Cloacoplasty in a 40-Day-Old Monk Parakeet with Cloacal Prolapse

Background: The monk parakeet (Myiopsitta monachus) is also known as the quaker parrot and belongs to the order Psittaciformes in the family Psittacidae. The cloaca is a posterior orifice common to reproductive, digestive and urinary systems and the cloacal prolapse is the displacement or inversion of its anatomic position. Nowadays, the non-conventional pet market in Brazil is rapidly growing, which demands more skills and competences from an avian veterinarian. This study case has as its main objective to present a 40-day-old monk parakeet (Myiopsitta monachus) with cloacal prolapse, treated using the cloacoplasty technique. It is important to mention that the occurrence of cloacal prolapse in this species and in such an early age is uncommon.Case: The patient presented 1 day before the physical examination an increased volume in the cloacal region and hematochezia, and diagnosed as cloacal prolapse. For the treatment, wounds were washed using physiological saline solution, ice and sugar were applied in order to reduce the edema, and mineral oil was used for repositioning the cloacal mucosa. Finally, local anesthesia was applied and 2 isolated contralateral sutures were done with the objective of reducing the sphincter’s diameter, without compromising the flow of urine and feces.  The monk parakeet was treated with antibiotic Avitrin®)  [oxytetracycline hydrochloride - 8.1 mg/mL] and a vermifuge [mebendazole 50 mg/mL]. A sample of feces was also obtained and sent to the Laboratory of Avian Pathology Diagnosis. The patient was discharged after 7 days of the treatment, obtaining a favorable result with no further complications.Discussion: The results of the coproparasitological examination were negative for the samples analyzed; nevertheless, the possibility of a false negative result cannot be totally dismissed. Cloacal prolapse may be related to cases of hypersexual disorder or overexertion to defecate due to intestinal parasites, posture, polyps, enteritis, neoplasm or cloacal hyperplasia. Besides that, endoparasitism is common in captive birds. For the correct treatment, proceed with a cloacoplasty, in which 1 or 2 simple sutures are made separated laterally in both sides, promoting the narrowing of the orifice. The surgeries such as the cloacoplasty are currently being defended, but in most cases as an adjuvant therapy. Cloacal prolapse in birds is a disease considered as an intestinal emergency. The techniques presented in this work demand sedation or anesthesia for the patient, which were not authorized by the tutor due to the high risk involved. However, due to the characteristic of domestication and docile behavior of the bird, it was possible to perform the 2 sutures with a local anesthetic block only. Cloacal prolapse is relatively common in adult psittacine birds, but uncommon in monk parakeets and young birds.  The treatment performed was effective for the monk-parakeet presented in this study case. The authors, however, would like to strongly reinforce the need to identify the cause of cloacal prolapse in order to properly treat it. The importance of correctly identifying the anatomy of a psittacine bird as well as applying precisely the suture techniques are the most important conclusions obtained, making both the identification of the problem and its solution through surgical intervention a simpler and successful process.Keywords: birds, endoparasites, suture, wild

Humerus Fracture in a Buff-necked Ibis (Theristicus caudatus) - Anesthesia and Surgical Procedures

