The AAPS Journal

, Volume 15, Issue 2, pp 598–607 | Cite as

The Challenges of Assessing Osteoarthritis and Postoperative Pain in Dogs

Review Article Theme:Human and Veterinary Therapeutics: Interspecies Extrapolations and Shared Challenges

Abstract

The challenge of measuring pain in veterinary medicine is compounded by the lack of fully validated, reliable methods to measure and assess pain in nonverbal patients. In human medicine, there are numerous, validated pain assessment tools (PATs) for assessing various, specific types of pain. The advances in human medicine pain management and numerous validated pain scales should serve as incentives and templates to facilitate similar advances in the development of validated PATs for use in dogs (and other species). The limited number of canine PATs constrains our ability to adequately and reliably assess pain. Improving the ability to quantify osteoarthritis and postoperative pain in dogs would enhance the development of analgesics for animals, advance the management of animal pain, facilitate the use of animal pain models in preclinical trials for human analgesics, and provide insight into the quantification of pain responses in humans who lack the ability to adequately communicate. This review describes the need for practical, valid, and reliable PATs for use in veterinary patients and discusses some currently available PATs commonly used to evaluate acute and chronic pain in dogs.

KEY WORDS

pain assessment veterinary pain scales 

REFERENCES

  1. 1.
    International Veterinary Academy of Pain Management. http://www.iasp-pain.org/terms-p.html#Pain.
  2. 2.
    Loewenstein DA, Arguelles S, Bravo M, Freeman RQ, Arguelles T, Acevedo A, et al. Caregivers’ judgments of the functional abilities of the Alzheimer’s disease patient: a comparison of proxy reports and objective measures. J Gerontol B Psychol Sci Soc Sci. 2001;56(2):P78–84.PubMedCrossRefGoogle Scholar
  3. 3.
    Chang PC, Yeh CH. Agreement between child self-report and parent proxy-report to evaluate quality of life in children with cancer. Psychooncology. 2005;14(2):125–34.PubMedCrossRefGoogle Scholar
  4. 4.
    Fuchs-Lacelle S, Hadjistavropoulos T. Development and preliminary validation of the Pain Assessment Checklist for Seniors with Limited Ability to Communicate (PACSLAC). Pain Manag Nurs. 2004;5(1):37–49.PubMedCrossRefGoogle Scholar
  5. 5.
    Schnakers C, Chatelle C, Vanhaudenhuyse A, Majerus S, Ledoux D, Boly M, et al. The Nociceptive Coma scale: a new tool to assess nociception in disorders of consciousness. Pain. 2010;148(2):215–9.PubMedCrossRefGoogle Scholar
  6. 6.
    University of Glasgow Pain and Welfare Research Group. http://www.gla.ac.uk/Schools/Vet/Research/Painandwelfare/. Accessed 14 Sep 2012.
  7. 7.
    Pfizer market research, survey of 200 veterinarians. www.rimadyl.com. Accessed 14 Jan 2010.
  8. 8.
    Vail DM, MacEwen EG. Spontaneously occurring tumors of companion animals as models for human cancer. Cancer Invest. 2000;18(8):781–92.PubMedCrossRefGoogle Scholar
  9. 9.
    American College of Veterinary Anesthesiologists. American College of Veterinary Anesthesiologists’ position paper on the treatment of pain in animals. J Am Vet Med Assoc. 1998;213:628–30.Google Scholar
