# Novel Insights into Systemic Hyaluronic Acid Therapy in Dogs with Osteoarthritis from an Exploratory Postmarketing Study: Clinical Improvements Linked to Biomarker Changes

## TL;DR

This study shows that intravenous hyaluronic acid improves mobility and reduces inflammation in dogs with osteoarthritis, with no adverse effects.

## Contribution

The study provides new evidence linking clinical improvements in dogs with osteoarthritis to specific biomarker changes following hyaluronic acid therapy.

## Key findings

- Intravenous hyaluronic acid improved lameness and joint pain in nearly half of the dogs.
- Systemic inflammation and oxidative stress biomarkers significantly decreased after treatment.
- Physical activity increased in all dogs with low baseline activity, with no adverse effects observed.

## Abstract

Osteoarthritis is a common and progressive joint disease in dogs, leading to pain, reduced mobility, and decreased quality of life. One treatment option involves the intravenous administration of hyaluronic acid—a naturally occurring substance in the body that plays an important role in joint function. Although this approach is already used by some veterinarians, data on its effectiveness and systemic effects are still limited. This study evaluated the clinical and biological effects of intravenous administration of Bonharen Intravenous, an authorised veterinary medicinal product containing medium molecular weight hyaluronic acid, in client-owned dogs with naturally occurring osteoarthritis. Clinical signs such as lameness and joint pain were assessed, along with activity levels and blood biomarkers related to inflammation, oxidative stress, and tissue degradation. The results showed clear clinical improvement, accompanied by a reduction in systemic markers of inflammation, oxidative stress, and tissue degradation. No adverse effects were observed. These findings suggest that intravenous hyaluronic acid may offer a safe and effective option to help dogs with osteoarthritis lead more comfortable and active lives.

This prospective, single-arm, exploratory postmarketing study preliminarily evaluated the clinical response and plasma biomarker changes in 18 client-owned dogs with naturally occurring osteoarthritis (OA) treated with sodium hyaluronate (Bonharen). Patients received intravenous injections of Bonharen Intravenous at a dose of 0.15 mL/kg (1.3–1.6 mg/kg hyaluronic acid once a week for consecutive five weeks). Clinical parameters (lameness, joint pain, mobility, swelling) were assessed weekly and two weeks after the final dose was given via standardized scoring. The plasma concentrations of selected inflammatory, cartilage-related, and oxidative stress biomarkers were measured before treatment and two weeks after the final dose. Clinical improvement in lameness and/or joint pain on palpation was observed in nearly half of the patients. No clinical deterioration was recorded at any time point. Physical activity increased in all patients with reduced baseline activity. Significant decreases in the plasma levels of prostaglandin E2, Δ17-6-keto prostaglandin F1α, malondialdehyde, and hyaluronan were detected, indicating reduced systemic inflammation and oxidative stress. In addition, an increase in plasma hydroxybutyrate and decrease in the collagen-breakdown marker prolyl-hydroxyproline were observed. No adverse effects were reported. These findings suggest that intravenous hyaluronic acid (Bonharen) may represent a safe and promising component to multimodal OA management in dogs and demonstrate the feasibility of integrating plasma biomarkers in canine OA studies.