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Oct 4, 2011 - rabbits and guinea pigs by a sample of veterinarians in New. Zealand. AJ Keown ... interest in continuing education regarding pain recognition and .... Survey. An anonymous online survey (see Supplementary Table 11) was.
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Attitudes towards perception and management of pain in rabbits and guinea pigs by a sample of veterinarians in New Zealand a

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AJ Keown , MJ Farnworth & NJ Adams

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Department of Natural Sciences, Unitec Institute of Technology, Private Bag 92025, Auckland, 1025, New Zealand Available online: 04 Oct 2011

To cite this article: AJ Keown, MJ Farnworth & NJ Adams (2011): Attitudes towards perception and management of pain in rabbits and guinea pigs by a sample of veterinarians in New Zealand, New Zealand Veterinary Journal, 59:6, 305-310 To link to this article: http://dx.doi.org/10.1080/00480169.2011.609477

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New Zealand Veterinary Journal 59(6), 305–310, 2011

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Scientific Article

Attitudes towards perception and management of pain in rabbits and guinea pigs by a sample of veterinarians in New Zealand AJ Keown*, MJ Farnworth*x and NJ Adams*

Abstract

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AIMS: To determine the perceptions of a sample of veterinarians in New Zealand regarding pain and pain management in rabbits and guinea pigs. METHODS: Questionnaires were distributed to all members of the Companion Animal Society, part of the New Zealand Veterinary Association. The questionnaire gathered information on the demographics of respondents, obtained an assessment by veterinarians of the level of pain associated with clinical procedures for rabbits and guinea pigs, established the willingness of respondents to perform these, obtained information on the anaesthetics and analgesics used during these procedures, and the factors associated with selecting different types of drug. The level of knowledge of respondents and interest in continuing education regarding pain recognition and management in these species was also assessed. RESULTS: A total of 155/610 (25.4%) responses were obtained. Rodents and lagomorphs accounted for 0–5% of the total caseload in the practices of most (133/155; 86%) respondents. Anticipated pain scores differed for different procedures (p50.001) but did not differ between male and female respondents or between species of animal. There were also differences between procedures in the respondents willingness to perform them (p50.001). Selection of anaesthetics and analgesics was mainly determined by the amount of information available for the species, and ketamine was the drug most commonly used. Many veterinarians felt their level of knowledge regarding the recognition and treatment of pain in rabbits and guinea pigs was inadequate. CONCLUSIONS: Rabbits and guinea pigs represented a small percentage of the caseload of veterinarians in this study. From an animal welfare perspective this may be of concern as, anecdotally, these species are common pets. However, further study regarding the actual number of these animals kept as pets in New Zealand is required for validation. Veterinary perception of anticipated pain, and willingness to perform procedures, varied between procedures, but was not influenced by gender of veterinarian. Many respondents felt their knowledge of issues relating to pain recognition, anaesthesia and analgesia in rabbits and guinea pigs was inadequate. CLINICAL RELEVANCE: Understanding how veterinarians choose to provide analgesia or when they decline to perform

* Department of Natural Sciences, Unitec Institute of Technology, Private Bag 92025, Auckland 1025, New Zealand. x Author for correspondence. Email: [email protected]

surgeries for rabbits and guinea pigs may provide significant information for targeting professional development, and improving animal welfare. KEY WORDS: Attitudes, guinea pig, pain, rabbit, treatment, welfare, rodent, lagomorph

Introduction The recognition, evaluation and alleviation of pain associated with surgery, injury or disease are fundamental objectives of veterinary medicine. Associated with advances in neurophysiology and an understanding of neural function, the mechanisms by which animals perceive pain is now better known (Johnson 2005). Concomitantly, veterinary attitudes have changed, and pain is no longer considered as self-manageable, or in some cases, beneficial to the animal (Hugonnard et al. 2000; Shaffran 2005a). Current attitudes of veterinarians towards pain identify it as a serious clinical issue that needs to be managed (Stafford and Mellor 2007). Provision of anaesthetic and analgesic drugs to animals by veterinarians is the most widely used method of pain management. In New Zealand, research into pain perception and treatment by veterinarians has focussed on large companion animals, such as cats and dogs (Williams et al. 2005), horses (Waran et al. 2010), or cattle (Laven et al. 2009). Internationally, there is also a substantial body of literature addressing pain management in laboratory animals (Roughan and Flecknell 2006; Karas et al. 2008; Lipman et al. 2008), which often focussed on pain associated with more invasive procedures and manipulations (e.g. Farnworth et al. 2011). A number of papers detail the action pathways of certain drugs, and provide suggested doses used in small mammals (e.g. Flecknell 1998; Kohn et al. 2007; Lipman et al. 2008), and some authors suggest drug doses specifically for analgesia in rodents and lagomorphs (Johnston 2005; Shaffran 2005b). However, there is a relative paucity of information regarding pain recognition, and anaesthetic and analgesic protocols for rodents and lagomorphs outside laboratories. Anecdotal reports suggest rabbits and guinea pigs, as well as other rodents, are common companion animals in New Zealand. This is consistent with indications from the United States of America that suggest a large population of rabbits and guinea pigs is probable (Wise et al. 2002). Despite this, no papers are currently

