Morphometric descriptive report of scleral ossicle rings, by ultrasound and computed tomography, in three Testudines specimens / Relato descritivo morfobiométrico dos anéis de ossículos esclerais, por ultrassonografia e tomografia computadorizada, em três espécimes de Testudines

The scleral ossicle rings function has been related to mechanical protection, muscle fixation, support for eyeball shape and visual accommodation. There are few morphobiometric reports on these rings in different Testudines species, and we performed ultrasound (US) and computed tomography (CT) of the scleral ossicle rings in one green turtle (Chelonia mydas), one black-bellied slider (Trachemys dorbigni) and one red-footed tortoise (Chelonoidis carbonarius). The US and CT of the ossicle rings were performed for anatomical identification. The thickness, density, width, and diameters of each ring were measured. The US and CT of the scleral ossicle rings of three animals showed single and continuous circular structures, located in the anterior pole. These structures were easily observed in C. mydas, whose rings were the biggest, thickest and widest. The T. dorbigni CT presented decreased dimensions and the ossicles were the most difficult to identify. Bone density in the superior region was greater than in the inferior of each ring in all animals. Non-invasive imaging exams are good tools to study the anatomy of the ocular skeleton. The scleral ossicle rings of the three specimens presented general morphological similarities and CT enabled visualizing a greater number of details of the ring bone morphology.

Os anéis de ossículos esclerais têm sua função relacionada à proteção mecânica, fixação muscular, suporte para o formato do bulbo ocular e acomodação visual, contudo existem poucos relatos morfobiométricos sobre esses anéis em diferentes espécies de Testudines. Desta forma, foi realizada a avaliação morfobiométrica, por ultrassom (US) e tomografia computadorizada (TC), dos anéis de ossículos esclerais em uma tartaruga verde (Chelonia mydas), um tigre-d'água (Trachemys dorbigni) e um jabuti-piranga (Chelonoidis carbonarius). Foram realizadas US e TC dos anéis esclerais dos três animais para identificação anatômica, espessura, densidade, largura e diâmetros. A US e a TC dos três animais mostraram estruturas circulares únicas e contínuas, localizadas no polo anterior. Estas estruturas foram facilmente observadas na C. mydas, cujos anéis eram os maiores, mais espessos e mais largos. A TC da T. dorbigni apresentou dimensões reduzidas e os ossículos foram dificilmente identificados. A densidade óssea na região superior foi maior comparativamente a parte inferior de cada anel, em todos os animais. Exames de imagem não invasivos mostraram-se bons instrumentos para estudo do esqueleto escleral. Os anéis de ossículos esclerais dos três espécimes apresentaram semelhanças morfológicas gerais e a TC permitiu visualizar um maior número de detalhes da morfologia óssea do anel.

Outbreaks of philophthalmiasis in ostriches (Struthio camelus) in Northeast Brazil / Surtos de filoftalmíase em avestruzes (Struthio camelus) no Nordeste do Brasil

ABSTRACT: This study discusses the epidemiological, clinical, and pathological characteristics of two outbreaks of ocular infection in ostriches (Struthio camelus) caused by the trematode Philophthalmus sp. The outbreaks occurred in the states of Ceará and Rio Grande do Norte in Northeast Brazil. Ostrich farming was categorized as semi-intensive farming with free access to the weir and river. The clinical symptoms for infection included nictitating membrane inflammation, epiphora (tearing), eyelid edema, ocular congestion, eyeball destruction, emaciation, and death, and the infection period ranged from 8 to 16 months. Macroscopically, thickening of the eyelids and conjunctiva were observed, with orange parasites infestation. Histologically, the lesions were characterized as lymphoplasmacytic and heterophilic, multifocal to coalescing, moderate, chronic conjunctivitis associated with hyperplasia and ectasia of the Harderian gland, and numerous parasites. The parasites were oval and flattened with an oral suction cup, acetabulum, and thick cuticle containing spicules. The diagnosis of philophthalmiasis was based on epidemiological, clinical, and pathological findings associated with the morphological characteristics of the parasites present in the conjunctival sacs which were similar to the trematode Philophthalmus sp. Philophthalmiasis can occur in ostriches raised on urban and rural properties in Northeastern Brazil, probably associated with the contact of birds with contaminated water, and is characterized by severe conjunctivitis that can result in the loss of the eyeball and death of the animals.

RESUMO: Descrevem-se as características epidemiológicas, clínicas e patológicas de dois surtos de infecção ocular pelo trematódeo Philophthalmus sp. em avestruzes ocorridos nos estados do Ceará e Rio Grande do Norte no Nordeste do Brasil. As propriedades tinham em comum, a criação semi-intensiva e livre acesso a açude e rio. Os sinais clínicos incluíam protrusão da membrana nictante, lacrimejamento, edema palpebral, congestão ocular, destruição do globo ocular, emagrecimento e morte. A evolução clínica variou de oito a 16 meses. Macroscopicamente, observou-se espessamento das pálpebras e conjuntivas associado a numerosas estruturas parasitárias alaranjadas. No segundo surto, as lesões eram mais graves e consistiam em perda do globo ocular direito e anexos. Histologicamente, as lesões caracterizavam-se por conjuntivite linfoplasmocítica e heterofílica, multifocal a coalescente, moderada, crônica associada a hiperplasia e ectasia da glândula de Harderian e numerosas estruturas parasitárias. Os parasitas eram ovalados, achatados com ventosa oral e acetábulo e cutícula espessa contendo espículas. O diagnóstico de filoftalmíase foi realizado com base nos achados epidemiológicos, clínicos e patológicos associadas as características morfológicas dos parasitas presentes nos sacos conjuntivais compatíveis com o trematódeo Philophthalmus sp. A filoftalmíase pode ocorrer em avestruzes criados em propriedades urbanas e rurais no Nordeste do Brasil, provavelmente associado ao contato das aves com água contaminada e caracteriza-se por quadros de conjuntivite grave que pode resultar com a perda do globo ocular e morte dos animais.

