Sudden Acquired Retinal Degeneration Research Articles

Parasiticide use and obesity in dogs with sudden acquired retinal degeneration syndrome.

To investigate parasiticide use and describe signalment features in patients with sudden acquired retinal degeneration syndrome (SARDS). Retrospective case-control study of dogs with (n = 71) and without (136) SARDS. Parasiticide use, presentation season, weight, body condition, and signalment were compared between dogs diagnosed with SARDS and the reference population by use of descriptive statistics and logistic regression. Animals with SARDS were at a 5.99 times higher odds of having previously used imidacloprid (95% CI, 1.6 to 22.2; P = .003). However, time of last imidocloprid administration was > 6 years prior to diagnosis in 6 SARDS-affected individuals and 15, 26, or 42 months before diagnosis (n = 1 each). No other class of parasiticide had a significant association with SARDS. Seasonal variation was observed with a negative association identified between incidence of SARDS and tick season (October to January; P < .001). Overweight and obese dogs were 4.42 (95% CI, 1.9 to 10.4) and 4.96 (95% CI, 2.1 to 11.6) times more likely to have SARDS (P ≤ .001). History of polyphagia or weight gain was not associated with an increased likelihood of being overweight or obese within the SARDS-affected population (P > .108). While a statistically significant association was found between imidacloprid use and SARDS, this is unlikely to be clinically significant given the lack of a temporal association, sparse exposure numbers, and low point estimate of the OR. A positive association between being overweight or obese and a diagnosis of SARDS was found independent of polyphagia and weight gain, suggesting that it may be a risk factor for the development of SARDS.

Olfaction evaluation in dogs with sudden acquired retinal degeneration syndrome.

To evaluate olfaction in dogs with sudden acquired retinal degeneration syndrome (SARDS) compared with sighted dogs and blind dogs without SARDS as control groups. Forty client-owned dogs. 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. 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. 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.

Hemostatic profiles in dogs with sudden acquired retinal degeneration syndrome.

Sudden acquired retinal degeneration syndrome (SARDS) is a common cause of irreversible blindness in dogs. It bears clinical resemblance to hypercortisolism, which can be associated with hypercoagulability. The role of hypercoagulability in dogs with SARDS is unknown. Determine hemostatic profiles in dogs with SARDS. Prospective pilot study: Dogs with a history of SARDS (n = 12). Prospective case-control study: Dogs with recent onset of SARDS (n = 7) and age-, breed-, and sex-matched controls (n = 7). Prospective pilot study: We performed thromboelastography (TEG). Prospective case-control study: Dogs had CBC, serum biochemistry, urinalysis, TEG, fibrinogen concentration, antithrombin activity, D-dimers, thrombin-antithrombin complexes, and optical platelet aggregometry performed. Prospective pilot study: 9/12 dogs with a history of SARDS were hypercoagulable with increased TEG G value and 2/3 had hyperfibrinogenemia. Case-control study: All dogs with SARDS and 5/7 controls were hypercoagulable based on TEG G value. Dogs with SARDS had significantly higher G values (median, 12.7 kdynes/s; range, 11.2-25.4; P = .04) and plasma fibrinogen concentration (median, 463 mg/dL; range, 391-680; P < .001) compared to controls. Hypercoagulability was common in both dogs with SARDS and controls, but dogs with SARDS were significantly more hypercoagulable on TEG. The role of hypercoagulability in the pathogenesis of SARDS remains to be determined.

Unilateral blindness presumed as sudden acquired retinal degeneration syndrome (SARDS) in one Dachshund and four Maltese dogs.

To describe blindness, initially presenting as a unilateral condition and diagnosed as sudden acquired retinal degeneration syndrome (SARDS). 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. 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. 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.

Comparison of the qualitative and quantitative optical coherence tomographic features between sudden acquired retinal degeneration syndrome and normal eyes in dogs.