Background: The medical science of birds, with the exception of aviculture, has a very short history compared to other subdisciplines of veterinary medicine. With this in mind, the current work aims to report the case of a buff-necked ibis with an open fracture of the left humerus, presenting the surgical treatment and anesthetic protocol used, in order to contribute to the avian medical literature.Case: An adult buff-necked ibis (Theristicus caudatus) was referred to the University Veterinary Hospital with an open fracture of the left humeral shaft, 7 days after rescue. During the physical examination, a skin lesion was identified in the fracture area, with signs of low vascularization, devitalization, necrotic tissues, and purulent secretions being noted. On radiographic examination, the fracture was classified as comminuted, with exposure of the left humeral shaft. After evaluatingthe limb, it was decided to amputate the wing, and 24 h later, the patient was referred to the operating room after fasting for 4 h. As pre-anesthetic medication, ketamine (20 mg/kg) and midazolam (1 mg/kg) were administered, both intramuscularly. Orotracheal intubation was performed, after which the tracheal tube was connected to a Baraka-type gas-free system andthe supply of isoflurane was started through a universal vaporizer, diluted in 100% oxygen. For transoperative analgesia, brachial plexus block was performed using 2% lidocaine (2 mg/kg). During the surgical procedure, an incision was made in the skin and subcutaneous tissue in the middle third of the left humerus, and detachment of the greater deltoid muscle was performed with a periosteal elevator, followed by excision of the tensor propatagialis. In the ventrodorsal region, circular ligation of the brachial vein, ulnar vein and artery, and median-ulnar nerve was carried out, and disarticulation of the scapulacoracoid-humeral region. Subsequently, abolition of dead space and a myorrhaphy were performed, followed by demorrhaphy. In the immediate post-operative period, morphine (5 mg/kg), meloxicam (0.1 mg/kg), and enrofloxacin (10 mg/kg) were administered intramuscularly. The patient was discharged from the hospital 6 h after the end of the surgical procedure.Discussion: Interest in the conservation of wild birds is one of the causes of the increased demand for anesthetic and surgical procedures in these species. However, it is a challenge for professionals in the field. The use of analgesics is recommended for reasons of well-being, but also because of the possibility of reducing the concentration of inhalational anesthetics in surgical procedures. Ketamine associated with midazolam promotes sufficient sedation and muscle relaxation in the patient, enabling safe preoperative management, in addition to reducing the amount of inhaled anesthetics used during the transoperative period. Isofluorane promotes safe general anesthesia for birds and has an advantage over injectable drugs, as it provides better dynamic control of anesthetic depth in these species. The brachial plexus block performed is a simple procedure that promotes quality anesthesia and analgesia in the perioperative period. The choice for amputation was due to the absence of musculature for closure, severe skin, muscle, and bone devitalization, and the infectious process in the region, factors that would prevent osteosynthesis. Although amputation through the bone is preferable, the disarticulation technique was used due to the absence of a healthy proximal humeral fragment. The patient’s death can be explained by the poor nutritional status the bird was in, as it presented an open fracture with severe contamination, a concomitant injury that occurred during the possible trauma, and the excessive time between the day of the trauma and the day of medical attendance. However, the surgical and anesthetic procedures were adequate and satisfactory for the patient. The importance of identifying and treating diseases secondary to contaminated fractures in these species is emphasized. Keywords: bird, avian medicine, fauna, lesions, recovery. Título: Fratura de úmero em uma curicaca (Theristicus caudatus) - manejo anestésico e cirúrgico Descritores: aves, medicina aviária, fauna, lesões, recuperação

Carcinoma de células escamosas corneal em um cão - uso da Mitomicina C 0.02% como adjuvante no tratamento