CAS NSAID NZVA

Companion Animal Society Non-steroidal anti-inflammatory drug(s) New Zealand Veterinary Association

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New Zealand Veterinary Journal 59(6), 2011

available reporting on perceptions of pain and provision of analgesia for these animals by veterinarians in New Zealand. Here, we provide the first such information on this topic, and explore factors that might explain variations in provision of pain relief. The literature indicates that use of analgesics by veterinarians for treatment of pain in animals may differ depending on the amount of time since graduation (Doohoo and Doohoo 1996), gender of the veterinarian (Lascelles et al. 1999), and the species of animal being treated (Lascelles et al. 1999; Williams et al. 2005).

Materials and methods

Keown et al.

incomplete or ambiguous were classified as missing. Departures from parity in gender ratio of veterinarians were tested using a one-sample w2 test. Whether the time from graduation was independent of the proportion of female and male respondents and whether willingness to perform a procedure was associated with the species of animal were examined using contingency tables. A Mann-Whitney U test was used to assess differences in pain ratings between the two species for the different procedures. The Kruskal-Wallis protocol was used to examine differences in perceived pain score and willingness to perform particular procedures among different procedures and year of graduation. Where appropriate, post-hoc analyses were used to examine pairwise comparisons. Results were considered significant if p0.05.

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Survey

An anonymous online survey (see Supplementary Table 11) was developed similar to that used by Williams et al. (2005) and Waran et al. (2010). Invitation to participate was sent to veterinary practitioners who were current members of the Companion Animal Society (CAS) of the New Zealand Veterinary Association (NZVA). As of 2010, all 610 members of the CAS were qualified veterinarians with a gender distribution of 51% female to 49% male (S Blaikie,2 pers. comm.). The survey was created and distributed using an online survey system (www.surveymonkey. com). This research was approved by the Unitec (human) Research Ethics Committee, Auckland, New Zealand. The survey comprised four main sections. The first section covered demographic data, i.e. gender of respondent, year of graduation, institution of qualification, and percentage of total caseload constituted by rodents and lagomorphs, comprising rabbits, guinea pigs, rats and mice, although rats and mice are not considered further. The next section asked respondents to score the pain experienced by animals associated with a range of procedures, viz spay, neuter, abscess, tumour removal, teeth, and orthopaedics, conducted by veterinarians. Anticipated pain was scored on a 10-point scale, where 0¼no pain whatsoever, and 10¼worst pain imaginable. Descriptions of the anaesthetic and analgesic protocols utilised for the surgical procedures were also requested, as well as whether veterinarians would decline (or not) to perform each procedure. The third required respondents to score the importance of factors influencing their choice of drug class, viz non-steroidal antiinflammatory drugs (NSAID), opioids or corticosteroids, to manage pain. Factors included information available for species, analgesic potency, anti-inflammatory effects, potential side effects, ease of administration, cost, need for record keeping, and personal safety. Scoring was on a five-point Likert scale (Likert 1932), ranging from 1 (not important) to 5 (extremely important). In the final section, the perceptions of respondents regarding personal knowledge of pain recognition and treatments/strategies for eliminating pain in rodents and lagomorphs, and personal interest in continuing education in this field, were assessed. Statistical analysis

Data were analysed using predictive analytical software v18.0 for Windows (IBM Inc., Chicago IL, USA). Responses which were

