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A 40-year old female chimpanzee (Pan troglodytes) developed hyporexia, weight loss, followed by progressive and complete blindness. Tomography demonstrated an intracranial mass in the rostroventral brain involving the optic chiasm, with a presumptive diagnosis of neoplasm. However, histopathology revealed a granulomatous meningoencephalitis, and tissue samples tested positive for Mycobacterium tuberculosis., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: This preliminary study suggests a way to artificially extend vibrissae of blind dogs to assist ambulation and avoiding facial contact with obstacles., Procedures: Fourteen irreversibly blind dogs had 5-6 mystacial vibrissae on each side of the face supplementally extended by attaching carefully chosen adult pig hairs to them and were subjected to a maze test before and after the procedure. In three of these dogs the test was repeated one more time after all the extensions had fallen off. Collision counts and course times with and without extensions were analyzed and compared. A p-value > 0.05 was considered significant., Results: Median number of collisions was significantly higher post-extensions (5 IQR 2.25) and after extensions had fallen off (4 IQR 7.50) compared to pre-extensions (1 IQR 1), p = 0.021. Median times were significantly higher pre-extension (25.6 IQR 8.98) and after the extensions had fallen off, compared to the post-extension performance (22.8 IQR 8.55), p = 0.04., Conclusion: Vibrissae play an important role in the tactile perception of blind dogs, and our preliminary results suggest that extending this sensory organ possibly improves obstacle location and their quality of life., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Purpose: To evaluate olfaction in dogs with sudden acquired retinal degeneration syndrome (SARDS) compared with sighted dogs and blind dogs without SARDS as control groups., Animals Studied: Forty client-owned dogs., Procedure: Olfactory threshold testing was performed on three groups: SARDS, sighted, and blind/non-SARDS using eugenol as the test odorant. The olfactory threshold was determined when subjects indicated the detection of a specific eugenol concentration with behavioral responses. Olfactory threshold, age, body weight, and environmental room factors were evaluated., Results: Sixteen dogs with SARDS, 12 sighted dogs, and 12 blind/non-SARDS dogs demonstrated mean olfactory threshold pen numbers of 2.8 (SD = 1.4), 13.8 (SD = 1.4), and 13.4 (SD = 1.1), respectively, which correspond to actual mean concentrations of 0.017 g/mL, 1.7 × 10 -13  g/mL and 4.26 × 10 -13  g/mL, respectively. Dogs with SARDS had significantly poorer olfactory threshold scores compared with the two control groups (p < .001), with no difference between the control groups (p = .5). Age, weight, and room environment did not differ between the three groups., Conclusions: Dogs with SARDS have severely decreased olfaction capabilities compared with sighted dogs and blind/non-SARDS dogs. This finding supports the suspicion that SARDS is a systemic disease causing blindness, endocrinopathy, and hyposmia. Since the molecular pathways are similar in photoreceptors, olfactory receptors, and steroidogenesis with all using G-protein coupled receptors in the cell membrane, the cause of SARDS may exist at the G-protein associated interactions with intracellular cyclic nucleotides. Further investigations into G-protein coupled receptors pathway and canine olfactory receptor genes in SARDS patients may be valuable in revealing the cause of SARDS., (© 2023 The Authors. Veterinary Ophthalmology published by Wiley Periodicals LLC on behalf of American College of Veterinary Ophthalmologists.)

Objective: To describe blindness, initially presenting as a unilateral condition and diagnosed as sudden acquired retinal degeneration syndrome (SARDS)., Animals Studied: One Dachshund and four Maltese dogs presented with unilateral blindness, for which the results of general ophthalmic examinations were insufficient to explain the blindness. All dogs were spayed females., Results: Intraocular pressures were normal, and the optical media of the eyes were clear. Fundus appearances of the initially blind eyes were within normal variations, with slightly attenuated retinal blood vessels in some cases when compared with the sighted contralateral eyes. Electroretinography (ERG) amplitudes of the affected eyes were flat and reduced in the contralateral-sighted eyes in four dogs. One dog underwent ERG after the blindness progressed bilaterally 8 days after initial presentation (despite topical steroid medication). Two dogs had no recheck visits, but phone call follow-ups reported bilateral blindness 3 months later in one dog. One dog received no medication and retained vision in the contralateral eye until the last follow-up (94 days later). One dog received systemic cyclosporine and steroid medications and maintained vision in the contralateral eye; however, regular ERG rechecks showed a trend of declining amplitude (448 days). In this dog, optical coherence tomography (OCT) showed different stages of disorganized retinal layers as well as different retinal thickness between the eyes., Conclusions: Despite normal-looking fundi, ERG and OCT revealed different degrees of retinal changes between both eyes in this study. Eyes with vision might develop progressive blindness after a substantial amount of time in these presumed SARDS cases., (© 2023 American College of Veterinary Ophthalmologists.)

