Eyes Of Dogs Research Articles

Retrospective study on Encephalitozoon cuniculi infections in 118 cat and 9 dog eyes.

This study aims to inform about the clinical image, diagnostic possibilities, and treatment options for cats and dogs diagnosed with ocular encephalitozoonosis. Medical records of 7 dogs and 75 cats with ocular encephalitozoonosis presented at the Clinical Unit of Ophthalmology of the University of Veterinary Medicine Vienna between 08/2006 and 02/2022 have been compiled. Diagnosis was based on the presence of cataracts and positive antibody titer against Encephalitozoon cuniculi. Patient history, details on the characteristics of the cataracts, level of antibody titers, and the treatment regimen were summarized, as are the results of histological stainings of surgical samples to determine the presence of Encephalitozoon cuniculi, as well as PCR analyses to identify its sub-strains. Our analysis of the clinical data shows that focal cortical anterior cataracts often associated with anterior uveitis and lesions in the fundus are the most prevalent manifestation of ocular encephalitozoonosis in cats and dogs. Serological testing and PCR analysis of lens material are the most important diagnostic tools. Timely phacoemulsification with adjuvant anti-inflammatory and antiparasitic medication is the most promising therapy for Encephalitozoon cuniculi-induced cataracts.

Assessment of meibomian gland morphology and tear-film lipid layer using noncontact infrared meibography and meibometry, respectively, and tear-film osmolarity in healthy dogs.

To further investigate quantitative and qualitative tear-film dynamics through tear-film osmolarity, meibometry, meibography, and non-invasive tear-film break-up time and to describe a survey of parameters in normal eyes of healthy non-brachycephalic dogs. Thirty-two veterinary hospital staff and student owned dogs between 1 and 7 years with no known comorbidities or ocular disease. Complete ophthalmic examination, tear-film osmolarity (I-PEN® VET), meibometry (Meibometer MB560), meibography, and non-invasive tear-film break-up time (handheld Ocular Surface Analyzer) were performed. Significance threshold was 0.05. Q-Q plots and histograms were used to assess normality of measurements. Data were summarized descriptively with mean, standard deviation, median, and interquartile range (IQR). Pearson and Spearman's correlations were used to test for correlations between diagnostics with each other and tear-film break-up times. Thirty-two dogs (64 eyes) met the inclusion criteria. Mean tear-film osmolarity level was 293.6 ± 14.1 mOsm/L (IQR 282.5-302.3). Median meibomian lipid level was 30.4 Meibometry Units (MU) (IQR 11.5-59.1). Median percent loss of meibomian glands in the upper eyelids was 25.3% (IQR 13.5-26.8). Median percent loss of meibomian glands in the lower eyelids was 26.0% (IQR 13.5-52.3). Automatic assessment of meibomian gland loss showed that grade 0 was present in 4/128 (3.1%) eyelids, grade 1 in 78/128 (60.9%) eyelids, grade 2 in 30/128 (23.4%) eyelids, and grade 3 in 16/128 (12.5%) eyelids. Tear-film osmolarity, meibometry, meibography, and non-invasive tear break-up time can easily be incorporated into routine ophthalmic examinations to provide clinical information about meibomian gland morphology and function.

Coyotes can do 'puppy dog eyes' too: comparing interspecific variation in Canis facial expression muscles.

Facial expressions are critical for non-verbal communication. The Canis genus epitomizes the interplay between behaviour and morphology in the evolution of non-verbal communication. Recent work suggests that the levator anguli oculi medialis (LAOM) muscle is unique to dogs (Canis familiaris) within the Canis genus and evolved due to domestication. The LAOM raises the inner eyebrows, resulting in the 'puppy dog eyes' expression. Here, we test whether the LAOM is a derived trait in dogs by (i) examining the facial expression muscles of a closely related and ancestral wild Canis species, the coyote (C. latrans) and (ii) comparing our results with other Canis and canid taxa. We discover that coyotes have a well-developed LAOM like dogs, which differs from the modified/absent LAOM in grey wolves. Our findings challenge the hypothesis that the LAOM developed due to domestication. We suggest that the LAOM is a basal trait that was lost in grey wolves. Additionally, we find inter- and intraspecific variations in the size of the muscles of the outer ear, forehead, lips and rostrum, indicating potential adaptations related to sensory perception, communication and individual-level functional variations within canids. Together, this research expands our knowledge of facial expressions, their evolution and their role in communication.