Results Of the 610 members of CAS (NZVA membership statistics 2010), 155 (25.4%) responded. A total of 95/155 (61.3%) identified themselves as female, and 51/155 (32.9%) as male; 9/155 (5.8%) did not respond. There was a significant gender bias in the respondents (w2¼13.260; df¼1; p50.001). The majority of respondents (118/155; 76.1%) graduated in New Zealand. Respondents also graduated in the United Kingdom (15/155; 9.7%), Australia (10/155; 6.5%), the USA (5/155; 3.2%), and other (6/155; 3.9%); a single respondent provided no answer. Respondents were represented by more graduates from recent decades, and were more likely to be female (w2¼20.197; df¼4; p50.001) (Table 1). The majority of respondents had rabbits and guinea pigs within their caseload (142/150; 94.7%, and 82/107; 76.6%, respectively). Rodents and lagomorphs, comprised of rabbits, guinea pigs, rats and mice, represented a maximum of 15% of the total caseload of respondents, with. 133/155 (85.8%) having a total caseload percentage of 0–5%, 20/155 (12.9%) a caseload percentage of 6–10%, and 2/155 (1.3%) a caseload percentage of 11–15%. Orthopaedic procedures were scored as the most painful, and procedures on teeth the least. The pain scores of the different procedures differed for both rabbits (w2¼378.662; df¼5; p50.001) and guinea pigs (w2¼259.961; df¼5; p50.001). There were no differences in pain score between species for any of the procedures, or between male and female respondents in the pain scores given for any of the procedures. Table 1. Number (and percentage) of responses for decade of graduation and gender of 155 veterinarians in New Zealand who responded to a questionnaire on anaesthesia and pain management in rodents and lagomorphs. Number of graduates Decade

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http://dx.doi.org/10.1080/00480169.2011.609477 S Blaikie, Secretary of CAS, Kapiti Coast, New Zealand

Male

Female

1960–1969

2 (1.3)

2 (4)

0 (0)

1970–1979

12 (7.7)

9 (18)

3 (3)

1980–1989

39 (25.2)

16 (31)

19 (20)

1990–1999

48 (31.0)

14 (27)

30 (32)

2000–2009

54 (34.8)

10 (20)

43 (45)

155a

51

95

Total 1

Total

a

Total number differs from sum of adjacent columns due to missing values

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New Zealand Veterinary Journal 59(6), 2011

There were differences in pain scores between decades of graduation for three individual procedures, namely spaying rabbits (p¼0.012), tumour removal in rabbits (p¼0.009), and spaying guinea pigs (p¼0.017). Post-hoc analysis (Tukey) indicated the differences lay between veterinary graduates in 1970–1979 and 2000–2009 for spaying of rabbits, and between 1970–1979 and 1980–1989, and between 1990–1999 and 2000–2009 for both tumour removal in rabbits and spaying guinea pigs.

Table 3. Importance of factors, in descending order of importance, relating to selection of drug classes as ranked by 155 veterinarians in New Zealand who responded to a questionnaire on anaesthesia and pain management in rodents and lagomorphs.

Respondents were more likely to decline to spay a guinea pig than they were to spay a rabbit (w2¼10.808; df¼2; p¼0.004). No differences were found between male and female respondents with respect to willingness to perform a procedure. However, differences in willingness to perform were found amongst the different procedures for both rabbits (w2¼47.118; df¼5; p50.001) and guinea pigs (w2¼33.463; df¼5; p50.001) (Table 2).

NSAID

Important

Table 2. Median anticipated pain score for procedures conducted in rabbits and guinea pigs, with the respondents’ willingness to perform them, from a survey of 155 veterinarians in New Zealand. Percentages are for the number of complete responses; non-responses are included in a separate column. Pain scorea Procedure

Median

Min–max

Response

Not

Fairly

Extremely

Total valid

None

0

18

60

78

77

Renal side effects

0

22

45

67

88

Analgesic potency

0

15

48

63

92

GIT side effects

0

24

33

57

98

Anti-inflammatory effects

0

28

28

56

99 95

Factors

Information available for species

Ease of administration Behavioural side effects

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307

Ease of dosing Cost

4

45

11

60

12

37

11

60

95

3

36

11

50

105

57

19

1

77

78

1

17

55

73

82 88

Opioids Information available for species

Willing to perform procedure Yes

No

No response

Spay

Analgesic potency

1

12

54

67

GIT side effects

14

33

19

66

89

Renal side effects

15

24

22

61

94

Ease of dosing

3

38

10

51

104

Rabbit

7

0–10

60 (71%)

24 (29%)

71

Ease of administration

4

37

10

51

104

Guinea pig

7

3–10

35 (47%)

39 (53%)

81

Behavioural side effects

8

36

8

52

103

Neuter

Need for record keeping

44

20

6

70

85

Rabbit

75

Personal safety

26

32

4

62

93

Cost

60

15

1

76

79

3

22

51

76

79

Guinea pig

5

1–10

66 (83%)