Background: Although Squamous Cell Carcinoma (SCC) is most commonly seen in the epidermis, this malignant neoplasm can manifest in various other tissues. A wide range of factors may be related to the development of SCC in the cornea, with continuous exposure to ultraviolet radiation and chronic friction to the ocular surface being the most accepted theories. In addition to surgical procedures, the use of mitomycin C in the topical treatment of corneal SCC has shown good results in therapeutic management. Thus, the objective of the current work is to report the satisfactory response observed in the use of mitomycin C in a case of SCC in the cornea of a dog.Case: A 9-year-old male Pug dog was attended by the Veterinary Ophthalmology and Microsurgery Sector (SOMVET) of the University Veterinary Hospital (HVU) of the Federal University of Santa Maria (UFSM) with Squamous Cell Carcinoma (SCC) in the cornea of the left eye, which had recurred after a previous surgical intervention. Secretion and discomfort in the left eye were noted during clinical examination. In addition, both eyes presented pigmentary keratitis in the medial corner. Surgical excision of the neoplasm was performed using the surgical technique of anterior lamellar keratectomy.In the immediate postoperative period, topical therapy was started with eye drops based on mitomycin C at 0.02%, for a period of 28 consecutive days. The use of this chemotherapy drug in the topical form was intended to minimize the chances of recurrence of the clinical condition, since the patient is predisposed to this alteration. In addition, supportive therapy was implemented to improve patient comfort, consisting of the use of tobramycin-based eye drops (6 times a day, for 14 days), atropine 1% eye drops (BID, for 3 days), lubricating eye drops based on sodium hyaluronate (3 times a day, for continuous use), and immunomodulatory eye drops based on tacrolimus 0.02% (twice a day, for continuous use). The patient was evaluated 7, 14, 21, and 28 days after surgery, when good results were observed. One year after treatment, the dog was still showing no signs of recurrence of the treated clinical condition.Discussion: It is known that chronic friction on the surface of the cornea predisposes to the diagnosis of corneal SCC. Accordingly, in the clinical examination of the patient in this report, the presence of bilateral pigmentary keratitis was observed, an alteration that leads to a framework of chronic aggression to the cornea. Surgical treatment is recommended to remove the tumor mass in the ocular region. However, in cases of corneal SCC, the literature highlights that recurrence after surgical excision is a common factor. As the patient in this study arrived at the clinic with a history of recurrence, topical therapy with mitomycin C associated with surgical treatment was instituted. This chemotherapy drug has shown encouraging results in the treatment of some neoplasms, especially SCC. Its use in this case supported previous findings, pointing to a satisfactory result in which the patient had no recurrences after one year of follow-up. In addition, the concentration and frequency used of the active ingredient did not lead to adverse effects in the short or medium term. Keywords: corneal, dry keratitis, chronic, chemotherapy. Título: Carcinoma de células escamosas corneal em um cão - uso da MitomicinaC 0.02% como adjuvante no tratamento Descritores: corneal, ceratoconjuntivite seca, crônico, quimioterápico.Background: Although Squamous Cell Carcinoma (SCC) is most commonly seen in the epidermis, this malignant neoplasm can manifest in various other tissues. A wide range of factors may be related to the development of SCC in the cornea, with continuous exposure to ultraviolet radiation and chronic friction to the ocular surface being the most accepted theories. In addition to surgical procedures, the use of mitomycin C in the topical treatment of corneal SCC has shown good results in therapeutic management. Thus, the objective of the current work is to report the satisfactory response observed in the use of mitomycin C in a case of SCC in the cornea of a dog. Case: This study addresses the case of a 9-year-old male Pug dog who was attended by the Veterinary Ophthalmology and Microsurgery Sector (SOMVET) of the University Veterinary Hospital (HVU) of the Federal University of Santa Maria (UFSM). The patient presented with Squamous Cell Carcinoma (SCC) in the cornea of the left eye, which had recurred after a previous surgical intervention. Secretion and discomfort in the left eye were noted during clinical examination. In addition, both eyes presented pigmentary keratitis in the medial corner. Surgical excision of the neoplasm was performed using the surgical technique of anterior lamellar keratectomy. In the immediate postoperative period, topical therapy was started with eye drops based on mitomycin C at 0.02%, for a period of 28 consecutive days. The use of this chemotherapy drug in the topical form was intended to minimize the chances of recurrence of the clinical condition, since the patient is predisposed to this alteration. In addition, supportive therapy was implemented to improve patient comfort, consisting of the use of tobramycin-based eye drops (6 times a day, for 14 days), atropine 1% eye drops (BID, for 3 days), lubricating eye drops based on sodium hyaluronate (3 times a day, for continuous use), and immunomodulatory eye drops based on tacrolimus 0.02% (twice a day, for continuous use). The patient was evaluated 7, 14, 21, and 28 days after surgery, when good results were observed. One year after treatment, the dog was still showing no signs of recurrence of the treated clinical condition. Discussion: It is known that chronic friction on the surface of the cornea predisposes to the diagnosis of corneal SCC. Accordingly, in the clinical examination of the patient in this report, the presence of bilateral pigmentary keratitis was observed, an alteration that leads to a framework of chronic aggression to the cornea. Surgical treatment is recommended to remove the tumor mass in the ocular region. However, in cases of corneal SCC, the literature highlights that recurrence after surgical excision is a common factor. As the patient in this study arrived at the clinic with a history of recurrence, topical therapy with mitomycin C associated with surgical treatment was instituted. This chemotherapy drug has shown encouraging results in the treatment of some neoplasms, especially SCC. Its use in this case supported previous findings, pointing to a satisfactory result in which the patient had no recurrences after one year of follow-up. In addition, the concentration and frequency used of the active ingredient did not lead to adverse effects in the short or medium term

Aspectos morfológicos da glândula molar em leão (Panthera leo)/ Morphological aspects of the molar gland in lion (Panthera leo)