Voluntary head dunk: cooperative care for irrigating canine noses and eyes and rapid cooling.

To demonstrate the methods to teach dogs to voluntarily immerse (dunk) their head in a container of water, and to identify the 3 indications for voluntary head dunk: to clear a dog's nostrils of dust/debris, flush a dog's eyes, and cool a dog after exercise. Dogs. With the use of cooperative care and positive reinforcement training, the dog is taught to retrieve a toy or treat from a bucket or large container. Clean, room temperature water is added stepwise until the dog is comfortable immersing its nose and blowing bubbles or immersing its head to retrieve the toy or treat. The training may require minutes, weeks, or months, depending on the dog's motivation. Voluntary head dunk can remove dust and debris from the nasal passages and eyes and can facilitate cooling, especially after exercise. Positive reinforcement creates a cooperative environment in which first aid can be effectively administered. Contraindications include treatment of heat stroke, persistent or serious nasal or ocular discharge, or dogs that are uncomfortable or unable to dunk their heads. Pet owners and handlers of working dogs or canine athletes can teach their dogs to head dunk and implement this first aid technique for exercise-related cooling or ocular/nasal flush, even in environments with limited resources. Some dogs may be rapidly trained in the veterinary environment as an initial approach to a nasal or ocular flush. Cooperative care provides an effective intervention that preserves and enhances the human-animal bond.

Safety of intravitreally delivered AAV2 vector-mediated multi-characteristic opsin genetic construct in wild type beagle dogs.

A novel adeno-associated virus 2 (AAV2)-carried multi-characteristic opsin (MCO) (MCO-010) is undergoing several clinical trials as a novel therapeutic modality for the treatment of degenerative retinal diseases including retinitis pigmentosa and Stargardt disease. The present study aimed to determine the ocular and systemic safety of MCO-010 and the AAV2 vehicle in adult Beagle dogs following intravitreal (IVT) injection. The current safety/toxicology studies spanning 13 weeks described here utilized well-documented techniques to assess the effects of IVT injection of MCO-010 up to 2.2 × 1011 genome copies (gc) per eye, or the AAV2 capsid (vehicle control) on gross behavioral and immunogenic changes, alterations in body weights, blood biochemistry, hematology, blood coagulation, gross necropsy lesions, organ weight changes and histopathology in the dogs (n = 4 per group; two males and two females per group). Immunohistochemical and functional electroretinogram studies were also conducted to determine MCO expression in the retina and determine any retinal toxicity associated with MCO-010. There were no significant deleterious effects of the MCO-010 (or the AAV2 at the tested doses) on any of the examined parameters, including the absence of any severe ocular or systemic adverse events. However, as expected, inflammation after IVT delivery of AAV2 and MCO-010 was observed in the conjunctivae of all groups of animals, although this self-resolved within 1week post-injection. Quantitative immunohistochemical analyses of MCO-010-associated mCherry revealed successful delivery of the gene therapy within the inner retina. In summary, MCO-010 demonstrated a favorable safety profile when administered to the eyes of adult Beagle dogs of both sexes at dose levels up to 2.2 × 1011 gc per eye, with no adverse effects observed. This dose was identified as the No Observed Adverse Effect Level (i.e. NOAEL) and guided selection of safe doses for human clinical trials.

New host record of Thelazia callipaeda (Nematoda: Spirurida) with a notably wide host range and shared zoonotic lineage in Japan

Thelazia callipaeda (Nematoda: Spirurida: Thelaziidae) parasitizes the eyes of dogs, cats, humans, and various wild mammals, and is transmitted by drosophilid flies. In Japan, T. callipaeda is considered an emerging parasite that has expanded its endemic region northward. However, reports of its detection in mammals other than domestic animals and humans are scarce. This study reports the detection of T. callipaeda in Japanese red fox (Vulpes vulpes japonica), masked palm civet (Paguma larvata), Japanese badger (Meles anakuma), Japanese black bear (Ursus thibetanus japonicus), raccoon (Procyon lotor), Japanese raccoon dog (Nyctereutes viverrinus), domestic dog (Canis lupus familiaris), domestic cat (Felis silvestris catus), and human. Of these, the Japanese red fox, masked palm civet, Japanese badger, and Japanese black bear have been reported as novel host records. Sequence analysis of the cytochrome c oxidase subunit I gene of T. callipaeda revealed two unique lineages specific to Japan, with no regional or host species differences. These results suggest a wide host range for T. callipaeda, highlighting the significant role of wildlife as a reservoir for this parasite in Japan.

