The efficacy, tolerance and ease of administration of a nutraceutical, carprofen or meloxicam were evaluated in a prospective, double-blind study on 71 dogs with osteoarthritis. The client-owned dogs were randomly assigned to one of the three treatments or to a placebo control group. The influence of osteoarthritis on the dogs' gait was described by comparing the ground reaction forces of the arthritic dogs and 10 normal dogs. Before the treatments began, and 30 and 60 days later, measurements were made of haematological and biochemical variables and of the ground reaction forces of the arthritic limb, and subjective assessments were made by the owners and by the orthopaedic surgeons. Changes in the ground reaction forces were specific to the arthritic joint, and were significantly improved by carprofen and meloxicam but not by the nutraceutical; the values returned to normal only with meloxicam. The orthopaedic surgeons assessed that there had been an improvement with carprofen and meloxicam, but the owners considered that there had been an improvement only with meloxicam. The blood and faecal analyses did not reveal any changes. The treatments were well tolerated, except for a case of hepatopathy in a dog treated with carprofen.

This study aimed to characterize osteoarthritis (OA)-related chronic pain and disability in experimental cats with naturally occurring OA. Peak vertical ground reaction force (PVF), accelerometer-based motor activity (MA) and the von Frey anesthesiometer-induced paw withdrawal threshold were used to define OA and to test the efficacy of meloxicam. A diagnosis of OA was based on radiographic and orthopedic examinations. Cats with OA (n=39) and classified as non-OA (n=6) were used to assess the reliability and sensitivity of the parameters to assess OA over 3weeks while being administered placebo medication. A randomised parallel design study was then used to investigate the effects on OA of daily oral meloxicam treatment for 4weeks at different dose rates (0.025mg/kg, n=10mg/kg; 0.04mg/kg, n=10; 0.05mg/kg, n=9), compared to cats administered a placebo (n=10). The test-retest repeatability for each tool was good (intra-class correlation coefficient ⩾0.6). The PVF and the von Frey anesthesiometer-induced paw withdrawal threshold discriminated OA (P<0.05). Meloxicam did not add to the PVF improvement observed in placebo-treated cats during the treatment period (adj-P⩽0.01). The 0.025 and the 0.05mg/kg meloxicam-treated cats experienced a higher night-time (17:00-06:58h) MA intensity during the treatment period compared to the placebo period (adj-P=0.04, and 0.02, respectively) and this effect was not observed in the placebo group. The high allodynia rate observed in the 0.04mg/kg meloxicam-treated group may explain the lower responsiveness to the drug. The von Frey anesthesiometer-induced paw withdrawal threshold demonstrated no responsiveness to meloxicam. The results from this study indicated that daily oral meloxicam administration for 4weeks provided pain relief according to night-time MA.

Renal size is an important parameter in the assessment of renal disease in dogs. However, because of the great variability in body conformation, absolute renal measurements cannot solely be used when evaluating kidneys with ultrasonography. The use of a ratio comparing renal length and aortic luminal diameter (K/Ao) was investigated. After confirming the reproducibility of these measurements, K/Ao ratios were obtained in 92 dogs without clinical evidence of renal disease. Left and right K/Ao ratios were statistically similar. Based on 95% confidence intervals, renal size should be considered reduced if the K/Ao ratio is < 5.5 and increased when > 9.1.