Antioxidant supplementation during treatment of outpatient dogs with parvovirus enteritis ameliorates oxidative stress and attenuates intestinal injury: A randomized controlled trial

Abstract

A prospective randomized controlled clinical study was conducted to determine whether antioxidant supplementation as an adjunct therapy alters hemogram, oxidative stress, serum intestinal fatty acid binding protein-2 (IFABP-2) level, fecal viral load, clinical score (CS) and survivability in outpatient canine parvovirus enteritis (CPVE) dogs. The dogs with CPVE were randomized to one of the five treatment groups: supportive treatment (ST) alone, ST with N-acetylcysteine (ST+NAC), resveratrol (ST+RES), coenzyme Q10 (ST+CoQ10) or ascorbic acid (ST+AA). The primary outcome measures were reduction of CS and fecal HA titre, and enhancement of survivability. Secondary outcome measures were reduction of oxidative stress indices and IFABP-2 level from day 0 to day 7. The mean CS and HA titre were significantly (P < 0.05) decreased from day 0 to 7 in ST and all antioxidant groups. The supplementations of NAC, RES and AA along with ST markedly (P < 0.05) reduced the concentrations of malondialdehyde, nitric oxide and IFABP-2 on day 7 as compared to ST alone. Additionally, NAC and RES supplementations markedly (P < 0.05) improved the total leukocyte count and neutrophil count in CPVE-affected dogs. NAC and RES could serve as better antioxidants for the amelioration of oxidative stress in CPVE but, the antioxidants did not confer any additional benefits in reduction of CS, fecal HA tire, or survivability when compared with ST alone.

Keywords: Antioxidant; Canine parvovirus; N-acetylcysteine; Oxidative stress; Resveratrol.

Fig. 1

Study flow diagram for clinical study (“lost to follow-up” refers to not return for scheduled rechecks).

Fig. 2

Agarose gel electrophoresis of the PCR products for identification of VP2 gene of CPV in fecal samples collected from dogs CPVE. Lane M denotes 100-bp DNA ladder, lane N denotes negative control (no template), lane P denotes positive control (Megavac P vaccine, Indian Immunologicals Ltd, Hyderabad, India, containing tissue culture adapted strain of CPV), lanes 1–4, 7–9 and 11 denote positive, and lanes 5–6 and 10 denote negative for canine parvovirus in fecal samples.

Fig. 3

Changes of concentrations of intestinal fatty acid binding protein-2 (IFABP-2) in serum at days 0, 3 and 7 in CPV-infected ill dogs treated with supportive treatment (ST) alone or ST with antioxidants (NAC, RES, CoQ10 and AA). Data have been reported as 75th percentile. The 75th percentile values followed by the different uppercase letters (A, B) and lowercase letters (a, b) differ significantly among the groups and days, respectively at P = 0.05. ST, supportive treatment; NAC, N-acetylcysteine; RES, resveratrol; CoQ10, coenzyme Q10; AA, ascorbic acid.

Fig. 4

Changes of clinical score and hemagglutination (HA) titre (log₂ HA unit) at days 0, 3, 5 and 7 in CPV-infected ill dogs treated with supportive treatment (ST) alone or ST with antioxidants (NAC, RES, CoQ10 and AA). Data have been reported as 75th percentile. The 75th percentile values followed by the different lowercase letters (a, b,c, d) differ significantly among the days at P = 0.05. ST, supportive treatment; NAC, N-acetylcysteine; RES, resveratrol; CoQ10, coenzyme Q10; AA, ascorbic acid.

Fig. 5

Survivability of dogs with CPVE at day 7 in response to supportive treatment (ST) alone or ST with antioxidants (NAC, RES, CoQ10 and AA) The comparison by Log-rank (Mantel-Cox) test shows no significant difference among the groups (Chi square, 4.4048; df, 4; P value, 0.353).