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Physiologic Responses of Amazon Parrots (Amazona species) to Manual RestraintAuthor(s): Cheryl B. GreenacreDVM, Dipl ABVP (Avian) and Angela L. LusbyBSSource: Journal of Avian Medicine and Surgery, 18(1):19-22. 2004.Published By: Association of Avian VeterinariansDOI: http://dx.doi.org/10.1647/2003-011URL: http://www.bioone.org/doi/full/10.1647/2003-011

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Journal of Avian Medicine and Surgery 18(1):19–22, 2004q 2004 by the Association of Avian Veterinarians

Physiologic Responses of Amazon Parrots(Amazona species) to Manual Restraint

Cheryl B. Greenacre, DVM, Dipl ABVP (Avian), and Angela L. Lusby, BS

Abstract: Body temperature and heart and respiratory rates are measured routinely during thephysical examination of most animals. However, the influence of stress on these values has notbeen well evaluated in birds. In this study, we measured the cloacal temperature and heart andrespiratory rates serially during 15 minutes of restraint in 17 Amazon parrots (Amazona species).The mean cloacal temperature of the parrots increased significantly (P , .001) within 4 minutes ofmanual restraint and increased by 2.38C (4.28F) at 15 minutes. Mean respiratory rates also increasedsignificantly (P , .001) from 129 to 252 breaths/min during 15 minutes of manual restraint, whilemean heart rates did not significantly change. These findings emphasize the importance of limitingrestraint time and observing for tachypnea, even in healthy parrots, to avoid potentially life-threat-ening increases in body temperature.

Key words: temperature, cloacal temperature, restraint, avian, Amazon parrot, Amazona aestiva,Amazona ventralis

Introduction

Measuring body temperature in mammals is aroutine part of the physical examination and a valu-able diagnostic tool. In birds, however, many prac-titioners believe measuring the body temperatures isof little diagnostic value.1,2 This is because conven-tional mercury and digital thermometers may causetrauma to the cloaca, require several minutes tomeasure temperature, and may not read in the rangeof avian body temperatures.1,2 For example, the nor-mal cloacal temperature for most birds ranges from41.78C (107.08F) to 44.48C (112.08F), while the up-per range of most digital thermometers is approxi-mately 42.28C (107.98F).1 It is well known that bodytemperature in birds increases during stress and han-dling.1,3–6 Stress-induced temperature increases havebeen documented in several nonavian species, in-cluding rats,6 mice,7 fox,8 lizards,9 and turtles,10 buthave not been evaluated in parrots.

The purpose of this study was to evaluate chang-es in cloacal temperature, heart rate, and respiratoryrate during routine handling of Amazon parrots.

From the Department of Small Animal Clinical Sciences(Greenacre), and Class of 2004 (Lusby), Room C247, 2407 RiverDrive, College of Veterinary Medicine, The University of Ten-nessee, Knoxville, TN, 37996-4544, USA.

Materials and Methods

Birds and instrumentation

Six adult blue-fronted (Amazona aestiva) and 11adult Hispaniolan Amazon (Amazona ventralis) par-rots were used in this study. The birds were indi-vidually housed, with each species caged in a sep-arate room maintained at an ambient temperature of26.18C (79.08F). All body temperatures were re-corded in the room in which the birds were housedbetween 10:00 AM and 4:00 PM, while the bird wasmanually restrained in a towel that only covered theneck and back. All birds were given a physical ex-amination, and heart and respiratory rates were ob-tained by auscultation.

A thermistor thermometer (Tele-thermometer,Yellow Springs Instrument Company Inc, YellowSprings, OH) with an upper temperature limit of49.28C (120.68F) and a 3-mm-diameter probe tip(Model #402, Yellow Springs Instrument CompanyInc) was used to measure cloacal temperatures (Fig1). To determine accuracy, the thermistor thermom-eter was compared with a mercury glass thermom-eter (14-983-10B, Fisher Scientific, Pittsburgh, PA)by placing both thermometers into a 378C (98.68F)water bath to a depth of 1 cm. The thermistor ther-mometer read 0.58C (0.98F) higher than the mercury

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Figure 1. A thermometer (top) with a 3-mm-diameter probe (inset) marked at 5 and 10 mm from the tip that recordsup to 49.28C (120.68F) was used to obtain cloacal temperatures in Amazon parrots.

thermometer. The mercury thermometer was con-sidered the standard, made in accordance with andmeeting the accuracy requirements of the AmericanNational Standards Institute/Scientific ApparatusMaker Association (Z236.1-1983); therefore, 0.58C(0.98F) was subtracted from all cloacal temperaturereadings. The thermistor thermometer required ap-proximately 20 seconds to reach a stable reading.Cloacal temperatures were obtained by restrainingthe bird in dorsal recumbency and inserting theprobe, lubricated with a sterile lubricating gel, to adepth of 1 cm into the cloaca.

