Bilateral Phacoemulsification in an African Elephant (Loxodonta africana).

A 37-year-old bull African elephant (Loxodonta africana) at the North Carolina Zoo (NCZ) was diagnosed with bilateral cataracts leading to behavioral changes and significant weight loss secondary to functional blindness. On initial examination, a weight loss of 234 kg, a mature cataract in the right eye, and a focal cataract in the left eye were diagnosed. Ultrasound and electroretinography (ERG) indicated normal retinal attachment and both eyes were viable candidates for surgery. After careful planning and behavioral training, the left cataract was surgically removed via phacoemulsification and irrigation/aspiration. The right eye subsequently developed a ventral lens subluxation, and phacoemulsification and irrigation/aspiration were performed six months after the first procedure. Four years after surgery, menace response, palpebral reflex, dazzle reflex, and pupillary light reflexes were present in both eyes. Body weight was 5,515 kg, 88kg more than at the time of the second surgery. This is the first published report of an African bull elephant undergoing bilateral cataract removal using phacoemulsification and irrigation/aspiration. The lack of significant postoperative inflammation and uneventful recovery of the elephant suggests that this surgical procedure along with proper preoperative planning and postoperative medical management can be a safe and effective treatment option for elephants with cataracts.

Histopathological features of equine superficial, nonhealing, corneal ulcers.

OBJECTIVE: To evaluate corneal changes associated with chronic, nonhealing, superficial, corneal ulcers in horses via common histopathological stains. DESIGN: Retrospective study. ANIMALS: Twenty-four horses diagnosed with chronic, nonhealing, superficial, corneal ulceration. METHODS: The medical records of horses evaluated at North Carolina State University's Veterinary Teaching Hospital (NCSU-VTH) from 2005 to 2011, diagnosed with a chronic, nonhealing, superficial, corneal ulcer and treated with superficial keratectomy (SK) were reviewed. Inclusion criteria were superficial corneal ulceration, no cellular infiltration via slit-lamp biomicroscopy, no microorganisms evident on corneal cytology, and acquisition of samples for aerobic bacterial and common fungal cultures. Corneal tissue samples were evaluated histopathologically for the presence or absence of a nonadherent epithelial 'lip', epithelial dysmaturity, intraepithelial inflammatory cells, an acellular hyaline zone in the anterior stroma, and stromal inflammatory cells, fibrosis and vascularization. RESULTS: In the majority of analyzed samples, epithelial cells adjacent to the ulcerated site showed nonadherence to the basement membrane and dysmaturity. Intraepithelial inflammatory cell infiltration was uncommon. Histopathological features of an anterior stromal hyaline zone, intrastromal inflammation, fibrosis and vascularization were variably present. CONCLUSIONS: The most consistent histopathological characteristics of equine chronic, nonhealing, superficial, corneal ulcers include epithelial nonadherence, epithelial dysmaturity and mild to moderate stromal inflammation; however, one set of histopathological characteristics does not definitively define this syndrome in horses. Additionally, the anterior stromal acellular hyaline zone commonly cited in canine spontaneous chronic corneal epithelial defects (SCCED) is not a consistent finding in equine corneas.

Treatment of immune-mediated keratitis in horses with episcleral silicone matrix cyclosporine delivery devices.

PURPOSE: To describe the use of episcleral silicone matrix cyclosporine (ESMC) drug delivery devices in horses with immune-mediated keratitis (IMMK) with evaluation of tolerability and efficacy in long-term control of inflammation. METHODS: Retrospective study. ESMC implants (1.2 cm length, 30% wt/wt cyclosporine (CsA) in silicone; with approximately 2 µg/day steady-state release for at least 400 days) were used. RESULTS: Nineteen horses (20 eyes) received two or more ESMC implants for superficial stromal (n = 9), midstromal (n = 3), or endothelial (n = 5) IMMK. Three additional horses received two or more ESMC implants for pigmentary keratouveitis (PK). Nine eyes of eight horses with superficial and five eyes of five horses with endothelial IMMK were well controlled after placement of ESMC implants (mean follow-up 176.8 and 207.2 days, respectively). Horses with midstromal IMMK and PK were not controlled with ESMC implants alone, but instead required frequent use of other medications or surgery to control the disease. The mean duration of disease prior to ESMC implantation of horses with midstromal IMMK was 495 ± 203.9 days, compared with 121.6 ± 92.7 days with superficial IMMK. ESMC implants were well tolerated by all horses without documented loss of the device. CONCLUSIONS: Results from this preliminary retrospective study suggest that the ESMC implants were well tolerated and associated with treatment success with superficial and endothelial IMMK, especially if placed early in the disease process. Further study is needed to determine the duration of efficacy, number of implants required, and better therapies for chronic midstromal IMMK and pigmentary keratouveitis.