Comparison of Tonovet® and Tonovet plus® tonometers for measuring intraocular pressure in dogs, cats, horses, cattle, and sheep.

Reference ranges for intraocular pressure (IOP) in healthy animals are device-specific; therefore, it is strongly recommended to use appropriate reference values according to the device. Therefore, our aim was to compare IOP readings made by TonoVet® and TonoVet Plus® in healthy dogs, cats, sheep, cattle, and horses. We compared IOP values measured by TonoVet® and TonoVet Plus® tonometers in clinically normal eyes of dogs, cats, horses, cattle, and sheep. Five groups comprising 20 animals each of dogs (various breeds, 9 months-10 years old, 14 females, 6 males), cats (various breeds, 6 months-12 years old, 8 females, 12 males), horses (various breeds, 5-12 years old, 12 females, 8 males), cattle (Holstein, 1-7 lactation, female), and sheep (Latvian Darkhead ewes, 1-8 years old) were included in the study. Both eyes of all animals were subjected to ophthalmic examination, including evaluation of IOP by rebound tonometry using TonoVet® and TonoVet Plus® devices. Normality was determined using the Shapiro-Wilk test. The independent t-test was used to determine differences between IOP values in the right and left eyes and between both tonometers. This study was approved by the Ethical Commission of the Latvia University of Life Sciences and Technologies (Nr. LLU_Dzaep_2022-2-4). No differences in IOP between the right and left eyes were found in all cases (p > 0.05). The mean IOP ± standard deviation values in both eyes for TonoVet® and TonoVet Plus® tonometers were as follows: for dogs, 15.25 ± 2.73 mmHg and 19.65 ± 3.46 mmHg; and in cats, 18.88 ± 3.98 mmHg and 18.78 ± 4.26 mmHg, respectively. In horses, mean IOP was 22.15 ± 3.74 mmHg and 24.28 ± 3.00 mmHg; in cattle, 24.73 ± 2.89 mmHg and 23.28 ± 2.97 mmHg; and in sheep, 18.05 ± 3.54 mmHg and 22.49 ± 4.66 mmHg, respectively. Significant differences in IOP values were observed between the tonometers in sheep, dog, and horse groups (mean difference -4.40, -4.48, and 2.13, respectively). This study showed significantly higher IOP values measured by the TonoVet Plus® tonometer in dogs and sheep.

The relationship between corneal calcareous degeneration and various ophthalmic diseases in dogs: A retrospective study.

To investigate ocular factors that influence the development of corneal calcareous degeneration (CCD) in dogs. The medical records of 96 eyes of dogs with CCD and 288 eyes without CCD were retrospectively reviewed. Dogs with evidence of causative systemic illness associated with CCD were excluded from the study. Logistic regression analysis was used to identify the ocular factors associated with the development of CCD. To identify the effect of phosphate-containing eyedrops on CCD, the application periods of phosphate-containing antiglaucoma eyedrops were compared between the glaucomatous eyes in the CCD and non-CCD groups. Increased age, brachycephalic breed, keratoconjunctivitis sicca, advanced cataract, history of phacoemulsification, and topical corticosteroid application were significantly associated with CCD development. Glaucoma was significantly overrepresented in the non-CCD group, and the application period of phosphate-containing antiglaucoma eyedrops was significantly longer in eyes with CCD than in those without CCD. Ophthalmic diseases requiring long-term management of ocular inflammation and long-term application of phosphate-containing eyedrops may contribute to the development of CCD. Glaucoma is overrepresented in dogs without CCD, which is thought to be due to the differences in predisposed age and breeds between dogs with glaucoma and CCD.

Sequential Ahmed valve implantation after primary implant surgery in two dogs.