A 19-y-old American Saddlebred gelding was evaluated for epiphora of the right eye and generalized cachexia. Initial examination revealed anterior uveitis without ulceration, for which treatment was initiated. Despite the initial response to treatment, the signs progressively worsened to blindness. Histologic examination of the enucleated eye revealed granulomatous panuveitis and optic neuritis with intralesional nematode larvae identified as Halicephalobus gingivalis . Over time and despite anthelmintic treatment, blindness developed in the left eye along with neurologic signs, and the horse was euthanized. Disseminated halicephalobosis was diagnosed on postmortem examination, involving the heart, spleen, kidneys, oral cavity, tongue, left eye, lungs, CNS, adrenal glands, liver, and lymph nodes. Splenic involvement has not been reported previously, to our knowledge. Halicephalobosis is a sporadic parasitic disease that affects equids mostly and for which prognosis is poor despite aggressive systemic anthelmintic treatment. Parasitic granulomatous disease should be included as a differential diagnosis in equids with ocular or neurologic disease.

Objectives: Hypertensive emergency is well recognised in human medicine, yet there is limited veterinary evidence. This study aimed to determine the presentation, treatment and outcome in dogs and cats with hypertensive emergency., Materials and Methods: A retrospective case series of dogs and cats with hypertensive emergency identified as follows: acute history with non-invasive Doppler systolic blood pressure greater than 180 mmHg and target organ damage including acute onset seizures, altered mentation with or without lateral recumbency or blindness. Data collected included signalment, history, physical examination and clinicopathological findings, systolic blood pressure, antihypertensive treatment and outcome., Results: Seven dogs and eight cats were included presenting with seizures (n=9), blindness (n=4), altered mentation with (n=2) or without (n=2) lateral recumbency. Median age was 9 years (range 1 to 15) and duration of clinical signs before presentation was 1.5 days (range 1 to 15). Median systolic blood pressure on presentation was 230 mmHg (range 190 to 300). Amlodipine was the most common first-line agent (n=10), followed by hydralazine (n=4) and hypertonic saline (n=1). Aetiology of hypertensive emergency was acute kidney injury (n=9), idiopathic hypertension (n=3), hyperthyroidism (n=1), lymphoma (n=1) and suspected cutaneous and renal glomerular vasculopathy (n=1). Five cats and three dogs survived to discharge with an overall survival of 53.3%., Clinical Significance: Hypertensive emergencies had various presenting signs in this series. AKI was considered to be the cause of hypertension in the majority of patients. Further evaluation of treatment for hypertensive emergencies is warranted, considering almost half of the cases did not survive to discharge., (© 2022 The Authors. Journal of Small Animal Practice published by John Wiley & Sons Ltd on behalf of British Small Animal Veterinary Association.)

Objective: To describe common bacterial organisms cultured from retrobulbar cellulitis and abscess lesions, in vitro susceptibility patterns, common diagnostic techniques utilized, etiologies encountered, and prevalence of blindness., Animals Studied: Thirty-eight dogs diagnosed with retrobulbar cellulitis or abscessation from 2007 to 2017., Procedure: For cases of orbital cellulitis or abscess, signalment, orbital imaging, cytology, histopathology, bacterial culture and susceptibility testing, presence of vision at the initial examination and resolution, and presumed cellulitis/abscess etiology were recorded., Results: Most cases were medically (78.9%) versus surgically managed (18.4%). Most common form of orbital imaging was computed tomography (48.5%) followed by ocular ultrasound (18.2%). Fifteen of eighteen cultures (83.3%) showed growth of aerobic bacterial organisms, anaerobic bacterial organisms, or both. Most common aerobic bacteria were gram-negative bacilli (40.0%) followed by Corynebacterium sp. (26.7%) and α-hemolytic Streptococci sp. (26.7%) but Micrococcus and Bacillus spp. were also identified. Most common anaerobic bacteria were gram-negative bacilli (40.0%). Antibiotics with highest susceptibility patterns included gentamicin, followed equally by amoxicillin/clavulanic acid, cephalothin, chloramphenicol, and imipenem. No bacteria were susceptible to cefovecin. Six cases presented with vision loss due to retrobulbar disease (15.8%). Idiopathic (50%) disease and tooth root abscessation (23.7%) were most commonly diagnosed cause of orbital disease., Conclusion: Retrobulbar cellulitis/abscess is a serious and vision-threatening process, which can be effectively managed by broad-spectrum antibiotics such as gentamicin or amoxicillin/clavulanic acid, but not cefovecin. This study identified three organisms that have not been previously reported to be associated with orbital cellulitis (Corynebacterium sp., Bacillus sp. and Micrococcus sp.)., (© 2021 American College of Veterinary Ophthalmologists.)

