Oxidative Stress Evaluation in Dogs Affected with Canine Monocytic Ehrlichiosis

Oxidative Stress in Canine Diseases: A Comprehensive Review

Oxidative stress (OS), defined as a disruption in redox balance favoring oxidants, has emerged as a major contributor to numerous diseases in human and veterinary medicine. While several reviews have explored the implication of OS in human pathology, an exhaustive review of the canine species is lacking. This comprehensive review aims to summarize the existing literature on the role of OS in canine diseases, highlighting its potentially detrimental effect on various organs and systems. Some inconsistencies among studies exist, likely due to varying biomarkers and sample types. However, there is substantial evidence supporting the involvement of OS in the development or progression of numerous canine disorders, such as cardiovascular, oncologic, endocrine, gastrointestinal, hematologic, renal, neurologic, infectious, and parasitic diseases, among others. Additionally, this review discusses the efficacy of antioxidant and pro-oxidant therapeutic agents for these conditions. Dietary interventions to counteract OS in dogs have gained significant attention in recent years, although further research on the topic is needed. This review aims to serve as a foundational resource for future investigations in this promising field.

A Diet Supplemented with Oil-Free Olive Pulp Flour (MOP-ManniOlivePowder®) Improves the Oxidative Status of Dogs

Olive oil coproducts and their phenolic extracts have shown beneficial effects when added to the diets of food-producing animals, whereas data on their effects on pets are scarce. The aim of this study was to evaluate the effects of dietary supplementation with olive flour (MOP®) on oxidative blood biomarkers in dogs. Thirty dogs were recruited and divided into two groups. Both groups were fed the same kibble feed twice daily. The treatment group (T) also received canned wet feed supplemented with 11.5 mg/kg of body weight of organic olive flour per day, whereas the control group (C) received the same wet feed without any supplementation. The findings showed that oil-free olive pulp flour supplementation led to a significant decrease in d-ROMs (p < 0.044) in the blood of the T group (from 101.26 to 86.67 U CARR), whereas no significant changes were observed in the C group. An increasing OXY trend was found in the blood of the T group. Polyphenols in olive flour at a dose of 11.5 mg/kg of body weight contributed to lowering the oxidative stress threshold in dogs, reducing the levels of d-ROMs in dogs and leading to increasing trends in the amount of blood antioxidants. The use of olive pulp flour in dog diets has proven to be beneficial for their health and could also reduce the waste associated with olive oil production.

Evaluation of Oxidative Stress, Thyroid Hormones, Trace Elements and Some Biochemical Markers in Goats Naturally Infected with Theileria ovis

BACKGROUND

Theileriosis is a tick-borne disease caused by protozoon species in the Theileria genus of the Theileriidae family. The biochemical changes induced by infection are considered to be an important understanding of the pathophysiology of caprine theileriosis. In this study, it was aimed to determine oxidative stress, thyroid hormones, trace elements, and biochemical parameters in theileriosis infection.

MATERIALS AND METHODS

A sample of 14 goat was used for this purpose, of which 7 were healthy and 7 were infected with Theileria ovis. Theileria infection was diagnosed from the polymerase chain reaction (PCR). Sera from blood samples was tested for total antioxidant capacity (TAC), total oxidant capacity (TOC), oxidative stress index (OSI), alanine aminotransferase (ALT), aspartate transaminase (AST), gamma glutamyl transferase (GGT), total protein, albumin, triglyceride, cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), urea, blood urea nitrogen (BUN), creatinine, triiodothyronine (T3), thyroxine (T4), copper (Cu), zinc (Zn), cobalt (Co), manganese (Mn), selenium (Se), iron (Fe).

RESULT

TOC, OSI, AST, ALT and GGT values were higher in the patient group than in the healthy group (P < 0.05). On the other hand, there were decreases in TAC, T3, T4, total protein, albumin, creatinine, Cu, Zn, Se, and Co values (P < 0.05). However, there was not found to be a statistical difference between the healthy and patient groups in terms of triglyceride, cholesterol, HDL, LDL, urea, BUN, Mn, and Fe values (P > 0.05).

