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A 9.5-year-old, male castrated European Short-haired (ESH) cat was presented with bilateral glaucoma associated with pectinate ligament dysplasia and an open iridocorneal angle (ICA) upon gonioscopy. The right eye (OD) was avisual and slightly enlarged; the left eye (OS) was still visual. Intraocular pressure (IOP) had been controlled with medical therapy over a 1.5 year-period in both eyes (OU). Eventually IOP could not be adequately controlled medically and the painful and blind right eye was enucleated and transscleral diode laser cyclophotocoagulation was performed twice in the left eye with less than optimal results and progressive loss of vision. Histopathology of the right eye showed goniodysgenesis characterized by failure of differentiation of the pectinate ligament, which existed as a solid sheet of uveal tissue at the entrance of a hypoplastic ciliary cleft, which contained loose mucoid mesenchymal tissue. The trabecular meshwork was hypoplastic and the scleral venous plexus could not be identified. Other findings of chronic glaucoma were inner retinal atrophy, optic nerve atrophy with disc cupping, scleral thinning, peripheral corneal vascularization and pigmentation, and mild focal iridal mononuclear inflammatory cell infiltrate.

Glaucoma and inherited retinal degeneration/dystrophy are leading causes of blindness in veterinary patients. Currently, there is no treatment for the loss of vision that characterizes both groups of diseases. However, this reality may soon change as recent advances in understanding of the disease processes allow researchers to develop new therapies aimed at preventing blindness and restoring vision to blind patients. Elucidating the molecular mechanisms of retinal ganglion cell death in glaucoma patients has led to the development of neuroprotective drugs which protect retinal cells and their function from the disastrous effects of elevated pressure. Identification of the genetic mutation responsible for inherited degenerations and dystrophies of the outer retina has enabled researchers using gene therapy to restore vision to blind dogs. Other patients may benefit from retinal transplantation, stem cell therapy, neuroprotective drugs, nutritional supplementation and even retinal prostheses. It is possible that soon it will be possible to restore sight to some blind patients.

The rehabilitation and release of injured or ill raptors and owls is widespread. The overall aim of this intervention is the successful reintroduction of the bird into the wild population. Though many injuries are treatable, it is thought that vision-impaired birds have no change of survival and their release is refused. Here we report a case study and give a description of the rehabilitation and subsequent release of an injured Eagle Owl (Bubo bubo). The bird was found with an injured eye and a paralysed wing in the district of Soest, North Rhine-Westphalia, Germany. While the paralysis healed, the bird stayed blind in one eye. Nevertheless it was released with a radio-transmitter. The female Eagle Owl could be followed by radio-telemetry for more than half a year after release, by visual and acoustic skills for a full year after release. Although the female was only two years old, it paired successful with a partner, and raised a brood with three offspring. No differences in the behaviour compared to non-handicapped birds could be detected. This one-eyed Eagle Owl demonstrates not only survival, but also successful reproduction following reintegration into the wild population. However, low intraspecific competition in the area might have contributed to the reproductive success of the owl.

The emergency clinician is frequently in the position of receiving, evaluating, and initiating treatment on horses with ophthalmic emergencies or orbital trauma. In the best of circumstances, an ophthalmologist is available to guide initial therapy and ultimately assume responsibility for the management of the patient during the remainder of its hospitalization, but this is not always the case. The information presented here is meant to provide the emergency clinician with basic guidelines for the initial assessment and management of horses sustaining ocular injuries or presented with an ophthalmic emergency. The article provides initial information regarding prognosis, descriptions of indicated diagnostics and procedures that may need to be performed on an emergency basis, and suggestions regarding early therapy. Whenever possible, the management of such cases should be overseen or assumed by a veterinary ophthalmologist after the emergent stabilization of the patient.

