Prospective evaluation of a telmisartan suppression test as a diagnostic tool for primary hyperaldosteronism in cats.

BACKGROUND: In a previous study, telmisartan suppressed aldosterone secretion in healthy cats but not in cats with primary hyperaldosteronism (PHA). HYPOTHESES: Telmisartan suppresses aldosterone secretion in middle-aged healthy cat and cats with diseases that may result in secondary hyperaldosteronism, but not in those with PHA. ANIMALS: Thirty-eight cats: 5 with PHA; 16 with chronic kidney disease (CKD), subclassified as hypertensive (CKD-H) or non-hypertensive (CKD-NH); 9 with hyperthyroidism (HTH); 2 with idiopathic systemic arterial hypertension (ISH); and 6 healthy middle-aged cats. METHODS: Prospective, cross-sectional study. Serum aldosterone concentration, potassium concentration, and systolic blood pressure were measured before and 1 and 1.5 hours after PO administration of 2 mg/kg of telmisartan. The aldosterone variation rate (AVR) was calculated for each cat. RESULTS: No significant difference in the minimum AVR was observed among groups (median [quartile 1 (Q1); quartile 3 (Q3)]: 25 [0; 30]; 5 [-27; -75]; 10 [-6; -95]; 53 [19; 86]; 29 [5; 78]) for PHA, CKD, HTH, ISH, and healthy cats, respectively (P = .05). Basal serum aldosterone concentration (pmol/L) was significantly higher in PHA cats (median [Q1; Q3]: 2914 [2789; 4600]) than in CKD-H cats (median [Q1; Q3]: 239 [189; 577], corrected P value = .003) and CKD-NH cats (median [Q1; Q3]: 353 [136; 1371], corrected P value = .004). CONCLUSIONS AND CLINICAL IMPORTANCE: The oral telmisartan suppression test using a single dose of 2 mg/kg telmisartan did not discriminate cats with PHA from healthy middle-aged cats or cats with diseases that may result in secondary hyperaldosteronism.

Outcomes and Complications Associated with Superior and Inferior Subpalpebral Lavage Treatment Systems Placed in 61 Equine Eyes (2004-2021).

Painful eye conditions are a therapeutic challenge in horses. Subpalpebral lavage (SPL) treatment systems allow topical aqueous medications to be conveniently, safely, and frequently administered to the ocular surface. The aim of this retrospective study was to describe the outcomes and the complications associated with the location of the SPL treatment systems, in the superior or inferior eyelid in horses in a university practice. Clinical records of all horses admitted to the National Veterinary School of Alfort between January 2004 and October 2021, in which a SPL treatment system was used to administer the topical ophthalmic medications, were reviewed. Sixty horses were included in the study representing 61 SPL treatment systems. Uneventful outcomes occurred in 53 cases (86.9%) and complications were recorded in 8 cases (13.1%). Seven complications were reported for upper eyelid systems (23.3%) and 1 complication for lower eyelid systems (4.2%). The complication rates were not significantly different between these two locations (P= .06). The complications identified were iatrogenic corneal ulceration, palpebral abscess, overgrowth of conjunctiva over the footplate, and palpebral cellulitis. Median duration of SPL treatment system use was 7.5 days. The easier placement and removal and the lower incidence of complications identified in our study encourage the authors to favor the lower fornix for subpalpebral lavage treatment systems within our equine hospital.

Epidemiology and clinical presentation of feline presumed hereditary or breed-related ocular diseases in France: retrospective study of 129 cats.