CONCLUSIONS

It can be stated that oxidative stress is a complication of caprine theileriosis and it may be accompanied with hypothyroidism and deficits in trace minerals.

Effect of the Probiotic Bacillus subtilis DE-CA9TM on Fecal Scores, Serum Oxidative Stress Markers and Fecal and Serum Metabolome in Healthy Dogs

BACKGROUND

There is increasing interest in the use of Bacillus species as probiotics since their spore-forming ability favors their survival in the acidic gastric environment over other probiotic species. The subsequent germination of B. subtilis to their vegetative form allows for their growth in the small intestine and may increase their beneficial effect on the host. B. subtilis strains have also previously been shown to have beneficial effects in humans and production animals, however, no reports are available so far on their use in companion animals.

STUDY DESIGN

The goal of this study was therefore to investigate the daily administration of 1 × 109 cfu DE-CA9TM orally per day versus placebo on health parameters, fecal scores, fecal microbiome, fecal metabolomics, as well as serum metabolomics and oxidative stress markers in ten healthy Beagle dogs in a parallel, randomized, prospective, placebo-controlled design over a period of 45 days.

RESULTS

DE-CA9TM decreased the oxidative status compared to controls for advanced oxidation protein products (AOPP), thiobarbituric acid reactive substances (TBARS) and reactive oxygen metabolites (d-ROMS), suggesting an antioxidant effect of the treatment. Fecal metabolomics revealed a significant reduction in metabolites associated with tryptophan metabolism in the DE-CA9TM-treated group. DE-CA9TM also significantly decreased phenylalanine and homocysteine and increased homoserine and threonine levels. Amino acid metabolism was also affected in the serum metabolome, with increased levels of urea and cadaverine, and reductions in N-acetylornithine in DE-CA9TM compared to controls. Similarly, changes in essential amino acids were observed, with a significant increase in tryptophan and lysine levels and a decrease in homocysteine. An increase in serum guanine and deoxyuridine was also detected, with a decrease in beta-alanine in the animals that ingested DE-CA9TM.

CONCLUSIONS

Data generated throughout this study suggest that the daily administration of 1 × 109 cfu of DE-CA9TM in healthy Beagle dogs is safe and does not affect markers of general health and fecal scores. Furthermore, DE-CA9TM administration had a potential positive effect on some serum markers of oxidative stress, and protein and lipid metabolism in serum and feces.

Oxidative Stress and High-Mobility Group Box 1 Assay in Dogs with Gastrointestinal Parasites

This study aimed to evaluate the concentration of reactive oxidative metabolites, the antioxidant barrier, thiol groups of plasma compounds, and high-mobility group box 1 in shelter dogs naturally infected with helminths. In addition, the correlation between clinical signs and oxidative stress was investigated. Sixty-six (41 male and 25 female) adult mixed-breed dogs housed in a shelter with the diagnosis of gastrointestinal nematodes (i.e., Ancylostoma spp., Uncinaria stenocephala, Toxocara canis, Toxascaris leonina, or Trichuris vulpis) were enrolled in Group 1 (G1) and twenty healthy adult dogs were included in Group 2 (G2), which served as the control. A clinical assessment was performed using a physician-based scoring system. Oxidative stress variables and high-mobility group box 1 were assessed and compared by the means of unpaired t-tests (p < 0.05). Spearman’s rank correlation was performed to calculate the correlation between oxidative stress variables, high-mobility group box 1, hematological parameters, and clinical signs. The results showed statistically significant values for reactive oxidative metabolites, thiol groups of plasma compounds, and high-mobility group box 1 in G1. Negative correlations between thiol groups and the number of red cells and hemoglobin were recorded. These preliminary results support the potential role of oxidative stress and HGMB-1 in the pathogenesis of gastrointestinal helminthiasis in dogs.