MILBEMYCIN OXIME (INTERCEPTOR) TREATMENT OF PYCNOGONID SEA SPIDER INFESTATION IN THREE SPECIES OF CORALS.

A coral reef system at the Steinhart Aquarium in San Francisco, CA, USA experienced a population explosion of pycnogonid sea spiders (Arthropoda: Class Pycnogonida) with subsequent deleterious health effects on the corals in the system. Sixteen coral colonies across three species (Stylophora pistillata, Pocillopora damicornis, and Acropora tenuis) were chosen from this system for milbemycin oxime immersion therapy trials, with the goal of decreasing or eradicating the sea spider population with minimal detrimental effect to the corals. Corals underwent two milbemycin immersion treatments, administered 1 wk apart, at the previously published aquatic invertebrate dose of 0.016 parts per million (ppm; mg/L), but therapy did not reduce the number of sea spiders. Doubling the dose to 0.032 ppm milbemycin and repeating this immersion therapy 1/wk for three treatments successfully reduced the sea spiders. Histopathology was used to assess the health of the corals and tolerance to therapy, and posttreatment biopsies confirmed that there were no adverse effects to any of the three species of coral. Repeated 1/ wk treatments of milbemycin oxime immersion therapy at 0.032 ppm appears to be both safe and effective for reducing the numbers of pycnogonid sea spiders in the stony corals S. pistillata, P. damicornis, and A. tenuis.

Ocular anatomy of the black pacu (Colossoma macropomum): gross, histologic, and diagnostic imaging.

OBJECTIVE: To describe the ocular anatomy of the black pacu (Colossoma macropomum), a freshwater teleost fish of the Amazon River basin, including an unusual choroid laden with adipose tissue. PROCEDURES: Three adult black pacu were anesthetized and examined clinically and with ocular ultrasonography, then euthanized. Three fish were euthanized and their heads imaged immediately postmortem using computed tomography. One fish was euthanized and its exenterated eyes imaged by high-resolution magnetic resonance imaging. The exenterated eyes of all seven fish were fixed in formalin; eyes from three fish were examined grossly and histologically. Additionally, archived histologic sections from two smaller black pacu specimens were examined. RESULTS: Findings were consistent among the ocular imaging modalities used. Intrinsic to the sclera were circumferential ossicles and scleral cartilage. The lens was spherical and protruded through the ovoid pupil with an aphakic space inferiorly when the accommodative mechanism was relaxed under anesthesia. Both a small falciform process and epiretinal vasculature were present in the posterior segment. The retina was cone-rich, and processes of the retinal pigment epithelium enveloped the photoreceptor outer segments. Remarkably, the choroid occupied one-third of the anteroposterior length of the globe; histology confirmed that the bulk of the choroid was composed of adipose tissue. CONCLUSIONS: The eye of the pacu overall is typical of teleosts but has the notable and consistent finding of a substantive store of choroidal fat of unknown function.

An outbreak of Chlamydophila psittaci in an outdoor colony of Magellanic penguins (Spheniscus magellanicus).

An outbreak of Chlamydophila psittaci occurred in an outdoor colony of 63 Magellanic penguins (Spheniscus magellanicus) at the San Francisco Zoo. Affected penguins presented with inappetence, lethargy, and light green urates. Hematologic and serum biochemical findings were consistent with chronic inflammation. Penguins did not respond to initial supportive and antimicrobial therapy, and 3 died. Necropsy results of the 3 birds revealed hepatomegaly and splenomegaly, and histologic lesions included necrotizing hepatitis, splenitis, and vasculitis. Chlamydophila psittaci infection was confirmed by results of Gimenez staining, immunohistochemistry, and tissue polymerase chain reaction assay. As additional birds continued to present with similar clinical signs, the entire colony of penguins was prophylactically treated with a 30-day minimum course of doxycycline, administered orally or intramuscularly or as a combination of both. Despite treatment, 9 additional penguins died during a 3-month period. Pathologic results from these birds revealed renal and visceral gout (n = 4), cardiac insufficiency (n = 2), sepsis from a suspected esophageal perforation (n = 2), and no gross lesions (n = 1). During the outbreak, 4 birds presented with seizures, 5 developed dermatitis, and nearly 90% of birds in the colony showed severe keratoconjunctivitis, believed to be related to drug therapy with doxycycline. We report the clinical and pathologic features of Chlamydophila psittaci infection in an outdoor colony of penguins and the associated challenges of treatment.

Survey and clinical application of serum iron, total iron binding capacity, transferrin saturation, and serum ferritin in captive black and white ruffed lemurs (Varecia variegata variegata).

Serum samples from 63 clinically normal captive black and white ruffed lemurs (Varecia variegata variegata) were analyzed to survey serum iron, total iron binding capacity, transferrin saturation, and serum ferritin levels. Data analysis showed no differences in these analytes attributable to sex, but significantly higher levels of serum iron, transferrin saturation, and serum ferritin in older animals. The survey data were examined in light of two black and white ruffed lemurs that were treated for iron overload with serial phlebotomies. Prior to therapy, both phlebotomized lemurs had excess hepatic iron deposition, but had serum iron, transferrin saturation, and serum ferritin below the upper limits observed in the survey animals, suggesting that some clinically normal animals included in the survey may have accumulated excess systemic iron. Serial phlebotomy therapy reduced serum iron, transferrin saturation, and serum ferritin in both animals. Three years after the conclusion of therapy in the one remaining case, serum iron and transferrin saturation have risen substantially, whereas serum ferritin has risen slightly. Serum iron, transferrin saturation, and serum ferritin may be useful predictors of systemic iron stores in this species, though the correlation between these parameters and systemic iron stores needs to be determined.