1 Department of Veterinary Medicine, 2 Department of Veterinary Pharmacology & Toxicology, 3 Department of Animal Nutrition, College of Veterinary Science and Animal Husbandry, Orissa University of Agriculture and Technology, Bhubaneswar-751003, Odisha, India (email: rcpatra@gmail.com). Philipp J Vet Anim Sci 2016, 42 (2): 120-128 ERYTHROCYTIC OXIDATIVE STRESS INDICES AND CLINICO-BIOCHEMICAL ALTERATIONS IN GASTROENTERITIS IN DOGS WITH VARIED CLINICAL SCORES Amiya Kumar Rautray 1 , Ramesh Chandra Patra 2 , Ghanashyam S. Parida 1 , Kautuk Kumar Sardar 2 and Niranjan Panda 3 ABSTRACT The erythrocytic lipid peroxidation and antioxidant enzymes were assessed in 106 dogs with diarrhea and/ or vomition and 21 apparently healthy dogs. The total clinical score (CS) was calculated based on fecal consistency, depression and dehydration. Twenty-fve of 106 afected dogs were moderately afected (CS = 4 to 6), and 81 were severely afected (CS = 7 to 9). The dogs’ erythrocyte oxidative index (lipid peroxides level, LPO) and antioxidant enzyme activities (superoxide dismutase, SOD and catalase, CAT) were measured with respect to clinical score, ±blood in stool, breed and sex of the dog. The severely afected dogs had signifcantly (p<0.05) higher LPO (7.16 ±0.20 vs 4.94 ±0.17 nmol of MDA/mg of Hb) and CAT activities (0.33 ±0.01 vs. 0.21 ±0.01 units/mg of Hb) as compared to control dogs with clinical score 0. Dogs with bloody stool (n=39) with mean clinical score of 8.56 ±0.08 had signifcantly lower SOD activity (1.56 ±0.06 vs 1.93 ±0.09 units/ mg of Hb) as compared to dogs without blood in stool (mean CS 6.73 ±0.17). However, the level of LPO, and activities of SOD and CAT were signifcantly higher than healthy dogs (CS 0). It is concluded that increasing CS was associated with increased level of LPO along with alteration in activities of the antioxidant enzymes such as SOD and CAT. Keywords: dogs, catalase, gastroenteritis, lipid peroxides; superoxide dismutase 121 Stress indices and clinico-biochemical alterations in gastroenteritis in dogs INTRODUCTION Gastrointestinal disease with clinical manifestations of vomiting, diarrhea, gastric dilatation or volvulus is the most common presenting complaint in pet dogs (Parr and Otto, 2013). Diarrhea and/ or vomition associated with gastroenteritis is an emergency in small animal practice, and is responsible for many deaths in dogs, particularly in pups (Appel et al., 1979; Radostits et al., 2007). The precise etiologies of gastroenteritis remain unclear in many occasions, and sometimes overlapping (Juckett and Trivedi, 2011; Berset-Istratescu et al., 2013). Recent studies have revealed its association more often with lifestyle factors than specifc pathogens (Stavisky et al., 2011). But prospective studies to document the occurrence of diarrhea and vomiting are relatively limited in dogs, and the majority of the literature is based on information from clinical records (Saevik et al., 2012). Gastroenteritis may be divided into several categories based on etiology. Diarrhea and vomition are prevalent symptoms of gastroenteritis, and are more common in canine parvovirus infections, causing the patients to seek medical attention (Panda et al., 2009). The infammatory changes in the gastrointestinal tract may result in bloody infammatory diarrhea, abdominal pain, nausea, inappetence, rectal bleeding, perianal fstulae, weight loss, fever and anemia (Juckett and Trivedi, 2011). The growing evidences suggest involvement of oxidative stress in several diseases including acquired immunodefciency syndrome (AIDS), hepatitis and infuenza in humans (Semba and Tang 1999), neoplasm like mammary tumor in bitches (Kumaraguruparan et al., 2005), Babesia gibsoni infection (Murase et al., 1996), visceral leishmaniasis (Bildik et al., 2004), lactose intolerance in laboratory animals (Dellan et al., 2005) and diarrhea in calves (Ranjan et al., 2006). Imbalance in redox state as assessed by estimation of activities of superoxide dismutase (SOD) and catalase (CAT), the major antioxidant enzymes in erythrocytes, and level of malonalaldehyde (MDA) as the end of lipid peroxidation of polyunsaturated fatty acid-rich erythrocytic membrane, has been reported in canine parvoviral infections (Panda et al., 2009) and bacterial infections in diferent species (Moral et al., 1977; Fridovich, 1984). Acute cases of gastroenteritis in rats following exposure to lead have been reported to be associated with altered erythrocytic lipid peroxidation and antioxidant enzymes level (Gurer et al., 1998). However, there seems to have no report documenting oxidative stress indices in monogastric animals including dogs sufering from gastroenteritis. No controlled studies have been conducted to evaluate oxidant- antioxidant status in the erythrocytes of dogs sufering from gastroenteritis. Hence, the present clinical study is a novel attempt to investigate the erythrocytic oxidative stress, and compare the clinical score, hemato-biochemical parameters with respect to breed, age, sex and presence or absence of blood in stool in dogs suggestive of gastroenteritis. MATERIALS AND METHODS The clinically afected dogs (n=106) with signs of diarrhea with or without vomition, and 21 apparently healthy dogs were recruited for the present investigation. The detailed history including vaccination, deworming, and the management practices and feeding habits of 127 client-owned dogs, was collected before clinical examination. Owners’ consent was taken to use the dogs for the study, and guidelines of Institutional Animal Ethical Committee were followed. Each dog was assigned with the total clinical score (CS) based on degree of dehydration, depression and fecal consistency (Table 1) by modifying the protocol of Walker et al. (1998). Each of the three parameters was given a score ranging from 0-3 and the calculated total CS was used to classify the dogs into three diferent groups: healthy (total clinical score 0, n=21, group I), moderate (CS = 4 to 6, n=25, group III) and severely afected (CS = 7 to 9, n = 81, group IV). None of the dogs could be categorized under group II as none of the examined dogs had the total clinical score between 1 and 3. Table 1. Scoring of dogs using three diferent clinical signs. Score Fecal consistency Depression Dehydration 0 Normal and well formed Normal Normal eyes and bright 1 Pasty Mild Mild dehydration, slight loss of skin elasticity, skin tent less than 3 sec 2 Semi-liquid Moderate Moderately dehydrated, skin tents greater than 3 sec but less than 10 sec. 3 Watery Severe Unable to stand, dehydration, skin tents greater than 10 sec