No abstract

Background: Oxidative stress plays a role in the pathogenesis of many systemic diseases. Hospitalized human patients are glutathione, cysteine, and ascorbate deficient, and antioxidant depletion has been correlated with poor clinical outcome. To date little is known about antioxidant concentrations in hospitalized veterinary patients. The purpose of this study was to determine whether ascorbate, cysteine, or glutathione depletion is present in ill dogs and cats compared with healthy controls.Hypothesis: Clinically ill dogs and cats would be antioxidant depleted, and depletion would correlate with illness severity and clinical outcome.Animals: Clinically ill client-owned dogs (n 5 61) and cats (n 5 37), healthy control dogs (n 5 37) and cats (n 5 33). Methods: Prospective, observational, case control study. Erythrocyte reduced glutathione, plasma cysteine, and plasma ascorbate were quantified using high-performance liquid chromatography.Results: Clinically ill dogs had significantly lower erythrocyte glutathione concentrations (1.22 mM, range 0.55-3.61) compared with controls (1.91 mM, range 0.87-3.51; P 5 .0004), and glutathione depletion correlated with both illness severity (P 5 .038) and mortality (P 5 .010). Cats had higher ascorbate concentrations when ill (10.65 mM, range 1.13-25.26) compared with controls (3.68 mM, range 0.36-13.57; P 5 .0009).Conclusions and Clinical Importance: Clinically ill dogs had decreased erythrocyte glutathione concentrations, which could be a marker of illness severity and prognostic of a poor outcome. Clinically ill cats had an unexpectedly high plasma ascorbate, which could represent a unique species response to oxidative stress.

Results suggested that subclinical bacteriuria is a nonprogressive condition in healthy female dogs and can be persistent or transient. No significant difference in the prevalence of subclinical bacteriuria in young and middle-aged dogs versus senior and geriatric dogs was detected. No dogs with subclinical bacteriuria developed clinical signs requiring antimicrobial treatment during the 3-month observation period. Healthy female dogs with subclinical bacteriuria may be a population of dogs in which antimicrobial treatment is unnecessary.

The clinical use of cyclosporine is described in a group of client-owned cats diagnosed with idiopathic pure red cell aplasia (PRCA). All 10 cats were treated with combinations of glucocorticoids and cyclosporine. Of the 10 cats, the eight for which follow-up data was available achieved and maintained remission for a median of 31 and 406 days, respectively. Therapy was reduced or discontinued in 7/8 cats; 2/7 maintained remission off therapy and 5/7 cats relapsed. Remission was reinduced in four cats, with 3/4 cats maintained long-term on low dose therapy. Adverse effects associated with cyclosporine therapy were responsive to dose reduction or drug withdrawal. Feline idiopathic PRCA was responsive to combination immunosuppressive therapy with glucocorticoids and cyclosporine. Relapse was common, particularly after drug discontinuation; therefore, most cats required maintenance long-term low dose therapy.

Background: Antioxidant depletion and lipid peroxidation have been correlated with disease severity and associated with poor outcomes.Hypothesis/Objectives: Supplementing dogs with N-acetylcysteine (NAC) during the first 48 hours of hospitalization will increase cysteine, normalize glutathione concentrations, and decrease the degree of lipid peroxidation associated with illness.Animals: Sixty systemically ill hospitalized client-owned dogs and 14 healthy control dogs. Methods: Randomized investigator-blinded, placebo-controlled prospective study. Dogs were randomized to treatment with NAC (n = 30) versus placebo (n = 30). Antioxidants, urine 8-isoprostane/creatinine (IP/Cr), and clinical score were determined before and after treatment with NAC. Glutathione, cysteine, and vitamin E concentrations were quantified using high-performance liquid chromatography. Atomic absorption spectroscopy and enzyme-linked immunosorbent assays were used to quantify selenium and isoprostane concentrations, respectively.Results: Ill dogs had significantly lower vitamin E concentrations (27 versus 55 lg/mL; P = .0005) as well as elevated IP/Cr ratios (872 versus 399 pg/mg; P = .0007) versus healthy dogs. NAC supplementation significantly increased plasma cysteine (8.67 versus 15.1 lM; P < .0001) while maintaining glutathione concentrations. Dogs in the placebo group experienced a statistically significant decrease in glutathione concentrations (1.49 versus 1.44 mM; P = .0463). Illness severity and survival were unchanged after short duration NAC supplementation.Conclusions: Ill dogs experience systemic oxidative stress. Supplementation with NAC during the first 48 hours of hospitalization stabilized erythrocyte glutathione concentrations. The clinical impact of this supplementation and glutathione concentration stabilization was undetermined.