A 3-year-old, intact male, mixed breed dog was presented with a complaint of acute blindness. Ten days previously, the area where the dog was walking came under a rocket attack, and a rocket landed and exploded 300 meters away from the dog. Physical examination was unremarkable. Ophthalmoscopic examination revealed posterior segment fibrin clots and extensive vitreal hemorrhage in the right eye. A total retinal detachment (360 degrees retinal dialysis) with no evidence of hemorrhage was noted in the left eye. There was no sign of any penetrating ocular trauma, and it was assumed that the posterior segment findings were primary injuries caused by the blast wave itself. Following anti-inflammatory treatment, partial vision was restored in the right eye. Surgical re-attachment of the retina was discussed and declined by the owner. This report describes, for the first time, vitreal hemorrhage and retinal detachment as the sole injuries caused by an explosive blast wave.

Lymphoma is reported to be the most common nasal and second most common intracranial neoplasm in cats. Intracranial lymphoma may occur as a primary central nervous system lymphoma or as part of multi-centric disease. Two cats were presented with histopathologically confirmed nasopharyngeal lymphoma and concurrent mass within the middle fossa of the cranial cavity, with magnetic resonance imaging suggestive of direct communication. Both cats demonstrated evidence of bilateral oculomotor nerve deficits and upper respiratory tract noise. In one cat, bilateral optic nerve deficits were also present. The magnetic resonance imaging features were similar in both cases and demonstrated a contrast-enhancing intracranial mass on the ventral aspect of the middle fossa of the cranial cavity and an adjacent mass arising from the dorsal aspect of the nasopharynx. Lymphoma should be included as an important differential diagnosis in cats presented with middle cranial fossa syndrome (in particular ophthalmoplegia) and stertor.

Purpose: To perform ocular motility recordings of infantile nystagmus (IN) in RPE65-deficient canines and determine whether they can be used as a motor indicator of restored retinal function to investigate the effects of gene therapy., Methods: Treated and untreated canines were comfortably suspended in a custom-built sling and encouraged to fixate on distant targets at gaze angles varying between +/-15 degrees horizontally and +/-10 degrees vertically. Ocular motility recordings were made, using two distinct methods-infrared reflection and high-speed video. The resultant recordings from three untreated, four treated, and three pre- and post-treatment dogs were analyzed for using the eXpanded Nystagmus Acuity Function (NAFX), which yields an objective assessment of best potential visual acuity, based on the duration and repeatable accuracy of foveation and centralisation., Results: During fixation, the untreated dogs exhibited large-amplitude, classic IN waveforms, including pendular and jerk in both the horizontal and vertical planes, which prevented them from keeping the targets within the area centralis (the region of highest receptor density, spanning +/-3 degrees horizontally by +/-1.5 degrees vertically, analogous to the fovea). Some untreated dogs also had small-amplitude (0.5-1 degrees), high-frequency (6-9 Hz) oscillations. Under the same conditions, successfully treated canines no longer exhibited clinically detectable IN. Their IN was converted to waveforms with very low amplitudes that yielded higher NAFX values and allowed target images to remain well within the area centralis. Of note, uniocular treatment appeared to damp the IN in both eyes. Behaviorally, the treated dogs were able to successfully navigate through obstacles more easily without inadvertent contact, a task beyond the untreated dogs' ability., Conclusions: Gene therapy that successfully restored retinal function also reduced the accompanying IN to such a great extent that it was not clinically detectable approximately 90% of the time in many of the dogs. IN improvement, as quantified by the NAFX, is an objective motor indicator of visual improvement due to gene therapy.