OBJECTIVES: This study aimed to describe the epidemiology and clinical presentation of presumed hereditary or presumed breed-related ocular diseases in a population of cats in France. METHODS: Medical records from between September 2013 and August 2017 were reviewed to identify cats with at least one presumed hereditary or breed-related ocular disease. Cats with concurrent, or a history of, ocular or systemic infectious diseases were excluded. Signalment, history and clinical findings were recorded. RESULTS: Of the 1161 cats that presented to our institution during the study period, 129 were diagnosed with at least one presumed hereditary or presumed breed-related ocular disease (11.1%, 95% confidence interval [CI] 9.3-12.9). Five ocular abnormalities had a prevalence of >1%: entropion, corneal sequestration, persistent pupillary membrane, cataract and retinal dysplasia. The prevalence of entropion was 2.2% (95% CI 1.3-3.0), with Persians (P = 0.03), Maine Coons (P <0.01) and male cats (P <0.01) being over-represented. The prevalence of corneal sequestration was 2.4% (95% CI 1.5-3.3), with Persians (P <0.01) and Exotic Shorthairs (P = 0.02) being over-represented. Persistent pupillary membranes and cataracts had the same prevalence of 2.3% (95% CI 1.5-3.2), with no particular sex or breed significantly over-represented. Retinal dysplasia had a prevalence of 1.6% (95% CI 0.8-2.3) and Persian cats were over-represented (P = 0.04). Anterior segment dysgenesis had a low prevalence (0.9%, 95% CI 0.4-1.5), with all affected cats being domestic shorthairs and this breed therefore was over-represented (P = 0.04). CONCLUSIONS AND RELEVANCE: In a French population of cats, presumed hereditary or breed-related ocular diseases accounted for 11.1% of all ocular diseases. Cataracts, corneal sequestration, persistent pupillary membrane, entropion and retinal dysplasia were the most common conditions. Statistical breed over-representation was observed for entropion, corneal sequestration and retinal dysplasia. We recommend that more systematic screening of feline species is conducted.

Retinal phototoxicity and the evaluation of the blue light hazard of a new solid-state lighting technology.

Exposure Limit Values (ELV) for artificial lighting were defined in order to prevent light-induced damage to the retina. The evaluation of the lighting devices include the correction of their spectra by the B(λ) function or blue light hazard function, representing the relative spectral sensitivity of the human eye to the blue light. This weighting function peaks between 435 and 440 nm. In this study we evaluate a new generation of light emitting diode (LED), the GaN-on-GaN (gallium nitride on gallium nitride) LED, that present an emission peak in the purple part of the spectrum. Wistar rats were exposed to GaN-on-GaN and conventional diodes at different retinal doses (from 2.2 to 0.5 J/cm2). We show that GaN-on-GaN diodes are more toxic than conventional LED for the rat neural retina and the rat retinal pigment epithelium, indicating that the BLH (blue light hazard) weighting is not adapted to this type of diodes. One of the reasons of this increased toxicity is the effects of shorter wavelengths on mitochondria polarization. We also show that the threshold of phototoxic retinal dose in the rat (fixed at 11 J/cm2, BLH weighted) is overestimated, suggesting that the values used for regulations, calculated in primates using the same methods than in rats, should be revised.

Supposed endogenous endophthalmitis caused by Serratia marcescens in a cat.

An 8-year-old male neutered domestic shorthair cat was presented for evaluation of acute respiratory distress. Respiratory auscultation revealed a diffuse and symmetric increase in bronchovesicular sounds. Thoracic radiographs showed a diffuse unstructured interstitial pulmonary pattern with multifocal alveolar foci. Despite an aggressive treatment with supportive care, including oxygenotherapy and systemic antibiotics, progressive respiratory distress increased. Three days after the presentation, acute anterior uveitis was noticed on left eye. Ophthalmic examination and ocular ultrasonography revealed unilateral panuveitis with ocular hypertension. The right eye examination was unremarkable. Cytological examination of aqueous humor revealed a suppurative inflammation. Serratia marcescens was identified from aqueous humor culture. Primary pulmonary infection was suspected but was not confirmed as owners declined bronchoalveolar lavage. Active uveitis resolved and cat's pulmonary status improved after appropriate systemic antibacterial therapy. Vision loss was permanent due to secondary mature cataract. To the best of authors' knowledge, this is the first report of endogenous bacterial endophthalmitis secondary to S. marcescens infection in a cat.

Epidemiology and clinical presentation of feline cataracts in france: A retrospective study of 268 cases.