Study design

Cloacal temperature and heart and respiratoryrates were recorded after 30 seconds of manual re-straint and then every minute thereafter for a totalof 15 minutes. A mean of 2.5 minutes elapsed be-tween opening the cage door, capturing and restrain-ing the bird, and inserting the cloacal probe. Thistime was not included in the recorded restraint time.Therefore, the cloacal temperature and heart and re-

spiratory rates should be considered to have an ad-ditional 2.5 minutes of stress time associated withthe recorded restraint time interval. Birds were im-mediately released if their respiratory rate was over250 and 400 breaths per minute in the blue-frontedAmazon and Hispaniolan Amazon parrots, respec-tively, or if the birds appeared distressed. Restingrespiratory rates were obtained by observing thenonstressed birds in their enclosures before re-straint.

Statistical analysis

Data was analyzed with SPSS software (SPSSSoftware System, Version 11, SPSS Inc, Chicago,IL). Data were analyzed by using repeated measuresanalysis of variance. Significance level was set at#.05.

Results

The weight range of the parrots was 283–354 g(mean 320 g), with 1 blue-fronted Amazon parrot

21GREENACRE AND LUSBY—PHYSIOLOGIC RESPONSES OF PARROTS TO MANUAL RESTRAINT

Figure 2. Mean cloacal temperatures increased signifi-cantly (P , .001) by 4 minutes of manual restraint in 6blue-fronted and 11 Hispaniolan Amazon parrots. By 15minutes, temperatures had increased 2.38C (4.28F) (● 5blue-fronted and n 5 Hispaniolan Amazon parrots).

Figure 3. Mean respiratory rates increased significantly(P , .001) during 15 minutes of routine manual restraintin 6 blue-fronted and 11 Hispaniolan Amazon parrots(● 5 blue-fronted and n 5 Hispaniolan Amazon parrots).

Figure 4. Mean heart rate did not change significantlyduring 15 minutes of routine manual restraint in 6 blue-fronted and 11 Hispaniolan Amazon parrots (● 5 blue-fronted and n 5 Hispaniolan Amazon parrots).

considered overweight (354 g). During the 15-mi-nute restraint period, the mean cloacal temperatureincreased significantly (P , .001) from 41.6 61.08C (106.9 6 1.78F) to 43.9 6 1.08C (111.1 61.88F) (Fig 2). By 4 minutes, the mean temperatureincreased significantly from baseline (P , .001),with the temperature of 1 bird increasing 3.38C(6.08F) in 5 minutes. The highest temperature read-ing, 45.68C (114.18F), was recorded at 15 minutes.

The mean heart rate decreased from 383 6 67 to304 6 77 beats per minute (Fig 3), while the meanrespiratory rate significantly (P , .001) and con-stantly increased from 129 6 49 to 252 6 54breaths/min, the latter being 7 times the mean rest-ing rate of 32 6 6 breaths/min (Fig 4). At both 30seconds and 15 minutes, mean respiratory rateswere significantly higher (P , .001) in the Hispa-niolan Amazon parrots (151–272 breaths/minute)than in the blue-fronted Amazon parrots (90–183breaths/min). In 3 birds, the respiratory pattern be-came dyspneic and the birds were released imme-diately: 2 at 10 minutes and 1 at 13 minutes. Sub-jectively, the Hispaniolan Amazon parrots resistedrestraint more than the blue-fronted Amazon par-rots.