Morphometric descriptive report of scleral ossicle rings, by ultrasound and computed tomography, in three Testudines specimens / Relato descritivo morfobiométrico dos anéis de ossículos esclerais, por ultrassonografia e tomografia computadorizada, em três espécimes de Testudines

ABSTRACT: The scleral ossicle rings function has been related to mechanical protection, muscle fixation, support for eyeball shape and visual accommodation. There are few morphobiometric reports on these rings in different Testudines species, and we performed ultrasound (US) and computed tomography (CT) of the scleral ossicle rings in one green turtle (Chelonia mydas), one black-bellied slider (Trachemys dorbigni) and one red-footed tortoise (Chelonoidis carbonarius). The US and CT of the ossicle rings were performed for anatomical identification. The thickness, density, width, and diameters of each ring were measured. The US and CT of the scleral ossicle rings of three animals showed single and continuous circular structures, located in the anterior pole. These structures were easily observed in C. mydas, whose rings were the biggest, thickest and widest. The T. dorbigni CT presented decreased dimensions and the ossicles were the most difficult to identify. Bone density in the superior region was greater than in the inferior of each ring in all animals. Non-invasive imaging exams are good tools to study the anatomy of the ocular skeleton. The scleral ossicle rings of the three specimens presented general morphological similarities and CT enabled visualizing a greater number of details of the ring bone morphology.

RESUMO: Os anéis de ossículos esclerais têm sua função relacionada à proteção mecânica, fixação muscular, suporte para o formato do bulbo ocular e acomodação visual, contudo existem poucos relatos morfobiométricos sobre esses anéis em diferentes espécies de Testudines. Desta forma, foi realizada a avaliação morfobiométrica, por ultrassom (US) e tomografia computadorizada (TC), dos anéis de ossículos esclerais em uma tartaruga verde (Chelonia mydas), um tigre-d'água (Trachemys dorbigni) e um jabuti-piranga (Chelonoidis carbonarius). Foram realizadas US e TC dos anéis esclerais dos três animais para identificação anatômica, espessura, densidade, largura e diâmetros. A US e a TC dos três animais mostraram estruturas circulares únicas e contínuas, localizadas no polo anterior. Estas estruturas foram facilmente observadas na C. mydas, cujos anéis eram os maiores, mais espessos e mais largos. A TC da T. dorbigni apresentou dimensões reduzidas e os ossículos foram dificilmente identificados. A densidade óssea na região superior foi maior comparativamente a parte inferior de cada anel, em todos os animais. Exames de imagem não invasivos mostraram-se bons instrumentos para estudo do esqueleto escleral. Os anéis de ossículos esclerais dos três espécimes apresentaram semelhanças morfológicas gerais e a TC permitiu visualizar um maior número de detalhes da morfologia óssea do anel.

Dry-eye syndrome in Shih Tzu dog: Ocular surface clinical and morphological aspects in the different stages of keratoconjunctivitis sicca / Síndrome do olho seco em Shih Tzu: aspectos clínicos e morfológicos da superfície ocular nas diferentes fases da ceratoconjuntivite seca

ABSTRACT: This study analyzed clinical and cyto-histomorphological parameters of the ocular surface of Shih Tzu dogs, non-carriers and carriers of quantitative keratoconjunctivitis sicca (KCS) at different stages. Thirty-five eyes from 23 male and female Shih Tzu dogs between two and eight years were evaluated in four groups: control group (CG - without KCS), mild KCS group (KCS1), moderate KCS group (KCS2), and severe KCS group (KCS3). Most clinical variables among KCS carrier groups worsened at the more advanced stages of the disease, with a negative correlation between the Schirmer tear test (STT-1) and tear film break-up time (TBUT). Squamous metaplasia, lymphoplasmacytic inflammatory infiltrate, and decrease in conjunctival goblet cells on histopathological examination comprised disease severity parameters. Quantitative KCS non-carried Shih Tzu dogs have qualitative and tear film distribution changes. The cytomorphological exam is limited to evaluating the inflammatory infiltrate and quantifying conjunctival goblet cells. However, intermediate epithelial cells were higher in healthy eyes compared to eyes with KCS in Shih Tzu dogs. Also, moderate and severe KCS carrier Shih Tzu dogs have qualitative dysfunction of the tear film. KCS in Shih Tzu dogs is common and chronic and may be responsible for the loss of vision of these animals. Early identification of the disease and routine evaluation can improve these dogs' quality of life and ocular health.

RESUMO: Este estudo analizou os parâmetros clinicos e cito-histomorfológicos da superfície ocular de cães da raça Shih Tzu, portadores e não portadores de ceratoconjuntivite seca quantitative (CCS) em diferentes estágios. Trinta e cinco olhos de 23 cães da raça Shih Tzu, machos e fêmeas, entre as idades de dois e oito anos foram avaliados em quatro grupos: grupo controle (GC - sem CCS), grupo CCS inicial (CCS1), grupo CCS moderada (CCS2) e grupo CCS severa (CCS3). A maioria das variáveis clínicas dentro os grupos portadores de CCS pioraram a medida que os estágios da doença avançam, com correlações negativas entre o teste lacrimal de Schirmer (TLS) e o tempo de ruptura do filme lacrimal (TRFL). Metaplasia escamosa, infiltrado inflamatório linfoplasmocítico e diminuição das células caliciformes no exame histopatológico compreenderam parâmetros de severidade da doença. Cães Shih Tzu não portadores de CCS quantitativa tem alterações qualitativas e na distribuição do filme lacrimal. O exame citomorfológico é limitado para a avaliação do infiltrado inflamatório e quantificação de células caliciformes. Entretanto, células inermediárias epiteliais são mais presents nos olhos saudáveis quando comparados aos olhos portadores de CCS em Shih Tzus. Também, Shih Tzus portadores de CCS nos estágios moderados e severos possuem disfunções qualitativas da lágrima. A CCS em Shih Tzu é comum, crônica e pode ser responsável pela perda de visão dos animais. A identificação precoce da doença e avaliações rotineiras podem aumentar a qualidade de vida e a saúde ocular nesses cães.

