Characterization of osteoarthritis in cats and meloxicam efficacy using objective chronic pain evaluation tools

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 3 weeks 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 4 weeks at different dose rates (0.025 mg/kg, n = 10 mg/kg; 0.04 mg/kg, n = 10; 0.05 mg/kg, n = 9), compared to cats administered a placebo (n = 10).

The test–retest repeatability for each tool was good (intra-class correlation coefficient P0.6). 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 6 0.01). The 0.025 and the 0.05 mg/kg meloxicam-treated cats experienced a higher night-time (17:00–06:58 h) 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 0.04 mg/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 4 weeks provided pain relief according to night-time MA.

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The use of analgesic drugs by South African veterinarians

Abstract: According to a survey, non-steroidal anti-inflammatory agents were the most popular analgesic used in South Africa for management of peri-operative pain, acute post-operative pain and chronic pain. The most popular non-steroidal anti-inflammatory agents are flunixin meglumine and phenylbutazone.

The most popular opioid type drug is buprenorphine, followed by morphine. In the peri-operative setting, analgesic agents were not actively administered to 86.3 % of cats and 80.7 % of dogs. Analgesic premedications were frequently administered, e.g. xylazine or ketamine, but no specific drug was administered for post-operative pain. Veterinarians need to critically review their anaesthetic and analgesic practices in order to achieve balanced anaesthesia.

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Anaesthesia and analgesia for dogs and cats in South Africa undergoing sterilisation and with osteoarthritis – An update from 2000

Abstract: A survey was conducted in 2000 into the use of analgesic drugs by veterinarians in South Africa. This survey was repeated in 2005 to establish whether the use of analgesic drugs has increased and which analgesic drugs are being used for acute pain and osteoarthritis. The number of sterilisations performed and the number of new cases of osteoarthritis in dogs and cats was estimated. It is estimated that approximately 260 000 cats are operated on each year in South Africa and that 150 000 cats are sterilised.

Five hundred thousand dogs undergo surgery, of which 242 000 are sterilised. It appears that the number of surgical procedures performed in South Africa has decreased. The estimated death rate following anaesthesia has remained unchanged at 1:1004. Overall, the use of analgesics by South African veterinarians has increased significantly. Fifty-six per cent of cats and 74%of dogs were given peri-operative analgesics but this increased to 94 % and 84 % after including pre-anaesthetic medications with analgesic properties. The use of opioids (morphine and buprenorphine) and propofol has increased significantly. Approximately 253 000 dogs and 33 000 cats with osteoarthritis are seen by veterinarians in SouthAfrica annually.

The recognition by veterinarians of osteoarthritis in cats appears to be poor and is in need of attention. Carprofen and glucosamine/chondroitin are the most commonly used agents for the treatment of osteoarthritis. Details of the drugs used by veterinarians are given. Knowledge of analgesic drugs has increased significantly over the last 5 years. Continuing education is thought to have played an important role in the changes reported in this study.

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Relationship of orthopedic examination, goniometric measurements, and radiographic signs of degenerative joint disease in cats

Background: Available information suggests a mismatch between radiographic and orthopedic examination findings in cats with DJD. However, the extent of the discrepancy between clinical and radiographic signs of OA in companion animals has not been described in detail. This study aimed to evaluate the relationship between orthopedic examination findings, joint goniometry, and radiographic signs of DJD in 100 cats, in a prospective observational design.

Cat temperament, pain response to palpation, joint crepitus, effusion and thickening were graded. Radiographs of appendicular joints and the axial skeleton were made under sedation. Joint motion was measured by use of a plastic goniometer before and after sedation. Associations between radiographic degenerative joint disease (DJD) and examination findings were assessed to determine sensitivity, specificity and likelihood estimations.

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