14 (17%)

6

2–10

49 (69%)

22 (31%)

84

Rabbit

5

2–10

67 (86%)

11 (14%)

77

Guinea pig

5

1–10

52 (83%)

11 (17%)

92

Corticosteroids

Abscess

Tumour removal

Information available for species GIT side effects

5

22

31

58

97

Renal side effects

7

25

27

59

96

Rabbit

5

2–10

65 (83%)

13 (17%)

77

Analgesic potency

14

25

23

62

93

Guinea pig

5

1–10

50 (77%)

15 (23%)

90

Anti-inflammatory effects

1

24

27

52

103

Ease of administration

7

46

9

62

93

Rabbit

4

0–10

63 (77%)

19 (23%)

73

Ease of dosing

5

42

9

56

99

Guinea pig

5

0–10

47 (65%)

25 (35%)

83

Behavioural side effects

9

32

11

52

103

Rabbit

9

5–10

41 (47%)

47 (53%)

67

Guinea pig

9

5–10

34 (47%)

39 (53%)

82

Teeth

Orthopaedics

a

NSAID¼non-steroidal anti-inflammatory drugs; GIT¼gastrointestinal

The number of respondents giving a score ranged from 139 to 149 for procedures on rabbits, and from 93 to 106 for procedures on guinea pigs

The section of the survey addressing the importance of factors when considering drug choice had a poor completion rate; 450% of respondents failed to answer most questions. The most important factors when considering use of NSAID and opioids were information available for the species, analgesic potency, and side effects (renal and gastrointestinal). For corticosteroids, the most important factors were information available for the species, anti-inflammatory effects, and side effects (renal and gastrointestinal) (Table 3). Details on the range of drugs used on rabbits and guinea pigs across all procedures were given by 101/155 (65.2%) respondents. Each respondent was able to give multiple responses. Two main NSAID were used the most common of which was

meloxicam (59/101). The two main opioids were used equally by respondents, butorphanol (47/101), and buprenorphine (46/101). There were several other drug types used by respondents, which were mainly anaesthetic and inductive agents. The three most commonly used were ketamine (83/101), medetomidine (78/101), and isoflurane (74/101). When assessing their own level of knowledge regarding recognition and treatment of pain in rodents and lagomorphs, 80/104 (76.9%) respondents felt their knowledge of pain recognition was inadequate. Likewise, 64/102 (62.7%) respondents felt their knowledge of treatments used for anaesthesia and analgesia was inadequate. Sources of knowledge used by veterinarians varied, with publications being cited as the primary source by the majority of respondents (Table 4). A total of 73/101 (72.3%) respondents indicated an interest in continuing education regarding pain recognition and treatment in rabbits and guinea pigs. Of those who indicated no interest in

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Table 4. The main sources of knowledge concerning pain recognition and anaesthetic/analgesic treatments and strategies available for rodents and lagomorphs used by 104 veterinarians in New Zealand who responded to a questionnaire. Source of knowledge

Number (%)

Publications (books, journals, articles)

50 (48.1%)

Veterinary Information Networka

31 (29.8)

BSAVAb

30 (28.8)

University/continuing education opportunities

30 (28.8)

Personal experience

16 (15.4)

Extrapolation from other species Other sources

6 (5.8) 48 (46.2)

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a

Veterinary Information Network is a website which contains databases, online forums, message boards and other features where veterinary professionals can share their knowledge with colleagues and gain information though collegial discussion and discourse b The British Small Animal Veterinary Association (BSAVA) is a British organisation for veterinarians who treat companion animals. The organisation publishes many resources on small animal treatment and offers opportunities for members to access continuing education opportunities in the field of small animal treatment, specifically in the United Kingdom

continuing education, 19/28 (68%) cited a low caseload as the reason. Of the respondents who did indicate an interest in continuing education, 15/73 (21%) made comments stipulating further education was a low priority due to the small caseload presented by rodents and lagomorphs.

