Study of the effectiveness of glucosamine and chondroitin sulfate, marine based fatty acid compounds (PCSO-524 and EAB-277), and carprofen for the treatment of dogs with hip osteoarthritis: A prospective, block-randomized, double-blinded, placebo-controlled clinical trial

Introduction: Glucosamine hydrochloride and chondroitin sulfate are commonly used in dogs with OA, but evidence around efficacy is mixed. This study evaluated the effectiveness of glucosamine and chondroitin sulfate, marine based fatty acid compounds (PCSO-524 and EAB-277), and carprofen for the alleviation of canine hip OA pain. This was a prospective, block-randomized, double-blinded, placebo-controlled clinical trial.

Methods: Seventy-five owned pet dogs with hip OA were assigned randomly into five treatment groups: PCSO-524, Glucosamine and chondroitin sulfate, EAB-277, carprofen, and Placebo (sunflower oil). Peak vertical force (PVF) and subjective orthopedic assessment scores (OAS) were evaluated before treatment (week 0), and at weeks 2, 4, and 6 during treatment.

Results: At week 2, the carprofen group showed a significant increase in PVF (3.14 ± 5.33; mean ± SD). After 4 weeks, the increases in PVF of the PCSO-524 (3.90 ± 3.52), EAB-277 (4.17 ± 4.94), and carprofen (3.08 ± 5.87) groups were significant, and significantly greater than placebo (0.08 ± 1.90) and glucosamine (−0.05 ± 6.34) groups. After 6 weeks, the change of PVF in the PCSO-524 (4.14 ± 4.65), EAB-277 (4.45 ± 4.23), and carprofen (4.21 ± 6.52) groups were significant and significantly higher than the placebo group (−0.33 ± 3.65). The change in PVF in the glucosamine group (1.08 ± 5.49) lay between the placebo group and the other treatment groups. The OAS did not show any significant change in any group.

Discussion: PCSO-524 and EAB-277, but not glucosamine/chondroitin, resulted in significant improvements in PVF from baseline after 4 weeks, and 6 weeks, and to a similar degree to that seen with carprofen.

Introduction

Osteoarthritis (OA) is the most common joint disease and cause of chronic pain in dogs. OA can affect any joint, including hips, elbows, and stifles, but also vertebral facet joints, carpal joints, tarsal joints, and metacarpophalangeal and metatarsophalangeal joints (1, 2). Estimates from North America report age specific prevalence values ranging from 20% in dogs older than 1 year up to 80% in dogs older than 8 years, based on radiographic and clinical data from referral settings (3). A recent study suggested that OA and associated clinical signs may have a prevalence of ~37% in the canine population (4).

Non-steroidal anti-inflammatory drugs (NSAIDs) are currently the primary pharmaceutical therapy recommended for dogs with OA (5–7). Carprofen (Rimadyl^®) is one of the leading NSAIDs used globally (6, 8–10). NSAIDs may cause gastrointestinal ulceration as an adverse effect and are contraindicated in the presence of renal insufficiency (2, 11). However, the true incidence of adverse events is currently unknown (12).

Various combinations of glucosamine hydrochloride and chondroitin sulfate are probably the most common nutraceuticals used in dogs with OA (6). Based on the available literature (5, 13–18), the evidence for a benefit of glucosamine and chondroitin in is mixed.

PCSO-524 is a marine based fatty acid compound comprising of a patented extract stabilized marine lipids from the New Zealand green lipped mussel (Perna canaliculus). In dogs, it has been reported that the PCSO-524 is associated with beneficial effect outcomes in clinical OA cases (19–22).

Krill oil is an edible oil extracted from Euphausia superba; a small, red-colored crustacean found in the Antarctic. Bioavailability of krill oil has been suggested to be higher than fish oil as much of the EPA and DHA in krill oil are bound to phospholipids. A recent study in humans found that krill oil improved the subjective symptoms of knee pain in adults with mild knee pain (23). However, the efficacy of krill oil has not been studied in OA dogs. EAB-277 is a combination of phospholipids extracted from krill oil together with lipid fractions from the Green Lipped Mussel.

We hypothesized that Glucosamine/chondroitin sulfate supplements, PCSO-524, EAB-277 and carprofen would result in a superior therapeutic effect in treating OA in dogs compared to placebo and that PCSO-524 and EAB-277 would be more effective than Glucosamine/chondroitin sulfate supplementation.

Materials and methods

Study design

This study was a prospective, block-randomized, double-blinded, placebo-controlled clinical trial in client-owned dogs. The study protocol was approved by the Institutional Animal Care and Use Committee of Khon Kaen University (IACUC-KKU-77/60). The dogs remained under the care of their owners during the study. The study was explained to each owner prior to the start, and owners signed a consent form before beginning of the study. The study was conducted at the Veterinary Teaching Hospital (VTH), Faculty of Veterinary Medicine, Khon Kaen University (KKU), Thailand during 2018–2020.