Metals, Parasites, and Environmental Conditions Affecting Breeding Populations of Spotted Salamanders (Ambystoma maculatum) in Northern Arkansas, USA

Gastric Physaloptera Infection in 27 Dogs (1997-2019)

Infection with the stomach worm Physaloptera spp. in dogs can cause chronic vomiting, although the diagnosis is often difficult owing to a low worm burden, single-sex infections, a failure to produce ova, or ova that are of greater density than solutions routinely used for qualitative fecal flotation. A retrospective evaluation was performed of 27 dogs that had gastric Physaloptera spp. infection confirmed endoscopically. In 23 of 27 dogs (85.2%), chronic vomiting was the chief complaint, and Physaloptera was an incidental finding in 3 dogs with esophageal or gastric foreign bodies. The worm burden was low (1-3 worms) in 21 dogs (77.8%), but 2 dogs were infected with large numbers (>50 worms). Prior therapy with routine doses of anthelmintics was ineffective in eight dogs prior to endoscopy. A higher dose and longer duration of fenbendazole in combination with pyrantel pamoate is recommended for treatment of suspected or confirmed infections. Reinfection is common in some dogs and should not be viewed as treatment failure.

Natural tissue concentrations in adult Ambystoma maculatum and larval DNA damage from exposure to arsenic and chromium

Arsenic (As) and chromium (Cr) are two contaminants that are detected in aquatic and terrestrial habitats. Using the spotted salamander, Ambystoma maculatum, to assess impacts from these contaminants may be advantageous as adults live and breed in such environments. Adult amphibians typically exhibit elevated tissue concentrations of contaminants present in their environment, while larval stages were found to exhibit increased sensitivity to pollutants. From January through March of 2015, during the spring breeding season, 5 adults and approximately 32 egg masses were collected from a local breeding site. Field levels of As and Cr ranged from 5.99 to 8.88 µg/L and 1.45 to 2 µg/L, respectively, while mean adult As tissue concentrations were 56.74 µg/g dry weight for heart, 0.92 µg/g for liver, and 1.21 µg/g for tail tissue. Mean tissue concentrations for Cr were 87.64 µg/g for heart, 1.47 µg/g for liver, and 6.92 µg/g for tail. Developing larvae that were collected from the field and exposed in a lab setting for 12 d to 0.2 or 20 mg/L of either As or Cr displayed little DNA damage attributed to As, but marked damage due to exposure to 20 mg/L Cr when assessed using the comet assay. Exposure to a mixture of either 0.25:0.1 or 25:10 mg/L As and Cr resulted in significant DNA damage at the lower concentration of 0.25:0.1 mg/L. As adult spotted salamanders were found to possess high concentrations of these contaminants in cardiac tissue, and larvae were shown to be susceptible to DNA damage from increased exposures, assessing impacts and potential declines of amphibian populations exposed to As and Cr is needed.