Background: Canine sudden acquired retinal degeneration syndrome (SARDS) causes blindness for which there are no proven effective treatments. We aimed to clarify the time to vision loss, treatment response/side effects, and prognosis for life in dogs with SARDS., Methods: An online questionnaire was administered to owners of dogs with a historical diagnosis of SARDS. Mortality data were compared with a published purebred reference population. Select parameters were analyzed statistically using general linear model with least square means, two-sample t tests, and chi-squared or Fisher's exact tests., Results: Responses from owners that stated that their dog visited an ophthalmologist and had electroretinography performed (n = 434) were analyzed. The majority of owners (65.4%) reported the time from vision disturbance to complete vision loss as <2 weeks; 19.4% reported >4 weeks. Onset of systemic clinical signs to complete vision loss was >4 weeks in 44.5% of responses. A higher proportion of owners reported some vision recovery with combination treatment (14.4%) compared with monotherapy (3.2%, P = .0004). Side effects of treatment were commonly reported. Dogs with SARDS did not have a shorter lifespan than the reference population but had higher incidence of kidney disease (P = .0001) and respiratory disease (P = .0004) at death., Conclusions: Dogs with SARDS have a rapid onset of vision loss. In the owner's opinion, treatment is unlikely to restore vision and is associated with systemic side effects. The potential for systemic pathologies that arise after SARDS diagnosis warrants further study., (© 2020 American College of Veterinary Ophthalmologists.)

Animals evolve their sensory systems and foraging behaviours to adapt and colonize new and challenging habitats such as the dark cave environment. Vibration attraction behaviour (VAB) gives fish the ability to locate the source of a water disturbance in the darkness. VAB evolved in the blind Mexican cave tetra, Astyanax mexicanus. VAB is triggered in cavefish by vibration stimuli peaking at 35 Hz, which is within the main spectrum of water fluctuations produced by many prey crustaceans and insects. VAB has a genetic component and is correlated to an increased number of head mechanosensory neuromasts in the eye orbital region when compared to surface fish. Previous competitive prey capture assays have supported the advantage of VAB for foraging in the dark. Despite its putative adaptive function, VAB has been described as absent in some Astyanax cave populations (Tinaja and Molino) but present in others (Pachón, Piedras, Toro and Sabinos). Here we have tested the occurrence of VAB in the field and in multiple cave populations using a vibrating device in natural pools. Our results confirmed the presence of VAB in caves such as Pachón, Toro and Sabinos but showed that VAB is also present in the Tinaja and Molino cave populations, previously reported as VAB-negative in laboratory experiments. Thus, VAB is available throughout the range of hypogean A. mexicanus. However, and most notably, within a given cave the levels of VAB were highly variable among different pools. Fish at one pool may express no VAB, while fish at another nearby pool of the same cave may actively show VAB. While a variety of environmental conditions may foster this diversity, we found that individuals inhabiting pools with a high abundance of organic matter have reduced expression of VAB. In contrast, in pools with little organic debris where fish probably depend more on hunting than on scavenging, VAB is enhanced. Our results suggest that expression of VAB is a plastic trait whose variability can depend on local conditions. Such plasticity may be required within and among caves where high environmental variability between pools results in a diverse availability of food., (© 2020 Fisheries Society of the British Isles.)

Objective: In previous reports, almost half of Golden Retrievers with Pigmentary Uveitis (GRPU) have lost vision in an eye within a year of diagnosis. The purpose of this study was to determine the proportion of GRPU affected dogs with vision loss, risk factors for the development of glaucoma, and effect of treatment on disease progression., Animals Studied: Client owned Golden Retrievers., Procedures: Two complete ophthalmic examinations were performed at least 6 months apart. Visual status, presence of glaucoma, GRPU score, and treatment were recorded. A proportional odds (ordinal logistic) model was fitted to determine whether the use of topical steroidal or non-steroidal (NSAID) ophthalmic preparations was associated with a change in GRPU scores., Results: Twenty-nine Golden Retrievers, 58 eyes, were included. One eye was enucleated after the first examination. On first examination, 57/58 (98.3%) eyes and 29/29 (100%) dogs were visual. At the second examination, 48/57 (84.2%) eyes and 25/29 (86.2%) dogs were visual. Vision loss in 7/9 (77.8%) eyes was secondary to glaucoma. Posterior synechia and fibrinous material in the anterior chamber were significant risk factors for the development of glaucoma (P < .001). There was no significant difference in the change in GRPU score between eyes receiving topical steroids and topical NSAIDs (P = .14). Time between examinations was a significant factor in disease progression (increased GRPU score; P = .016)., Conclusion: The number of eyes and dogs that retained vision was higher than previous reports. No topical treatment was superior in slowing disease progression. Golden Retriever Pigmentary Uveitis is a slowly progressive disease., (© 2020 American College of Veterinary Ophthalmologists.)