To report the outcomes of sequential Ahmed valve implantation in two dogs with uncontrolled intraocular pressure (IOP) after primary Ahmed valve implantation. A 6-year-old castrated male American Cocker Spaniel (case 1) and a 12-year-old spayed female mixed-breed dog (case 2) presented with glaucoma management in the left eyes of both dogs. Primary Ahmed valve implantation was performed because of uncontrolled IOP despite antiglaucoma medications used in both dogs. The IOP was maintained within the normal range for 14 and 2 months after surgery in cases 1 and 2, respectively. In both cases, the IOP gradually increased, which was assumed to be caused by bleb fibrosis. In particular, in case 2, one bleb revision surgery was performed during that period, but it was unsuccessful. Therefore, we decided to perform sequential implantation surgery. In case 1, hyphema occurred the day after sequential surgery and resolved with anti-inflammatory treatment. In case 2, it occurred immediately after the surgery and resolved after surgical blood clot removal. IOP remained below 15 mmHg, and menace response was positive until 40 and 23 months after the sequential surgery in cases 1 and 2, respectively. As a long-term complication, cataracts occurred at 17 months in case 1 and 10 months in case 2. Sequential implantation surgery in the same eye could be an effective alternative for long-term IOP management and vision maintenance. A better understanding of complications and appropriate postoperative management is essential for better outcomes.

Long-term success rate of entropion surgery is equivalent in juvenile and adult dogs.

To compare long-term outcomes of lower lid entropion surgery performed in juvenile dogs versus adult dogs and evaluate the success rate of temporary tacking procedures in dogs < 1 year of age. 116 client-owned dogs. A retrospective study was performed evaluating dogs younger than 3 years old diagnosed with primary lower lid entropion between 2010 and 2020. Recurrence of entropion following temporary tacking sutures was evaluated. Surgical outcomes were evaluated of entropion surgery in dogs < and > 1 year of age. 44 dogs with entropion (71 eyes) had a temporary tacking procedure. The entropion resolved in 36.6% of eyes, requiring no further therapy. The median age of dogs successfully treated with a temporary tacking procedure was younger than those that failed. Forty-seven dogs (75 eyes) had entropion surgery at maturity, and 52 dogs (79 eyes) were juvenile. Twenty-seven dogs had temporary tacking procedure prior to surgery, accounting for the difference in number. There was no statistically significant difference in the recurrence rate of entropion between eyes of adult (6/75 [8%]) and juvenile dogs (10/79 [12.7%]) following surgery. Entropion surgery in juvenile dogs is not associated with a higher risk of recurrence and need not be delayed until dogs are older than 1 year of age.

CATARACT IN SHIH TZU DOG

Cataracts are a common cause of blindness in dogs. Cataracts are a condition in the eye where light cannot penetrate the eye lens or loss of transparency of the eye lens. The purpose of writing this case report is to find out the causes of cataracts in animals, how to diagnose and the therapy that can be given for cataracts. The case animal is a Shih Tzu dog named Jojo, male, 14 years old, 8.4 kg body weight, white-brown hair color. The abnormality in both dog's eyes was realized six months ago, namely in both dog's eyes there was a bright white color on the lens, the dog had never received any treatment. In testing the pupil reflexes of the two dogs' eyes did not show any pupil reflexes to light. On examination of the 0 diopter ophthalmoscope in dilated eye conditions it was found that the light could not penetrate the fundus and at 10 diopter the eye lens looked cloudy in both eyes. On fluorescein examination, it was seen that there was no color absorbed in the two dogs' eyes which indicated that there were no ulcers in both eyes of the case dog. Based on clinical signs, the case dog was diagnosed with bilateral cataracts. The treatment plan for case dogs is giving herbal supplements, namely eyevit as much as 2 tablets a day. Based on clinical symptoms, clinical examination, ophthalmoscope examination, fluorescein test, animal cases were diagnosed with bilateral cataracts with causative factors, namely race and age with a diagnosis of dobius. Supplementation with high-quality antioxidants can be an option to prevent and slow the development of cataracts. To treat cataracts in dog eyes, cases of phacoemulsification surgery should be done.