O conhecimento morfológico das glândulas salivares é importante nas espécies silvestres e domésticas. As glândulas salivares dos felinos são mandibulares, parótida, sublingual, zigomática e molar. As glândulas molares são um total de duas no leão (Panthera leo), com secreção predominante mucosa. Dessa forma, o objetivo desse trabalho foi descrever anatomicamente a glândula molar. O presente trabalho foi realizado no laboratório de anatomia na Universidade Federal de Santa Maria. Foi dissecada uma cabeça de uma leoa (Panthera leo) de vinte e três anos que pertencia a um criadouro de Santa Maria/RS. Fixou-se e realizou-se a dissecação das glândulas molares de ambos os lados da face, com rebatimento da pele, do músculo platisma e remoção do músculo subcutâneo. A forma, posição e a relação das glândulas foram observadas. Com a fita métrica foram realizadas medidas da extremidade do nariz até o ponto mais alto da crista nucal (Medida A), desta até o ponto médio entre os ângulos mediais dos olhos (Medida B), e de uma linha reta transversal partindo do processo angular da mandíbula até o dorso da cabeça (Medida C). Mediram-se também com auxílio de um parquímetro o comprimento, a largura e a profundidade das glândulas. Logo, a glândula molar apresentou uma forma retangular alongada, com medidas proporcionais em relação ao tamanho da cabeça, de 1/6 a 1/7 do comprimento, e de 1/16 a 1/23 da largura

Consolidation of Tibia Fractures in Rabbits

Background: Disorders of the locomotor system are among the main treatments for this species, among the main causes are falls from a cage, arms or stairs and aggression by animals, such as dogs and cats. Biological osteosynthesis promotes early formation of secondary bone callus and allows a less accurate reconstruction of difficult interfragmentary apposition of 100% of the fragments. The objective of this work is to report the method of external immobilization with an aluminum channel aiming at the use of bone biology for the healing of unexposed tibial fractures in 3 rabbits (Oryctolagus cuniculus). Cases: Between 2020 and 2021, 3 cases of rabbits with unexposed tibial fractures were treated at the Veterinary Hospital. The 3 patients were diagnosed through physical examination and radiographic examination. All patients underwent anesthesia, underwent external immobilization with an aluminum channel, received analgesics and anti-inflammatory drugs, and recommended rest and care with the maintenance of external immobilization. Approximately at 30 days of rigid immobilization, all cases were evaluated by means of radiographic examination revealing the formation of bone callus at different post-immobilization times in the case 1 - 30 days, case 2 - 23 days and case 3 - 37 days. Discussion: Some surgical principles in rabbits must be followed, such as preserving vascularity if the open technique is decided, providing adequate diet, controlling edema, promoting analgesia and deciding on closed reduction if the fracture is recent and stable. The external coaptation method is a non-invasive method for the treatment of fractures and is also indicated with a high success rate for fractures of metacarpal, metatarsal and phalange bones in rabbits. The patient's age contributed to the early healing, which corroborates with case 1 (3-month-old), case 2 (6-month-old) and a little later the healing in case 3 (24-month-old), allowing unrestricted use of the member. It is worth reinforcing the point of view which defends that "biological osteosynthesis" promotes a favorable environment, especially in the preservation of the vascular supply of the periosteum when compared to traditional open surgical approaches. In this species, the surgical approach is a challenge due to the fact that the bones break or crack very easily, because the bones have a low density and higher mineral composition. Together, the skeleton represents 7% of the body weight, lower when compared to dogs and cats, which is 12%. In addition to these factors, rabbits are prone to secondary fractures, postoperative infections and rapid development of osteomyelitis, which significantly worsens the prognosis. The aluminum used in the manufacture of the aluminum channel has properties that offer resistance, lightness and radio transparency radiographic examination without removal of the channel, avoiding excessive micro-movement of the focus of the fracture due to lack of stabilization and possible refracture of the tibia. Rigid external immobilization with an aluminum channel was satisfactory in the 3 patients evaluated and preserved bone biology and anatomical axis. The treatment of choice was easy to apply, in addition to enabling better radiographic follow-up, promoting rapid bone healing for patients and early use of limbs without restrictions. However, for the effectiveness of the technique, the collaboration of tutors is essential. Keywords: biological, fracture, immobilization, osteosynthesis, orthopedics. Título: Consolidação de fraturas de tíbia em coelhos Descritores:  biológica, fratura, imobilização, osteossíntese, ortopedia