Glaucoma in dogs and cats - management with cyclocryotherapy

Background: The treatment of glaucoma often requires numerous therapeutic modalities to achieve the desired reduction in intraocular pressure (IOP). Cyclodestructive procedures or ciliary body destruction have been performed using techniques with considerable differences in efficacy and complication rates. Among these methods, cyclocryotherapy is non-invasive and simple for the management of uncontrolled glaucoma in dogs and cats. The objective of this case report is to describe the technique of carbon dioxide cyclocryotherapy to reduce intraocular pressure in dogs and cats with glaucoma. Cases: Nine canine patients and one cat with glaucoma were treated with cyclocryotherapy performed under general anaesthesia. Clinical signs patients included blepharospasm, ocular pain, episcleral congestion and ocular hypertension. The patients showed higher levels of IOP, higher than 30 mmHg. Surgical treatment with general anaesthesia was applied. The pre-anaesthesia protocol included acepromazine 0.05 mg/kg with methadone 0.2 mg/kg, followed by intravenous propofol and maintenance with isoflurane and oxygen. An ophthalmological cryocautery unit was used with carbon dioxide as the cryogenic agent and a retinal cryoprobe of 3.2 mm diameter tip for the procedure. The method used was a double cycle of freezing and thawing for 60 s in each site. The cryoprobe was centred approximately 5 mm posterior to the corneoscleral limbus over the ciliary body. The temperature of each cyclocryotherapy spot was between -60°C and -80°C and each site was maintained in place for 60 s; 4 to 6 spots of the double freeze-thaw cycle were made. This technique did not have any serious complications during or after the application of cryotherapy, but chemosis and hyperaemia of the bulbar conjunctiva developed. Subconjunctival anti-inflammatory steroids were injected to minimise swelling and patient discomfort. Satisfactory results were observed; in all cases, the intraocular pressure decreased, with the usual result being a cosmetic and painless eye. Discussion: Even with recent surgical and medical advances, pain and blindness are still common occurrences in glaucoma in human and veterinary practice. The cyclodestructive procedures included cyclodialysis, cyclodiathermy, cyclocryotherapy, and cyclophotocoagulation. The cryosurgery in veterinary ophthalmology has many indications for the treatment of ocular diseases and is effective at decreasing intraocular pressure in patients with persistent uncontrolled glaucoma. Cyclocryotherapy has been shown to reduce intraocular pressure in dogs, cats, rabbits and humans with normotensive and glaucomatous eyes. The application of a cryoprobe over the ciliary processes results in ablating ciliary tissue so that aqueous humour inflow is reduced to acceptable levels. In the clinical cases evaluated, there was a reduction in intraocular pressure reaching acceptable levels, with the usual result being cosmetic and painless eye. Medical therapy remains the predominant method for treating glaucoma in veterinary patients; therefore, cyclocryotherapy is an effective, simple way to lower IOP and is a reasonable treatment option for glaucoma management. Cyclocryotherapy has shown good results, with a low learning curve and it can also be repeated if necessary.

Characterization of nonpathological intrascleral cartilage in the domestic sheep (Ovis aries) / Caracterização de cartilagem intraescleral não patológica em ovinos (Ovis aries)

ABSTRACT: Birds, cartilaginous and teleost fish, reptiles, and some amphibians have intrascleral cartilage and/or bone; however, these are rarely reported in therian mammals. This study aimed to investigate and characterize a nonpathological formation of cartilage in the posterior sclera of sheep macroscopically, histologically, and by immunohistochemical exam (IHC). Ninety eyes from 45 domestic sheep were collected, underwent gross examination, fixed in formalin, and embedded in paraffin for the microscopical assessment. Sections with histological shreds of cartilage were selected to perform IHC to confirm the presence of cartilage. Intrascleral cartilage was detected in 60 eyeballs (66.66%) from 37 sheep (82.22%). A slight whitish thickening was grossly seen in the posterior sclera. The histologic exam revealed a few scattered, isolated chondrocytes to larger aggregates of cartilaginous islands in the posterior sclera. Eighteen (30%) of 60 eyeballs revealed marked anti-collagen type II immunolabeling. The development of cartilaginous structures in the eyes is considered rare in mammalian animals. The high occurrence of intrascleral cartilage in the examined sheep eyes suggests that this finding corresponds to an anatomical component of sheep sclera, despite the age, breed, or body condition.

RESUMO: Aves, peixes cartilaginosos e teleósteos e répteis, bem como alguns anfíbios possuem cartilagem e/ou osso intraescleral, contudo, isso é raramente descrito em marsupiais. O objetivo deste trabalho foi investigar e caracterizar a formação não patológica de cartilagem hialina na esclera posterior de ovinos, por exame macroscópico, histológico e imuno-histoquímico. Olhos de 45 ovinos foram coletados, submetidos a exame macroscópico, fixados em formalina a 10% tamponada e incluídos em parafina para o exame histológico. Amostras com evidência de formação cartilaginosa ao exame histológico foram selecionadas para a realização da técnica de imuno-histoquímica para confirmação. Cartilagem intraescleral foi detectada em 60 amostras oculares (66,66%) de 37 ovinos (82,22%), caracterizada na avaliação macroscópica como discretos espessamentos esbranquiçados na esclera posterior. O exame histológico revelou formações que variaram de condrócitos isolados e dispersos a grandes agregados, formando ilhas cartilaginosas na esclera. Dezoito (30%) de 60 bulbos oculares mostraram imunomarcação anti-colágeno tipo II. O desenvolvimento de estruturas cartilaginosas nos bulbos oculares é considerado raro em mamíferos. A identificação de cartilagem intraescleral em 66% dos olhos ovinos avaliados no estudo indica que a formação de cartilagem corresponde a um componente anatômico normal na esclera de ovinos, independente de idade, raça ou condição corporal.

Unusual parasitism site of Dermacentor nitens (Acari: Ixodidae) on a horse / Parasitismo em local incomum de Dermacentor nitens (Acari: Ixodidae) em um cavalo

ABSTRACT: Dermacentor nitens Neumann is the most common tick species infesting horses in the main Brazilian biomes. It has a predilection to attach to horse the ears, the nasal diverticulum, perineal and perianal regions. The infestations can generate severe damage in the ears, anemia, and the tick also acts as vector of Babesia caballi (Nuttall and Strickland), the causative agent of equine babesiosis. Our study describes unusual parasitism site of D. nitens on a female cross breed horse, approximately ten years old that presented high parasitism by ticks on the perineal and perianal region, ears, and the left eye orbit region, where an enucleation process had been performed a few years earlier. To our knowledge this is the first report of D. nitens parasitism on a formerly enucleated eye orbit.

RESUMO: Dermacentor nitens Neumann é a espécie de carrapato mais comum infestando equinos nos principais biomas brasileiros. Tem predileção por se fixar ao cavalo nas orelhas, divertículo nasal, e nas regiões perineal e perianal. As infestações podem gerar danos severos nas orelhas, anemia, e o carrapato também atua como vetor de Babesia caballi (Nuttall and Strickland), agente causador da babesiose equina. Nosso estudo descreve um local de parasitismo incomum de D. nitens em uma égua mestiça de aproximadamente dez anos de idade, que apresentou alto parasitismo por carrapatos nas regiões perineal e perianal, orelhas e região da órbita do olho esquerdo, onde havia sido realizado processo de enucleação alguns anos anteriores. Para o nosso conhecimento, este é o primeiro relato de parasitismo de D. nitens em uma órbita ocular anteriormente enucleada.