OBJECTIVE: To describe the epidemiology and the clinical presentation of cataracts in a population of cats in France. PROCEDURES: A review of medical records of cats presented to the Ophthalmology Unit of the National Veterinary School of Alfort between January 2010 and June 2017 was carried out to identify cats affected by cataracts. The signalment of affected cats, medical history, etiology of cataract, age of onset, stage of development, location of opacities, and concurrent ocular lesions were evaluated. RESULTS: Of 2054 cats which were presented to the Ophthalmology Unit of the National Veterinary School of Alfort during the study period, 268 (383 eyes) were diagnosed with a cataract (13%; CI [11.3-14.7]). The median age of all cats affected by cataract was 9.5 years (range: 0.1-18.6 years). Eighteen breeds were represented. The recorded causes of cataract were uveitis (35.8%), congenital (15.7%), aging (10.8%), presumed hereditary (8.2%), trauma (7.8%), lens luxation (3.3%), glaucoma (1.5%) and diabetes mellitus (0.4%). In 16.4% of the cases, the etiology could not be determined. The domestic short-hair was significantly overrepresented in cats with uveitis-related cataract (P < .001). The most common ocular lesions associated with cataracts were lens subluxation or luxation (17.8%), glaucoma (14.9%), and retinal detachment (4.4%). Lens subluxation/luxation and glaucoma were also significantly associated with uveitis-related cataract (P < .001). CONCLUSIONS: In a French population of referred cats, 13% were affected by cataract. The main causes identified were anterior uveitis, congenital, and aging. Lens subluxation/luxation and glaucoma were associated with uveitis-related cataract.

Caloric restriction increases lifespan but affects brain integrity in grey mouse lemur primates.

The health benefits of chronic caloric restriction resulting in lifespan extension are well established in many short-lived species, but the effects in humans and other primates remain controversial. Here we report the most advanced survival data and the associated follow-up to our knowledge of age-related alterations in a cohort of grey mouse lemurs (Microcebus murinus, lemurid primate) exposed to a chronic moderate (30%) caloric restriction. Compared to control animals, caloric restriction extended lifespan by 50% (from 6.4 to 9.6 years, median survival), reduced aging-associated diseases and preserved loss of brain white matter in several brain regions. However, caloric restriction accelerated loss of grey matter throughout much of the cerebrum. Cognitive and behavioural performances were, however, not modulated by caloric restriction. Thus chronic moderate caloric restriction can extend lifespan and enhance health of a primate, but it affects brain grey matter integrity without affecting cognitive performances.

Bilateral bullous keratopathy secondary to melting keratitis in a Suri alpaca (Vicugna pacos).

An young alpaca was evaluated for bilateral progressive melting corneal ulcers and developped secondary bullous keratopathy during hospitalization. The tragic progression of melting ulcers in both eyes observed in our case leads us to recommend a rapid intensive medical therapy in young and debilitated alpacas presenting a corneal ulcer.

Cataracts in a population of Bengal cats in France.

OBJECTIVE: To document the clinical appearance and prevalence of cataracts in a French population of Bengal cats. METHODS: Two distinct populations of Bengal cats were examined as follows: (i) 51 animals recruited for evaluation of national prevalence of ocular diseases in an observational study conducted between October 2014 and November 2016 at the Alfort ophthalmology unit; (ii) 12 patients referred for cataract diagnosis examined at a veterinary eye clinic located in central France, between December 2014 and February 2016. Buccal swabs or blood samples for DNA analysis were collected from all patients. The pedigrees of the examined Bengal cats were also investigated. RESULTS: Cataracts were diagnosed in 23 of 51 (45%) cats in the observational study and in all cats in the referral population, mostly bilaterally. Visual impairment was never reported. Age of subjects affected by cataracts ranged from 3 months to 9.6 years (median: 1.9 years). Cataracts were classified as nuclear cataracts (14 of 23 in the observational group and 12 of 12 in the referral group) with a focal, perinuclear, posterior, or complete nuclear pattern, or posterior polar subcapsular cataracts (10 of 23 only in the observational group). An inherited congenital origin appears to be the most likely hypothesis. The pedigree analysis suggests a hereditary component of cataract formation, but further analyses in a larger population or test matings are needed to determine the exact mode of inheritance. CONCLUSION: Presumed inherited cataracts appear to have a high prevalence in Bengal cats in France. The main manifestations are nuclear or subcapsular form, mostly bilateral, symmetrical, and apparently nonprogressive.