Evaluation of the effects of tricaine methanesulfonate on retinal structure and function in koi carp (Cyprinus carpio).

OBJECTIVE: To determine whether repeated exposure to clinically relevant concentrations of tricaine methanesulfonate (MS-222) would alter retinal function or induce histologically detectable retinal lesions in koi carp (Cyprinus carpio). DESIGN: Prospective, controlled, experimental study. ANIMALS: 18 healthy koi carp. PROCEDURES: 2 fish were euthanized at the start of the study, and eyes were submitted for histologic evaluation as untreated controls. Anesthesia was induced in the remaining fish with 200 mg of MS-222/L and maintained with concentrations of 125 to 150 mg/L for a total exposure time of 20 minutes daily on 1 to 13 consecutive days. On days 1, 7, and 13, electroretinography of both eyes was performed in all fish remaining in the study, and 2 fish were euthanized immediately after each procedure for histologic evaluation of the eyes. Median b-wave amplitudes were compared among study days for right eyes and for left eyes via 1-way repeated-measures ANOVA with a Bonferroni correction for multiple comparisons. RESULTS: Median b-wave amplitudes on days 1, 7, and 13 were 17.7, 20.9, and 17.6 µV, respectively, for right eyes and 15.1, 16.9, and 14.3 µV, respectively, for left eyes. No significant differences in b-wave amplitudes were detected among study days. No histopathologic abnormalities were identified in the retinas of any fish treated with MS-222 or in control fish. CONCLUSIONS AND CLINICAL RELEVANCE: Short-term exposure of koi carp to clinically relevant concentrations of MS-222 daily for up to 13 days was not associated with changes in retinal structure or function as measured in this study.

Ehrlichia ewingii infection and exposure rates in dogs from the southcentral United States.

We used PCR and a novel serologic assay to determine infection and exposure rates to Ehrlichia ewingii in dogs from an area of northeast Oklahoma and northwest Arkansas where Amblyomma americanum ticks are abundant. Of 143 dogs assayed, 13 (9.1%) harbored E. ewingii by PCR and 64 (44.8%) had antibodies to E. ewingii detected using a peptide-based microtiter plate ELISA. Dogs were more likely (P=0.001) to be positive by PCR if sampled in August (30.8%) but no association was found between seropositive status and month of collection of sample (P>0.05). Additional testing revealed PCR evidence of Ehrlichia chaffeensis (4/143; 2.8%) and Anaplasma platys (5/143; 3.5%) as well as antibodies reactive to E. chaffeensis (25/143; 17.5%), Ehrlichia canis (2/143; 1.4%), and Anaplasma spp. (8/143; 5.6%). Testing of another 200 dogs from the area revealed additional PCR and/or serologic evidence of E. ewingii, E. canis, E. chaffeensis, and A. platys. None of the 343 dogs evaluated had evidence of Borrelia burgdorferi exposure. These data support the interpretation that E. ewingii may be the primary agent of canine ehrlichiosis in this region, and suggest that diagnostic evaluation of dogs suspected to have a tick-borne disease should include assays targeting this organism.

Detection of Babesia gibsoni and the canine small Babesia 'Spanish isolate' in blood samples obtained from dogs confiscated from dogfighting operations.

OBJECTIVE: To determine the prevalence of Babesia gibsoni infection in dogs that were confiscated from dogfighting operations. DESIGN: Cross-sectional study. ANIMALS: 157 pit bull-type dogs that were confiscated as part of dogfighting prosecution cases in Iowa, Michigan, Mississippi, Ohio, Pennsylvania, Virginia, and Washington and 218 randomly selected animal shelter dogs with no known history of dogfighting. PROCEDURES: Blood samples collected from confiscated dogs were tested for infection with B gibsoni by use of a nested PCR assay. Samples that yielded positive results underwent DNA sequencing to confirm infection with B gibsoni. Control blood samples collected from 218 randomly selected dogs in animal shelters (ie, dogs that had no known involvement in dogfighting events) were also analyzed. RESULTS: Results of nested PCR assays indicated that 53 of 157 (33.8%) confiscated dogs were infected with B gibsoni; 1 (0.6%) dog was infected with the canine small Babesia 'Spanish isolate' (also known as Theileria annae). To the authors' knowledge, this is the first report of infection with this small Babesia 'Spanish isolate' in a North American dog. Dogs with scars (indicative of fighting) on the face, head, and forelimbs were 5.5 times as likely to be infected with B gibsoni as were dogs without scars. Of the control dogs, 1 (0.5%) pit bull-type dog was infected with B gibsoni. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that B gibsoni is a common parasite of dogs confiscated from dogfighting operations and suggested that dogs with a history of fighting should be evaluated for infection with B gibsoni.