Discussion

The results of this study show that Amazon par-rots develop a stress-induced temperature increaseduring prolonged restraint. A 15-minute restrainttime was chosen because a previous study in chick-ens showed that cloacal temperatures tended to pla-teau or oscillate slightly after 9–12 minutes of re-

straint.4 The temperature rise observed with restraintwas dramatic in most birds in our study, with sometemperatures increasing as much as 3.38C (6.08F)within 5 minutes after the beginning of restraint. In4 of the 17 birds, the temperatures increased above43.38C (1108F) within 5 minutes of restraint (7.5minutes of stress time). In 1 bird, cloacal tempera-ture reached 45.68C (114.18F), nearing the lethalbody temperature of most birds 46.1–47.28C(115.0–117.08F).5,11 Interestingly, during hyperther-mia, birds can maintain brain temperatures up to18C (1.88F) cooler than core body temperature bymeans of a vascular counter-current heat exchangesystem.11 The results of this study emphasize theimportance of limiting restraint time in parrots evenwhen performing physical examinations and briefprocedures.

Mean initial heart rates of 383 beats per minutewere higher than published normal resting heartrates of 154–163 beats per minute for an Amazonparrot.1 It was expected that heart rates would con-tinue to increase because of the stress of captureand prolonged restraint, but instead, rates decreased.The cause for this response is unknown, but perhapsit can be attributed to decreased physical movementduring prolonged restraint.

The significant increase in respiratory rate in

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these birds during restraint was likely caused bytheir use of panting to dissipate heat as body tem-peratures rise. Increases in respiratory rate directlycorrelate with increases in heat load when avianbody temperature reaches some point in the variablerange of 41.0–44.08C (105.8–111.28F).5 Sympathet-ic stimulation caused by stress may also account forsome of the increase in respiratory rate. The signif-icantly higher respiratory rate (P , .001) observedin the Hispaniolan Amazon parrots was probablyrelated to their smaller body size and resistance torestraint compared with the blue-fronted Amazonparrots.

This study provides clinically useful informationregarding appropriate and safe duration of restraintin Amazon parrots. These data demonstrate signif-icant temperature increases occurred within 4 min-utes of manual restraint of healthy Amazon parrots.Results suggest that Amazon parrots restrained formore than 4 minutes should be monitored closelyfor signs of overheating, such as tachypnea.

Acknowledgments: We thank Nancy Zagaya, RVMT,for technical assistance. Part of this study was fundedthrough the University of Tennessee College of Veteri-nary Medicine, Center of Excellence Summer StudentFellowship Program.

References

1. Harrison GJ, Ritchie BW. Making distinctions in thephysical examination. In: Ritchie BW, Harrison G,

Harrison L, eds. Avian Medicine: Principles and Ap-plication. Lake Worth, FL: Wingers; 1994:148–169.

2. Samour J, McKinney P. Clinical examination. In: Sa-mour J, ed. Avian Medicine. Philadelphia, PA: Mos-by; 2000:15–27.

3. Cabanac AJ, Guillemetter M. Temperature and heartrate as stress indicators of handled common eider.Physiol Behav. 2001;74:475–479.

4. Cabanac M, Aizawa S. Fever and tachycardia in abird (Gallus domesticus) after simple handling. Phy-siol Behav. 2000;69:541–545.

5. Dawson WR, Hudson JW. Birds. In: Whittow GC,ed. Comparative Physiology of Thermoregulation.Vol 1. New York, NY: Academic Press; 1970:224–310.

6. Briese E, Cabanac M. Stress hyperthermia: physio-logical arguments that it is a fever. Physiol Behav.1991;49:1153–1157.

7. Cabanac A, Briese E. Handling elevates the colonictemperature of mice. Physiol Behav. 1992;51:95–98.

8. Moe RO, Bakken M. Effect of indomethacin on LPSinduced fever and on hyperthermia induced by phys-ical restraint in the silver fox (Vulpes vulpes). J Ther-mal Biol. 1997;22:79–85.

9. Cabanac A, Cabanac M. Heart rate response to gentlehandling of a frog and lizard. Behav Proc. 2000;52:89–95.

10. Cabanac M, Berhieri C. Behavioral rise in body tem-perature and tachycardia by handling of a turtle(Clemmys insculpta). Behav Proc. 2000;49:61–68.

11. Dawson WR, Whittow GC. Regulation of body tem-perature. In: Whittow GC, ed. Sturkie’s Avian Phys-iology. 5th ed. San Diego, CA: Academic Press;2001:344–390.