To quantitatively and qualitatively characterize the retinal optical coherence tomographic features of sudden acquired retinal degeneration syndrome (SARDS) and SARDS suspect dogs. Fourteen SARDS affected dogs, 11 age-, breed-, and sex-matched control dogs, and two SARDS suspect dogs. Spectral-domain optical coherence tomography (OCT) images were used to evaluate the quantitative features, including thickness, intereye asymmetry, and longitudinal changes in retinal layer thickness and the qualitative features, including retinal architecture and vitreous haze. Mean outer retinal layer thickness (ORT), outer nuclear layer thickness (ONL), and photoreceptor layer thickness (PRL) were significantly lower in the SARDS group, whereas mean inner retinal layer thickness was significantly higher in the SARDS group than in the control group. While thickness values of all retinal layers did not differ significantly between paired eyes in each group, the absolute intereye asymmetries in the ORT (p<.0001), ONL (p=.008), and PRL (p<.0001) were significantly higher in the SARDS group than in the control group. Some SARDS patients and SARDS suspects had a greater PRL than the control group, and serial OCT evaluation showed an increase in PRL in one SARDS suspect. Vitreous haze severity was greater in the SARDS group than in the control group (vitreous relative intensity, p=.030). We described the OCT features of SARDS patients and suspects. In particular, PRL thickening in the SARDS suspects might indicate an early change in SARDS. Although further studies are needed, this finding might provide new insights into the pathogenesis of SARDS.

Ocular abnormalities in Polish Hunting Dogs.

This study aimed to describe and determine the prevalence of ocular abnormalities in Polish Hunting Dogs. The study was conducted with 193 Polish Hunting Dogs: 101 female and 92 male animals, aged between 3 months and 12 years. Ophthalmic examinations were performed using slit lamp biomicroscopy, ophthalmoscopy, and tonometry based on the ophthalmological protocol for the examination of hereditary eye diseases. Spectral-domain optical coherence tomography (SD-OCT) was performed for dogs with sudden acquired retinal degeneration syndrome (SARDS) and progressive retinal atrophy (PRA), while electroretinography was also performed in dogs with SARDS. Five dogs (2.6%) were diagnosed with cataract, iris coloboma in 3 dogs (1.6%), ocular dermoid in 1 dog (0.5%), and retinal dysplasia, distichiasis and entropion in 1 dog (1%). Three dogs (1.6%) were diagnosed with PRA and SARDS occurred in 1 dog. Retinal lesions was observed in 16 dogs (8.3%). The clinical signs of retinopathy observed in Polish Hunting Dogs included discoloration of the tapetal fundus, patchy increased reflectivity in the region of discoloration, focus of hyperpigmentation and an area of tapetal hyper-reflectivity with a pigmented center. SD-OCT performed in the 3 dogs with PRA revealed alteration in the retinal layers, which was most advanced in the non-tapetal fundus. Although SD-OCT revealed retinal layers with normal architecture only in some parts of the dorsal, nasal and temporal regions in dogs with SARDS, areas of disorganized external limiting membrane, myeloid zone, ellipsoid zone, outer photoreceptor segment and interdigitation zone were also observed. Polish Hunting Dogs should undergo periodic ophthalmological examination for the evaluation of other hereditary eye diseases. The prevalence of retinal lesions in Polish Hunting Dogs requires further research.

Presumed neuroprotective therapies prescribed by veterinary ophthalmologists for canine degenerative retinal and optic nerve diseases.

To investigate veterinary ophthalmologists' use of presumed neuroprotective therapies for degenerative retinal and optic nerve diseases in dogs. An online survey was sent to 663 board-certified veterinary ophthalmologists who were Diplomates of the American College of Veterinary Ophthalmologists (ACVO), Asian College of Veterinary Ophthalmologists (AiCVO), Latin American College of Veterinary Ophthalmologists (Colegio Latinoamericano de Oftalmólogos Veterinarios, CLOVE), or European College of Veterinary Ophthalmologists (ECVO). The survey was created using Qualtrics® software and focused on the prescription of presumed neuroprotective treatments for canine glaucoma, sudden acquired retinal degeneration syndrome (SARDS), progressive retinal atrophy (PRA), and retinal detachment (RD). A total of 165 completed surveys were received, representing an overall response rate of 25%, which was comparable across the four specialty colleges. Of all respondents, 140/165 (85%) prescribed some form of presumed neuroprotective therapies at least once in the last five years: 114/165 (69%) for glaucoma, 51/165 (31%) for SARDS, 116/165 (70%) for PRA, and 50/165 (30%) for RD. The three most recommended neuroprotective reagents were the commercial Ocu-GLO™ Vision Supplement for animals, amlodipine, and human eye supplements. Despite lack of published clinical efficacy data, the majority of surveyed board-certified veterinary ophthalmologists previously prescribed a presumed neuroprotective therapy at least once in the last five years in dogs with degenerative retinal and optic nerve diseases.

Canine sudden acquired retinal degeneration syndrome: Owner perceptions on the time to vision loss, treatment outcomes, and prognosis for life.

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. 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. 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 <2weeks; 19.4% reported >4weeks. Onset of systemic clinical signs to complete vision loss was >4weeks 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. 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.