The births of domestic dogs with pigment deletion and associated congenital hearing and/or vision impairments are increasing, as a result of mutations of certain genes expressing popular coat colour patterns (Merle, piebald, Irish spotting). The future of these dogs is often pessimistic (early euthanasia or placement in rescues/fosters, lack of interactions and activities for adults). These pessimistic scenarios result from popular assumptions predicting that dogs with congenital hearing/vision impairments exhibit severe Merle-related health troubles (cardiac, skeletal, neurological), impairment-related behavioural troubles (aggressiveness, anxiety), and poor capacities to communicate, to be trained, and to be engaged in leisure or work activities. However, there is no direct scientific testing, and hence no evidence or refutation, of these assumptions. We therefore addressed an online questionnaire to owners of 223 congenitally sensory impaired (23 vision impaired, 63 hearing impaired, 137 hearing and vision impaired) and 217 sensory normal dogs from various countries. The sensory normal cohort was matched in age, lifetime with owner, breed and sex with the sensory impaired cohort, and was used as a baseline. The questionnaire assessed demographics, morphology, sensory impairments, health and behavioural troubles, activities, and dog-owner communication. Most hearing and/or vision impaired dogs exhibited abnormal pigment deletion in their coat and irises. Vision impaired dogs additionally exhibited ophthalmic abnormalities typically related to Merle. The results are opposed to all above-listed assumptions, except for neurological troubles, which were more frequently reported in sensory impaired dogs. However, we suggest that this finding could be partially accounted for by a lack of diagnosis of breed-related drug sensitivity and impairment-related compulsive behaviours. Results about communication and activities are particularly optimistic. The need for future studies of numerous dogs from various breeds tested for Merle, piebald and medical-drug-resistance genes, and the beneficial effects that present and future research may have on the future of sensory impaired dogs, are discussed., Competing Interests: The authors have declared that no competing interests exist.

Background: The primary purpose of this survey was to determine how veterinary ophthalmologists manage cases of irreversible blindness and to report the most common causes of blindness., Methods: Respondents completed a questionnaire sent by email with the cooperation of the American College of Veterinary Ophthalmologists, the European College of Veterinary Ophthalmologists and the Latin American College of Veterinary Ophthalmologists. The questionnaire was developed containing 12 questions with both open and closed multiple-choice response options., Results: One hundred and eight veterinary ophthalmologists answered the questionnaire. Of the respondents, 83 per cent had graduated for more than 10 years. Glaucoma (63.56 per cent) was the main cited cause of blindness, followed by progressive retinal atrophy (PRA) (17.80 per cent) and retinal detachment (6.78 per cent). The major concerns of owners refer to the impact of blindness on quality-of-life, (39.31 per cent), followed by depression and anxiety (20 per cent), and environment adaptation (11.72 per cent). General recommendations include avoidance of changes in the domestic environment (18.45 per cent), use of auditory stimulation (14.09 per cent) and avoidance of dangerous areas (12.75 per cent). Almost 31 per cent of professionals do not recommend the use of literature on how to deal with blind pets., Conclusions: The survey determined glaucoma and PRA as the most common causes of irreversible blindness in pets. Several recommendations that are frequently given to owners of blind pets are presented., Competing Interests: Competing interests: None declared., (© British Veterinary Association 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Four free-ranging peregrine falcons (Falco peregrinus) were submitted with a history of unilateral or bilateral blindness and central nervous signs to a veterinary clinic in Germany. There were no indications of trauma or ocular disease. Likewise, other differential diagnoses for CNS signs were ruled out within the diagnostic process. The clinical diagnostic panel in live falcons included general examination, radiography, endoscopy, hematology, ophthalmoscopy and parasitological examination of the feces, blood gas analysis and blood chemistry as well as computed tomography, and magnetic resonance imaging (MRI). A complete pathological and histopathological examination was performed post-mortem. The only common finding in all birds was an infection with the nematode parasite Serratospiculum tendo. The parasite was confirmed morphologically and via PCR. In two falcons intracerebral vermicoses was suspected in MRI and confirmed in subsequent histopathology, but molecular biological identification of the parasite species failed from brain tissue. Until today, S. tendo had been reported to affect the respiratory system, the liver and different parts of the gastrointestinal tract and to cause cachexia, inappetence, regurgitation, dyspnea and general signs of illness such as lethargy, poor plumage, and reduced reproduction. Our findings indicate that aberrant migration should be considered as cause for CNS signs in falcons. As S. tendo might be a possible cause for this, CNS signs might be included in the list of clinical signs of serratospiculiasis in falcons., Competing Interests: Declaration of Competing Interest All authors declare that there is no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objective: To compare the effects of topical 0.005% latanoprost (L) vs combined 0.005% latanoprost and 1% atropine (LA) on control of postoperative ocular hypertension (POH), development of posterior synechiae formation, pupil size, and blindness after phacoemulsification surgery in dogs., Animal Studied: Dogs with postoperative ocular hypertension were included in the study: L-group, latanoprost (eight dogs, 14 eyes) and LA-group, latanoprost and atropine (nine dogs, 15 eyes)., Procedures: Complete ophthalmic examinations including tonometry were performed at 1, 7, and 21 days following phacoemulsification., Results: No significant differences were found between the measured intraocular pressure (IOP) at days 1 and 7 postphacoemulsification surgery in the L-group and the LA-group (P = 0.26 [14.12 ± 1.76 mmHg vs 16.96 ± 1.68 mmHg] and P = 0.71 [15.45 ± 1.43 mmHg vs 16.20 ± 1.36 mmHg], respectively). No significant differences were found between pupil sizes at day 7 for the two groups (P = 0.25 [13.83% vs 24.77%]). No significant differences were found between odds of posterior synechiae formation at day 21 (P = 0.92) with a probability ± SE for L-group vs LA-group at 0.27 ± 0.14 vs 0.25 ± 0.13. No significant differences were found in odds of postoperative blindness between groups (P = 0.58) with a probability ± SE of 0.21 ± 0.11 vs 0.13 ± 0.09, respectively for L and LA., Conclusions: Combined topical latanoprost and atropine in dogs maintains normal postoperative IOPs but does not seem to cause increased mydriasis compared to latanoprost alone., (© 2019 American College of Veterinary Ophthalmologists.)