Surgical correction of third eyelid gland prolapsed (Cherry eye) in dog - First case report in Bangladesh

Nictitans Gland Prolapse (NGP), also known as third eyelid gland prolapse or Cherry eye disease, is a serious and common surgical affection of eyes of dogs. Although numerous surgical procedures have been documented, more studies are required to find out the most efficient method. The objective of the present case study is to investigate the outcome of surgical correction of Cherry eye in a dog. In the study a castrated male Labrador Retriever dog of 2.5 years old, weighing 26 kg was presented to the Shahedul Alam Quadary Teaching Veterinary Hospital, Chattogram Veterinary and Animal Sciences University, Chattogram. The patient came with a history of swollen mass at medial canthus of the right eye since 3 months. Clinical examination revealed swollen mass, congested blood vessels, frequent blinking of eyelid and epiphora in right eye. According to the clinical history and examination, the present case was diagnosed as third eyelid gland prolapse (Cherry eye) and was decided for surgical correction by Morgan’s Pocket technique. Surgery was performed by xylazine and ketamine anaesthesia. After the successful surgery and proper postoperative care for 2 weeks, the patient was fully recovered. No reoccurrence or complication was noticed upto 6 months of post operation. The authors suggest that the Morgan’s Pocket technique can be applied for the Cherry eye correction in dogs.

The use of sub-Tenon's anesthesia versus a low-dose neuromuscular blockade for canine cataract surgery: Acomparative study of 224 eyes.

Assess the utility of a Sub-Tenon's anesthesia (STA) protocol to provide suitable operating conditions for canine cataract surgery and compare it to an alternative low-dose neuromuscular blockade (LD-NMB) protocol used for canine cataract surgery. Clinical study of dog eyes undergoing cataract surgery with either an STA or LD-NMB protocol. While intraoperative vitreal expansion scores and intraoperative complications were collected prospectively, globe position, intraocular pressure, return of vision, and postoperative complications were collected retrospectively. Statistical testing was used to compare results between the STA and the LD-NMB groups for the data available. A total of 224 eyes from 126 dogs were assessed, with 133/224 (59.4%) eyes from 99/126 (78.6%) dogs receiving STA and 91/124 (40.6%) eyes from 72/126 (57.1%) dogs receiving LD-NMB. Forty-five of these dogs (45/126; 37.7%) received STA for one eye and LD-NMB for the other eye. There was no significant change in intraocular pressure measurements following STA administration. This was not measured for the LD-NMB group. The globe achieved a central position in 110/133 (82.7%) of eyes that received STA. This was not measured for the LD-NMB group. Intraoperative vitreal expansion scores were slightly higher in STA-treated eyes compared to LD-NMB-treated eyes. The intraoperative complication rate for STA-treated eyes was higher (73/133; 54.8%) compared to NMB-treated eyes (12/91; 13.2%). The most common intraoperative complication for STA was chemosis (64/133; 48.1%), the risk of which increased with an increase in the volume of local anesthetic injected. The post-operative complication rate was higher in STA-treated eyes (28/133; 21.1%) compared to NMB-treated eyes (16/91; 17.6%). Post-operative corneal ulceration was the most common postoperative complication in STA-treated eyes (6/133; 4.5%). The STA protocol described resulted in suitable operating conditions, but more intraoperative and postoperative complications compared to the LD-NMB protocol. Despite these complications, the STA protocol did not cause a significant deleterious impact on post-operative outcomes as defined in the present study.

The non-human animal reading the mind in the eyes test (NARMET): A new measure for the assessment of social cognition.

The Reading the Mind in the Eyes test (RMET) is a widely applied test of social cognition, based on mental state judgments in response to photographs of human eyes, which can elicit impairment in patients with numerous psychiatric and neurological disorders. However, interpretation of task performance is limited without the use of appropriate control tasks. In addition to a matched task requiring age judgments of the RMET stimuli, it was recently shown that a mental state judgment task of comparable difficulty, could be developed using photographs of domestic cat eyes. The current study aimed to further develop a Non-human Animal RMET (NARMET) by testing additional stimuli in the form of photographs of domestic dog eyes. A variety of additional tasks were used alongside the eyes test stimuli in a large sample of healthy young adults, to explore how alexithymia, schizotypal features, and autistic tendencies may differentially influence mental state attribution in response to cat, dog, and human eyes test stimuli. The resulting NARMET features both cat and dog trials, depicting a similar range of complex mental states to the human RMET. It shows favorable psychometric properties as well as being well matched to the RMET in terms of linguistic variables, length and difficulty. However, reading measures predicted performance on the RMET, but not on the NARMET. Although further testing is required in samples with a higher proportion of males, future application of the NARMET in neuropsychiatric populations exhibiting cognitive and behavioral difficulties could offer enhanced assessment of social cognitive skills.