Presumed cancer-associated retinopathy (CAR) mimicking Sudden Acquired Retinal Degeneration Syndrome (SARDS) in canines.

ObjectiveTo describe functional and structural features of presumed cancer‐associated retinopathy (CAR) mimicking sudden acquired retinal degeneration syndrome (SARDS) in dogs and describe treatment outcomes.AnimalsSubjects were 17 dogs from 8 eight US states and Canada diagnosed with SARDS or immune‐mediated retinitis (IMR) by 12 ophthalmologists. Nine eyes from seven deceased patients were used for microarray (MA), histology, or immunohistochemical (IHC) analysis.ProceduresDogs underwent complete ophthalmic examination, including retinal photography, optical coherence tomography (OCT), chromatic pupil light reflex testing (cPLR), and electroretinography (ERG), in addition to complete systemic examination. Histology, microarray, and IHC analysis were performed in CAR retinas to evaluate histological and molecular changes in retinal tissue.ResultsNone of the patients evaluated satisfied previously established criteria for diagnosis of SARDS (flat ERG+ no red – good blue PLR), and all were diagnosed with IMR. All patients were diagnosed with a cancer: meningioma (24%), sarcoma (18%), pituitary tumor (12%), and squamous cell carcinoma (12%), other (34%). Median survival time was 6 months from diagnosis (range 1‐36 months). Most frequent systemic abnormalities were as follows: proteinuria (78%); elevated liver enzymes (47%); and metabolic changes (PU/PD, polyphagia – 24%). Immunosuppressive therapy resulted in the reversal of blindness in 44% of treated patients, with 61% of all treated patients recovering and/or maintaining vision. Median time for preservation of vision was 5 months (range 1‐35 months).ConclusionsObserved changes are highly suggestive of immune‐mediated damage in IMR‐CAR eyes. A relatively high percentage of patients with CAR responded positively to immunosuppressive therapy.

Retinal Diseases of Senior Dogs

Abstract Aging consists of a physiological decline of an organism’s functional activity. During the aging process, the structural and functional changes of the retina can be observed. In most cases, progressive vision loss occurs due to the age related changes of the anterior segment. Retinal diseases, characteristic for senior dogs are: retinal detachment, hypertensive chorioretinopathy, sudden acquired retinal degeneration syndrome (SARDS), progressive retinal atrophy (PRA), glaucoma, retinopathy, cystoid degeneration and neoplasms. The examination of the retina in senior dogs is based on: ophthalmoscopic examination, electroretinography, spectral-domain optical coherence tomography (AD-OCT) and if necessary, histopathological examinations. Comprehensive knowledge regarding the senior dog’s health, significantly increases their quality of life.

Detection of circulating anti-retinal antibodies in dogs with sudden acquired retinal degeneration syndrome using indirect immunofluorescence: A case-control study

Sudden acquired retinal degeneration syndrome (SARDS) in dogs is proposed to have an immune-mediated etiology. However, there is conflicting evidence regarding the presence of antiretinal antibodies, as assessed by western blotting, in the serum of SARDS patients. Because of the possibility that antibodies recognize only conformational epitopes, we hypothesized that a more sensitive method to investigate circulating retinal autoantibodies in SARDS is immunofluorescence. Sera from 14 dogs with early SARDS, and 14 age- and breed-matched healthy control dogs were screened for circulating antiretinal IgG, IgM, IgE and IgA using indirect immunofluorescence on lightly fixed frozen sections of normal canine retina. Controls without canine serum were also performed. A nuclear counterstain was used to identify cellular retinal layers. Images were obtained using a fluorescence microscope, and 2-3 separate masked observers graded retinal layers for fluorescence staining intensity using a 0–3 scale. Total circulating IgG and IgM was assessed by radial immunodiffusion. Statistical analysis was performed using 2-way ANOVA, paired 2-tailed student's t-test and correlation analysis. Intensity of IgG staining of photoreceptor outer segments was significantly higher using serum from dogs with SARDS compared with healthy controls in 2/3 observers (P < 0.05). Intensity of IgM staining throughout the retina was higher in SARDS dogs compared to matched healthy controls (P < 0.0001), although no specific retinal layer was statistically significant. There were no differences in staining intensity for IgE or IgA. Dogs with SARDS had a comparably lower circulating IgG and higher IgM than healthy controls (P = 0.01 and 0.001 respectively) and IgG and IgM were negatively correlated (r = −0.69, P = 0.007). Despite having decreased serum IgG compared with healthy controls, circulating IgG in dogs with SARDS binds photoreceptor outer segments to a greater extent. Dogs with SARDS have a relatively higher circulating IgM than matched healthy controls. The pathogenic nature of these antibodies is unknown.