Objective: To compare client perception of outcome of phacoemulsification in dogs with information obtained from medical records., Design: Retrospective cohort study., Animals: 108 dogs (203 eyes) undergoing phacoemulsification from May 1999 through April 2004., Procedure: Data obtained from medical records included signalment, presence of diabetes mellitus, cataract stage, whether surgery was unilateral or bilateral, intraocular lens (IOL) placement, and postoperative complications. Owners completed a survey concerning outcome of phacoemulsification in their dog. Survey responses from owners classified as satisfied or dissatisfied with the outcome of phacoemulsification on the basis of their willingness, in retrospect, to have the surgery performed again were compared., Results: Data from medical records and survey responses were available for 108 dogs (203 eyes). Median follow-up was 3 months via medical record review and 12 months via owner survey responses. Most (81%) owners were satisfied with outcome. The most common reason for dissatisfaction was loss of vision after surgery; however, most dissatisfied owners did not return their dog for examinations. Owner perception of success was not associated with patient age, sex, presence of diabetes mellitus, cataract stage, or IOL placement in at least 1 eye but was associated with perceived improvement of their pet's vision and activity level. Dissatisfied owners were significantly more likely to report that explanation of risks and complications before surgery was inadequate., Conclusions and Clinical Relevance: Owner perception of outcome after phacoemulsification in dogs was highly favorable. However, surgical risks and the importance of postoperative examinations, particularly in dogs undergoing visual deterioration, must be conveyed to clients.

A 14-year-old, spayed female Cocker Spaniel was presented to the Boren Veterinary Medical Teaching Hospital at Oklahoma State University with acute loss of vision in the right eye and a history of intermittent bloody diarrhea of unknown duration. Small, white, plaque-like lesions in the retina and subretina were visualized by direct ophthalmic examination, and aspirated with ultrasound-guidance. A direct smear of the subretinal fluid was highly cellular and contained large numbers of pleomorphic organisms consistent with Prototheca sp. The structures were round, oval, or elongated, 4-6 microm width and 8-16 microm in length and surrounded by a thin, clear cell wall. Small, central, pink to purple nuclei were observed in some organisms, but in most, the nuclei were obscured by a deeply basophilic, granular cytoplasm. Some organisms contained endospores. Negatively-stained structures of similar size and shape were considered to be empty casings (theca) of ruptured sporulating and nonsporulating forms of the organism. Protothecosis usually is a disseminated, fatal disease in dogs. The Prototheca organisms observed in this case showed characteristic morphology, illustrating the ability to diagnose protothecosis in cytologic samples.

A 9-week-old miniature mule foal presented to the Veterinary Medical Teaching Hospital for acute blindness, ataxia, and depression following an overdose of an over-the-counter ivermectin-based de-worming medication. Ophthalmic examination and electrodiagnostic evaluation eliminated outer retinal abnormalities as the primary cause of the bilateral blindness, implicating instead a central neurologic effect of the drug. With symptomatic and supportive care, the foal recovered fully and regained its vision.

Objective: To characterize the clinical and morphologic aspects of aqueous humor misdirection syndrome (AHMS) in cats and provide a hypothesis regarding its pathogenesis on the basis of detailed analysis of affected cats., Design: Retrospective study., Animals: 32 cats (40 eyes)., Procedure: Medical records of cats in which AHMS was diagnosed from July 1997 to August 2003 were reviewed. In certain cats, results of additional diagnostic testing were also obtained, including A-scan, B-scan, and high-resolution ultrasonography; streak retinoscopy; video keratometry; and infrared neutralizing videoretinoscopy as well as results of analysis of flash-frozen sections and histologic examination of enucleated globes., Results: Cats had a uniformly shallow anterior chamber, intact lens zonules, and a narrowed approach to an open iridocorneal angle. Mean age of affected cats was 11.7 years (range, 4 to 16 years), and female cats were significantly more often affected than male cats. Clinical signs included mydriasis, decreased pupillary light reflex, decreased menace response, and blindness. Glaucomatous changes to the optic nerve, incipient cataracts, and eventual blindness were seen. Intraocular pressure was > or = 20 mm Hg (range, 12 to 58 mm Hg) in 32 of 40 eyes. Ultrasonography and histologic examination revealed a thickened anterior vitreal face interposed between the lens and ciliary body, partial ciliary cleft collapse, and cavitated vitreal regions. Various treatment modalities were used., Conclusions and Clinical Relevance: AHMS affects older cats, especially females, and may result in glaucoma, vision loss, and signs of ocular pain. Topical administration of carbonic anhydrase inhibitors decreased intraocular pressure.