Visual Processing of the Faces of Humans and Dogs by Children with Autism Spectrum Disorder: An Eye-Tracking Study

ABSTRACT Recent studies indicate a positive correlation between canine-assisted interventions and social and communicative abilities in people with autism. These benefits could be due to more efficient processing of socially informative areas when dog faces are processed. Using an eye tracker, this study aimed to assess the visual processing of faces in 13 children with autism spectrum disorder (ASD) and 13 neurotypical (NT) children when gazing at the faces of humans and of dogs. We divided the faces into two categories. First, individual faces of adult humans, children, and dogs were used in a free-viewing paradigm, where the area of interest was the eyes. We recorded the total time spent gazing at the eyes (dwell time), latency to the first look, and continuous gaze time. Second, pairs of faces were presented at the same time in a pair paradigm, and preferences in terms of face position (left/right) and type (dog/human), and the number of transitions between faces, were measured. When presented with pairs of faces, ASD children gazed for longer at the dog’s face, regardless of its position, and showed a higher number of shifts between pictures when the face of a dog was present. However, the NT group did not discriminate between the two faces. The results for individual faces showed significant differences in how ASD children look at the eyes of faces rather than differences in the total duration of the gaze; they are faster in terms of their first gaze and exhibit a longer average fixation time when gazing at the eyes of dogs compared with those of humans. Both human and dog faces were processed atypically in children with ASD, who seemed to engage with dogs more rapidly and for extended periods. This suggests possible socio-communicative benefits of human–dog interactions for people with autism, from a visual processing point of view.

A new perspective on the corneo‐scleral junction with three types of microscopy techniques

The conjunctions of the cornea and sclera in the eyes of donkeys, cattle, dogs, sheep, pigs and rabbits, regardless of gender, were examined in this study. No animals were specifically sacrificed for this investigation. Scanning electron microscopy, light microscopy, and dissecting microscopy were used in this research. In the limbus of all the animals investigated, the cornea and sclera fused in accordance with a pattern. At the corneo-scleral junction, the sclera was situated anteriorly and the cornea posteriorly in the dorsal and ventral sections of the bulbus oculi. In the medial and lateral parts of the eyeball, the cornea and sclera were facing each other and interlaced. Pigmentation and the sulcus scleralis externus could be used to identify the macro-and micro-anatomical boundaries of the limbus. In addition, the cytoplasm of basal epithelial cells shrank, signaling the end of the corneal epithelium and the start of the conjunctival epithelium. The presence of Bowman's membrane in cattle and sheep eyes was definitely determined in histological examinations. Bowman's membrane in these animals came to an end at the limbus, which is where the conjunctival epithelium starts and the corneal epithelium ends. In all areas of the cornea, Bowman's membrane revealed irregular, abrupt thickening and thinning. The corneal epithelium was thick in the vertex and thinner towards the limbus, whereas Descemet's membrane was thin in the center (vertex) and thick in the periphery (near the limbus). In this study, pictures and diagrams were used to illustrate the general anatomical, histological, and morphometric characteristics of the limbus in the species under investigation. The data from our study showed that the limbus region of the bulbus oculi was narrow in the lateral and medial parts and wide in the dorsal and ventral parts. This was confirmed in the studied animals as a general rule. The width value will undoubtedly affect the number of cells covered by the regions. It is conceivable that these cells will play a significant role in the decision of where to perform surgical procedures in order to promote wound healing, giving doctors an advantage. In this circumstances, we think that the limbus should be studied in terms of clinical methods because it has different shapes depending on the species and the position of the bulbus.

Manajemen Bedah Prolaps Membran Niktitan pada Anjing Beagle di DNA Animal ClinicBogor

An 11-year-old female Beagle dog weighing 18 Kg was brought to the clinic with redness discoloration in her right eye, a cherry like lump, and ocular discharge. Based on the clinical signs, the diagnosis was a prolaps of the nictitating membrane or “Cherry Eye” with a fausta prognosis. The treatment was a surgery using the Morgan Pocket method to maintain the mobility of the nictitating membrane and lymphoid tissue. The postoperative therapy given was the anti-inflammatory drug meloxicam 0.2 mg/kg once a day orally and gentamicin eye ointment (Genoint 0.3% Eye Oint) topically twice a day. Five days after the surgery and treatment, the dog's eyes had improved, and there was no lump observable

Study of ocular manifestations and humoral immune response in eyes of dogs with leishmaniasis.