  10. 10.
    AVMA adopts position regarding animal pain. J Am Vet Med Assoc. 2001;218:1694.Google Scholar
  11. 11.
    Schnitzler A, Ploner M. Neurophysiology and functional neuroanatomy of pain perception. J Clin Neurophysiol. 2000;17(6):592–603.PubMedCrossRefGoogle Scholar
  12. 12.
    The American Animal Hospital Association and the American Association of Feline Practitioners. AAHA/AAFP pain management guidelines for dogs and cats. J Amer Anim Hosp Assoc. 2007;43:235–48.Google Scholar
  13. 13.
    Stallard P, Williams L, Velleman R, Lenton S, McGrath PJ, Taylor G. The development and evaluation of the Pain Indicator for Cognitively Impaired Children (PICIC). Pain. 2002;98(1–2):145–9.PubMedCrossRefGoogle Scholar
  14. 14.
    Hielm-Björkman AK, Kuusela E, Liman A, Markkola A, Saarto E, Huttunen P, et al. Evaluation of methods for assessment of pain associated with chronic osteoarthritis in dogs. J Am Vet Med Assoc. 2003;222(11):1552–8.PubMedCrossRefGoogle Scholar
  15. 15.
    Wiseman ML, Nolan AM, Reid J, Scott EM. Preliminary study on owner-reported behaviour changes associated with chronic pain in dogs. Vet Rec. 2001;149(14):423–4.PubMedCrossRefGoogle Scholar
  16. 16.
    Dobromylskyij P, Flecknell PA, Lascelles BD, et al. Pain assessment. In: Flecknell PA, Waterman-Pearson A, editors. Pain management in animals. London: Saunders; 2000. p. 53–79.CrossRefGoogle Scholar
  17. 17.
    Hansen BD, Lascelles BD, Keene BW, Adams AK, Thomson AE. Evaluation of an accelerometer for at-home monitoring of spontaneous activity in dogs. Am J Vet Res. 2007;68(5):468–75.PubMedCrossRefGoogle Scholar
  18. 18.
    Brown DC, Boston RC, Coyne JC, Farrar JT. Ability of the canine brief pain inventory to detect response to treatment in dogs with osteoarthritis. J Am Vet Med Assoc. 2008;233(8):1278–83.PubMedCrossRefGoogle Scholar
  19. 19.
  20. 20.
  21. 21.
  22. 22.
  23. 23.
    McGrath PJ, Unruh AM. Measurement and assessment of paediatric pain. In: Wall PD, Melzack R, editors. Textbook of pain. 4th ed. London: Churchill Livingstone; 1999. p. 371–82.Google Scholar
  24. 24.
    Aissaoui Y, Zeggwagh AA, Zekraoui A, Abidi K, Abouqal R. Validation of a behavioral pain scale in critically ill, sedated, and mechanically ventilated patients. Anesth Analg. 2005;101(5):1470–6.PubMedCrossRefGoogle Scholar
  25. 25.
    Crellin D, Sullivan TP, Babl FE, O’Sullivan R, Hutchinson A. Analysis of the validation of existing behavioral pain and distress scales for use in the procedural setting. Paediatr Anaesth. 2007;17(8):720–33.PubMedCrossRefGoogle Scholar
  26. 26.
    Soetenga D, Frank J, Pellino T. Assessment of the validity and reliability of the University of Wisconsin Children’s Hospital pain scale for preverbal and nonverbal children. Pediatr Nurs. 1999;25(6):670–6.PubMedGoogle Scholar
  27. 27.
    Bellieni CV. Pain assessment in human fetus and infants. AAPS J. 2012;14(3):456–61.PubMedCrossRefGoogle Scholar
  28. 28.
    Schnakers C, Chatelle C, Demertzi A, Majerus S, Laureys S. What about pain in disorders of consciousness? AAPS J. 2012;14(3):437–44.PubMedCrossRefGoogle Scholar
  29. 29.