Circulating neurohormone imbalances in canine sudden acquired retinal degeneration syndrome and canine pituitary-dependent hypercortisolism.

BackgroundSudden acquired retinal degeneration syndrome (SARDS) has clinical similarity to pituitary‐dependent hypercortisolism (PDH) in dogs. Some studies have identified a greater frequency of SARDS in seasons with reduced daylight hours. Neurohormone imbalances contribute to retinal lesions in other species, warranting further study in dogs with SARDS.HypothesisDysregulation of circulating melatonin concentration is present in dogs with SARDS but not in dogs with PDH.AnimalsFifteen client‐owned dogs with spontaneous SARDS (median time of vision loss 18 days), 14 normal dogs, and 13 dogs with confirmed PDH.ProceduresProspective case‐control study. ELISA on samples (obtained in the morning) for measurement of plasma melatonin and dopamine, serum serotonin, urine 6‐sulfatoxymelatonin (MT6s), and creatinine. Statistical analysis was performed using 1‐way ANOVA, Spearman correlation and receiver operator characteristic area under the curve analysis.ResultsThere were no significant differences in circulating melatonin, serotonin or dopamine concentrations between the 3 groups, although the study was underpowered for detection of significant differences in serum serotonin. Urine MT6s:creatinine ratio was significantly higher in dogs with PDH (4.08 ± 2.15 urine [MT6s] ng/mL per mg of urine creatinine) compared with dogs with SARDS (2.37 ± .51, P < .01), but not compared with normal dogs.Conclusions and Clinical RelevanceWe have identified neurohormone differences between dogs with SARDS and PDH.

Evaluation of the major histocompatibility complex (MHC) class II as a candidate for sudden acquired retinal degeneration syndrome (SARDS) in Dachshunds.

ObjectiveSudden acquired retinal degeneration syndrome (SARDS) is one of the leading causes of acute blindness in dogs, with an unknown etiology and no effective treatment. Certain breeds such as Dachshunds are overrepresented among SARDS patients, and therefore, the syndrome is suspected to have a genetic component. The objective of this study was to determine if a genetic locus associated with SARDS in Dachshunds could be identified using a genome‐wide association study (GWAS).ProceduresGenome‐wide association mapping was performed in 15 SARDS‐affected and 16 unaffected Dachshunds. Genotyping of three classical DLA class II genes (DLA‐DRB1, DLA‐DQA1, and DLA‐DQB1) was performed in 34 SARDS‐affected and 66 unaffected Dachshunds to evaluate for an association in this region.ResultsAlthough no single nucleotide polymorphisms (SNPs) were of genome‐wide statistical significance (P Bonferroni < 0.05), 5 of the top 9 SNPs were in the major histocompatibility complex (MHC). Using DLA typing, the allele DLA‐DRB1*09401 was identified as a risk factor for the development of SARDS (P = 0.0032, OR = 4.0). The alleles DLA‐DQB1*00101 (P = 0.0050, OR = 0.31), DLA‐DQA1*00901 (P = 0.0087, OR = 0.33), and a previously identified DLA‐DRB1allele described as “DRB1‐T” (P = 0.0284, OR = 0.37) were identified as protective factors.ConclusionsAlthough far from definitive, association of SARDS with alleles of immunologic importance further supports the hypothesis that autoimmunity may play a role in the pathogenesis of SARDS.

Electroretinography in small animal practice

During the last years, clinical electrophysiology has considerably improved, allowing the evaluation of the retina and visual pathways. In small animal practice, electroretinography is more useful than other diagnostic techniques for the assessment of retinal function, because of the fact that this method doesn't require patient's cooperation. Electroretinography (ERG) is an electrophysiological technique, which measures the retinal action potentials in response to light stimulation. Flash ERG evaluates the function of outer retina and is performed by the using of flashlight units that uniformly stimulate the retina. The evaluation of ERG requires the well understanding of the morphology as well as the physiologic function of the retina. Furthermore, a number of factors, which can influence the quality of the ERG, are totally controlled during the procedure. Because of the fact that electroretinographic values vary, according to many factors and different diagnostic protocols, comparison of results, obtained from different laboratories, would be difficult. Therefore, each veterinary ERG laboratory obtains its own normal values. ERG is indicated, when retinal disease is suspected. ERG can also help to identify the cause of blindness. In small animal practice, the majority of ERGs are performed on candidates for cataract surgery. Other ERG indications include the early diagnosis of central or generalized progressive retinal atrophy (PRA), the differential diagnosis between the sudden acquired retinal degeneration (SARD) and optic neuritis, the glaucoma and many cases of retinal detachments. Furthermore, ERG is used to evaluate the progression of many retinal disorders.