Persistência do vítreo primário hiperplásico e catarata em cão / Persistence of hyperplastic primary vitreous and cataract in a dog

Background: Persistent hyperplastic primary vitreous is a rare ocular condition that is usually unilateral, formed when normal regression of the hyaloid vascular system does not occur. Diagnosis is possible through ultrasonography, by obtaining images that provide information and also serve as a differential diagnosis. Clinically the condition presents with signs of leukocoria, microphthalmia, and cataracts, and it can be further classified into 6 degrees according to the evolution. The objective of this work is to describe the case and treatment of a canine of the Pointer breed that presented opacity in both eyes, with diagnosis confirmed through ocular ultrasonography. Case: A 6-year-old male pointer dog, weighing 27 kg, was referred to the Veterinary Medical Teaching Hospital of the Federal University of Santa Maria (UFRGS), Santa Maria, RS - Brazil with a history of blindness. According to the owner, the animal's right eye has always been "white", since it was a puppy and the left eye began to present the same characteristic a short time ago. On ophthalmological examination, neither eye showed signs of ocular discomfort, the Schirmer's tear test was within the range expected for the species, fluorescein and threat tests were negative, and a positive pupillary reflex was observed in the left eye. The right eye had total corneal opacity associated with a chronic lesion and the presence of pigment cells in the medial portion of the eyeball, the opacity making it impossible to visualize the other internal structures of the eyeball. The left eye presented lens opacity. In the ultrasound of the right eye, there were several alterations, the presence of a triangular-shaped hyperechogenic structure in the vitreous chamber, a decrease in the depth of the anterior chamber, and the presence of abnormality in the development of the lens. The findings are compatible with and confirmed the diagnosis of PHPV. In the left eye, the ultrasound images indicated hyperechogenicity of the posterior and anterior poles of the lens, findings compatible with cataracts. Through the animal's history, complete ophthalmic examination, and use of ocular ultrasonography, it was possible to diagnose and differentiate the causes of the white eye in the patient. The preoperative screening was continued with an electroretinography examination, which showed a satisfactory electrical response for the retina of the left eye and an unsatisfactory electrical response for the retina of the right eye. Phacoemulsification surgery was performed to remove the cataract in the left eye with intraocular lens implantation. The positive threat reflex returned in this eye, with a return of visual acuity. Discussion: Persistent hyperplastic tunica lentis and persistent hyperplastic primary vitreous (PHTVL/PHPV) are congenital anomalies caused by a failure to regress the fetal hyaloid vasculature. These conditions are not common, but occur sporadically in dogs. The PHPV classification can be classified into degrees, based on the morphological aspect of the lesion. Following this classification scheme, the PHPV of the animal in question refers to the 6th degree of evolution. The total opacity of the cornea in the right eye was associated with the presence of a hyperplastic primary vitreous and the leukocoria in the left eye was due to the presence of a mature cataract. The conclusion of the diagnosis was only possible through ocular ultrasonography, which is very useful to differentiate the causes of ocular opacity and leukocoria, in addition to allowing complete evaluation of the intraocular structures and being considered an essential exam to confirm the diagnosis of PHPV.

Inhibition potential of Caryocar brasiliense on methicillin-resistant Staphylococcus pseudintermedius isolated from the ocular surface of dogs with ophthalmopathies / Potencial de inibição do Caryocar brasiliense sobre Staphylococcus pseudintermedius resistente à meticilina isolado da superfície ocular de cães com oftalmopatias

The indiscriminate use of antibiotics has contributed to the emergence of multiresistant bacteria. Faced with this, the search for antibiotics from plants has proven to be a promising alternative. The objective of this work was to isolate and identify Staphylococcus sp. resistant to methicillin of the ocular surface of dogs with ophthalmopathies and to evaluate its susceptibility to alcoholic extract of the bark and hexane extract of the pulp of Caryocar brasiliense. Biological material was collected from the ocular surface of 21 dogs presenting ophthalmopathies. We isolated 64 S. pseudintermedius, among these, 4 isolates were identified as methicillin-resistant S. pseudintermedius (MRSP). The alcoholic extract of C. brasiliense peel was able to inhibit the bacterial growth of MRSP isolates at a concentration of 2.2%. Thus, the extract from the C. brasiliense peel has antimicrobial potential and represents an alternative in the control of MRSP.

O uso indiscriminado de antibióticos tem contribuído para o surgimento de bactérias multirresistentes. Diante disso, a busca por antibióticos a partir de plantas tem se mostrado uma alternativa promissora. O objetivo deste trabalho foi isolar e identificar Staphylococcus sp. resistente à meticilina da superfície ocular de cães com oftalmopatias e avaliar sua susceptibilidade ao extrato alcoólico da casca e ao extrato hexânico da polpa de Caryocar brasiliense. O material biológico foi coletado da superficie ocular de 21 cães com oftalmopatia. Isolaram-se 64 S. pseudintermedius; entre esses, quatro isolados foram identificados como S. pseudintermedius resistente à meticilina (MRSP). O extrato alcoólico da casca de C. brasiliense foi capaz de inibir o crescimento bacteriano dos isolados de MRSP na concentração de 2,2%. Dessa forma, o extrato da casca de C. brasiliense possui potencial antimicrobiano e representa uma alternativa no controle de MRSP.

Specular microscopy of the different regions of the cornea in enucleated swine eyes: ex vivo evaluation / Microscopia especular das diferentes regiões da córnea de suínos: estudo ex vivo

The objective of this study was to determine the endothelial cell density (ECD) and hexagonality of the cornea in the different regions of healthy swine corneal endothelium using specular microscopy. Twenty-four eyeballs from 12 male, 6-month-old Large White pigs (Sus scrofa domesticus) were studied. Contact specular microscopy was performed in the central, superior, inferior, lateral and medial regions. The corneal parameters analysed in this study were ECD and hexagonality. The ECD in the central region was 1865 cells/mm2; in the upper region, it was 1877 cells/mm2, in the lower region, it was 1854 cells/mm2, in the lateral region, it was 1847 cells/mm2, in the medial region, it was 1831 cells/mm2. Hexagonality in the central region, was 53%; in the upper region, it was 54%, in the lower region, it was 54%, in the lateral region, it was 54%, in the medial region, it was 54%. There was no significant difference regarding to the evaluated parameters in all corneal regions evaluated. No statistically significantly differences were observed in ECD and hexagonality between the left and the right eyes. This study demonstrates that ECD and hexagonality of the central cornea area represent the entire endothelial mosaic.