Georgina Mills discusses a study that has discovered a genetic mutation linked to a severe eye condition., (British Veterinary Association.)

Purpose: To investigate factors associated with long-term visual outcome in cats with hypertensive chorioretinopathy., Animals Studied: Eighty-eight client-owned cats diagnosed with hypertensive chorioretinopathy., Procedure: Medical records from cats with systemic hypertension and associated retinal lesions were reviewed., Results: Most cats (61%) were blind in both eyes at presentation. Presence of menace response at last follow-up evaluation was positively correlated with presence of menace response at presentation (P = .0025), time to complete retinal reattachment (P < .0001), and gender (P = .0137). Seventy-six of 132 eyes (57.6%) that were blind at presentation regained some vision following treatment. At the time of last evaluation, 101/176 eyes (60%) had a positive menace response, while 34/46 (74%) eyes with a follow-up of >6 months had a positive menace response. Eyes that had a menace response at presentation were 17 and 37 times more likely to have a menace response at last examination compared to eyes blind for less than 2 weeks and eyes blind greater than 2 weeks, respectively. Female cats were overrepresented (62.5% of cases), and male cats were 4.2 times more likely to be visual at time of last examination compared to female cats., Conclusions: With treatment, the prognosis for long-term vision in cats with hypertensive chorioretinopathy, even following complete retinal detachment, is good., (© 2018 American College of Veterinary Ophthalmologists.)

We describe the clinicopathologic features of a mortality event characterized by blindness and dermatitis affecting eastern grey kangaroos ( Macropus giganteus), secondary to hepatogenous photosensitization. Affected animals exhibited photophobic behavior, blindness, ataxia, recumbency, lethargy, ear shaking, and behavior consistent with distress or depression. The photophobia manifested as abnormal shade-seeking during the day, including finding refuge under or in structures used frequently by people. Severely affected kangaroos were jaundiced and had markedly elevated serum bilirubin and gamma glutamyl-transpeptidase concentrations. Blindness in affected animals was attributed to moderate to severe corneal opacity due to corneal edema and inflammation. Skin lesions were typically subtle on gross examination even in cases which had severe necrotizing dermatitis histologically. Histologic lesions in the liver of affected animals included the presence of acicular clefts typical of steroidal saponins. The outbreak was associated with pasture dominated by the invasive grass, Panicum gilvum, which is a recognized source of saponin-induced photosensitization in livestock.

Objective: To determine factors associated with sudden acquired retinal degeneration syndrome (SARDS) diagnosed within one referral population., Animals Studied: 151 dogs diagnosed with SARDS., Procedures: Breed, age, sex, and body weight were compared between dogs with electroretinogram-confirmed SARDS and dogs presented to the UC Davis Veterinary Medical Teaching Hospital (UCD-VMTH) from 1991 to 2014., Results: SARDS was diagnosed in 151 dogs, representing 1.3% of dogs presented to the UCD-VMTH for ophthalmic disease. Although dogs of 36 breeds were affected, the Dachshund (n = 31, 21%), Schnauzer (16, 11%), Pug (11, 7%), and Brittany (5, 3%) were significantly overrepresented, and the Labrador Retriever (3, 2%) was significantly underrepresented vs. the reference population (P < 0.001). Median (range) age and body weight of affected vs. reference dogs were 8.9 (3-20) vs. 6.8 (0.1-26) years and 12.4 (2.8-52.7) vs. 22.3 (0.1-60) kg, respectively. Dogs 6-10 years of age and between 10-20 kg in body weight were significantly overrepresented in the SARDS population, while dogs <6 years of age were significantly underrepresented (P < 0.01). Spayed females (59% of affected dogs) were significantly overrepresented compared to the reference population, whereas intact females (1% of affected dogs) were significantly underrepresented., Conclusions: Consistent with previous studies, smaller, middle-aged, spayed female dogs may be at increased risk of developing SARDS. Unlike previous studies, this is the first study comparing a variety of SARDS-affected breeds to a reference population. Potentially increased risk of SARDS in several breeds, particularly Dachshunds, suggests a familial factor that warrants further investigation using genetic techniques., (© 2017 American College of Veterinary Ophthalmologists.)

