OBJECTIVE To identify cardiac tissue genes and gene pathways differentially expressed between dogs with and without dilated cardiomyopathy (DCM).
ANIMALS 8 dogs with and 5 dogs without DCM.
PROCEDURES Following euthanasia, samples of left ventricular myocardium were collected from each dog. Total RNA was extracted from tissue samples, and RNA sequencing was performed on each sample. Samples from dogs with and without DCM were grouped to identify genes that were differentially regulated between the 2 populations. Overrepresentation analysis was performed on upregulated and downregulated gene sets to identify altered molecular pathways in dogs with DCM.
RESULTS Genes involved in cellular energy metabolism, especially metabolism of carbohydrates and fats, were significantly downregulated in dogs with DCM. Expression of cardiac structural proteins was also altered in affected dogs.
CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that RNA sequencing may provide important insights into the pathogenesis of DCM in dogs and highlight pathways that should be explored to identify causative mutations and develop novel therapeutic interventions.
OBJECTIVE To determine the pharmacokinetics and adverse effects following SC administration of ceftiofur crystalline free acid (CCFA) in New Zealand White rabbits.
ANIMALS 6 adult sexually intact female New Zealand White rabbits.
PROCEDURES Each rabbit was administered 40 mg of CCFA/kg SC. A blood sample was obtained immediately before (0 minutes), at 5 and 30 minutes after, and at 1, 1.5, 2, 3, 4, 8, 12, 24, 48, 72, 95, 120, 144, and 168 hours after administration, and plasma concentrations of ceftiofur free acid equivalents (CFAE) were measured. Pharmacokinetic parameters were calculated. For each rabbit, body weight, food consumption, fecal output, and injection site were monitored. Minimum inhibitory concentrations of ceftiofur for 293 bacterial isolates from rabbit clinical samples were determined.
RESULTS Mean ± SD peak plasma concentration of CFAE and time to maximum plasma concentration were 33.13 ± 10.15 μg/mL and 1.75 ± 0.42 hours, respectively. The mean terminal half-life of CFAE was 42.6 ± 5.2 hours. Plasma CFAE concentration was > 4 μg/mL for approximately 24 hours and > 1 μg/mL for at least 72 hours after CCFA administration. An apparently nonpainful subcutaneous nodule developed at the injection site in 3 of 6 rabbits.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that CCFA (40 mg/kg) could be administered SC every 24 to 72 hours to New Zealand White rabbits to treat infections with ceftiofur-susceptible bacteria. Single-dose administration of CCFA resulted in minimal adverse effects. Additional studies are needed to evaluate the effects of repeated CCFA administration in New Zealand White rabbits.