Effects of Hepatozoon Infection on PON-1 Activity and Sialic Acid Levels in Dogs

Abstract

Hepatozoon infections are tick-borne protozoan diseases commonly observed in dogs; however, their effects on the host's biochemical and oxidative stress parameters remain poorly understood. The present study aimed to evaluate serum total sialic acid (TSA), paraoxonase 1 (PON-1), reduced glutathione (GSH), and malondialdehyde (MDA) levels in dogs naturally infected with Hepatozoon spp. This study was conducted on dogs housed at the Kars Municipality Animal Shelter in Kars Province, northeastern Türkiye. Blood samples were collected from a total of 50 dogs for molecular and biochemical analyses, and infection status was determined using PCR. Based on PCR results, approximately 60% of the dogs were Hepatozoon spp.-positive, while the remaining animals served as apparently healthy controls. Serum TSA, PON-1, GSH, and MDA concentrations were measured using standard biochemical assays. Results showed that serum TSA and MDA levels were significantly higher (p<0.05), while PON-1 activity was significantly lower (p<0.05) and GSH levels were significantly decreased (p<0.01) in infected dogs compared to PCR-negative controls. A comprehensive literature review indicated that TSA and PON-1 have not been previously assessed in canine Hepatozoon infections, highlighting the novelty of these findings. These results contribute to a better understanding of the host's biochemical and oxidative stress responses to Hepatozoon infections and suggest that TSA, PON-1, GSH, and MDA may serve as potential biomarkers for disease monitoring.

Keywords

• Dogs
• hepatozoon
• oxidative stress
• paraoxonase 1
• serum total sialic acid

Supporting Institution

This study did not receive any support from an institution.

Ethical Statement

This study was approved by the Kafkas University Animal Experiments Local Ethics Committee (KAU/HADYEK) with the approval number 2025-260.

HEPATOZOON İLE ENFEKTE KÖPEKLERDE OKSİDATİF STRESİN PON-1 AKTİVİTESİ VE SİALİK ASİT DÜZEYLERİ ÜZERİNE ETKİSİ

Abstract

Hepatozoon enfeksiyonları, köpeklerde yaygın olarak görülen kene kaynaklı protozoon hastalıklardır; ancak bu enfeksiyonların konakçının biyokimyasal ve oksidatif stres parametreleri üzerindeki etkileri yeterince anlaşılmamıştır. Mevcut çalışma, doğal olarak Hepatozoon spp. ile enfekte olan köpeklerde serum total sialik asit (TSA), paraoksanaz 1 (PON-1), indirgenmiş glutatyon (GSH) ve malondialdehit (MDA) düzeylerini değerlendirmeyi amaçlamıştır. Çalışma, Türkiye’nin kuzeydoğusundaki Kars İli, Kars Belediyesi Hayvan Barınağı’nda bulunan köpekler üzerinde gerçekleştirilmiştir. Moleküler ve biyokimyasal analizler için toplam 50 köpekten kan örnekleri alınmış ve enfeksiyon durumu PCR ile belirlenmiştir. PCR sonuçlarına göre köpeklerin yaklaşık %60’ı Hepatozoon spp. pozitif bulunmuş, geri kalan hayvanlar ise görünürde sağlıklı kontroller olarak değerlendirilmiştir. Serum TSA, PON-1, GSH ve MDA konsantrasyonları standart biyokimyasal yöntemlerle ölçülmüştür. Sonuçlar, enfekte köpeklerde TSA, PON-1, GSH ve MDA düzeylerinde PCR-negatif kontrollere kıyasla anlamlı değişiklikler olduğunu göstermiştir. Kapsamlı bir literatür taraması, köpeklerde Hepatozoon enfeksiyonlarında TSA ve PON-1’in daha önce değerlendirilmediğini ortaya koymuş ve bu bulguların yeniliğini vurgulamıştır. Bu sonuçlar, konakçının Hepatozoon enfeksiyonlarına karşı biyokimyasal ve oksidatif stres yanıtlarının daha iyi anlaşılmasına katkı sağlamaktadır ve TSA, PON-1, GSH ile MDA’nın hastalık takibi için potansiyel biyobelirteçler olarak kullanılabileceğini düşündürmektedir. Tüm enfeksiyonlar barınak koşullarında doğal olarak meydana gelmiş olup, herhangi bir deneysel enfeksiyon uygulanmamıştır. Biyokimyasal analizler, önceden belirlenen dahil etme kriterlerini karşılayan hayvanlar üzerinde gerçekleştirilmiştir.

Keywords

• Dogs
• hepatozoon
• oxidative stress
• paraoxonase 1
• serum total sialic acid.

Supporting Institution

Bu çalışma herhangi bir kurumdan destek almamıştır.

Ethical Statement

Bu çalışma, Kafkas Üniversitesi Hayvan Deneyleri Yerel Etik Kurulu (KAU/HADYEK) tarafından 2025-260 onay numarası ile onaylanmıştır.

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