Objective: To investigate the causes of hyphema in dogs and identify factors associated with poor visual outcomes., Animals Studied: Ninety-nine dogs (120 eyes) that presented with hyphema., Procedure: Medical records from the Colorado State University Veterinary Teaching Hospital between the years 2004-2015 were reviewed., Results: Overall, 36.4% of dogs were diagnosed with hyphema from systemic causes, 32.9% due to local ocular disease, 26.1% due to trauma, and 4.5% due to idiopathic causes. Regardless of cause, 55.4% of eyes were blind at their last recheck, but the percentage of eyes that lost vision ranged from 11.1 to 100%, depending on the cause. Causes of hyphema with poor outcomes were ocular neoplasia, chronic uveitis, and trauma. Enucleation was performed or recommended in 36 eyes (39.5%), and 27 eyes (31.4%) were diagnosed with glaucoma. Initial exam findings associated with a significantly increased risk of blindness were absent consensual PLR (odds ratio (OR) = 28.6), absent dazzle (OR = 19.4), elevated intraocular pressure (IOP) (OR = 9.1), presence of a retinal detachment (OR = 7.6), unilateral hyphema (OR = 5.8), and complete hyphema (OR = 3.9). Factors associated with a significantly increased risk of glaucoma included hyphema present for 8-30 days (OR > 6), absent consensual PLR (OR = 6.4), absent dazzle (OR = 5.3), and the presence of a retinal detachment at the final evaluation (OR = 5.8)., Conclusion: Prognosis for vision is highly dependent on the cause of hyphema and initial exam findings. Poor prognostic factors on presentation include absent dazzle, absent consensual PLR, elevated IOP, unilateral hyphema, and complete hyphema., (© 2017 American College of Veterinary Ophthalmologists.)

Background: Venous air embolism is a potentially life-threatening complication of IV catheter use in horses. Despite widespread anecdotal reports of their occurrence, few cases have been reported in the literature and the prognosis is currently unknown., Hypothesis/objectives: Our objective was to describe the surrounding circumstances, clinical signs, treatment, progression, and outcome of venous air embolism in hospitalized horses., Animals: Thirty-two horses with acute onset of compatible clinical signs associated with IV catheter disconnection or damage., Methods: Multicenter retrospective study. Data extracted from clinical records included signalment, presenting complaint, catheter details, clinical signs, treatments, and outcome., Results: Most cases resulted from extension set disconnection occurring within approximately 24 hours after catheter placement. In fewer horses, extension set damage was cited as a cause. Common clinical signs included tachycardia, tachypnea, recumbency, muscle fasciculations and agitation, with abnormal behavior including kicking and flank biting. Less commonly, pathological arrhythmias or more severe neurologic signs, including blindness and seizures, were noted. Progression was unpredictable, with some affected horses developing delayed-onset neurologic signs. Mortality was 6/32 (19%), including 2 cases of sudden death and other horses euthanized because of persistent neurologic deficits. Negative outcomes were more common in horses with recorded blindness, sweating or recumbency, but blindness resolved in 5/8 affected horses., Conclusions and Clinical Importance: The prognosis for resolution of clinical signs after air embolism is fair, but permanent neurologic deficits or pathologic cardiac arrhythmias can arise. Unpredictable progression warrants close monitoring. Systematic clinic-based surveillance could provide additional useful information to aid prevention., (Copyright © 2018 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

Ocular setariases of cattle were reported but those of equine hosts have never been reported in the Republic of Korea (Korea). We found motile worms in the aqueous humor of 15 horses (Equus spp.) from 12 localities in southern parts of Korea between January 2004 and November 2017. After the affected animals were properly restrained under sedation and local anesthesia, 10 ml disposable syringe with a 16-gauge needle was inserted into the anterior chamber of the affected eye to successfully remove the parasites. The male worm that was found in 7 of the cases showed a pair of lateral appendages near the posterior terminal end of the body. The papillar arrangement was 3 pairs of precloacal, a pair of adcloacal, and 3 pairs of postcloacal papillae, plus a central papilla just in front of the cloaca. The female worms found in the eyes of 8 horses were characterized by the tapering posterior terminal end of the body with a smooth knob. Worms were all identified as Setaria digitata (von Linstow, 1906) by the morphologic characteristics using light and electron microscopic observations. This is the first blindness cases of 15 horses infected with S. digitata (Nematoda: Filarioidea) in Korea.

