Evaluation of non-essential amino acid levels in dogs with parvoviral enteritis

Objective: In this study, the levels of non-essential amino acids in dogs with parvoviral enteritis were determined and examined throughout the hospitalization period (on days 0, 3, and discharge); the relationships between these parameters and the Modified Glasgow Coma Scale (MGCS), C-reactive protein (CRP) levels, and hospitalization duration were determined; and to investigate the differences between surviving and deceased cases to explore their prognostic value. Materials and Methods: The animal material for the study consisted of 23 dogs aged 2–6 months with parvoviral enteritis and 10 dogs forming the control group. Serum samples were collected from the patient group at three different time points: on days 0, 3, and discharge; and from the control group once. The levels of glycine, proline, serine, alanine, aspartic acid, glutamic acid, asparagine, glutamine, cysteine, arginine, and tyrosine were measured in the obtained samples. In addition, the MGCS, CRP concentration, and hematological parameters of the patients were evaluated. Furthermore, comparisons of the aforementioned parameters were made between the surviving and deceased dogs in the patient group. The relationships between amino acid levels, MGCS, and CRP concentrations and hospitalization duration were statistically analyzed. Findings: In dogs with parvoviral enteritis, glycine, proline, serine, alanine, asparagine, and glutamine levels were found to be lower than in the control group (p<0.05). Proline and glycine levels in the patient group were found to be significant between days. CRP concentration was high in the patient group; WBC, NEU, LYM, RBC counts, and HCT values were found to be low. In particular, alanine, arginine, glycine, serine, and tyrosine levels on day 0 were found to have a strong and significant negative correlation with MGCS, while proline levels on day 3 were found to have a strong and significant positive correlation with MGKS. A significant relationship was found between asparagine and cysteine levels on day 3 and the length of hospital stay. Asparagine levels showed a strong and significant positive correlation with hospitalization duration (r = 0.54, p = 0.03), whereas cystine levels showed a strong and significant negative correlation (r = –0.59, p < 0.05). The NEU count (p<0.05) and MGKS value (p<0.01) of deceased dogs were found to be lower than those of surviving dogs. No significant difference was observed between the amino acid levels of deceased and surviving dogs. Conclusion: It has been determined that levels of certain non-essential amino acids are reduced in dogs with parvoviral enteritis and may change during hospitalization. In particular, the significant correlation between glycine, proline, and serine levels and parameters related to clinical course suggests that these amino acids may play a role in metabolic stress, inflammation, and cellular damage processes. However, no significant difference in amino acid levels was detected between surviving and deceased cases. Therefore, strong evidence supporting a direct association between these parameters and prognosis could not be obtained. The findings indicate the need for further studies with larger sample sizes and prospective designs to clarify the potential roles of these amino acids in the clinical process.