    Holen JC, Hjermstad MJ, Loge JH, Fayers PM, Caraceni A, De Conno F, et al. Pain assessment tools: is the content appropriate for use in palliative care? J Pain Symptom Manage. 2006;32(6):567–80.PubMedCrossRefGoogle Scholar
  30. 30.
    Bolognese JA, Schnitzer TJ, Ehrich EW. Response relationship of VAS and Likert scales in osteoarthritis efficacy measurement. Osteoarthritis Cartilage. 2003;11(7):499–507.PubMedCrossRefGoogle Scholar
  31. 31.
    Auburn F, Paqueron X, Langeron O, Coriat P, Riou B. What pain scales do nurses use in the postanaesthesia care unit? Eur J Anaesthesiol. 2003;20(9):745–9.CrossRefGoogle Scholar
  32. 32.
    Jensen MP, Karoly P, Braver S. The measurement of clinical pain intensity: a comparison of six methods. Pain. 1986;27(1):117–26.PubMedCrossRefGoogle Scholar
  33. 33.
    Todd KH, Funk JP. The minimum clinically important difference in physician-assigned visual analog scores. Acad Emerg Med. 1996;3(2):142–6.PubMedCrossRefGoogle Scholar
  34. 34.
    Stahmer SA, Shofer FS, Marino A, Shepherd S, Abbuhl S. Do quantitative changes in pain intensity correlate with pain relief and satisfaction? Acad Emerg Med. 1998;5(9):851–7.PubMedCrossRefGoogle Scholar
  35. 35.
    Lee JS, Hobden E, Stiell AG, Wells GA. Clinically important change in the visual analog scale after adequate pain control. Acad Emerg Med. 2003;10(10):1128–30.PubMedCrossRefGoogle Scholar
  36. 36.
    Collins SL, Moore RA, McQuay HJ. The visual analogue pain intensity scale: what is moderate pain in millimeters? Pain. 1997;72(1–2):95–7.PubMedCrossRefGoogle Scholar
  37. 37.
    Hoeksma HL, van den Ende CH, Breedveld FC, Ronday HK, Dekker J. A comparison of the OARSI response criteria with patient’s global assessment in patients with osteoarthritis of the hip treated with a non-pharmacological intervention. Osteoarthritis Cartilage. 2006;14(1):77–81.PubMedCrossRefGoogle Scholar
  38. 38.
    Hellyer PW. Pain assessment and multimodal analgesic therapy in dogs and cats. ABVP Proceedings. San Antonio, TX. 2006.Google Scholar
  39. 39.
    Pesudovs K, Noble BA. Improving subjective scaling of pain using Rasch analysis. J Pain. 2005;6(9):630–6.PubMedCrossRefGoogle Scholar
  40. 40.
    Lee JS. Pain measurement: understanding existing tools and their application in the emergency department. Emerg Med. 2001;13(3):279–87.CrossRefGoogle Scholar
  41. 41.
    Waxman AS, Robinson DA, Evans RB, Hulse DA, Innes JF, Conzemius MG. Relationship between objective and subjective assessment of limb function in normal dogs with experimentally induces lameness. Vet Surg. 2008;37(3):241–6.PubMedCrossRefGoogle Scholar
  42. 42.
    Impellizeri JA, Tetrick MA, Muir P. Effect of weight reduction on clinical signs of lameness in dogs with hip osteoarthritis. J Am Vet Med Assoc. 2000;216(7):1089–91.PubMedCrossRefGoogle Scholar
  43. 43.
    Renberg WC. Evaluation of the lame patient. Vet Clin North Am Small Anim Pract. 2001;31:1–16.PubMedGoogle Scholar
  44. 44.
    Kapatkin AS, Tomasic M, Beech J, Meadows C, Boston RC, Mayhew PD, et al. Effects of electrostimulated acupuncture on ground reaction forces and pain scores in dogs with chronic elbow joint arthritis. J Am Vet Med Assoc. 2006;228(9):1350–4.PubMedCrossRefGoogle Scholar
  45. 45.