Effects of white light-emitting diode (LED) exposure on retinal pigment epithelium in vivo.

Ageing and alteration of the functions of the retinal pigment epithelium (RPE) are at the origin of lost of vision seen in age-related macular degeneration (AMD). The RPE is known to be vulnerable to high-energy blue light. The white light-emitting diodes (LED) commercially available have relatively high content of blue light, a feature that suggest that they could be deleterious for this retinal cell layer. The aim of our study was to investigate the effects of "white LED" exposure on RPE. For this, commercially available white LEDs were used for exposure experiments on Wistar rats. Immunohistochemical stain on RPE flat mount, transmission electron microscopy and Western blot were used to exam the RPE. LED-induced RPE damage was evaluated by studying oxidative stress, stress response pathways and cell death pathways as well as the integrity of the outer blood-retinal barrier (BRB). We show that white LED light caused structural alterations leading to the disruption of the outer blood-retinal barrier. We observed an increase in oxidized molecules, disturbance of basal autophagy and cell death by necrosis. We conclude that white LEDs induced strong damages in rat RPE characterized by the breakdown of the BRB and the induction of necrotic cell death.

Epidemiology and clinical presentation of canine cataracts in France: a retrospective study of 404 cases.

OBJECTIVE: To determine the epidemiology and the clinical presentation of cataracts in a population of dogs in France. PROCEDURES: Records of dogs affected by a cataract presented at the Ophthalmology Unit of Alfort Veterinary School during 2009-2012 were reviewed. The etiology was determined for each dog. The signalment of affected dogs, their medical history, age of onset, stage of progression, location of opacities, and ocular lesions associated were evaluated for each etiology. RESULTS: A total of 2739 dogs were presented at the Ophthalmology Unit from 2009 to 2012. Four hundred and four dogs (14.7%) (716 eyes) were diagnosed with a cataract. The population included 218 males (54%) and 185 females (46%). The gender was not recorded for one dog. The mean age (±SD) of all dogs affected by a cataract was 9 years (±3.9 years). Fifty-four breeds were represented. The Yorkshire Terrier was the only breed significantly overrepresented. The causes of cataracts observed were breed predisposition (28%), aging (22.8%), progressive retinal atrophy (12.4%), congenital cataract (5%), diabetes mellitus (4.7%), trauma (3.7%), uveitis (3%), and hypocalcemia (0.2%). In 20.3% of the cases, the etiology could not be determined. Ocular lesions associated with cataracts reported were lens luxation or subluxation (11.1%), glaucoma (3.7%), and retinal detachment (4.2%). CONCLUSIONS: In a French population of referred dogs, 14.7% were affected by a cataract. The main causes identified were breed predisposition, aging, and progressive retinal atrophy. A breed predisposition for the Yorkshire Terrier was recorded.

Scleral and corneal xanthomatous inflammation in a gray mouse lemur (Microcebus murinus).

Bilateral multifocal corneal opacity was detected in a 4.5-year-old male captive gray mouse lemur (Microcebus murinus) without other clinical ocular changes. Histopathological examination revealed a severe diffuse granulomatous scleritis and focal keratitis with intralesional cholesterol, consistent with xanthomatous inflammation. This is the first report of xanthomatous inflammation in a gray mouse lemur. This condition may be the result of systemic factors (lipid metabolism disorders) and/or local predisposing factors such as hemorrhage or inflammation. The pathogenesis in this case could not be fully determined. Further studies on lemurs are required for a better understanding of their lipid metabolism, as well as for diagnosing and evaluating the incidence of xanthomatous inflammation in these species.

A reverse genetic approach identifies an ancestral frameshift mutation in RP1 causing recessive progressive retinal degeneration in European cattle breeds.

