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The coccidian parasite Toxoplasma gondii infects humans and warm-blooded animals worldwide. The ecology of this parasite in marine systems is poorly understood, although many marine mammals are infected and susceptible to clinical toxoplasmosis. We summarized the lesions associated with T. gondii infection in the California sea lion (Zalophus californianus) population and investigated the prevalence of and risk factors associated with T. gondii exposure, as indicated by antibody. Five confirmed and four suspected cases of T. gondii infection were identified by analysis of 1,152 medical records of necropsied sea lions from 1975-2009. One suspected and two confirmed cases were identified in aborted fetuses from a sea lion rookery. Toxoplasmosis was the primary cause of death in five cases, including the two fetuses. Gross and histopathologic findings in T. gondii-infected sea lions were similar to those reported in other marine mammals. The most common lesions were encephalitis, meningitis, and myocarditis. The antibody prevalence in stranded, free-ranging sea lions for 1998-2009 was 2.5% (±0.03%; IgG titer 640). There was an increase in odds of exposure in sea lions with increasing age, suggesting cumulative risk of exposure and persistent antibody over time. The occurrence of disseminated T. gondii infection in aborted fetuses confirms vertical transmission in sea lions, and the increasing odds of exposure with age is consistent with additional opportunities for horizontal transmission in free-ranging sea lions over time. These data suggest that T. gondii may have two modes of transmission in the sea lion population. Overall, clinical disease was uncommon in our study which, along with low prevalence of T. gondii antibody, suggests substantially less-frequent exposure and lower susceptibility to clinical disease in California sea lions as compared to sympatric southern sea otters (Enhydra lutris nereis).

Objective Corneal ulcers are commonly encountered in pinnipeds. Prolonged oral antibiotics and topical ophthalmic solutions may not be practical to administer, and novel treatment techniques are desired. Thermodynamic gels are a potential solution because they hold antimicrobials at the site of injection, slowly releasing drug. This study investigated the clinical efficacy of antibiotic-impregnated poloxamer gel in management of corneal ulceration. Animal studied Twenty-six California sea lions undergoing rehabilitation at The Marine Mammal Center. Procedures A poloxamer gel mixed with 2% enrofloxacin was subconjunctivally injected in the treatment group. Control animals received oral doxycycline. Systemic anti-inflammatories and analgesics were administered as needed. Corneal examinations under general anesthesia were repeated weekly, and included sampling for bacterial culture and corneal cytology, collection of high-quality corneal images, and treatment administration until the ulcers were healed. Results There was no gross or histologic evidence of a localized tissue reaction to the gel administration in the conjunctiva, and no evidence of systemic reaction to therapy in animals that died due to unrelated causes during the study period ( n = 17). In animals that experienced a superficial corneal ulcer involving only epithelium or superficial stroma ( n = 12), all lesions resolved completely, in both treatment and control groups. Of those animals with deeper or more complex ulcers involving keratomalacia or descemetoceles ( n = 15), four demonstrated complete lesion resolution (all four received gel treatment). Conclusions This study demonstrates that subconjunctival antibiotic poloxamer gel administration is a safe and effective alternative therapeutic option to traditional treatments for superficial corneal ulceration in pinnipeds. [ABSTRACT FROM AUTHOR]

Effects of cetacean morbillivirus (CeMV) on dolphins vary from causing epidemics to subclinical infections. The former have been documented in the North Atlantic Ocean and Mediterranean Sea but not in the North Pacific Ocean, and the reasons for this are unknown. To explore the distribution of this virus in areas that have not experienced epidemics, we reviewed evidence for morbilliviral infection in odontocetes stranded along the California coast, US from 2000-15. Nine of 212 animals examined histologically had lesions compatible with morbilliviral infection, and 11 were tested for CeMV via reverse transcriptase-PCR. One striped dolphin ( Stenella coeruleoalba) was PCR positive, and the sequenced product was most closely related to sequences in two strains found in cetaceans in Hawaii. This study suggests that CeMV may be a cause of morbidity and a rare contributor to mortality in cetaceans stranding along the California coast. Additional work is needed to understand CeMV distribution and host species susceptibility in this region. [ABSTRACT FROM AUTHOR]