    Theiler R, Sangha O, Schaeren S, Michel BA, Tyndall A, Dick W, et al. Superior responsiveness of the pain and function sections of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) as compared to the Lequesne-Algofunctional Index in patients with osteoarthritis of the lower extremities. Osteoarthritis Cartilage. 1999;7(6):515–9.PubMedCrossRefGoogle Scholar
  46. 46.
    Roos EM, Klässbo M, Lohmander LS. WOMAC Osteoarthritis Index. Reliability, validity, and responsiveness in patients with arthroscopically assessed osteoarthritis. Western Ontario and MacMaster Universities. Scand J Rheumatol. 1999;28(4):210–5.PubMedCrossRefGoogle Scholar
  47. 47.
    Baron G, Tubach F, Ravaud P, Logeart I, Dougados M. Validation of a short form of the Western Ontario and McMaster Universities Osteoarthritis Index function subscale in hip and knee osteoarthritis. Arthritis Rheum. 2007;57(4):633–8.PubMedCrossRefGoogle Scholar
  48. 48.
    Dawson J, Linsell L, Doll H, Zondervan K, Rose P, Carr A, et al. Assessment of the Lequesne index of severity for osteoarthritis of the hip in an elderly population. Osteoarthritis Cartilage. 2005;13(10):854–60.PubMedCrossRefGoogle Scholar
  49. 49.
    Lynch S, Savary-Bataille K, Leeuw B, Argyle DJ. Development of a questionnaire assessing health-related quality of life in dogs and cats with cancer. Vet Comp Oncol. 2011;9(3):172–82.PubMedCrossRefGoogle Scholar
  50. 50.
    Lascelles BD, Gaynor JS, Smith ES, Roe SC, Marcellin-Little DJ, Davidson G, et al. Amantadine in a multimodal analgesic regimen for alleviation of refractory osteoarthritis pain in dogs. J Vet Intern Med. 2008;22(1):53–9.PubMedCrossRefGoogle Scholar
  51. 51.
    Gingerich DA, Strobel JD. Use of client-specific outcome measures to assess treatment effects in geriatric, arthritic dogs: controlled clinical evaluation of a nutraceutical. Vet Ther. 2003;4(4):376–86.PubMedGoogle Scholar
  52. 52.
    Brown DC, Boston RC, Coyne JC, Farrar JT. Development and psychometric testing of an instrument designed to measure chronic pain in dogs with osteoarthritis. Am J Vet Res. 2007;68(6):631–7.PubMedCrossRefGoogle Scholar
  53. 53.
    Brown DC, Boston R, Coyne JC, Farrar JT. A novel approach to the use of animals in studies of pain: validation of the canine brief pain inventory in canine bone cancer. Pain Med. 2009;10(1):133–42.PubMedCrossRefGoogle Scholar
  54. 54.
    Cleeland CS, Ryan KM. Pain assessment: global use of the brief pain inventory. Ann Acad Med Singapore. 1994;23(2):129–38.PubMedGoogle Scholar
  55. 55.
    Keller S, Bann CM, Dodd SL, Schein J, Mendoza TR, Cleeland CS. Validity of the brief pain inventory for use in documenting the outcomes of patients with noncancer pain. Clin J Pain. 2004;20(5):309–18.PubMedCrossRefGoogle Scholar
  56. 56.
    Kapstad H, Rokne B, Stavem K. Psychometric properties of the brief pain inventory among patients with osteoarthritis undergoing total hip replacement surgery. Health Qual Life Outcomes. 2010;8(148):1–8.Google Scholar
  57. 57.
    Tyler EJ, Jensen MP, Engel JM, Schwartz L. The reliability and validity of pain interference measures in persons with cerebral palsy. Arch Phys Med Rehabil. 2002;83(2):236–9.PubMedCrossRefGoogle Scholar
  58. 58.