O objetivo do presente estudo foi avaliar a densidade endotelial e a hexagonalidade das células endoteliais nas diferentes regiões da córnea de suínos utilizando a microscopia especular de contato. Foram estudados 24 bulbos oculares de 12 suínos (Sus scrofa domesticus), machos, com seis meses de idade e da raça Large White. A microscopia especular de contato foi realizada nas regiões central, superior, inferior, lateral e medial da córnea. A densidade endotelial média na região central foi de 1865 células/mm2, na região superior foi de 1877 células/mm2, na região inferior foi de 1854 células/mm2, na região lateral foi de 1847 células/mm2 e na região medial foi de 1831 células/mm2. Na região central, a hexagonalidade foi de 53%, na região superior foi de 54%, na região inferior foi de 54%, na região lateral foi de 54%, na região medial foi de 54%. Não foram observadas diferenças significativas na densidade celular e na hexagonalidade nas diferentes regiões da córnea analisadas. Este estudo demonstrou que a densidade endotelial e a hexagonalidade da área central da córnea representam todo o mosaico endotelial.

Uso de soro autólogo no tratamento de úlcera ocular em cães: uma revisão bibliográfica / Use of autologus serum in the treatment of ocular ulcers in dogs: a bibliographic review / Uso de suero autólogo em el tratamiento de úlceras oculares em perro: una revisión bibliográfica

Sendo considerada uma doença de alto acometimento na oftalmologia veterinária de cães, a úlcera de córnea é um distúrbio caracterizado por uma ferida exposta na região corneal do olho. Os sinais são variados conforme o grau de agressividade da lesão, acarretando em perda da visão caso a intervenção não seja iniciada imediatamente. Devido a estes fatores e ao elevado nível de importância da doença, torna-se necessário o uso de terapêuticas que auxiliem o processo de reparo ocular, como a utilização do soro autólogo. Essa substância realiza uma função de evitar degradação da córnea e diminuir os sinais inflamatórios, o que torna essa prática um apoio eficaz para a finalização do tratamento, além de ser barato e de fácil acesso. Levando essas informações em consideração, o presente artigo realiza uma revisão com base em publicações apresentando o soro autólogo como um elemento adicional para o paciente poder concluir o tratamento de úlcera de córnea em menor tempo e com maior qualidade, retomando-o ao seu estado saudável.(AU)

Being considered a disease of high involvement in the veterinary ophthalmology of dogs, the corneal ulcer is a disorder characterized by an exposed wound in the corneal region of the eye. The signs vary according to the degree of aggressiveness of the lesion, leading to loss of vision if intervention is not started immediately. Due to these factors and the high level of importance of the disease, it becomes necessary to use therapies that help in the process of ocular repair, such as the use of autologous serum. This substance performs a function of preventing corneal degradation and reducing inflammatory signs, which makes this practice an effective support for the completion of treatment, besides being cheap and easily accessible. Taking this information into consideration, the present article performs a review based on publications presenting the autologous serum as an additional element for the patient to finish the corneal ulcer treatment in less time and with higher quality, returning him to his healthy state.(AU)

Siendo considerada una enfermedad de alto ataque en la oftalmología veterinaria de perros, la úlcera de córnea es una alteración caracterizada por una herida expuesta en la región corneal del ojo. Los signos son variados según el grado de agresividad de la lesión, acarreando en pérdida de la visión en caso de que la intervención no sea iniciada inmediatamente. Debido a estos factores y al alto nivel de importancia de la enfermedad, es necesario utilizar terapias que ayuden al proceso de reparación ocular, como el uso de suero autólogo. Esta sustancia cumple una función de evitar la degradación corneal y disminuir los signos inflamatorios, lo que hace de esta práctica un apoyo eficaz para el final del tratamiento, además de ser barata y de fácil acceso. Teniendo en cuenta esta información, el presente artículo realiza una revisión basada en publicaciones que presentan el suero autólogo como un elemento adicional para que el paciente finalice el tratamiento de la úlcera corneal en menor tiempo y con mayor calidad, devolviéndolo a su estado saludable.(AU)

Distiquíases em gatos / Distichiasis in cats

Background: Distichiasis is a disease that is rare in cats, but very common in dogs. The term distichiasis may be controversial when used in the feline species, given that they do not possess true cilia, but rudimentary hair along the superior palpebra. The patients may be asymptomatic, though some show signs of ocular discomfort and ulcerative keratitis. The diagnosis is reached through an ophthalmological exam, and the treatment consists of the removal of the cilium with or without its hair follicle. With this work, we aim to report a series of cases of distichiasis in cats, as it is an uncommon anomaly, and has the potential to cause ocular discomfort in cats. Cases: Two mobile services of veterinary ophthalmology, one in the federal district of Brasília (DF) and the other in the municipality of Valinhos (SP), attended to 9 cats over a period of 5 years (2018 to 2022). The cats (n = 9) attended are of an undefined breed with ages varying from 10 months to 9 years, with an average of 3.9-year-old. The number of distichiasis presented by the animals was classified according to their quantity, being categorized as a mild grade when there was a single cilium, moderate grade when there were 2 to 4 cilia, and severe grade when there were more than 5 cilia. The highest incidence of distichiasis in this study was in males (78%) while females accounted for (22%) of the cases. The clinical changes reported by the owners consisted of signs of ocular discomfort (photophobia, blepharospasm, and periocular itching), ocular discharge and ocular redness. In the ophthalmological evaluations, blepharospasm (22%), serous to mucosal secretion (56%), chemosis (22%), mild (44%) to moderate (11%) conjunctival hyperemia, and ulcerative keratitis (22%) were observed. Distichiasis was more frequent affecting both eyes (56%), while in only (44%) of cases it affected the left eye only. The highest occurrence of cilia was identified in the upper palpebra (78%). Distichiasis was found more often in the temporal palpebral portion (78%), and in 2 patients the identification was more challenging since these cilia lack pigmentation. Single cilium affected (44%) of patients, while 5 cats had multiple distichiasis (56%). A total of 29% of the cats had a mild grade, whereas 14% had a moderated grade, and 57% had a severe grade. The treatments performed consisted of manual epilation (ME) and electroepilation (EE). ME was carried out in 56% of the cats, with relapses occurring in 80% of the patients, while 44% of the cats submitted to EE had a relapse in 20% of the cases. Discussion: Distichiasis is an inherited disorder very frequent in dogs, but considered uncommon in cats. Its causative factor is still unknown, as is its mode of inheritance. In distichiasis therapy, epilation, electroepilation, electrolysis, diode laser, cryotherapy and surgical palpebral resection techniques are referred to as procedures. Among the treatments used in this study, we observed a lower incidence of relapse with the electroepilation technique, which proved to be a viable and successful therapeutic modality. This series of cases shows that perhaps this disorder is much more frequent than what has been reported in the literature, being sometimes underdiagnosed and consequently underreported. Therefore, distichiasis in cats should be considered as a differential diagnosis in patients with clinical signs of ocular discomfort and ulcerative keratitis.