Ocular manifestations in dogs with leishmaniasis are frequent and complications in affected tissues can lead to blindness. Immune processes play a very important role in the pathogenesis of ocular inflammation. Therefore, the immunology of ocular manifestations in dogs with leishmaniasis remains complex and poorly understood. Estimation and characterisation of ocular and periocular manifestations in dogs naturally infected with Leishmania infantum and investigation of the production site of specific anti-Leishmania infantum IgG. The present investigation used 53 confirmed dogs infected with Leishmania infantum, presenting ocular and periocular lesions, and 10 control non-infected dogs. Complete macroscopic ophthalmic examination of eyelids and globes was performed. Both total and anti-Leishmania infantum IgG antibodies were studied in sera and aqueous humour (AH) of all dogs by ELISA technique. A Goldmann-Witmer coefficient (C value) was calculated. The main ophthalmological findings were keratoconjunctivitis (71.7%; 38/53), hyperplasia of conjunctival lymphoid follicles (54.7%; 29/53), blepharitis (50.9%; 27/53) and uveitis (20.7%; 11/53). Ocular production of anti-Leishmania infantum IgG was detected in 73.6% (39/53) of infected dogs. There was no correlation between the antibody levels in AH and sera of the same dog. The mean anti-Leishmania infantum IgG in AH was higher in uveitis, followed by lesions affecting only the adnexa (p < 0.0001). The highest mean C values were observed for uveitis, conjunctivitis and keratitis. Our findings suggest that production of anti-Leishmania IgG in dogs infected with Leishmania infantum with ocular manifestations begin in situ and follows by a transfer of antibodies from the bloodstream to the AH.

Reading emotions in Dogs’ eyes and Dogs’ faces

Our primary goal was to investigate human ability to recognize basic emotions from only the eyes of dogs in comparison to the whole face. Simultaneously, we replicated and extended previous research (Bloom et al., 2021), while validating American canine emotional facial expression photographs cross-culturally to Brazil. Participants (N = 120) viewed behaviorally-anchored photographs of three breeds. Half the participants in each condition (faces or eyes-only) viewed two-word forced choice items while the other half viewed four-word forced choice items. Participants identified target emotions from images of both dogs’ faces and eyes-only at a higher rate than chance. Fear was accurately recognized more than the other emotions. When dogs are afraid, they open their eyes and expose the sclera, a conspicuous signal. Emotion identification accuracy was highest for the Rhodesian Ridgeback, who is similar in morphology to common Brazilian stray dogs (Vira-Latas Carmelo). We conjectured that Brazilians were more accustomed to seeing dogs with the Rhodesian Ridgeback morphology than the erect-eared breeds, thus increasing accuracy for this breed. Further studies with additional dog morphologies are desirable. In addition to research interest, our Canine Eyes task has the potential to become a test of individual differences in Theory of Mind with clinical applications.

Through a Dog's Eyes: fMRI Decoding of Naturalistic Videos from the Dog Cortex.

Recent advancements using machine learning and functional magnetic resonance imaging (fMRI) to decode visual stimuli from the human and nonhuman cortex have resulted in new insights into the nature of perception. However, this approach has yet to be applied substantially to animals other than primates, raising questions about the nature of such representations across the animal kingdom. Here, we used awake fMRI in two domestic dogs and two humans, obtained while each watched specially created dog-appropriate naturalistic videos. We then trained a neural net (Ivis) to classify the video content from a total of 90 min of recorded brain activity from each. We tested both an object-based classifier, attempting to discriminate categories such as dog, human, and car, and an action-based classifier, attempting to discriminate categories such as eating, sniffing, and talking. Compared to the two human subjects, for whom both types of classifier performed well above chance, only action-based classifiers were successful in decoding video content from the dogs. These results demonstrate the first known application of machine learning to decode naturalistic videos from the brain of a carnivore and suggest that the dog's-eye view of the world may be quite different from our own.