Osteogenic Potential of 3-D printed Multilayered Poly L-lactic Acid (PLLA) Scaffold on the Healing of Critical-sized Bone Defect in Dogs

Critical sized bone defect is a major challenge for orthopedic surgeons. These defects result following any pathologic condition leading to massive bone loss. Synthetic and biological based tissue engineered biomaterials and their combinations provide a promising substitute to fill the defect site. The aim of the present study was to evaluate the osteogenic potential of 3-D printed multilayered medical grade PLLA scaffold with collagen and nano hydroxyapatite for the healing of induced critical-sized bone defect in dogs. An experimental study was conducted on 12 skeletally mature male dogs. Critical defect (25mm) was induced into the right femur of all dogs. Dogs were randomly allocated into one of the following groups (4 dogs/group). PLLA scaffold seeded with nano hydroxyapatite and collagen molded on the defect (PLLA/Collagen/nHA group), the second group; the defect seeded with collagen and nano hydroxyapatite (Collagen/nHA group), the third one was left without scaffold or additives (Sham operated group), and the operated animals were left for 12 weeks. Animals were evaluated clinically, radiographically and histopathologicaly. In (PLLA/Collagen/nHA group), all dogs showed an improvement in lameness degree from sever to apparently free from lameness. Radiography showed newly formed bone filling the defect with no inter zone. Histopathology showed more maturation of the newly formed bone in the defect site had occurred as well as defined bone trabeculae in comparing to other groups. In conclusion, 3D printed multilayered medical grade PLLA with collagen and nano hydroxyapatite provide biodegradable osteoconductive scaffold for enhancing the healing of critical sized bone defect.

Studies on A-PRF and A-PRF/Coral powder for Reconstruction of Induced Bone Defects in Dogs

Activated platelets-rich plasma (A-PRP) was used extensively in various experimental and clinical models. However, the use of anticoagulant in A-PRP preparation may interfere with healing process. Second generation of A-PRP were developed without adding anticoagulants or activators which where know as platelet rich fibrin (PRF). The PRF was improved during preparation and were known as advanced-PRF (A-PRF). In vitro studies, A-PRF showed releasing of significantly higher growth factors over time than PRF however, limited studies document its efficiency in vivo. Stony coral was used as a bone substitute for its osteo-conductivity. It can be used either alone or a part of a composite with reported success and low complication rates. The aim of the present study to evaluate the efficacy of A-PRF alone or with combination. Twelve adult mongrel dogs (15-25 kg body weight) of both sexes were used in this experiment. A 3 drill hole defects of 10 mm diameter were made in the tibial tuberosity 1 cm apart. The upper hole was filled with A-PRF alone, the middle hole was left empty as control and the lower hole was filled with mixture of A-PRF & coral powder. Sequential radiographs were obtained every week for the first month and every two weeks until completion of the study at 12 weeks. Radiographic opacity score of the defect compared to adjacent bone range from -3 to +3 and radiopacity score of host-implant interface which ranged from 0 to +3. Dogs were euthanized at the end of respective observation period at 2nd, 4th, 8th and 12th week post-operative for histological evaluation using Emery scoring system. By the end of the study, using A-PRF and with or without combination of coral powder was significantly improved and accelerate bone healing. Addition of coral powder scientifically improves the quality of remodeled bone histologically however, there was no significant radiographic differences.

Study on repairing canine mandibular defect with porous Mg-Sr alloy combined with Mg-Sr alloy membrane.

To discuss the feasibility of the application of porous Mg–Sr alloy combined with Mg–Sr alloy membrane in the repair of mandibular defects in dogs. The second and third mandibular premolars on both sides were extracted from six dogs. The model of mandible buccal fenestration bone defects were prepared after the sockets healed. Twelve bone defects were randomly divided into groups A and B, then Mg–Sr alloy was implanted in bone defects of group A and covered by Mg–Sr alloy membrane while Mg–Sr alloy was implanted in bone defects of group B and covered by mineralized collagen membrane. Bone defects observed on cone beam computed tomographic images and comparing the gray value of the two groups after 4, 8 and 12 weeks. After 12 weeks, the healing of bone defects were evaluated by gross observation, X-ray microscopes and histological observation of hard tissue. Bone defects in each group were repaired. At 8 and 12 weeks, the gray value of group A was higher than that of group B (P < 0.05). At 12 weeks, the bone volume fraction of group A was higher than that of group B (P < 0.05). The newly woven bone in group A is thick and arranged staggered, which was better than that of group B. Porous Mg–Sr alloy combined with Mg–Sr alloy membrane could further promote the repair of mandibular defects, and obtain good osteogenic effect.

A Self-Setting Hydrogel of Silylated Chitosan and Cellulose for the Repair of Osteochondral Defects: From in vitro Characterization to Preclinical Evaluation in Dogs.

