Equine recurrent uveitis: A clinical manifestation of leptospirosis

Leptospirosis is a zoonosis of worldwide distribution affecting domestic animals, wildlife and man. The bacterial disease is caused by pathogenic Leptospira spp., which are transmitted from reservoir hosts to accidental hosts. Horses are accidental hosts and can become susceptible to leptospiral infections. Widespread exposure to leptospires exists and is significantly more common than clinical disease. Leptospirosis can have different clinical manifestations including abortion, still birth, systemic disease with hepatic or renal dysfunction, and equine recurrent uveitis (ERU). ERU is the most frequently encountered clinical manifestation and this article will focus on the review of leptospira‐associated ERU. Equine recurrent uveitis is the most common cause of vision impairment and blindness in horses. The pathogenesis of leptospira‐associated ERU involves direct bacterial effects and immune‐mediated responses. Clinical signs vary between the acute and chronic phases of the disease and progress over time. The diagnosis of leptospira‐associated ERU can be difficult and usually requires a combination of diagnostic tests. Medical and surgical treatments have been described with varying outcomes. The prognosis for sight is usually poor, although core vitrectomy may improve the outcome. Avoidance of leptospiral exposure of horses is the only reliable prevention of leptospira‐associated disease.     

Leptospirosis and panuveitis in a dog

A case of panuveitis as a result of leptospiral infection in an 8-year-old Jack Russell Terrier is reported. Mild hyphema, aqueous flare, and partial serous retinal detachments were noted in both eyes on initial ophthalmic examination. The serum microscopic agglutination testing for Leptospira serovarieties revealed titers of 1 : 12 800 for Leptospira canicola and 1 : 200 for Leptospira icterohemorrhagiae. With medical therapy, the panuveitis resolved and functional vision was regained. Four weeks after the initial presentation, convalescent titers were 1 : 200 for L. canicola and 1 : 100 for L. icterohemorrhagiae. The incidence of leptospirosis, along with difficulties diagnosing, and current medical therapies for this disease are also discussed.     

Stress induced expression of the angiotensinogen gene in rat anterior pituitary

AIM:To investigate the expression of angiotensinogen (ANG)mRNA and the changes of AngⅡ content in rat anterior pituitary during acute stress.METHODS:The expression of ANG mRNA was determined usingin situhybridization technique, and the AngⅡ content were determined by RIA.RESULTS:The ANG mRNA expression and AngⅡ content were significantly increased, and ANG mRNA was increased more significantly than AngⅡ content. CONCLUSION:The local renin-angiotensin system (RAS) in anterior pituitary is obviously activated during stress, which strongly supports the view that local RAS contributes to stress reaction.     

Bartonellosis in cats: a role in uveitis?

Bartonellosis has been widely studied in human and veterinary medicine over the past two decades. Despite this fact, it remains an enigmatic disease in many ways. The causative bacteria, Bartonella spp, are transmitted to cats by fleas and thus the prevalence in cat populations, particularly in temperate climates, is high. Most cats, whether infected naturally or experimentally, remain asymptomatic. Thus, correlating the presence of the organism to clinical disease, including uveitis, in cats has been difficult. This review summarizes what is known of the transmission and pathogenesis of Bartonella spp in cats, the possible role of the organism in feline ocular disease, as well methods of diagnosis and treatment.     

Anterior uveitis as an atypical presentation of large granular lymphoma in a caracal (Caracal caracal)

An 11-year-old, female, spayed caracal (Caracal caracal) presented with a 3-month history of intermittent anorexia, vomiting, and weight loss. At examination, bilateral anterior uveitis with anisocoria was present. Further examination under general anesthesia revealed the anterior chamber of the right eye contained copious amounts of thick fibrin, hypopyon, and hyphema obscuring the ventral pupil margin and ventral iris. Aqueous paracentesis revealed a cytologic diagnosis of large granular lymphoma. Additional antemortem diagnostics (computed tomography, ultrasound with fine needle aspiration, and cytology) confirmed the diagnosis of multicentric large granular lymphoma with associated intestinal perforation. Necropsy and histopathology confirmed multicentric large granular lymphoma in the right eye, jejunum, mesenteric lymph nodes, and right kidney. Large granular lymphoma in nondomestic felids is likely rare since it has not been previously reported, but should be considered as a differential in any felid species with anterior uveitis or when lymphoma is considered. In the case of this caracal, the use of aqueous paracentesis with cytology was a powerful diagnostic.     