Flape de rotação em padrão axial caudal lateral superficial após remoção de adenocarcinoma de glândula perianal em cão: Superficial lateral caudal axial pattern flap after removal perianal gland adenocarcinoma in dog

A cirurgia reconstrutiva tem sido frequentemente utilizada, principalmente para o fechamento de defeitos secundários à remoção de neoplasias. As neoplasias de glândula perianal geralmente acometem cães machos, inteiros e de meia idade à idosos. Dentre os tumores desta glândula, os adenocarcinomas são menos frequentes quando comparados aos adenomas e exigem excisão cirúrgica com margem de segurança, tornando o defeito secundário maior e, muitas vezes, sendo necessário a utilização de técnicas reconstrutivas para o seu fechamento. O presente trabalho objetiva descrever o caso de um canino que apresentava um nódulo em região perianal, na base da cauda, e o uso da cirurgia reconstrutiva para o fechamento do defeito oriundo da excisão cirúrgica nessa região. Foi atendido no Hospital Veterinário, um canino, macho, sem raça definida (SRD), de 12 anos de idade, apresentando um nódulo na região perianal, na base da cauda, há cerca de três meses que, segundo exame histopatológico após a remoção, tratava-se de um adenocarcinoma de glândula perianal. Para a remoção cirúrgica do tumor, foi necessária a utilização de reconstrução com flape de rotação de padrão axial caudal lateral superficial, resultando no fechamento completo do defeito cirúrgico, retorno funcional da área afetada, perfusão adequada, bons resultados estéticos, ausência de grandes complicações e permitindo a remoção da neoplasia com ampla margem de segurança, confirmando o sucesso da técnica escolhida

Intrastromal Fluconazole - Effectiveness in the Surgery of Stromal Abscess in a Horse

Background: Due to its ocular microflora, the equine species is predisposed to develop mycotic ulcers which, when not properly treated, can lead to the formation of a stromal abscess. A stromal abscess occurs through the introduction of microorganisms into the corneal stroma. During re-epithelialization, the foreign body is encapsulated, thus creating a barrier that protects bacteria or fungi from treatment with antimicrobial medication. This framework can end up resulting in blindness due to chronic iridocyclitis, putting the animal's vision at risk. The current work aims to report a case of corrective surgery for stromal abscess in a mare with the administration of intraoperative intrastromal fluconazole, in order to corroborate the effectiveness of the technique.  Case: A 9-year-old mare was evaluated, with the complaint that her right eye was closed and “yellowish” and that she had already been treated with intramuscular injectable anti-inflammatory drugs based on flunexin meglumine (Banamine® - 50 mg) for 15 days, referring to a possible ulcer in the right eye.  Ophthalmic screening resulted in a negative direct reflex and no threat response in the right eye. Examination of the conjunctiva showed congestion and chemosis. Examination of the cornea of the right eye was negative for Fluorescein and Green Lissamine tests, and opacity and corneal neovascularization were noted. The final diagnosis was a corneal abscess of probable fungal origin secondary to a keratomycosis. After the consultation, complementary blood and biochemical tests were performed, which showed normal results for the species in question, and treatment was started with eye drops based on atropine 1% (Fagra® - 20 mL), ciprofloxacin antimicrobial eye drops (Ciprovet Colirio® - 5 mL), and antifungal eye drops based on ketoconazole 1% (manipulated), in addition to an intramuscular injectable anti-inflammatory based on flunexin meglumine (Banamine® - 50 mg - 1.1 mg/kg SID) and an intramuscular injectable analgesic based on sodium dipyrone (Febrax® - 0.5 g - 15 mL/animal SID) until the day of surgery, which was booked for 3 days later. The surgical intervention was then instituted by the technique of anterior lamellar keratectomy followed by intrastromal hydration with fluconazole and the forming of a bipedicled flap, in order to remove the necrotic tissue and antigenic stimulation factors, while the conjunctival flap aimed to improve blood supply and protect the injured area, thus favoring local healing. For better postoperative quality for the animal, continuation of the same treatment as prior to surgery was prescribed for a period of 15 days. The return of the animal for the removal of the flap was scheduled for 45 days after surgery, however, due to the COVID-19 pandemic, there was a delay of 135 days. When the animal returned the flap was still stable. A second surgery was instituted for the removal of the flap, during which it was possible to affirm that the cornea had recovered total integrity and partial transparency with only a leukoma in the previous location of the abscess.Discussion: The technique of anterior lamellar keratectomy together with the use of a conjunctiva flap for the treatment of stromal abscess in horses is a known technique that is used routinely, although some cases report the formation of a second infection in the same space. However, there are few reports on the use of intrastromal hydration with antifungal medication adjuvant to the surgical technique, which, as shown in this report, proved to be effective since even with the issue of a delay in removing the conjunctival flap, the eye remained whole and there was no second infection. The use of this technique can therefore be indicated for the treatment of stromal abscess in horses, given the safety that the application of intrastromal antifungal provides.Keywords: azole, abscess, stromal, keratectomy, ophthalmology, equine, mare.Descritores: azol, abscesso, estroma, ceratectomia, oftalmologia, equino, égua.