Prior to this study, it was believed that epigean and hypogean Astyanax differ markedly in their display of agonistic behavior. Research suggested that surface-dwelling individuals were extremely aggressive whereas their blind, cave-dwelling counterparts tended to show little or no aggressive behavior. Aggression in Astyanax was thought to be triggered by visual stimuli because surface fish in a dark environment or surface fish blinded late in life did not show aggression. Here, we demonstrate that surface fish blinded early on in their embryonic development are highly aggressive as adults. We also report the first case of a population of blind cave-dwelling Astyanax that is highly aggressive. We conclude that reduced aggression is not the only evolutionary pathway for troglobitic Astyanax and that there is some degree of developmental plasticity in the releaser of aggression and in the selection of its triggering stimuli.

A young, partially blind Holstein steer was affected by mild cerebral atrophy. Formalin-fixed cerebral gray matter was diffusely yellow brown. Microscopically, there were eosinophilic, autofluorescent granules primarily in the cytoplasm of cerebral neurons. There was also extensive retinal atrophy with complete loss of the rod and cone layers. Ultrastructural examination of affected cerebral neurons revealed a mixture of granular osmiophilic and lamellar patterns in the cytoplasmic storage bodies. This suggests the existence of neuronal ceroid-lipofuscinosis in the Holstein breed.

Equine recurrent uveitis (ERU) is one of the most common causes of blindness in horses. Until recently, treatment of this condition consisted only of symptomatic therapy, typically with steroidal and nonsteroidal medications. A better understanding of the disease process(es) has permitted new medical and surgical therapies that have recently been described. This article highlights clinical features of ERU, the causes of ERU, and new management and treatment options for horses with ERU.

Effects of traumatic injury or inflammation on the equine eye can be catastrophic. These ocular conditions can frequently result in blindness or chronic pain. In addition to blindness and pain, permanent unsightly cosmetic defects can occur. This article addresses options available for improved cosmetic outcome in horses with ocular scars or requiring enucleation. Many of these options have been described in detail previously. New information has been added to the discussion of each option where pertinent.

Two 12-week-old Tippler pigeons were evaluated for ocular abnormalities associated with congenital blindness. The pigeons were emaciated and blind. Biomicroscopy and direct and indirect ophthalmoscopy findings of the Tippler pigeons were normal with the exception of partially dilated pupils at rest. Scotopic (blue stimuli) and photopic monocular electroretinograms were extinguished in the blind Tippler pigeons. Histological and electron microscopy studies revealed reduced numbers of rods and cones, and an absence of the double cone complex. The photoreceptor cells' outer segments were absent, and the inner segments were short and broad. The number of cell nuclei in the outer and inner nuclear layers was decreased, and the internal and external plexiform layers were reduced in width. Photoreceptor cell endfeet with developing synaptic ribbons were present in the external plexiform layer. Inflammatory cell and subretinal debris was not seen. The electroretinographic, histopathological, and ultrastructural findings of the blind Tippler pigeons support the diagnosis of a photoreceptor cell dysplasia.

A male mixed breed dog of unknown age was presented with sudden onset of blindness and a slightly exophthalmic right eye. Ophthalmoscopically, a spherical, pinkish mass protruding from the region of the optic disc into the vitreous was seen in the right eye. Ultrasound and computer tomography demonstrated an extension of the mass into the right retrobulbar space, continuing intracranially to the optic chiasm. Cytologic findings, obtained by ultrasound-guided fine needle aspiration from the retrobulbar space, were consistent with myxosarcoma. On the basis of these findings of a well-delineated mass in the brain stem area, irradiation was planned as the therapy of choice. The dog was treated under general anesthesia using a proton beam at the Paul Scherrer Institute (PSI, Villigen, Switzerland). A curative protocol (56 Gy in 16 fractions over 4 weeks, 3.5 Gy/fraction) was used. Twenty-seven days post radiation therapy the dog was euthanized, as clinical symptoms progressed. Enlargement of the intracranial tumor was seen on a CT study repeated on the day of euthanasia. A gross pathologic and histologic examination were performed and confirmed the diagnosis of a myxosarcoma involving the eye, retrobulbar space of the right side, and the optic chiasm. Post-mortem examination failed to identify any abnormalities or metastases elsewhere in the body.