This study reviewed clinical data from dogs diagnosed with sudden acquired retinal degeneration syndrome (SARDS) in western Canada. Medical records from the Western College of Veterinary Medicine from 2002 to 2016 showed that 93 cases of SARDS were diagnosed based on presentation for sudden blindness and a bilaterally extinguished electroretinogram. The most common pure breeds were the miniature schnauzer, dachshund, and pug. The mean age at diagnosis was 8.1 years and males and females were equally affected. Most of the dogs were presented with normal non-chromatic, but abnormal chromatic pupillary light reflexes. The incidence of retinal degeneration as detected via ophthalmoscopy increased over time after SARDS diagnosis. Polyuria, polydipsia, polyphagia, weight gain, elevated liver enzyme values, isosthenuria, and proteinuria were common clinical and laboratory findings. Chromatic pupillary light reflex testing may be more valuable than non-chromatic pupillary light testing in detecting pupil response abnormalities in dogs with SARDS, although electroretinography remains the definitive diagnostic test., Competing Interests: Use of this article is limited to a single copy for personal study. Anyone interested in obtaining reprints should contact the CVMA office (hbroughton@cvma-acmv.org) for additional copies or permission to use this material elsewhere.

This study reports on two Hanwoo (a native Korean breed of cattle) calves, a 3- and 6-month-old presenting with diarrhea, anorexia and blindness. Ophthalmoscopic examination revealed bilateral papilledema in both calves. Reverse-transcription polymerase chain reaction tests for bovine viral diarrhea virus, rotavirus and coronavirus were all negative. The levels of serum vitamin A in the two affected calves were 0.317 µg/dl and 0.481 µg/dl, respectively. These values are much lower than the normal vitamin A levels; therefore, the calves were diagnosed with hypovitaminosis A.

A 10-month-old male Welsh Corgi with a history of acute blindness underwent neuro-ophthalmological testing and magnetic resonance imaging (MRI). Vision testing revealed complete visual deficits but the electroretinograph and pupillary light reflex were normal in both eyes. The motor and sensory functions of the eyelids and eyes were also normal. The MRI revealed compression of the optic chiasm caused by severe ventriculomegaly in the lateral and third ventricles. Such lesions are associated with inflammatory stenotic lesions in the mesencephalic aqueduct. Moderate neutrophilic pleocytosis was observed during cerebrospinal fluid analysis and Acinetobacter lwoffii was isolated, leading to a diagnosis of Acinetobacter-positive obstructive hydrocephalus. This is the first reported case of culture-proven Acinetobacter-associated postencephalitic hydrocephalus with acute blindness in a dog.

The first report of multiple, blind, wild birds in good health suggests vision is not necessary for the survival of kiwi.

A 6-year-old castrated male boxer dog with right-sided dark purulent nasal discharge and acute bilateral blindness was diagnosed on magnetic resonance imaging (MRI) and then on necropsy with primary nasal malignant melanoma that extended into the brain, as well as concurrent ocular melanosis. There was no evidence of metastasis in other organs.

A 29-year-old stallion presented with bilateral blindness following the chronic purulent nasal drainage. The mass occupied the right caudal nasal cavity and right paranasal sinuses including maxillary, palatine and sphenoidal sinuses, and the right-side turbinal and paranasal septal bones, and cribriform plate of ethmoid bone were destructively replaced by the mass growth. The right optic nerve was invaded and involved by the mass, and the left optic nerve and optic chiasm were compressed by the mass which was extended and invaded the skull base. Histologically, the optic nerves and optic chiasm were degenerated, and the mass was diagnosed as lymphoma which was morphologically and immunohistochemically classified as a diffuse large B-cell lymphoma. Based on these findings, the cause of the blindness in the stallion was concluded to be due to the degeneration of the optic nerves and chiasm associated with lymphoma occurring in the nasal and paranasal cavities. To the best of our knowledge, this is the first report of the equine blindness with optic nerve degeneration accompanied by lymphoma.

Sudden acquired retinal degeneration syndrome (SARDS) is one of the leading causes of currently incurable canine vision loss diagnosed by veterinary ophthalmologists. The disease is characterized by acute onset of blindness due to loss of photoreceptor function, extinguished electroretinogram with an initially normal appearing ocular fundus, and mydriatic pupils which are slowly responsive to bright white light, unresponsive to red, but responsive to blue light stimulation. In addition to blindness, the majority of affected dogs also show systemic abnormalities suggestive of hyperadrenocorticism, such as polyphagia with resulting obesity, polyuria, polydipsia, and a subclinical hepatopathy. The pathogenesis of SARDS is unknown, but neuroendocrine and autoimmune mechanisms have been suggested. Therapies that target these disease pathways have been proposed to reverse or prevent further vision loss in SARDS-affected dogs, but these treatments are controversial. In November 2014, the American College of Veterinary Ophthalmologists' Vision for Animals Foundation organized and funded a Think Tank to review the current knowledge and recently proposed ideas about disease mechanisms and treatment of SARDS. These panel discussions resulted in recommendations for future research strategies toward a better understanding of pathogenesis, early diagnosis, and potential therapy for this condition., (© 2015 American College of Veterinary Ophthalmologists.)

