Blood concentration of symmetric dimethylarginine correlates with kidney damage as assessed with a proposed histologic grading system for chronic kidney disease in tigers (Panthera tigris).

OBJECTIVE: To determine the utility of blood symmetric dimethylarginine (SDMA) concentration measurement as a diagnostic tool for chronic kidney disease (CKD) in tigers (Panthera tigris) by comparing results for SDMA with those for traditional renal biomarkers and investigating correlations between these biomarkers and histopathologic kidney changes in tigers with CKD. SAMPLE: Blood, urine, and kidney samples from 35 tigers with CKD from 2 sanctuaries. PROCEDURES: Blood (serum or plasma) and urine samples were collected antemortem. Necropsy, including gross and histologic assessment, was performed for tigers that died or were euthanized for quality-of-life reasons. Results for CKD biomarkers in blood (BUN, creatinine, phosphorus, and SDMA concentrations) and urine (protein concentration, urine protein-to-creatinine ratio, and urine specific gravity) were evaluated for correlation with histologic kidney damage scored with an objective grading scale defined by percentage of inflammation, fibrosis, and tubular atrophy. RESULTS: Symmetric dimethylarginine had the strongest significant correlation (ρ = 0.667) with histologic kidney damage score, followed by urine specific gravity (ρ = -0.639), blood creatinine concentration (ρ = 0.624), and BUN (ρ = 0.588). No significant correlation with kidney score was identified for blood phosphorus concentration, urine protein concentration, or the urine protein-to-creatinine ratio. CLINICAL RELEVANCE: We recommend SDMA be prioritized as a renal biomarker in tigers, with SDMA results considered in addition to those of other traditional renal biomarkers when assessing kidney function in tigers. Additionally, the grading scale we developed could be replicated across patients and pathologists for more consistent postmortem assessment of CKD in tigers.

Effects of hyperbaric oxygen therapy on uncomplicated incisional and open wound healing in dogs.

OBJECTIVE: To determine the safety of a hyperbaric oxygen therapy (HBOT) protocol and its influence on the healing of uncomplicated open and incisional wounds in dogs. STUDY DESIGN: Prospective, controlled experimental study. ANIMALS: Adult dogs (n = 10). METHODS: Two 2 × 2-cm open wounds and two 3-cm-long full-thickness dermal incisions were created on the dorsum of each dog. Dogs in the hyperbaric oxygen treatment group (HBO) received HBOT once daily (1.7 atmospheres absolute [ATA], 30 minutes on day 1; 2.0 ATA, 40 minutes on days 2-7) for 7 consecutive days, and dogs in the control group (CON) received standardized wound care. Dogs were monitored during HBOT for adverse side effects. Total wound area, percentage epithelialization, and percentage contraction were compared for the open wounds. Subjective wound scores were compared for the open and incisional wounds. Biopsies of both wound types were taken and used to determine histopathology scores. Bacterial cultures were completed on open wounds. RESULTS: No difference was detected between HBO and CON uncomplicated open and incisional wounds at any time for contraction, epithelialization, subjective wound scores, histopathology scores, or bacterial loads. All HBO dogs tolerated hyperbaric oxygen treatments with no adverse effects. CONCLUSION: The HBOT protocol tested here was safe but did not enhance the healing of uncomplicated acute wounds and incisions of dogs. CLINICAL SIGNIFICANCE: These results do not provide evidence to support the use of HBOT to manage uncomplicated wounds in dogs.