Osteossíntese de úmero em um gato-maracajá (Leopardus Wiedii) / Humeral osteosynthesis in a margay (Leopardus Wiedii)

Os felídeos selvagens são os mamíferos mais admirados pelo ser humano, mas a maior causa do declínio desses animais na natureza é a destruição e a fragmentação dos seus habitats. A espécie Leopardus wiedii, de nome popular gato-maracajá, está listada como Quase Ameaçada pela Lista Vermelha de Espécies Ameaçadas da IUCN. Em felídeos selvagens, as correções de fraturas oriundas de traumatismos são uma das intervenções cirúrgicas mais comuns. Logo, o objetivo desse trabalho é apresentar um gato maracajá com fratura de úmero, do qual optou-se pelo tratamento cirúrgico com dois pinos de Steinmann intramedulares. Ressalta-se a eficácia do método escolhido, que foi avaliado aos 30, 45 e 60 dias do pós-operatório e alta clínica da paciente aos 60 dias, com ganho de 700 gramas de massa corporal

Sheep corneal endothelium morphology : evaluation with trypan blue and alizarin red

Background: The endothelium is a layer fundamental to maintaining corneal transparency. In ophthalmology, sheep eyes have been used as a model in research related to corneal transplantation. Different techniques have been used to evaluate the corneal endothelium. Concerning vital dyes, corneal endothelial cell analyses have not yet been studied in ovines. The purpose of the present study was to evaluate the morphology of endothelial cells from different regions of the cornea of sheep after staining with alizarin red and trypan blue using an optical microscope. Materials, Methods & Results: Twenty healthy eyes of 10 male sheep obtained from a licensed commercial slaughterhouse were studied. The study was approved by the Research Committee of the Faculty of Veterinary at UFRGS and followed the ethical standards of the Association for Research in Vision and Ophthalmology (ARVO). Immediately after the slaughter, the eyes were enucleated and underwent eye examination. The corneal endothelium was stained with trypan blue and alizarin red and examined and photographed using an optical microscope. The central, superior, inferior, nasal and temporal areas of the cornea were evaluated for cell morphology. Data were compared by t-tests. Differences were considered statistically significant at P < 0.05. Immediately after staining the corneal endothelium, it was possible to examine with an optical microscope, obtain images and analyse the shape of endothelial cells from all regions of the sheep cornea. Polygonal, uniform and continuous cells were observed in all samples studied. Considering all the corneas analysed, cells with 6 sides (75.11%), 5 sides (12.76%) and 4 sides (12.12%) were found. In the central region of the cornea 75.91% of cells with 6 sides, 12.6% of cells with 5 sides and 11.48% with 7 sides were found. In the superior region of the cornea 76.07% of cells with 6 sides, 13.25% with 5 sides and 10.68% with 7 sides were found. In the lower region were found 74.72% of cells with 6 sides, 13% with 5 sides and 12.27% with 7 sides. In the temporal region, 74.14% were 6-sided cells, 11.42% had 5 sides, and 14.43% had 7 sides. Furthermore, in the nasal region, 74.72% of the cells had 6 sides, 13.54% had 5 sides, and 11.73% had 7 sides. No significant differences were found between cell morphology in all corneal regions evaluated. In addition, no significant difference was found when comparing the right eye with the left eye. Discussion: Different methods are used for the analysis of corneal endothelium. For ex vivo research optical microscopy after endothelial staining is an alternative low-cost technique that allows the analysis of all regions of the cornea. Quan¬titative analyses must characterise the endothelial parameters of the different species. The analysis of the morphology of corneal endothelium with an optic microscope after staining with alizarin red has been described as an effective, rapid and cost-efficient method, since this dye blends with the borated cells, allowing identification. In the present study, using optical microscopy and coloration with alizarin red it was possible to explore and obtain images of the ovine endothelium of all regions of the cornea. In the current study, the endothelium had a predominance of cells will 6 sides in all regions studied. This study allowed us to obtain images of the endothelium as well as quantitative data on the morphology of the different regions of the sheep cornea. This study demonstrated that morphology did not differ between the central and peripheral regions. The findings of this study represent a further source of reproducible data that should be considered when using sheep cornea as ex vivo model for experimental research