Cofactors associated with Sudden Acquired Retinal Degeneration Syndrome: 151 dogs within a reference population.

To determine factors associated with sudden acquired retinal degeneration syndrome (SARDS) diagnosed within one referral population. 151 dogs diagnosed with SARDS. 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. 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 6-10years of age and between 10-20kg in body weight were significantly overrepresented in the SARDS population, while dogs <6years 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. 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.

The combined use of surgical debulking and diode laser photocoagulation for limbal melanoma treatment: a retrospective study of 21 dogs.

To evaluate effectiveness and safety of debulking and diode laser photocoagulation (DPC) for the treatment of limbal melanoma (LM). Retrospective multi-institutional case series. Medical records of animals diagnosed with LM at the Centro Veterinario Specialistico (CVS) and at the Long Island Veterinary Specialists from 1994 to 2014 were retrieved. Signalment, location, extent of tumors, recurrence rate, and early and late complications were reported. Patient follow-up information was obtained from veterinary ophthalmologists, primary care veterinarians, and where appropriate, owners. Twenty-one eyes of 21 dogs (13 females and 8 males) were included in this study. The dogs' average age was 6 years (range: 7 months-11 years). The follow-up period ranged from 1-108 months (median 48 months) after the last DPC procedure. Long-term follow-up was obtained by telephone interviews in 6 of 20 cases and by clinical re-evaluations in 14 of 20 cases. The most common early complications were a moderate anterior uveitis and peripheral corneal edema (21/21 eyes). Late complications included corneal fibrosis and/or pigmentation (20/21). In one case, a severe bullous keratopathy associated with extensive corneal fibrosis was observed (1/21). One case was blind due to concurrent Sudden Acquired Retinal Degeneration (SARD). However, after surgery 2 of 20 eyes lost vision and one of these was enucleated. Debulking, in addition to diode laser photocoagulation, was technically straightforward to perform, minimally invasive, well tolerated, and highly successful in this case series.

Sudden acquired retinal degeneration in dogs: breed distribution of 495 canines.

The purpose of this study was to describe breed, age, gender, and weight distribution of dogs affected with sudden acquired retinal degeneration (SARD) and to investigate whether SARD is more common in small breed dogs. Medical records of dogs diagnosed with SARD confirmed by an electroretinogram were reviewed. Breed, age, gender, and weight were recorded when available. The same data were obtained for dogs with SARD described in the veterinary literature. Three hundred and two dogs were included from the ophthalmology practices and 193 dogs from the veterinary literature. Sixty breeds were present in the study. Mixed-breed dogs were the most common at 108 dogs (21.8%), followed by the Dachshund (68, 13.7%), Chinese Pug (44, 8.9%), Miniature Schnauzer (39, 7.9%), Maltese (23, 4.6%), Cocker Spaniel (22, 4.4%), Bichon Frise (18, 3.6%), Beagle (16, 3.2%), Brittany (15, 3.0%), and Pomeranian (10, 2.0%). Fifty other breeds were represented by 1-9 dogs each. The median age was 9 years (range = 10 months-16 years). The weight was known for 197 dogs. About 60.9% of dogs were less than 25 pounds, 31.5% were between 25 and 50 pounds, and 7.6% were greater than 50 pounds. Gender was recorded in 393 dogs: 217 female dogs and 176 male dogs. As previously reported, SARD is most common in middle-aged to older dogs. Smaller dogs of less than 25 pounds appear overrepresented, while large/giant breed dogs of greater than 50 pounds are infrequently diagnosed. In this study, there was no statistical significance between female and male dogs.

Sudden acquired retinal degeneration syndrome (SARDS) - a review and proposed strategies toward a better understanding of pathogenesis, early diagnosis, and therapy.

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.

Long-term outcome of sudden acquired retinal degeneration syndrome in dogs

To investigate long-term outcomes and owner-perceived quality of life associated with sudden acquired retinal degeneration syndrome (SARDS) in dogs. Survey study. 100 dogs with SARDS examined at 5 academic veterinary institutions from 2005 to 2010. 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. 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. 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.

Sudden acquired retinal degeneration syndrome (SARDS)

Sudden acquired retinal degeneration syndrome (SARDS) is a disease of dogs causing sudden onset blindness. There is no treatment and it causes permanent blindness. This article aims to give an overview of the disease and its diagnosis.