Discussion The results of this study indicated that most veterinarians who were members of CAS were presented rabbits and guinea pigs in practice. However, the proportion presented in relation to the potential population under care was probably very small compared with other companion animals. There are no published data available on numbers of rabbits/guinea pigs kept as pets in New Zealand. Assuming a similar per-capita ownership as the USA (Wise et al. 2002), populations of rabbits and guinea pigs in New Zealand are estimated at approximately 75,000 and 10,000, respectively. Given the potentially large populations of rabbits and guinea pigs, the low caseload seen at veterinary practices may indicate inadequate provision of care by owners. However, a more accurate determination of the population is required to support this hypothesis. Alternatively, low caseload may have reflected a relatively small population, or that these animals did not routinely require veterinary attention, e.g. annual vaccinations. The 25.4% response rate to the survey was similar to that of others conducted in New Zealand, on cats and dogs (28%; Williams et al. 2005), and horses (23%; Waran et al. 2010), although the completion rate for some questions was substantially lower. Response to questionnaires has been shown to have a female bias in other studies (Rourke and Lakner 1989). In the current study, there was an evident female bias when compared with the female-to-male ratio of 51%:49% expected from CAS membership statistics. Therefore, any conclusions drawn from this study may not be absolutely representative of the target population. However, given the novelty of the research the findings should still be considered valuable.

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There were no differences in anticipated pain scores provided by male or female respondents in respect of a range of procedures conducted by veterinarians. This is in contrast to results presented for other animal species under veterinary care, e.g. Huxley and Whay (2006), Laven et al. (2009), and Waran et al. (2010). Nevertheless, as was found in this study, other studies have demonstrated a difference in anticipated pain scores (Lascelles et al. 1999; Raekallio et al. 2003; Laven et al. 2009) and use of analgesia (Doohoo and Doohoo 1996) between older and more recent graduates. Those showed more recent graduates scored anticipated pain higher than less recent graduates. That was likely due to the advances in understanding of the pain experience and a greater emphasis on animal welfare (Marcella 2007). A similar relationship was shown for some (but not all) procedures in the study presented here. Given the lower number of respondents graduating in earlier decades, this finding should be viewed with caution, and requires further exploration. There was no difference in anticipated pain score between species (rabbits vs guinea pigs) for any of the procedures, indicating that veterinarians in this study did not consider rabbits and guinea pigs to be different in their experience of pain. The range of procedures selected for inclusion in the survey varied from potentially invasive orthopaedics to relatively minor interventions such as those on teeth. Accordingly, the differences in median pain score were not unexpected. Specific details for each procedure were not stipulated in the survey, and this may have explained some individual variation in the anticipated pain scores given for some procedures. Veterinarians were more likely to decline a spay procedure for guinea pigs than rabbits. This may be due to the complexity, and more invasive nature, of the procedure, and perceived differences in the resilience of the two species. When a range of procedures was considered there was no apparent association between pain score and likelihood of performing a procedure. Orthopaedics, the surgery with the highest median pain score, had the highest percentage of respondents that were unwilling to perform. Factors such as invasiveness of the procedure, complexity and cost of the procedure, and anticipated recovery times may also have played a role in the consideration of whether or not to perform a procedure. Further research would be valuable to identify reasons for non-provision of treatment by veterinarians. Factors considered important when choosing which drug to use were similar across all drug classes. Veterinarians in this study were most concerned by side effects and potency of drugs, and focussed on providing the best possible treatment for animals under their care regardless of species of animal or financial cost. The most important factor during selection of drugs appeared to be information available for the species; this was possibly linked to the lack of confidence veterinarians felt about their knowledge of anaesthetic and analgesic protocols for these species. Opioid-induced ileus is well documented, particularly in rabbits (Johnston 2005; Neyens and Jackson 2007; Schnellbacher 2010), and this concern was reflected in the results, as gastrointestinal side effects ranked as the third most important factor when considering opioids. The most commonly used drug intended specifically for analgesia (meloxicam) was used by 59/101 (58%) respondents who gave indications of their drug protocols. Buprenorphine and butorphanol were the opioids most commonly used, and both were used by 550% of the 101 respondents. Use of these two opioids was consistent with previous findings where these were the most