Sheep Corneal Endothelium Morphology - Evaluation with Trypan Blue and Alizarin Red

Background: The endothelium is a layer fundamental to maintaining corneal transparency. In ophthalmology, sheep eyes have been used as a model in research related to corneal transplantation. Different techniques have been used to evaluate the corneal endothelium. Concerning vital dyes, corneal endothelial cell analyses have not yet been studied in ovines. The purpose of the present study was to evaluate the morphology of endothelial cells from different regions of the cornea of sheep after staining with alizarin red and trypan blue using an optical microscope. Materials, Methods &amp; Results: Twenty healthy eyes of 10 male sheep obtained from a licensed commercial slaughterhouse were studied. The study was approved by the Research Committee of the Faculty of Veterinary at UFRGS and followed the ethical standards of the Association for Research in Vision and Ophthalmology (ARVO). Immediately after the slaughter, the eyes were enucleated and underwent eye examination. The corneal endothelium was stained with trypan blue and alizarin red and examined and photographed using an optical microscope. The central, superior, inferior, nasal and temporal areas of the cornea were evaluated for cell morphology. Data were compared by t-tests. Differences were considered statistically significant at P &lt; 0.05. Immediately after staining the corneal endothelium, it was possible to examine with an optical microscope, obtain images and analyse the shape of endothelial cells from all regions of the sheep cornea. Polygonal, uniform and continuous cells were observed in all samples studied. Considering all the corneas analysed, cells with 6 sides (75.11%), 5 sides (12.76%) and 4 sides (12.12%) were found. In the central region of the cornea 75.91% of cells with 6 sides, 12.6% of cells with 5 sides and 11.48% with 7 sides were found. In the superior region of the cornea 76.07% of cells with 6 sides, 13.25% with 5 sides and 10.68% with 7 sides were found. In the lower region were found 74.72% of cells with 6 sides, 13% with 5 sides and 12.27% with 7 sides. In the temporal region, 74.14% were 6-sided cells, 11.42% had 5 sides, and 14.43% had 7 sides. Furthermore, in the nasal region, 74.72% of the cells had 6 sides, 13.54% had 5 sides, and 11.73% had 7 sides. No significant differences were found between cell morphology in all corneal regions evaluated. In addition, no significant difference was found when comparing the right eye with the left eye. Discussion: Different methods are used for the analysis of corneal endothelium. For ex vivo research optical microscopy after endothelial staining is an alternative low-cost technique that allows the analysis of all regions of the cornea. Quantitative analyses must characterise the endothelial parameters of the different species. The analysis of the morphology of corneal endothelium with an optic microscope after staining with alizarin red has been described as an effective, rapid and cost-efficient method, since this dye blends with the borated cells, allowing identification. In the present study, using optical microscopy and coloration with alizarin red it was possible to explore and obtain images of the ovine endothelium of all regions of the cornea. In the current study, the endothelium had a predominance of cells will 6 sides in all regions studied. This study allowed us to obtain images of the endothelium as well as quantitative data on the morphology of the different regions of the sheep cornea. This study demonstrated that morphology did not differ between the central and peripheral regions. The findings of this study represent a further source of reproducible data that should be considered when using sheep cornea as ex vivo model for experimental research. Keywords: ovine, endothelial cells, ex vivo model, vital staining, hexagonality