The requirement for effective and suitable pain management is as necessary for avian species as it is for any other animals in our care. The difficulty that often arises in species not commonly seen within practice is that individuals can often struggle to confidently assess, diagnose and treat pain. Historically, and to a certain extent today, birds have been more challenging patients, and ones which have an increased likelihood of perishing when compared to a dog or a cat patient. While other factors cannot be minimised, and the avian patient is at times challenging, the fact that pain has a high impact upon the success or failure of a patient’s outcome within practice cannot be negated or ignored.
Recognising pain in the avian patient
To treat pain effectively, one must first be able to recognise it. In the avian patient there are common signs to look out for which could be indicative of pain. This list is not exhaustive, but it can often include lethargy, dropped wings (Figure 1), a preference for certain legs, inability or reluctance to perform normal behaviours, reduced appetite, open beak breathing breaking and narrowing of the eyes (Figure 2) (Pollock, 2011). In addition, self-trauma can often be seen, especially in parrot species which will often damage their own feathers within the painful areas. However, what can make recognising pain in avian patients challenging is the fact that a sick patient who is not necessarily in pain will often show the same clinical signs, as avian patients are naturally inclined to hide any weakness for as long as possible. As such, a thorough clinical examination should be performed on a patient who shows these signs to determine if there are any injuries, such as broken bones. Other diagnostics such as radiography can also be effective to determine this.
A key thought process to remember is “would you provide analgesia to an animal of another species for what you are seeing?” If the answer is yes, then the likely conclusion is that the avian patient needs treatment for pain as well.
Creating a treatment plan
Once pain has been identified then a suitable decision on a treatment plan must be made. This is more complex in the avian patient given the diversity of the bird family, with around 10,000 species being agreed upon and recognised globally. This, in turn, further deepens in comparative complexity given that numerous scientific publications have shown that different dose requirements and types are necessary among the avian family. As such, these factors can make extrapolating dosages challenging as the suitable analgesic provision for a budgerigar, a chicken or a falcon, for example, may differ.
[Creating treatment plan] is more complex in the avian patient given the diversity of the bird family, with around 10,000 species being… recognised globally
Medication
The provision of medications to birds (Figure 3) is often performed via three methods – intramuscular injection, intravenously or orally – and this is true of analgesia too. It is important to note that some non-analgesic medications provided intramuscularly can be painful and cause localised trauma, resulting in the need for analgesia when there was no need before. In turn, provision of analgesia should not be reactive, and better practice is to provide pre-emptive analgesia which is especially true in surgical cases. Analgesia relieves pain without blocking the conduction of nerve impulses as it affects the sensory perception of pain (Tully, 2017); however, it can also affect the conscious state of a patient and in avian species who naturally perch and feed frequently to maintain condition, these factors also need to be considered.
Opioids
Opioid analgesia is arguably one of the most used pain management techniques in practice. Opioids act on the kappa, mu or delta receptors to block perception of pain in an individual. Studies in birds have shown a higher presence of kappa receptors when compared to mu receptors in most species. As such, the use of butorphanol in birds is the most commonly used injectable analgesic, given it has been seen to provide a more consistent effect. However, studies in birds of prey are showing that the potential for buprenorphine to be an effective alternative is increasing. It is, however, important to note that buprenorphine has been shown to have comparatively little effect on parrot species.
Studies in birds have shown a higher presence of kappa receptors when compared to mu receptors in most species. As such, the use of butorphanol in birds is the most commonly used injectable analgesic
NSAIDs
The other most commonly used drugs for avian analgesia are non-steroidal anti-inflammatory drugs (NSAIDs). These target the cyclooxygenase (COX) enzyme in the arachidonic acid pathway. COX-2 inhibitors are preferred, given the reduction in the physical side effects seen with COX-1. In particular, the reduction of side effects seen within the renal and gastrointestinal systems is marked (Hawkins, 2006). Meloxicam is a frequently used and effective COX-2 inhibitor, and a good option for orally medicating birds.
Commonly used dosages
Hawkins et al. (2013) suggest these dosages for commonly used analgesic medications:
- Butorphanol: 0.5–3.0 mg/kg IM q4–6h
- Buprenorphine: 0.25–0.5 mg/kg IM q6h
- Gabapentin: 10 mg/kg PO q12h
- Hydromorphone HCl: 0.6 mg/kg IM q6h
- Meloxicam: 0.2–0.5 mg/kg PO or IM q24h
- Tramadol HCl (raptors): 5–11 mg/kg PO q12h
- Tramadol HCl (psittacines): 15–30 mg/kg q6h
Monitoring pain in avian patients
Currently no universally accepted pain scale is in place for monitoring avian patients. Presence of the signs mentioned earlier can indicate pain and thus the need for an intervention; however, these are subjective. In turn, some of the signs described can indicate stress; therefore, it is important to minimise stress for the patient within the hospital environment. Keeping the patient within a quiet ward, providing suitable patient items and minimising interference are all important steps to decrease stress.
Keeping the patient within a quiet ward, providing suitable patient items and minimising interference are all important steps to decrease stress
Conclusion
The provision of analgesia in avian patients can often be seen as challenging; however, by following simple steps the comfort of these patients can be maintained, as their requirements dictate.
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