By Matt Gurney - RCVS & EBVS European Specialist in Veterinary Anaesthesia & Analgesia
Maia is a cute little Parson Terrier who was referred by Portsmouth Vets4Pets to Anderson Moores with a long-term skipping lameness on her left pelvic limb. At one point, Maia became wary of the other dog in the house and would often attack him. I often attribute such behavioural changes as a sign of pain. Over time, the skipping became more frequent and a course of meloxicam was prescribed. This resulted in an improvement in behaviour towards other dogs.
Keen to get to the bottom of the problem, Maia’s vet took some stifle radiographs, which were normal. Palpation for a patella luxation was unrewarding. With the obvious differentials ruled out, Maia then had an appointment with our Head of Orthopaedics, Andy Moores. After examining Maia, Andy was also a little perplexed, having been unable to find a specific source which could account for Maia’s problem.
Further clues to the source of the problem were evident when Maia’s meloxicam course came to an end and she started chewing her left thoracic limb and, once again, became less tolerant of the other dog in the house. This led Andy to question whether the problem was actually in the thoracic limb and the pelvic was a non-significant terrier skipping lameness – a frustrating problem but one that rarely requires treatment. Maia was not showing a lameness from the front leg but, on examination, there was now pain evident in her left elbow.
CT of the elbow identified evidence of humeroulnar incongruity and secondary osteoarthritis, which could account for the elbow discomfort. Since the localisation of Maia’s problem was not straight-forward, an intraarticular steroid-bupivacaine injection was trialled prior to committing to surgical options. This resulted in a significant improvement in Maia’s stiffness and behaviours but it was relatively short-lived. Therefore, Maia returned for a left-sided bioblique proximal ulnar osteotomy to improve the incongruity.
Maia’s surgery went well and her road to recovery was started by our physiotherapy team. Our aim is for every surgery patient to have a tailored rehabilitation plan for their owners to work on at home. Encouraging movement in the operated area without causing pain has been shown to improve strength and hasten recovery. In the weeks after her surgery, Maia made excellent progress.
Over time, Danielle, Maia’s owner, noticed a recurrence of some of Maia’s previous signs which she associated with pain. In discussion with Laura Batten, Maia’s physiotherapist, it became clear that pain was once again a problem. Laura recommended a consultation with our pain management service, which is when I met Maia.
My main objective is getting a handle on the degree of pain and how that pain affects the patient on a day-to-day basis – we always say that pain is whatever the patient says it is. I find the Canine Brief Pain Inventory1 really useful for assessing this. Maia scored highly on both elements of the CBPI, giving us clear information that further analgesics were necessary. Explaining to Danielle the concept of maladaptive pain – pain which serves no useful purpose – was really useful to her in her understanding of what we are treating and trying to achieve. This also helps to reinforce the importance of ongoing analgesic provision, but also the importance of targeted rehabilitation through exercise and physiotherapy in an overall multimodal approach to pain.
Given the high likelihood that Maia was experiencing central sensitisation, I selected an analgesic which targets the NMDA receptor. This receptor is located in the dorsal horn of the spinal cord and is activated with long-term or intense pain. The efficacy of amantadine has been documented in dogs with osteoarthritis2 and one case describes its use in a dog with neuropathic pain3.
Maia’s response to the meloxicam amantadine combination has been excellent and her owner is really pleased. Our aim right now is to keep Maia pain free to allow her to continue her physiotherapy. As with many chronic pain drugs, the long-term use of amantadine is based on experience with no information other than this to guide prescribing4. Our experience to date is in agreement with the work of Lascelles et al (2008) that amantadine significantly improves comfort in such patients. As well as osteoarthritis, we use amantadine as a second line in many chronic pain cases.
Maia is a great example of how an integrated approach to patient care is important. With a collaborative approach between orthopaedic surgery, physiotherapy and pain management, we have given this lovely little dog a pain-free life.
Our pain specialists at Anderson Moores see referred cases from across the south of England and are always pleased to offer advice on chronic pain cases.