BACKGROUND: Domestication and artificial selection have resulted in strong genetic drift, relaxation of purifying selection and accumulation of deleterious mutations. As a consequence, bovine breeds experience regular outbreaks of recessive genetic defects which might represent only the tip of the iceberg since their detection depends on the observation of affected animals with distinctive symptoms. Thus, recessive mutations resulting in embryonic mortality or in non-specific symptoms are likely to be missed. The increasing availability of whole-genome sequences has opened new research avenues such as reverse genetics for their investigation. Our aim was to characterize the genetic load of 15 European breeds using data from the 1000 bull genomes consortium and prove that widespread harmful mutations remain to be detected. RESULTS: We listed 2489 putative deleterious variants (in 1923 genes) segregating at a minimal frequency of 5 % in at least one of the breeds studied. Gene enrichment analysis showed major enrichment for genes related to nervous, visual and auditory systems, and moderate enrichment for genes related to cardiovascular and musculoskeletal systems. For verification purposes, we investigated the phenotypic consequences of a frameshift variant in the retinitis pigmentosa-1 gene segregating in several breeds and at a high frequency (27 %) in Normande cattle. As described in certain human patients, clinical and histological examination revealed that this mutation causes progressive degeneration of photoreceptors leading to complete blindness in homozygotes. We established that the deleterious allele was even more frequent in the Normande breed before 1975 (>40 %) and has been progressively counter-selected likely because of its associated negative effect on udder morphology. Finally, using identity-by-descent analysis we demonstrated that this mutation resulted from a unique ancestral event that dates back to ~2800 to 4000 years. CONCLUSIONS: We provide a list of mutations that likely represent a substantial part of the genetic load of domestication in European cattle. We demonstrate that they accumulated non-randomly and that genes related to cognition and sensory functions are particularly affected. Finally, we describe an ancestral deleterious variant segregating in different breeds causing progressive retinal degeneration and irreversible blindness in adult animals.

Keratomycosis in a pet rabbit (Oryctolagus cuniculus) treated with topical 1% terbinafine ointment.

This report describes the clinical presentation, diagnosis, and medical management of a 2-year-old spayed female dwarf rabbit (Oryctolagus cuniculus) suffering from an ulcerative keratitis and a stromal abscess with a rapid evolution. The diagnosis of fungal keratitis was based on fungal culture identifying the pathogen as Aspergillus fumigatus. Treatment by topical terbinafine was efficacious in resolving the keratomycosis within 8 weeks. To our knowledge, this is the first reported case of spontaneous keratomycosis in a rabbit and the first description of successful therapy by terbinafine.

Retinal damage induced by commercial light emitting diodes (LEDs).

Spectra of "white LEDs" are characterized by an intense emission in the blue region of the visible spectrum, absent in daylight spectra. This blue component and the high intensity of emission are the main sources of concern about the health risks of LEDs with respect to their toxicity to the eye and the retina. The aim of our study was to elucidate the role of blue light from LEDs in retinal damage. Commercially available white LEDs and four different blue LEDs (507, 473, 467, and 449nm) were used for exposure experiments on Wistar rats. Immunohistochemical stain, transmission electron microscopy, and Western blot were used to exam the retinas. We evaluated LED-induced retinal cell damage by studying oxidative stress, stress response pathways, and the identification of cell death pathways. LED light caused a state of suffering of the retina with oxidative damage and retinal injury. We observed a loss of photoreceptors and the activation of caspase-independent apoptosis, necroptosis, and necrosis. A wavelength dependence of the effects was observed. Phototoxicity of LEDs on the retina is characterized by a strong damage of photoreceptors and by the induction of necrosis.

Comparative evaluation of the prophylactic activity of a slow-release insecticide collar and a moxidectin spot-on formulation against Thelazia callipaeda infection in naturally exposed dogs in France.