    Kumar SP. Utilization of brief pain inventory as an assessment tool for pain in patients with cancer: a focused review. Indian J Palliat Care. 2011;17(2):108–15.PubMedCrossRefGoogle Scholar
  59. 59.
    Hielm-Bjorkman AK, Rita H, Tulamo RM. Psychometric testing of the Helsinki chronic pain index by completion of a questionnaire in Finnish by owners of dogs with chronic signs of pain caused by osteoarthritis. Am J Vet Res. 2009;70(6):727–34.PubMedCrossRefGoogle Scholar
  60. 60.
    Wiseman-Orr ML, Scott EM, Reid J, Nolan AM. Validation of a structured questionnaire as an instrument to measure chronic pain in dogs on the basis of effects on health-related quality of life. Am J Vet Res. 2006;67(11):1826–36.PubMedCrossRefGoogle Scholar
  61. 61.
    Wiseman-Orr ML, Nolan AM, Reid J, Scott EM. Development of a questionnaire to measure the effects of chronic pain on health-related quality of life in dogs. Am J Res. 2004;65(8):1077–84.CrossRefGoogle Scholar
  62. 62.
    Hercock CA, Pinchbeck G, Giejda A, Clegg PD, Innes JF. Validation of a client-based clinical metrology instrument for the evaluation of canine elbow osteoarthritis. J Small Anim Pract. 2009;50(6):266–71.PubMedCrossRefGoogle Scholar
  63. 63.
    Holton L, Reid J, Scott EM, Pawson P, Nolan A. Development of a behaviour-based scale to measure acute pain in dogs. Vet Rec. 2001;148(17):525–31.PubMedCrossRefGoogle Scholar
  64. 64.
    Melzack R. The short-form McGill pain questionnaire. Pain. 1987;30(2):191–7.PubMedCrossRefGoogle Scholar
  65. 65.
    Morton CM, Reid J, Scott EM, Holton LL, Nolan AM. Application of a scaling model to establish and validate an interval level pain scale for assessment of acute pain in dogs. Am J Vet Res. 2005;66(12):2154–66.PubMedCrossRefGoogle Scholar
  66. 66.
    Reid J, Nolan AM, Hughes JML, Lascelles BD, Pawson P, Scott EM. Development of the short-form Glasgow Composite Measure Pain Scale (CMPS-SF) and derivation of an analgesic intervention score. Anim Welf. 2007;16S:97–104.Google Scholar
  67. 67.
    Murrell JC, Psatha EP, Scott EM, Reid J, Hellebrekers LJ. Application of a modified form of the Glasgow pain scale in a veterinary teaching centre in the Netherlands. Vet Rec. 2008;162(13):403–8.PubMedCrossRefGoogle Scholar
  68. 68.
    Firth AM, Haldane SL. Development of a scale to evaluate postoperative pain in dogs. J Am Vet Med Assoc. 1999;214(5):651–9.PubMedGoogle Scholar
  69. 69.
    McGrath PJ, Johnson G, Goodman JT, et al. CHEOPS: a behavioral scale for rating postoperative pain in children. In: Fields HL, Dubner R, Cervero F, editors. Advances in pain research and therapy, vol. 9. NY: Raven; 1985. p. 395–402.Google Scholar
  70. 70.
    Conzemius MG, Hill CM, Sammarco JL, Perkowski SZ. Correlation between subjective and objective measures used to determine severity of postoperative pain in dogs. J Am Vet Med Assoc. 1997;210(11):1619–22.PubMedGoogle Scholar
  71. 71.
    Holton LL, Scott EM, Nolan AM, Reid J, Welsh E. Relationship between physiological factors and clinical pain in dogs scored using a numerical rating scale. J Small Anim Pract. 1998;39(10):469–74.PubMedCrossRefGoogle Scholar
  72. 72.
    Gellasch KL, Kruse-Elliott KT, Osmond CS, Shih AN, Bjorling DE. Comparison of transdermal administration of fentanyl versus intramuscular administration of butorphanol for analgesia after onychectomy in cats. J Am Vet Med Assoc. 2002;220(7):1020–4.PubMedCrossRefGoogle Scholar