A 11.5-yr-old female Przewalski's wild horse (Equus caballus przewalskii) presented for unilateral blepharitis and drainage from the left eye. The left cornea was not ulcerated, and intraocular evaluation was hampered by severe corneal edema. The left eye appeared to respond positively to treatment with anti-inflammatories and a topical mydriatic agent. During the ensuing 2 yr, there were minor episodes of epiphora from the left eye. The discharge then increased, and a luxated lens was noted during an examination by a veterinary ophthalmologist as part of the preshipment examination. Initially, the lens was located in the anterior compartment but was in the vitreal compartment at the time of surgery, complicating the intracapsular extraction. After successful removal of the lens, the horse was transferred to a new institution without incident, where it appears to have adapted well to its probable loss of vision in the left eye. No further episodes of uveitis, corneal edema, or epiphora have been reported, and the horse has successfully foaled at the new institution.

Purpose: To identify the locus responsible for rge (retinopathy globe enlarged) in chickens and further characterise the rge phenotype., Methods: A colony of chickens carrying the rge mutation was rederived from a single heterozygous animal of the original line. The eyes of blind, heterozygous and normal birds were subjected to ophthalmic, morphometric and histopathological examination to confirm and extend published observations. DNA samples were obtained and subjected to a whole genome linkage search., Results: From 138 classified backcross progeny, 56 birds were blind and 82 sighted. Heterozygous birds were indistinguishable from wild type, but homozygotes had sluggish or unresponsive pupils, posterior sub-capsular lens opacities and an atrophic pecten. The fundus appeared normal with no significant pigmentary disturbance, but axial length and eye weight were increased. Pathology revealed focal retinal lesions. Linkage analysis placed the rge locus in a small region of chicken chromosome 1., Conclusions: rge is a severe recessive retinal dystrophy in chickens, with associated globe enlargement. Linkage mapping has highlighted chicken chromosome 1 in a region most probably homologous to human chromosomes 7q31-35, 21q21 or 22q12-21. Candidate disease loci include RP10 (IMPDH1) and uncharacterised Ushers (USH1E) and glaucoma (GLC1F) loci.

Thirty-three live 9-day-old broiler chicks were submitted for laboratory evaluation because of blindness. Blindness was observed in up to 1% of 25,000 birds from four different houses. All the chicks were from the same breeder source. Blindness was apparent when the chicks were 2-3 days old. Clinically, the blind chicks were smaller than their counterparts, were unable to find feed and water, and wandered aimlessly. Necropsy did not reveal any lesions. Two chicks examined clinically at 14 days of age lacked pupillary reflexes after light stimulation, and the anterior and posterior segments of the eye were normal. Microscopically, degeneration of photoreceptor cells characterized by vacuoles was evident at 9 days of age, and rosette formation of the retina, disorganization of retinal layers, synechia of the retina with mild inflammation in the choroid, and proliferation of the retinal pigment epithelial cells were evident by 15 days of age. Because the chicks came from the same breeder source and the incidence of blindness was low, a probable genetic etiology is suspected as the cause of blindness in this flock.

