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This study examines the trajectories, size, and spatial distribution of aerosols during breathing events of common bottlenose dolphins (Tursiops truncatus) in the National Aquarium in Baltimore, MD. Accounting for the aerodynamic drag and inertia of the small droplets, the trajectories are used for estimating the volumes and flow rates of the exhaled and inhaled air. Data are acquired by training two male and four female dolphins to breathe at the side of the pool within the field-of-view of a high-speed holography system. Droplet-tracking and size measurements are performed for twenty-six datasets involving normal, chuff, and post-exercise breaths, some repeated to assess repeatability. The exhaled liquid originates either from the respiratory system or from the water trapped above the blowhole. The 150–400 ms exhalations have multiple velocity peaks, with the maximum air speed occurring during the first peak for post-exercise breaths. The droplet concentrations and sizes peak at the time of maximum velocity and then gradually decrease. The exhaled liquid volumes vary between 0.1–16 mL, peaking for post-exercise breaths. About 0.5% of the exhaled aerosol travels 2–5 times faster than the surrounding air and droplets, presumably due to ejection from deep within the respiratory tract. A fraction of the airborne liquid (0.02-1.0 mL) is subsequently inhaled during the more than 550 ms long inhalation phase, characterized by low speeds and small droplets. The exhaled and inhaled tidal volumes estimated from the trajectories are consistent with prior measurements of dolphins in the wild and other facilities. To the best of our knowledge, the droplet concentrations, size distributions, and total liquid volumes ejected and aspirated have never been reported for common bottlenose dolphins. Such data are vital for assessing the aerosols generated and inhaled by surface breathing mammals, a critical first step in characterizing health risks to cetaceans in adverse environments.
Water can serve as a vector for distribution and exposure to both toxins and toxicants. Because water is essential for all species, water quality impacts the health of wildlife and animals under managed care. Waterborne toxicants and toxins in exotic species include heavy metals, pesticides, fungicides, herbicides, algal blooms, nitrogenous wastes, and water treatment chemicals. Susceptibility varies by species, and mitigation typically requires supportive care and removal of the source of contamination.
Natural infections of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been documented in over 60 animal species, some distantly related. Several marine mammals have been predicted as highly susceptible to SARS-CoV-2 infection based on the homology of their ACE2 receptors to those of humans. To assess potential exposure of marine mammals to SARS-CoV-2, we conducted an opportunistic survey from 2020 to 2025 and tested 1,808 swabs and 378 serum samples from 21 marine mammal species in the United States. All the swabs tested by RT-qPCR were negative, indicating the absence of active infection. A low level of SARS-CoV-2 neutralizing antibodies was detected in three pinniped species, including Phoca vitulina (harbor seal, 13.6%, 95% CI: 5.2-27.4%), Zalophus californianus (California sea lion, 7%, 95% CI: 1.9-17.0%), and Halichoerus grypus (grey seal, 3.7%, 95% CI: 0.5-12.7%). These findings represent the first serological evidence of SARS-CoV-2 exposure in marine mammals in the United States, highlighting the need for continued monitoring of these populations and further research on SARS-CoV-2 transmission dynamics in wildlife.
Anurans under managed care are often susceptible to ocular diseases secondary to underlying systemic diseases or environmental conditions. Twenty-one (five female, 16 male) healthy smooth-sided toads (Rhaebo guttatus) under managed care were examined to establish normal, species-specific ocular examination findings. This included a large oval-shaped globe, brown iris, rectangular optic nerve, and finely vascularized fundus. Rebound tonometry was performed, and intraocular pressures followed an approximately normal distribution with means and standard deviation of 7.1 ± 1.0 mm Hg for females and 7.7 ± 1.7 mm Hg for males. On average, lower intraocular pressure values were found in toads with larger palpebral fissure lengths (horizontal measurements). Endodontic paper point tear testing was performed to measure aqueous tear film production. The distribution of endodontic paper point tear testing results was uniform, with means and standard deviation of 2.5 ± 1.1 mm in 30 sec for females and 2.7 ± 1.4 mm in 30 sec for males. Neither intraocular pressures nor endodontic paper point tear testing were significantly predicted by toad sex or weight. An average blink rate was determined in a subset of five toads, averaging 1.2 blinks per 10 min. Corneal cultures were performed in a subset of 15 toads with the most common bacteria isolated including Bacillus sp., Pseudomonas sp., and Corynebacterium sp. These findings may aid veterinarians in diagnosing and managing ophthalmic diseases in this species because ophthalmic examination parameters have not been published for smooth-sided toads to date.