Unusual parasitism site of Dermacentor nitens (Acari: Ixodidae) on a horse / Parasitismo em local incomum de Dermacentor nitens (Acari: Ixodidae) em um cavalo

Dermacentor nitens Neumann is the most common tick species infesting horses in the main Brazilian biomes. It has a predilection to attach to horse the ears, the nasal diverticulum, perineal and perianal regions. The infestations can generate severe damage in the ears, anemia, and the tick also acts as vector of Babesia caballi (Nuttall and Strickland), the causative agent of equine babesiosis. Our study describes unusual parasitism site of D. nitens on a female cross breed horse, approximately ten years old that presented high parasitism by ticks on the perineal and perianal region, ears, and the left eye orbit region, where an enucleation process had been performed a few years earlier. To our knowledge this is the first report of D. nitens parasitism on a formerly enucleated eye orbit.

Dermacentor nitens Neumann é a espécie de carrapato mais comum infestando equinos nos principais biomas brasileiros. Tem predileção por se fixar ao cavalo nas orelhas, divertículo nasal, e nas regiões perineal e perianal. As infestações podem gerar danos severos nas orelhas, anemia, e o carrapato também atua como vetor de Babesia caballi (Nuttall and Strickland), agente causador da babesiose equina. Nosso estudo descreve um local de parasitismo incomum de D. nitens em uma égua mestiça de aproximadamente dez anos de idade, que apresentou alto parasitismo por carrapatos nas regiões perineal e perianal, orelhas e região da órbita do olho esquerdo, onde havia sido realizado processo de enucleação alguns anos anteriores. Para o nosso conhecimento, este é o primeiro relato de parasitismo de D. nitens em uma órbita ocular anteriormente enucleada.

Carcinoma de células escamosas corneal em um cão - uso da Mitomicina C 0, 02% como adjuvante no tratamento / Corneal squamous cell carcinoma in a dog - use of Mitomycin C 0. 02% as an adjuvant therapy

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.

Promising use of nanotechnology in Pythium insidiosum: a systematic review / Utilização promissora de nanotecnologia em Pythium insidiosum: uma revisão sistemática

ABSTRACT: The aquatic oomycete Pythium insidiosum is an emerging pathogen highly relevant in human and veterinary medicine and an etiologic agent of pythiosis, a disease of worldwide distribution mainly affecting horses, dogs, and humans, presenting cutaneous, subcutaneous, ocular, gastrointestinal, and systemic forms. The available therapeutic methods to treat this disease and its forms are not entirely effective, thus highlighting the need to investigate the forms of treatments with better efficacy, such as compounds from different pharmacological classes, compounds of natural origin, and new technological alternatives, including nanotechnology. Therefore, this study evaluated scientific publications regarding the use of nanotechnology in P. insidiosum treatment. For this, a systematic literature review, was carried out on articles published from 2010 to 2022 on the LILACS, MEDLINE, Google Scholar, PubMed, and SciELO databases using the descriptors 'Pythium insidiosum,' 'pythiosis,' 'nanotechnology,' 'nanoparticles,' 'nanoemulsion,' and 'treatment.' We reported 162 articles for the researched theme; although, only four studies were included because they met the criteria established herein. A meta-analysis was used for the statistical analysis of the data obtained in vitro studies, and we reported the use of nanotechnology can be a promising alternative in developing antimicrobial compounds with anti-P. insidiosum activity. Nevertheless, additional research is needed to verify the potential use of this technology in clinical therapy against P. insidiosum infections.

RESUMO: O oomiceto aquático Pythium insidiosum é um patógeno emergente de relevância em medicina humana e veterinária. É o agente etiológico da pitiose, uma enfermidade de distribuição mundial, que acomete principalmente em equinos, caninos e seres humanos, podendo apresentar-se nas formas cutâneas, subcutâneas, oculares, gastrointestinais e sistêmicas. Considerando que os métodos terapêuticos disponíveis para o tratamento da doença não são completamente efetivos, há uma necessidade de investigar formas de tratamentos com melhor eficácia, como os compostos de diferentes classes farmacológicas, compostos de origem natural, bem como, novas alternativas tecnológicas, incluindo a nanotecnologia. Deste modo, este trabalho objetivou avaliar publicações científicas referentes a utilização de nanotecnologia em P. insidiosum. Para isso, realizou-se uma revisão sistemática da literatura, buscando artigos no período de 2010 a 2022, nas bases de dados LILACS, MEDLINE, Google Scholar, PubMed e SciELO, utilizando-se os descritores Pythium insidiosum, pitiose, nanotecnologia, nanopartículas, nanoemulsão e tratamento. Encontrou-se 162 artigos com familiaridade a temática pesquisada; no entanto, apenas quatro estudos foram incluídos, pois atendiam os critérios estabelecidos na pesquisa. Para análise estatística dos dados obtidos nos estudos in vitro, utilizou-se meta-análise. Demonstrou-se o promissor uso de nanotecnologia como alternativa no desenvolvimento de compostos antimicrobianos com atividade anti-P. insidiosum. Entretanto, constata-se que estudos adicionais se fazem necessários para verificar o potencial uso desta tecnologia na terapêutica clínica contra infecções por P. insidiosum.