An 8-year-old, castrated male Domestic Short-haired cat was referred for evaluation of a possible intraocular neoplasm following previous ocular trauma. The eye was blind, and uveitis and an iridal mass were noted on examination. An enucleation was performed and the mandibular lymph node excised. Histopathologic examination revealed neoplastic proliferation of plasma cells in the iris and lymph node. No other evidence of disseminated disease was detected. This is the first case reported of an intraocular extramedullary plasmacytoma in the cat. The variation in clinical manifestations and potential association with multiple myeloma are not known at this time. Disseminated metastasis from a primary plasmacytoma of the uveal tract could also involve the bone marrow and be indistinguishable from multiple myeloma. Early enucleation, as in trauma-associated sarcomas, may be indicated to prevent metastasis. Periodic systemic evaluation for evidence of multiple myeloma should be performed.

A two-year-old, female chihuahua presented with a six-month history of visual dysfunction. Computed tomography revealed dilation of the lateral ventricles in the central nervous system (CNS). The dog was tentatively diagnosed as having hydrocephalus and a month later was euthanased at the owner's request. The skull was expanded and dome-like in shape and an open fontanelle was observed on postmortem examination. Histologically, swollen neurons possessing yellowish pigment granules in the cytoplasm were observed throughout the CNS. These storage materials stained positively with periodic acid Schiff, Schmorl method for lipofuscin and oil red O for lipid, and showed autofluorescence under fluorescence microscopy. Ultrastructurally, the storage materials consisted of dense lamellar structures. This case was unique in having ceroid-lipofuscinosis in association with hydrocephalus.

A 12-year-old cat presented for sudden blindness was diagnosed with hypertensive retinopathy on the basis of ophthalmologic and ultrasonic examination. Renal failure due to a large intranephric cyst obstructing the right ureter and renal artery was the suggested cause of the systemic hypertension. The cat died 8 hours after unilateral nephrectomy.

Although the exact mechanism of fluoroquinolone-induced retinal degeneration in cats remains to be elucidated, it appears from the literature that a similar retinal degeneration can be reproduced from either direct intravitreal injection of high concentrations of drug or exposure to UVA light and drug in laboratory animals. (19,25) The fluoroquinolone molecular structure is also similar structurally to other drugs that are known to directly induce retinal degeneration, including the cinchona alkaloids and halogenated hydroquinolones. Experimental evidence suggests that both the parent compound and its breakdown products via metabolism and photodegradation are active inducers of retinal degeneration. (18,25) Development of toxicoses also appears to be dependent on the maximum concentration of active drug, metabolite, or both reaching the retina over time. (18) Evaluation of the literature suggests that risk factors predisposing cats to fluoroquinolone-induced retinal degeneration may include the following: 1) large doses or plasma concentrations of drug, 2) rapid IV infusion of the antibiotic, 3) prolonged courses of treatment, and 4) age. Theoretically, other risk factors may also be involved including the following: 1) prolonged exposure to UVA light while the antibiotic is being administered, 2) drug interactions, and 3) drug or metabolite accumulation from altered metabolism or reduced elimination. To date, there are no published reports suggesting that the dose of fluoroquinolones should be reduced in geriatric cats or those with renal or hepatic failure. However, accumulation of fluoroquinolone metabolites in dogs and of the parent compound in humans with decreased renal function has been reported. (8-10) In humans with decreased renal function has been reported. (8-10) humans, fluoroquinolone doses are typically decreased in response to the degree of renal impairment. (28) In general, all fluoroquinolone antibiotics should be reserved for severe or recurrent infections, and whenever possible their use should be based on results whenever possible their use should be based on results of culture and susceptibility tests. When indicated, the fluoroquinolones, including enrofloxacin, can be used with limited risk of developing retinal degeneration in cats, provided the manufacturer's guidelines are adhered to and dose reduction is considered in geriatric cats or those with renal impairment. Dosing on renal impairment. Dosing on exact body weight using split dosing (2.5 mg/kg, PO, q 12 h) and avoidance of rapid IV infusions, and drug interactions may help to reduce the risk of retinal degeneration in some cases. Furthermore, monitoring cats for mydriasis and avoidance of UVA light while undergoing treatment may also be of benefit. Further evaluation of the pharmacokinetics of enrofloxacin and the other fluoroquinolones is required in geriatric cats or those with mild to moderate renal or liver impairment to determine whether drug accumulation, elevated peak concentrations of drug, or both may be occurring in this subset of cats. Therapeutic monitoring of drug concentrations may not always be feasible because of time and cost, but renal panels with dose or frequency reduction in response to the degree of renal impairment and the site and severity of infection may help to reduce retinal toxicosis.