Articular cartilage (AC) may be affected by many injuries including traumatic lesions that predispose to osteoarthritis. Currently there is no efficient cure for cartilage lesions. In that respect, new strategies for regenerating AC are contemplated with interest. In this context, we aim to develop and characterize an injectable, self-hardening, mechanically reinforced hydrogel (Si-HPCH) composed of silanised hydroxypropymethyl cellulose (Si-HPMC) mixed with silanised chitosan. The in vitro cytocompatibility of Si-HPCH was tested using human adipose stromal cells (hASC). In vivo, we first mixed Si-HPCH with hASC to observe cell viability after implantation in nude mice subcutis. Si-HPCH associated or not with canine ASC (cASC), was then tested for the repair of osteochondral defects in canine femoral condyles. Our data demonstrated that Si-HPCH supports hASC viability in culture. Moreover, Si-HPCH allows the transplantation of hASC in the subcutis of nude mice while maintaining their viability and secretory activity. In the canine osteochondral defect model, while the empty defects were only partially filled with a fibrous tissue, defects filled with Si-HPCH with or without cASC, revealed a significant osteochondral regeneration. To conclude, Si-HPCH is an injectable, self-setting and cytocompatible hydrogel able to support the in vitro and in vivo viability and activity of hASC as well as the regeneration of osteochondral defects in dogs when implanted alone or with ASC.

Unilateral Renal Agenesis in Chilean-Flamingo (Phoenicopterus chilensis)

Background: Phoenicopterus chilensis is a South American wild bird classified a species near threatened in the National List of Endangered Species of the International Union for Conservation of Nature. With the increase of the contact between human population and wild animals, this species’ habitat is becoming increasingly vulnerable, with a declining population. Due to the importance of its conservation, the knowledge of abnormalities that affect this species becomes essential. This report aims to describe the first diagnosed case of unilateral renal agenesis in chilean-flamingo.Case: A captive male chilean-flamingo (Phoenicopterus chilensis) was found dead in its enclosure and then was referred at necropsy. The cause of death was the presence of tracheal fungal granuloma, caused by Aspergillus sp. Macroscopically, during the examination of the cellomatic cavity, the absence of the right kidney was noted, also evidencing the absence of the caudal renal vein. Emerging from the caudal division of the kidney was noted a blind-end renal vessel (Figure 1). For the histopathological examination, the remaining kidney was fixed in 10% formalin, processed by paraffin embedding technique and stained with Hematoxylin and Eosin (HE). When analyzing the left kidney parenchyma, preserved histological architecture was noted, without any changes in the tissue structures of the organ. Thus, no hypertrophy by compensatory mechanisms of the remaining kidney was observed (Figure 2).Discussion: Unilateral renal agenesis is a very rare congenital defect in dogs, cats and also in birds. It occurs in the complete absence of one of the kidneys, a situation with which the animal can live satisfactorily if there is a normal kidney to assume the functions. In association, ipsilateral ureteral agenesis and compensatory hypertrophy of the remaining kidney may occur. At the time of necropsy, due to the remaining kidney has normal size and within topographic limits, dorsally in contact with the pelvis and sinsacrum, the absence of compensatory hypertrophy was suspected, which was confirmed by histopathological examination. Clinical signs of unilateral renal agenesis, when present, are related to renal failure. The signs develop when the remaining kidney fails to fully absorb the other's functions and fails to maintain the organism's homeostasis. In the case of this report, the specimen showed no clinical signs related to renal agenesis, probably because was no functional compensation for the single kidney. This condition was only noticed after flamingo necropsy, who death because tracheal fungal granuloma, caused by Aspergillus sp. Other reported ways of diagnosing this malformation in animals while alive were imaging and abdominal cavity surgery. The etiopathogenesis of unilateral renal agenesis in animals is uncertain, however, the hereditary cause is commonly described in rats and small animals. It cannot be concluded that the same happened with the animal of this study due to the fact of lack of data regarding the parents and history of animal. It is concluded that in unilateral renal agenesis, the compensatory hypertrophy of the remaining kidney and any clinical symptoms may not be present. Necroscopic and complementary exams are essential to obtain the diagnosis of unilateral renal agenesis. Knowing that the chilean-flamingo is considered as a species near threatened of extinction, it is important to know the abnormalities that affect this species, because this information may be essential for conservation programs.

Corneoconjunctival transposition for the treatment of deep stromal to full-thickness corneal defects in dogs: A multicentric retrospective study of 100 cases (2012-2018).

To describe and evaluate the use of corneoconjunctival transposition (CTT) as a surgical treatment for canine deep stromal ulcers, descemetoceles, and full-thickness corneal defects and to determine its efficacy in preserving corneal graft transparency and vision. One hundred client-owned dogs with deep stromal ulcers, descemetoceles, or full-thickness corneal defects. Medical records of canine patients that underwent CCT, from 2012 to 2018, were reviewed. Only, patients with preoperative positive consensual pupillary light and dazzle reflexes were included. There were 59 males and 41 females, from 0.3 to 17years. Brachycephalic breeds were overrepresented (65%). All patients were unilaterally affected, with 16 deep stromal ulcers, 33 descemetoceles, and 51 corneal perforations, of a median (range) size of 4 (2-8) mm. The central cornea was affected in the majority of cases (57%), and euryblepharon and keratoconjunctivitis sicca were the most common concurrent ocular diseases (42% and 40%, respectively). The graft was most frequently harvested from dorsal (67%), and 9/0 absorbable suture material was used. Intraoperative and postoperative complications were seen in 7 and 21 cases, respectively. Mean follow-up time was 107.8days. Vision was preserved in 96% patients, with 62% showing faint to mild opacification. Among the statistically analyzed variables, euryblepharon and pigmentary keratitis were found to be significantly associated with greater corneal graft opacification (P=.040 and P=.028, respectively). Corneoconjunctival transposition is an effective surgical treatment for deep stromal, descemetocele, and full-thickness corneal defects in dogs, achieving a highly satisfactory degree of corneal graft transparency and preserving vision.