BACKGROUND: The relative efficacy of a collar containing 10% imidacloprid and 4.5% flumethrin (Seresto, Bayer HealthCare Animal Health) and a spot on formulation containing 10% imidacloprid and 2.5% moxidectin (Advocate, Bayer HealthCare Animal Health) was evaluated as a control measure to prevent canine thelaziosis in dogs in an endemic area of France. FINDINGS: Ninety-six privately-owned dogs were enrolled in the multicentre, controlled study. Before summer (the period of transmission by fruit flies), dogs were allocated to one of three groups: Group A (n = 36)- treated once with a collar containing 10% imidacloprid and 4.5% flumethrin; Group B (n = 33)- treated every month for 8 months with a spot-on containing imidacloprid 10% and moxidectin 2.5%; and Group C (n = 27)- untreated control animals. Dogs were regularly subjected to ocular examination in order to assess Thelazia callipaeda infection. During the trial, T. callipaeda nematodes were detected in 12 (33%) collared dogs (group A) whereas no eyeworm could be found in dogs who received a monthly spot on application of moxidectin (group B). In the control group, 8 (30%) dogs became infected. CONCLUSIONS: The monthly application of a spot on formulation containing 10% imidacloprid and 2.5% moxidectin was shown to be highly effective in preventing T. callipaeda infection in a population of dogs living in an endemic area in France. On the contrary, the slow-release collar tested in this study did not display any protection against canine thelaziosis.

The activation of the atypical PKC zeta in light-induced retinal degeneration and its involvement in L-DNase II control.

Light-induced retinal degeneration is characterized by photoreceptor cell death. Many studies showed that photoreceptor demise is caspase-independent. In our laboratory we showed that leucocyte elastase inhibitor/LEI-derived DNase II (LEI/L-DNase II), a caspase-independent apoptotic pathway, is responsible for photoreceptor death. In this work, we investigated the activation of a pro-survival kinase, the protein kinase C (PKC) zeta. We show that light exposure induced PKC zeta activation. PKC zeta interacts with LEI/L-DNase II and controls its DNase activity by impairing its nuclear translocation. These results highlight the role of PKC zeta in retinal physiology and show that this kinase can control caspase-independent pathways.

A case of primary choroidal malignant melanoma in a cat.

This report describes the clinical presentation, diagnosis, histological lesions, and prognosis of a primary choroidal malignant melanoma in a 15-year-old cat. The animal was presented for unilateral blindness. On ocular examination, a raised pigmented mass protruding from the posterior pole into the vitreous body was observed by diffuse transillumination and indirect ophthalmoscopy. Ocular ultrasound and computer tomography (CT) scan confirmed localization of the tumor to the posterior segment. The diagnosis of primary choroidal melanoma was confirmed by histopathology after enucleation. To our knowledge, this is the first reported case of a feline malignant melanoma with a primary choroidal localization without iris involvement.

Light induced retinal degeneration activates a caspase-independent pathway involving cathepsin D.

Neuroprotection strategies in the retina aim at interference with regulatory mechanisms of cell death. To successfully target these mechanisms it is necessary to understand the molecular pathways activated in the degenerating retina. Induced retinal degeneration models, like the light damage model, give a synchronized response allowing their detailed investigation. In this study we exposed Fisher rats to a continuous white light. This induced a caspase-independent cell death in which the activation of cathepsin D has an important role via the activation of L-DNase II. Inhibition of this enzyme by intravitreal administration of pepstatin A protects photoreceptors indicating that this enzyme might be an interesting target for neuroprotection.

Congenital cataract in 1-day-old French Mulard ducklings.

Ocular opacity, associated with reluctance to move and inability to feed properly, was observed in approximately 1% of all newly hatched females from several related flocks of Mulard ducks. A 5-week follow-up study of 10 1-day-old affected females was performed, and they were compared with 10 control animals. Clinical, ocular and ultrasonographic examinations, and a complete necropsy of two animals per group with histological examination of the eye, were performed weekly. A bilateral immature cortical anterior cataract was diagnosed at ocular examination and confirmed by ultrasonography in affected ducks. Dyscoria was occasionally observed in affected animals. Severe cataract, with Morgagnian globules, severe anterior fibre liquefaction and disorganization were observed by photonic microscopy. No retinal or choroidal lesions were observed. No progression or repair of ultrasonographic and microscopic lesions could be detected during the 5 weeks of examination. The female predisposition for the ocular lesions suggests a congenital sex-linked recessive cataract.