There have been major advances in the canine genome map over recent years, with an agreed karyotype for all 38 pairs of autosomes and an integrated linkage-radiation-hybrid map now available. An individual dog breed represents a closed, isolated population, and many suffer genetic diseases. Some are homologs of human conditions, and dogs represent naturally occurring, potentially useful large mammal models. Other conditions may be unique to this species, but study of these offers new insights into metabolic pathways. Linkage analysis may identify a locus linked to a particular condition. Dog pedigrees facilitate these studies by being relatively more informative than human families, although planned breeding strategies to maximize the informativeness may be required. A study of a late-onset, acquired heart disease, dilated cardiomyopathy (DCM), in Newfoundland dogs highlights some of the problems. The disease occurs naturally in pedigrees within the UK in dogs kept as pets and breeding stock. Problems encountered include confirmation of the mode of inheritance and determination of phenotype. A genome-wide linkage analysis study with over 200 markers failed to detect linkage. The study indicates that more detailed linkage maps are required, and further synteny information between dog and human gained before study of diseases affecting naturally occurring families of dogs from inbred pedigrees may have maximal chance of success in order to utilize this model.

A 15-year-old female collared peccary (Tayassu tajacu) was presented for ophthalmic examination following sudden onset of blindness. Bilateral retinal detachment was diagnosed, neoplasia suspected, and euthanasia performed. Widespread tumor dissemination was apparent at autopsy, and transitional cell carcinoma was diagnosed histologically. The tumor was identified as arising from the ovary. Epidemiologic features of this case are discussed.

Purpose: The exon-intron structure of the canine Phosducin (PDC) gene was identified and the gene evaluated as a candidate for generalized progressive retinal atrophy (gPRA) in 20 dog breeds., Methods: Intronic sequences of the PDC gene were analyzed after amplification using polymerase chain reaction (PCR) and following sequencing from clones isolated from a canine genomic library. Mutation screening was performed by PCR with single strand conformation polymorphism (SSCP) analysis. Conspicuous banding patterns were analyzed via sequence analyses to detect the underlying nucleotide variations., Results: No polymorphisms were identified after PCR-SSCP analysis within the entire coding region of the PDC gene. A 3 bp deletion in intron intervening sequence (IVS) 3 (position -16 to -18) was observed in 9 breeds, a T->A transversion (position IVS3 -63) in 10 breeds and an A->T transversion (position IVS3 -64) in 2 dog breeds. CONCLUSIONS PDC was excluded as a candidate gene for autosomal recessively (ar) transmitted gPRA in 11 of the 20 dog breeds investigated.

Toxoplasma gondii affects most species of warm-blooded animals, including birds. There is considerable confusion regarding the identity of T. gondii-like parasites and the diagnosis of toxoplasmosis in wild birds. In this review, T. gondii-like infections in different species of wild birds are reviewed with particular reference to prevalences, clinical signs, pathology, diagnosis, and treatment. Although subclinical T. gondii infections are prevalent in many avian species, toxoplasmosis can be clinically severe in pigeons and canaries. Blindness associated with T. gondii in canaries is reviewed in detail.

The clinical work-up, diagnosis and follow-up of an 8-year-old, female-spayed Shih Tzu with diffuse, granulomatous meningoencephalomyelitis (GME)-causing visual deficits is reported. The use of cytosine arabinoside as an alternative treatment for GME is discussed.