Criptococose respiratória e cutânea em gato de vida livre da cidade de Sobral/CE / Respiratory and cutaneous Cryptococcosis in a free-range cat in the city of Sobral/CE

A criptococose é uma doença infecciosa sistêmica de origem fúngica, causada pelas espécies: Cryptococcus neoformans e Cryptococcus gattii. É considerada uma micose oportunista capaz de infectar mamíferos domésticos, animais silvestres e seres humanos, sendo classificada como uma doença zoonótica. Esse patógeno é encontrado principalmente em ambientes contaminados por fezes de pombos (Columba livia), que atuam como importantes fontes de infecção do fungo. De acordo com sua disseminação para os tecidos do organismo, a doença pode causar diferentes síndromes tanto em seres humanos como em animais síndrome respiratória, síndrome neurológica, síndrome ocular e síndrome cutânea. O diagnóstico pode ser realizado através da pesquisa de antígeno polissacarídeo circulante no soro ou líquor, por meio da prova de látex. Testes imunoenzimáticos (ELISA) também podem ser realizados para detecção de antígenos dessa levedura. Exame citológico, histopatológico e cultura fúngica para a identificação do agente tornam o diagnóstico da criptococose mais fácil. O tratamento é baseado no uso de antifúngicos e sua escolha é realizada através da avaliação dos sinais clínicos observados. Diante do exposto, o objetivo deste trabalho é relatar um caso de criptococose respiratória e cutânea em felino doméstico de vida livre da cidade de Sobral/CE.

Cryptococcosis is a systemic infectious disease of fungal origin caused by the species: Cryptococcus neoformans and Cryptococcus gattii. It is considered an opportunistic mycosis capable of infecting domestic mammals, wild animals, and humans, being classified as a zoonotic disease. This pathogen is mainly found mainly in environments contaminated by pigeon (Columba livia) feces, which act as important sources of fungal infection. According to its spread to the body's tissues, the disease can cause different syndromes in both humans and animals: respiratory syndrome, neurological syndrome, ocular syndrome, and cutaneous syndrome. The diagnosis can be made through the investigation of circulating polysaccharide antigen in serum or cerebrospinal fluid using the latex test. Immunoenzymatic tests (ELISA) can also be performed to detect yeast antigens. Cytological examination, histopathological examination, and fungal culture to identify the agent make the diagnosis of cryptococcosis easier. The treatment is based on the use of antifungals, and its choice is made through the evaluation of the observed clinical signs. In this context, this work aims to report a case of respiratory and cutaneous cryptococcosis in a free-range domestic cat in the city of Sobral/CE.

Maternal and fetal ultrasonography, vulvar temperature and vaginal mucous impedance for the prediction of parturition in Saanen does

The aim of this study was to evaluate and correlate modifications of vaginal mucous impedance, vulvar temperature and ultrasonographic measurements (echobiometric parameters) to parturition in pregnant Saanen does. 30 does were selected for the study and submitted to an estrus synchronization protocol and natural mating. The females were evaluated daily from Day 143 of pregnancy to parturition. For the sonographic evaluations, the following structures were measured: biparietal diameter, thoracic diameter, abdominal diameter, ocular orbit, kidney length, kidney height, cardiac area, placentome length, cervical measurement and fetal heart rate; by means of two different approaches: transrectal and transabdominal, using a 7.5 MHz linear transducer. The vaginal mucous impedance was assessed using an electric estrous detector and vulvar temperature was measured using a non-contact infrared thermometer. Statistical analysis was performed using the R-project software and the significance level was set at 5% for all tests. 25 Saanen does became pregnant, resulting in 80.33% pregnancy rate. Fetal heart rate was negatively correlated to the hours to parturition (p<0,001; r-Pearson= -0,451), as well as vaginal temperature (p= 0,001; r-Pearson= -0,275), while cervical thickness was positively correlated to hours to parturition (p<0,001; r-Pearson= 0,490). The echobiometric parameters (biparietal diameter, thoracic diameter, abdominal diameter, ocular orbit, kidney length and height, cardiac area, placentome length), as well as vaginal mucous impedance did not vary throughout the timepoints of evaluation and did not correlate to the moment of parturition. It was concluded that the parameters of fetal heartbeat, vaginal temperature and cervical effacement in the last week of pregnancy provide valuable information regarding the proximity of parturition.(AU)

Retinopatia deficiente de taurina em uma gata / Taurine deficiency retinopathy in a cat

Background: Taurine is an essential amino acid for cats and its deficiency causes an ocular disorder called taurine deficiency retinopathy. The retinal lesion is definitive and can be classified into five progression stages. In an advanced stage, it leads to blindness that in most cases is irreversible. This disease is considered rare as taurine is currently supplemented in commercial cat food. The objective of this report is to describe the ophthalmic changes in a cat with advanced taurine deficiency retinopathy, a rare but current disease that is important for differential diagnosis of blindness in cats. Case: We report the case of an adult mixed-breed cat (weighing 3.4 kg), that was attended by the Ophthalmology Service of the College of Veterinary Medicine and Animal Science (UNESP - Botucatu), which was treated due to complaints of poor visual acuity for about 1 year. The animal, which was previously a stray animal, had been adopted for 2 years and provided premium cat food ad libitum. Ophthalmic examination showed bilateral mydriasis, with negative menace, direct pupillary, and consensual light reflexes. No change was observed in the ocular appendages, cornea, anterior chamber, lens, and vitreous humor. The eyes were normotensive and fluorescein test negative. Direct and indirect fundoscopy revealed an area of ellipsoidal hyperreflexia with darkened margins laterally to the optic nerve disk in the tapetal region and intense retinal vascular attenuation in both eyes, with a diagnosis of taurine deficiency retinopathy. Complete blood count and biochemical analysis parameters were within the normal range, including the leukocyte count. The guardian was instructed to continue feeding the cat balanced cat food and received information on the proper care and management of a blind animal. Discussion: Although taurine deficient retinopathy is currently underdiagnosed due to the supplementation of this amino acid in commercial cat food, animals that are not properly fed, such as those receiving dog food or homemade food, may be deficient in this amino acid. Taurine deficiency and in this case, the consequent taurine deficiency retinopathy, was diagnosed by visualizing the lesion characteristic of this amino acid deficit since no other retinal change presents this aspect in cats. Therefore, this lesion is considered pathognomonic of this deficiency. Hyperreflective retinal lesions with darkened margins indicate the slow chronic progression in the already stabilized lesions. The animal in this report presented pigmented lesion margins, indicating the chronicity of these retinal changes. Moreover, lesion signs are visible on fundoscopy only after a period of 2-11 months of nutritional amino acid deficiency, and complete retinal atrophy usually occurs after at least nine months of taurine deficiency. Thus, complete blindness associated with advanced retinal changes reinforced the suspicion that the animal had taurine deficiency for a prolonged period of time prior to its adoption. Its guardian was instructed to provide balanced commercial cat food, because although retinal lesions are irreversible, cardiac changes resulting from taurine deficiency are reversed with dietary supplementation. In addition, taurine deficiency affects other organs and systems, such as the central nervous, immune, and reproductive systems. In conclusion, although taurine deficiency retinopathy is currently rare, this condition should be considered one of the possible differential diagnoses for blindness in feline patients.