  73. 73.
    Drendel AL, Kelly BT, Ali S. Pain assessment for children: overcoming challenges and optimizing care. Pediatr Emerg Care. 2011;27(8):773–81.PubMedCrossRefGoogle Scholar
  74. 74.
    Marco CA, Plewa MC, Buderer N, Bowles J, Lee J. Self-reported pain scores in the emergency department: lack association with vital signs. Acad Emerg Med. 2006;13(9):974–9.PubMedCrossRefGoogle Scholar
  75. 75.
    Bennett RL, DeCamp CE, Flo GL, Hauptman JG, Stajich M. Kinematic gait analysis in dogs with hip dysplasia. Am J Vet Res. 1996;57(7):966–71.PubMedGoogle Scholar
  76. 76.
    Lequang T, Maitre P, Roger T, et al. Is a pressure walkway system able to highlight a lameness in dog? J Anim Vet Adv. 2009;8(10):1936–44.Google Scholar
  77. 77.
    Lascelles BD, Roe SC, Smith E, Reynolds L, Markham J, Marcellin-Little D, et al. Evaluation of a pressure walkway system for measurement of vertical limb forces in clinically normal dogs. Am J Vet Res. 2006;67(2):277–82.PubMedCrossRefGoogle Scholar
  78. 78.
    Brebner NS, Moens NM, Runciman JR. Evaluation of a treadmill with integrated force plates for kinetic gait analysis of sound and lame dogs at a trot. Vet Comp Orthop Traumatol. 2006;19(4):205–12.PubMedGoogle Scholar
  79. 79.
    Gillette RL, Angle TC. Recent developments in canine locomotor analysis: a review. Vet J. 2008;178(2):165–76.PubMedCrossRefGoogle Scholar
  80. 80.
    Oosterlinck M, Bosmans T, Gasthuys F, Polis I, Van Ryssen B, Dewulf J, et al. Accuracy of pressure plate kinetic asymmetry indices and their correlation with visual gait assessment scores in lame and nonlame dogs. Am J Vet Res. 2011;72(6):820–5.PubMedCrossRefGoogle Scholar
  81. 81.
    Hortsman CL, Conzemius MG, Evans R, Gordon WJ. Assessing the efficacy of perioperative oral carprofen after cranial cruciate surgery using noninvasive, objective pressure platform gait analysis. Vet Surg. 2004;33(3):286–92.CrossRefGoogle Scholar
  82. 82.
    van Klaveren NJ, Suwankong N, De Boer S, van den Brom WE, Voorhout G, Hazewinkel HA, et al. Force plate analysis before and after dorsal decompression for treatment of degenerative lumbosacral stenosis in dogs. Vet Surg. 2005;34(5):450–6.PubMedCrossRefGoogle Scholar
  83. 83.
    Budsberg SC, Johnston SA, Schwarz PD, DeCamp CE, Claxton R. Efficacy of etodolac for the treatment of osteoarthritis of the hip joints in dogs. J Am Vet Med Assoc. 1999;214(2):206–10.PubMedGoogle Scholar
  84. 84.
    Bockstahler BA, Henninger W, Müller M, Mayrhofer E, Peham C, Podbregar I. Influence of borderline hip dysplasia on joint kinematics of clinically sound Belgian Shepherd dogs. Am J Vet Res. 2007;68(3):271–6.PubMedCrossRefGoogle Scholar
  85. 85.
    Martinez SA, DeCamp CE, Cimino D, et al. Repeatability of kinematic variables in the normal gait of adult Greyhounds. Vet Surg. 1995;24:431–2.Google Scholar
  86. 86.
    Rumph PF, Kincaid SA, Baird DK, Kammermann JR, Visco DM, Goetze LF. Vertical ground reaction force distribution using experimentally induced acute synovitis in dogs. Am J Vet Res. 1993;54(3):365–9.PubMedGoogle Scholar
  87. 87.