Measurements of canine aqueous humor inflammatory mediators and the effect of carprofen following anterior chamber paracentesis

Objectives Phase I: To evaluate levels of prostaglandin E₂ (PGE₂), nitrites and nitrates (NO_x), tumor necrosis factor‐alpha (TNF‐α) and expression of inducible cyclo‐oxygenase (COX‐2), nitric oxide synthase (NOS‐2), and matrix metalloproteinases (MMP‐3 and ‐9) in canine aqueous humor following repeated anterior chamber paracenteses (ACP). Phase II: to evaluate the effect of carprofen on PGE₂, NO_x, and TNF‐α in canine aqueous humor following ACP. Animals studied Four beagles in phase I and 8 beagles in phase II. Procedures Phase I: ACP was performed at time (T) 0, 4 and 8 h. Phase II: A randomized, placebo‐controlled cross‐over design with four dogs per group where carprofen was given 4.4 mg/kg/day on day (D) 1, 2 and 3. ACP was performed at T0 and T1.5 on D3. Statistical analysis was performed with repeated measures anova and post hoc Tukey‐Kramer multiple‐comparison procedure. In phase II, TNF‐α level was analyzed with a Wilcoxon signed‐rank test. Results Phase I: PGE₂ significantly increased (P < 0.0001) to plateau at T4. NO_X was decreased at T4 (P < 0.06), but increased at T8 (P < 0.0001). COX‐2 showed detectable expression only at T8. TNF‐α, NOS‐2, MMP‐3 and ‐9 were undetectable at all time points. Phase II: At T1.5, PGE₂ was significantly elevated in both groups but was lower in the carprofen group (P = 0.037). NO_x and TNF‐α did not statistically increase in either group. Conclusions Following ACP, significant increases in PGE₂ levels confirmed inflammation characterized by a rise of COX‐2. The NO_x pathway took longer to induce as compared with PGE₂. Carprofen decreased PGE₂ levels and could help control intraocular inflammation.     

Normal corneal thickness measurements in pigmented rabbits using spectral‐domain anterior segment optical coherence tomography

Objective  To document the thickness of the central cornea in pigmented rabbits using spectral‐domain anterior segment optical coherence tomography (AS‐OCT). Animals studied  Seventeen pigmented rabbits (6 male, 11 female, both eyes) were involved in this study. Procedures  Thirty‐four eyes from healthy pigmented rabbits underwent a complete ophthalmologic examination, including AS‐OCT. Eight radial scans, 6 mm in length and centered on the cornea, were obtained using the AS‐OCT. Corneal thickness was automatically calculated using pachymetry software. Measurements were displayed as the mean and standard deviation for each of the 17 regions defined by the software. The regions were the center (1 mm radius, area a), the inner ring (2.5 mm radius, area b), the outer ring (3 mm radius, area c), and the eight radial scan lines in eight directions (Superior (1), SN (2), Nasal (3), IN (4), Inferior (5), IT (6), Temporal (7), ST (8)) with an angle of 45° between each consecutive scan line (a, b 1–8, c 1–8). Results  There was no statistically significance difference in corneal thickness between gender, eye, and the eight directions (P = 0.804, P > 0.05, P > 0.05). There was a statistical difference between the thickness in areas a, b, and c (P < 0.05). The corneal thickness increased gradually from the center to the periphery of the 6 mm measured. The center corneal thickness was 387 ± 19.8 μm for OD and 384 ± 20.2 μm for OS. The corneal thicknesses of the thinnest point of the right eyes (OD) and the left eyes (OS) were 376 ± 20.2 and 370 ± 16.8 μm, respectively. There was positive correlation between the thinnest point and area a in both the right eyes (r = 0.892, P < 0.001) and the left eyes (r = 0.832, P < 0.001). Conclusions  This is the first documentation of the rabbit corneal thickness in vivo using the spectral‐domain AS‐OCT. Pigmented rabbit corneas were almost 150 μm thinner than human corneal values. Gender and eye were not associated with any statistical differences in central corneal thickness in this study.