Lutein and zeaxanthin content in corn imported from three countries of the American continent and in corn cultivated in Colombian territory / Conteúdo de luteína e zeaxantina em milho importado de três países do continente americano e em milho cultivado em território colombiano

Lutein and zeaxanthin are the major xanthophyll pigments found in corn kernels. These pigments provide the orange-red color of the broiler chicken skin and of the egg yolk. Therefore, knowing the corn xanthophyll content is important for the poultry feed producer. The objective of this study was to determine the lutein and the zeaxanthin content in corn cultivated in Colombia and in corn imported to Colombia from the United States, Argentina, and Brazil. Large differences in total lutein plus zeaxanthin content were found among the corn samples analyzed, with the highest mean level found in Colombian corn (2,758µg/100g), followed by Argentina (1,861µg/100g), United States (1,041µg/100g) and Brazil (947µg/100g). Large differences in lutein plus zeaxanthin content were also found among different corn hybrids cultivated in Colombia. Differences among geographical regions might be due to differences in UV-B radiation or in the light hours received by the crop during its growth. The differences among different corn hybrids might probably be due to genetic differences. Corn growers might be interested in cultivating hybrids higher in lutein and zeaxanthin as these pigments are very important in poultry production and human eye health.

Luteína e zeaxantina são os principais pigmentos xantofilas encontrados nos grãos de milho. Em aves, esses pigmentos naturais conferem a cor vermelho-alaranjada típica da pele do frango de corte e da gema do ovo. Assim, é importante conhecer o teor de xantofilas do milho utilizado nas dietas de aves. O objetivo deste estudo foi determinar o teor de luteína e zeaxantina em milho cultivado na Colômbia e em milho importado para a Colômbia dos Estados Unidos, da Argentina e do Brasil. Foram encontradas diferenças significativas no teor de luteína total mais zeaxantina entre as amostras de milho analisadas, com o nível médio mais elevado no milho colombiano (2.758µg/100g), seguido pelo milho argentino (1.861µg/100g), pelo milho dos Estados Unidos (1.041µg/100g) e pelo milho brasileiro (947µg/100g). Grandes diferenças no teor de luteína e zeaxantina também foram encontradas entre variados híbridos de milho cultivados na Colômbia. As diferenças entre as regiões geográficas podem ser devido a diferenças na radiação UV-B ou nas horas de luz recebida pela cultura durante seu crescimento. As diferenças entre os diversos híbridos de milho provavelmente podem ser devido a diferenças genéticas. Os produtores de milho podem estar interessados ​​em cultivar híbridos mais ricos em luteína e zeaxantina, pois esses pigmentos são muito importantes na produção de aves e na saúde ocular humana.

Determination of the minimum alveolar concentration (MAC) of isoflurane and sevoflurane in Callithrix penicillatac

Background: The minimum alveolar concentration (MAC) is a measure of quantitative anesthetic potency and has become the standard index for the evaluation and comparison of volatile anesthetics, in addition to guiding dose administration. Black-tufted marmosets (Callithrix penicillata) are primates present in the clinical and surgical routine of veterinary hospitals, as well as experimental models, especially in neuroscience. Few studies have evaluated the potency of the main volatile anesthetics in this species. This study aimed to determine the MAC of isoflurane and sevoflurane in C. penicillata using the up-and-down method and to evaluate the effects of these drugs on the quality of anesthetic induction, maintenance, and recovery. Materials, Methods & Results: Twenty-four animals of undetermined age were used. All marmosets were healthy according to hematological and physical evaluation. The animals were randomly divided into 2 groups: ISOMAC and SEVOMAC. Each animal was induced to general anesthesia in an anesthetic box with oxygen (5 L/min) and sevoflurane at 7% in the SEVOMAC group or isoflurane at 5% in the ISOMAC. Upon reaching lateral decubitus, orotracheal intubation was performed. General anesthesia was maintained with isoflurane or sevoflurane diluted in oxygen (0.8 L/min) using a non-rebreathing delivery system under spontaneous ventilation. As defined in the pilot study, the first animal from ISOMAC started the maintenance of anesthesia with 2.6% isoflurane, while the first animal in SEVOMAC received 4% sevoflurane. After finishing the instrumentation to assess heart rate, respiratory rate, systolic blood pressure, pulse oximeter oxygen saturation, end-tidal carbon dioxide concentration, and rectal temperature, a 15-min wait to reach anesthetic equilibrium was allowed, and then an electrical noxious stimulation (50 mA and 50 Hz) was performed on the lateral aspect of the thigh (a faradic current of 3 consecutive single stimuli, followed by 2 continuous stimuli). The animals' responses to the electrical stimulus were observed. The presence of a positive response (gross movement of the limbs, head, or vocalization) or a negative response (absence of gross movements) determined the increase or reduction, respectively, of the inhalation anesthetic concentration by 10% in the subsequent marmoset. The quality of anesthetic induction and recovery from anesthesia was evaluated using a scale that measured the intensity of agitation, coughing, nausea, and vomiting. Physiological variables were recorded before (M0) and after (M1) applying the nociceptive stimulus. Isoflurane and sevoflurane MAC values in C. penicillata were 2.29 ± 0.10% and 3.93 ± 0.61 % respectively. Physiological parameters, quality of anesthetic induction and recovery did not differ significantly between groups. However, isoflurane caused irritation of the airway and ocular mucous membranes, more coughing episodes, and tearing at induction. There was no difference between groups for time to extubation and recovery time to regain sternal position. Discussion: Previous studies in primates found lower MAC values for both anesthetics, except for Lemur catta. Those findings may be explained by the use of different nociceptive stimuli and the MAC determination method employed, although no differences in MAC values have been described between bracketing or up-and-down methods in human primates and dogs. It is unlikely that the stimulus and technique alone are the determining factors for the high concentration of isoflurane and sevoflurane observed in the present study since MAC was high with both halogenates, indicating that dose extrapolation from other species can lead to the wrong anesthetic dosage.