    DeCamp CE. Kinetic and kinematic gait analysis and the assessment of lameness in the dog. Vet Clin North Am. 1997;27(4):825–40.Google Scholar
  88. 88.
    Hudson JT, Slater MR, Taylor L, Scott HM, Kerwin SC. Assessing repeatability and validity of a visual analogue scale questionnaire for use in assessing pain and lameness in dogs. Am J Vet Res. 2004;65(12):1634–43.PubMedCrossRefGoogle Scholar
  89. 89.
    Innes JF, Fuller CJ, Grover ER, Kelly AL, Burn JF. Randomized, double-blind, placebo-controlled parallel group study of P54FP for the treatment of dogs with osteoarthritis. Vet Rec. 2003;152(15):457–60.PubMedCrossRefGoogle Scholar
  90. 90.
    Vasseur PB, Johnson AL, Budsberg SC, Lincoln JD, Toombs JP, Whitehair JG, et al. Randomized, controlled trial of efficacy of carprofen, a nonsteroidal anti-inflammatory drug, in the treatment of osteoarthritis in dogs. J Am Vet Med Assoc. 1995;206(6):807–11.PubMedGoogle Scholar
  91. 91.
    Cross AR, Budsberg SC, Keefe TJ. Kinetic gait analysis assessment of meloxicam efficacy in a sodium urate-induced synovitis model in dogs. Am J Vet Res. 1997;58(6):626–31.PubMedGoogle Scholar
  92. 92.
    McLaughlin R, Roush JK. A comparison of two surgical approaches to the scapulohumeral joint in dogs. Vet Surg. 1995;24(3):207–14.PubMedCrossRefGoogle Scholar
  93. 93.
    Budsberg SC, Jevens DJ, Brown J, Foutz TL, DeCamp CE, Reece L. Evaluation of limb symmetry indices using ground reaction forces in healthy dogs. Am J Vet Res. 1993;54(10):1569–74.PubMedGoogle Scholar
  94. 94.
    Rumph PF, Steiss JE, West MS. Interday variation in ground reaction force in clinically normal Greyhounds at the trot. Am J Vet Res. 1999;60(6):679–83.PubMedGoogle Scholar
  95. 95.
    Liikavainio T, Bragge T, Hakkarainen M, Karjalainen PA, Arokoski JP. Gait and muscle activation changes in men with knee osteoarthritis. Knee. 2010;17(1):69–76.PubMedCrossRefGoogle Scholar
  96. 96.
    Allet L, Armand S, de Bie RA, Pataky Z, Aminian K, Herrmann FR, et al. Gait alterations of diabetic patients while walking on different surfaces. Gait Posture. 2009;29(3):488–93.PubMedCrossRefGoogle Scholar
  97. 97.
    Culhane KM, O’Connor M, Lyons D, Lyons GM. Accelerometers in rehabilitation medicine for older adults. Age Aging. 2005;34(6):556–60.CrossRefGoogle Scholar
  98. 98.
    Wernham BG, Trumpatori B, Hash J, Lipsett J, Davidson G, Wackerow P, et al. Dose reduction of meloxicam in dogs with osteoarthritis-associated pain and impaired mobility. J Vet Intern Med. 2011;25(6):1298–305.PubMedCrossRefGoogle Scholar
  99. 99.
    Guidance for Industry Clinical Development Programs for Drugs, Devices, and Biological Products Intended for the Treatment of Osteoarthritis (OA). http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/UCM071577.pdf. Accessed 10 Sept 2012.
  100. 100.
    Hofmeister EH, King J, Read MR, Budsberg SC. Sample size and statistical power in the small animal analgesia literature. J Small Anim Pract. 2007;48(2):76–9.PubMedCrossRefGoogle Scholar

Copyright information

© American Association of Pharmaceutical Scientists 2013

Authors and Affiliations

  1. 1.Office of New Animal Drug Evaluation, HFV-114, Center for Veterinary MedicineFood and Drug AdministrationRockvilleUSA

Personalised recommendations