Background: Ivermectin is widely used in veterinary practice for the treatment of ecto- and endo-parasites. In wildlife, an extra-label use this parasiticide is sometimes associated with toxicity. Different treatment regimens have been used in ivermectin toxicosis. The present report describes a successful reversal of ivermectin toxicity by intravenous administration of a commercially available lipid emulsion in a captive African lion (Panthera leo)., Case Presentation: A 2-year old captive African lion (Panthera leo) weighing ~130 kg was presented with acute neurological impairment and bilateral blindness that had developed 24 h after ivermectin exposure. The animal was treated with a commercially available lipid emulsion along with supportive therapy and experienced complete recovery., Conclusion: To our knowledge, this is the first case report of the use of lipid emulsion in the management of ivermectin induced blindness in an African lion and it appears that intravenous lipid emulsion may be an effective therapy in ivermectin toxicity in lions. Further testing in expanded clinical trials is clearly warranted.

Sudden loss of vision is an ophthalmic emergency with numerous possible causes. Abnormalities may occur at any point within the complex vision pathway, from retina to optic nerve to the visual center in the occipital lobe. This article reviews specific prechiasm (retina and optic nerve) and cerebral cortical diseases that lead to acute blindness. Information regarding specific etiologies, pathophysiology, diagnosis, treatment, and prognosis for vision is discussed., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The utility of stem cells and their progeny in adult transplantation models has been limited by poor survival and integration. We designed an injectable and bioresorbable hydrogel blend of hyaluronan and methylcellulose (HAMC) and tested it with two cell types in two animal models, thereby gaining an understanding of its general applicability for enhanced cell distribution, survival, integration, and functional repair relative to conventional cell delivery in saline. HAMC improves cell survival and integration of retinal stem cell (RSC)-derived rods in the retina. The pro-survival mechanism of HAMC is ascribed to the interaction of the CD44 receptor with HA. Transient disruption of the retinal outer limiting membrane, combined with HAMC delivery, results in significantly improved rod survival and visual function. HAMC also improves the distribution, viability, and functional repair of neural stem and progenitor cells (NSCs). The HAMC delivery system improves cell transplantation efficacy in two CNS models, suggesting broad applicability., (Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.)

Case Description: A 4-year-old castrated male Chihuahua was evaluated because of unilateral vision loss following extraoral administration of a caudal maxillary nerve block during a dental procedure., Clinical Findings: The menace response was absent in the left eye, but the pupillary light reflex was intact. Vitreal hemorrhages and opacities were present on ophthalmic examination of the left eye. Ultrasonographic findings were supportive of the clinical findings. The posterior lens capsule and retina appeared to be undisturbed., Treatment and Outcome: Treatment consisted of administration of carprofen and prophylactic administration of amoxicillin-clavulanate. Vision was clinically normal with an intact menace response 1 week later., Clinical Relevance: Findings indicated that intravitreal injection of the local anesthetic agent should be considered as a potential complication when performing nerve blocks prior to dental procedures in dogs.

A group of beef cattle in eastern Alberta was investigated due to sudden onset of blindness after grazing on standing corn in mid-winter. Fumonisin-producing Fusarium spp. were isolated from the corn. Blindness was due to an optic nerve degeneration suspected to be secondary to fumonisin mycotoxin.

Blindness was observed in 10- to 14-day-old guinea fowl. The incidence ranged from 25% to 80% in nine flocks within a total population of 110,000 guinea fowls. Clinical signs of blindness in birds included aimless wandering, failure to find feed and water, lateral recumbency, loss of weight, and increased mortality. The birds lacked papillary reflexes to light, and there were no gross lesions in the eyes. Histologically there was degeneration and disorganization of photoreceptors in the retina. The guinea fowl came from three different breeder sources but all of the birds were given the same feed. The condition was not observed in the subsequent flocks that came from the same breeder sources but that were given different feed. Based on these observations, toxicity of an unknown ingredient in the feed is suspected as the cause of blindness in the guinea fowl.

Objective: To investigate long-term outcomes and owner-perceived quality of life associated with sudden acquired retinal degeneration syndrome (SARDS) in dogs., Design: Survey study., Animals: 100 dogs with SARDS examined at 5 academic veterinary institutions from 2005 to 2010., Procedures: The diagnosis was based on documented acute vision loss, normal results of ophthalmic examinations, and evaluation of extinguished bright-flash electroretinograms. Primary owners of affected dogs completed a questionnaire addressing outcome measures including vision, systemic signs, and perceived quality of life for their dogs., Results: Age at diagnosis was significantly correlated with positive outcome measures; dogs in which SARDS was diagnosed at a younger age were more likely to have alleged partial vision and higher owner-perceived quality of life. Polyphagia was the only associated systemic sign found to increase in severity over time. Medical treatment was attempted in 22% of dogs; visual improvement was not detected in any. Thirty-seven percent of respondents reported an improved relationship with their dog after diagnosis, and 95% indicated they would discourage euthanasia of dogs with SARDS., Conclusions and Clinical Relevance: Blindness and concurrent systemic signs associated with SARDS appeared to persist indefinitely, but only polyphagia increased in severity over time. Most owners believed their pets had good quality of life and would discourage euthanasia of dogs with SARDS.