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common analgesics used in laboratory rats and mice (Richardson and Flecknell 2005). In contrast, in the same study, the most common NSAID used was carprofen, which was used relatively rarely in the current study. The most commonly used drugs were primarily anaesthetics (ketamine, isoflurane), and a sedative with short-term analgesic effects (medetomidine). These drugs have limited, variable or unknown analgesic properties, particularly in rabbits (Sawyer 1998). They are also recommended to be combined with other anaesthetics or analgesics for maximum effect (Plumb 2005; Ramsey 2008). Different preparations of drugs are likely to be more effective than others (Murphy et al. 2010). However, as the specific preparations used by respondents to this survey were not reported, it is difficult to assess the effectiveness of the analgesia used. Drugs reported as used by respondents were largely consistent with recommended drugs within the literature (Plumb 2005; Kohn et al. 2007; Ramsey 2008), however, the low number of respondents who indicated use of analgesics in particular may be cause for concern. The results suggest that many rabbits and guinea pigs may not be receiving adequate analgesia, particularly post-operatively. Similarly, many veterinary professionals in Britain used anaesthetic-action drugs rather than analgesics for pain relief (Lascelles et al. 1999). The short-term analgesic effects from the administration of anaesthetic agents may not be sufficient to ameliorate post-operative pain. Further study would be useful to determine general protocols for and effectiveness of anaesthesia and analgesia in these species. Because optimum drug protocols for analgesia in small animals such as rodents and rabbits have not been extensively validated, it is difficult to identify the most appropriate preparations from the extensive suggestions within the literature. Suggested doses have been compiled for rabbits, based on clinical experience and extrapolation from other species, with methods of administration, and timing of administration (Johnston 2005). For example, the drug butorphanol (0.5 mg/kg 2–4-hourly I/V or S/C), buprenorphine (0.01–0.05 mg/kg 6–10-hourly I/V or S/C), and ketamine, for analgesia (0.5 mg/kg I/V before surgery; 10 mg/kg/ minute I/V (constant rate-infusion) during surgery; 2 mg/kg/ minute I/V (constant-rate infusion) for 24 h post-operatively in combination with an additional analgesic agent such as an opioid. Similarly, suggested drug protocols have been given, dependent upon the level of pain, which required the administrator of the drug to be able to accurately assess pain in the animal (Kohn et al. 2007). These included suggested doses for drugs including buprenorphine (0.01–0.05 mg/kg S/C, I/M, or I/V 6–12-hourly; 1.5 mg/kg by mouth 12-hourly), butorphanol (0.1–0.5 mg/kg I/M or I/V 4-hourly), carprofen (4.0 mg/kg S/C 24-hourly), and meloxicam (0.2–0.3 mg/kg S/C, by mouth single dose; 0.3–1.5 mg/kg by mouth 24-hourly). More recently comprehensive suggestions of analgesics and their dosages for rabbits have been made, as well as non-pharmacological considerations for pain management. However, their effectiveness remains scientifically unquantified and usage, although valuable for practitioners, is based on experience and anecdotal reports (Barter 2011). Similar information for Guinea pigs is not available. The variability in response to anaesthesia in small animals such as rabbits and guinea pigs is well documented within the literature (Longley 2008). Johnston (2005) highlighted a lack of available information regarding safe doses for populations of pets, rabbits in particular, and quoted extrapolation from other species as a popular method of determination for doses in rabbits.

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Due to the small caseload represented by rodents and lagomorphs, it was not surprising to find that many respondents felt their current knowledge regarding pain recognition and treatment in these animals was inadequate. Without routine examination and treatment of these animals, it is unlikely veterinarians are able to gain knowledge through experience. Amongst British veterinarians, 75% (n¼958) of respondents considered their knowledge to be inadequate, with most respondents citing experience in practice as the major source of their knowledge (Lascelles et al. 1999). Additional comments from a majority of respondents indicated interest in continuing education due to concern that their knowledge of recognition and treatment of pain in rodents and lagomorphs was inadequate. Additional comments from respondents suggested veterinarians in this survey considered knowledge of pain recognition in rodents and lagomorphs and its treatment as useful for ensuring best standards of practice for animals under their care. In conclusion, rabbits and guinea pigs represented a small percentage of the caseload of veterinarians in this study. Further research into the demographics of the pet population in New Zealand would be valuable to ascertain whether the low caseload percentage was indicative of suboptimal standards of care and welfare, or reflective of a small population. Anticipated pain scores given by respondents for routine procedures were not influenced by gender, or, in general, by the species of animal being considered. For some procedures the pain score differed with year of graduation. The most important factor for respondents when selecting drugs was information available for the species, but many felt their knowledge of issues relating to pain recognition, anaesthesia and analgesia in rabbits and guinea pigs was inadequate. Further education about this topic should be considered for veterinarians in New Zealand.

Acknowledgements Thanks go to the Universities Federation for Animal Welfare, which provided funding and to Dr Virginia Williams for her invaluable guidance. Finally, thanks to the NZVA and the CAS for assistance with data collection.

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Submitted 22 December 2010 Accepted for publication 06 July 2011 First published online 04 October 2011

*Non-peer-reviewed