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Health Factors Associated with Microchip Insertion in Horses
Abstracts Vol 29, No 5 (2009)
414
was not different. Changing the horses from group housing to individual stalls, however, resulted in significant increases in pre-transport concentrations of those stressrelated compounds.
This scar capsule has also been determined to be important in binding with the glass capsule to prevent movement of the microchip after insertion.3 The objective of this study was to characterize the inflammatory response and migration of microchips.
Keywords: Transport; Cortisol; DHEA
MATERIALS AND METHODS REFERENCES 1. Council of the European Union. Council Regulation No. 1/2005: On the protection of animals during transport and related operations. 2005. 2. Collins MN, Friend TH, Jousan FD, Chen. Effects of density on displacement, falls, injuries, and orientation during horse transportation. Appl. Anim. Behav. Sci. 2002;67:169-179. 3. Gibbs AE, Friend TH. Horse preference for orientation during transport and the effect of orientation on balancing ability. Appl. Anim. Behav. Sci. 1999;63:1-9. 4. Iacono C, Friend TH, Keen H, Martin T, Krawczel P. Effects of density and water availability on the behavior, physiology, and weight loss of slaughter horses during transport. J. Equine Vet. Sci. 2007;27: 355-361. 5. Kusunose R, Torikai K. Behavior of untethered horses during vehicle transport. J. Equine Vet Sci. 1996;7:21-26. 6. Stull CL. Responses of horses to trailer design, duration and floor area during commercial transportation to slaughter. J. Anim. Sci. 1999;77:2925-2933. 7. Toscano MJ, Friend TH. A note on the effects of forward and rear-facing orientations on movement of horses during transport. Appl. Anim. Behav. Sci. 2001;73:281-287. 8. Waran NK., Robertson V, Cuddeford D, Kokoszko A, Marlin DJ. Effects of transporting horses facing either forwards or backwards on their behaviour and heart rate. Vet. Rec. 1996;139:7-11.
Quarter horse mares (n ¼ 18) assigned randomly to 3 groups with 7 in the micro-chipped group, 7 in the dry needle group and 4 as control animals. All of the horses that were microchipped were implanted in the nuchal ligament. Skin temperature, swelling area, and algometer measurements were collected over a 2 week period. The algometer is used to quantify the pressure necessary to induce a pain threshold response.4 The skin temperature measurements were analyzed with nested longitudinal mixed effects ANCOVA with the covariate of outdoor (ambient) temperature. The algometer readings were analyzed with nested longitudinal mixed effects ANOVA. To assess migration, the 7 horses that were microchipped had lateral radiographs taken at 0,1,2,4 and 6 m. All images included a metal marker of known length (for scaling), the microchip and vertebrae 2 and 3. Measurements were recorded from the most cranial portion of the fourth vertebrae to the microchip and analyzed through linear regression.
RESULTS
31656 Health Factors Associated with Microchip Insertion in Horses M.I. Gerber,* A.M. Swinker, W.B. Staniar, J.R. Werner, E.A. Jedrzejewski, and A.L. Macrina, The Pennsylvania State University, University Park, PA, USA
INTRODUCTION Inflammation and migration were two major health concerns of horse owners when weighing the advantages and disadvantages of using microchips. The use of radiofrequency devices as a permanent identification method in horses is being evaluated as the standard method for the National Animal Identification System. Animal identification is the 2nd part of a 3 part registration that also includes premise registration and animal movement tracing.1 When microchips are inserted, the skin damage from the needle immediately initiates a local immune response to address any introduction of bacteria or other disease-causing organisms and to begin repair on the damaged tissues. Further, the chip doesn’t present antigens for the immune system response, but it does cause tissue irritation until a capsule of scar tissue begins to form around the chip.2
The microchip insertion and dry needle did not cause a detectable increase in temperature throughout the 2 week interval. The microchipped horses were more sensitive to the algometer than the dry needle group at 2 h, 1 and 3d post insertion (p < 0.05). The swelling begins 2 h post insertion and resolves by 3d. There was not a detectable difference in swelling area between injected groups. Measurements for migration found no difference between each measurement for each horse over time within a 2 cm margin of error. The marker length was also used to determine the error of measurements and to determine that magnification did not occur.
DISCUSSION The characterization and comparison of inflammatory indicators with microchip insertion can be used to describe to horse owners what is expected during this process. The inflammatory reaction that occurs from the implantation of the microchip is comparable to the dry needle injection. As such, horse owners can expect slight swelling to occur and localized heat at the injection site to increase several degrees between 6 h and 3d post injection. Also, there may be increased sensitivity to that area up to three days after insertion. No movement of the microchip was detected when implanted according to standard protocol.
Abstracts Vol 29, No 5 (2009)
Therefore, this research indicates that when performed according to standard protocol, microchip insertion is not detrimental to the health of the horse. Keywords: Equine; NAIS; Microchip; Inflammation REFERENCES 1. http://animalid.aphis.usda.gov/nais/ 2. Spire M, Drouillard J, Galland J, Sargeant J. Use of infrared thermography to detect inflammation caused by contaminated growth promotant ear implants. J Am Vet Med Assoc 1999;215;1320-1324. 3. Jansen J, van der Waerden J, Gwalter R., van Roy S. Biological and migrational characteristics of transponders implanted into beagle dogs. The Veterinary Record 1999;145:329-333. 4. Stafford K, Mellor D. The assessment of pain in cattle: a review. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutriton and Natural Resources 2006;1-10.
ACKNOWLEDGEMENTS PSU Horse Barns
31849 Sodium Pentobarbital Residues in Compost Piles Containing Carcasses of Euthanized Equines L.M. Cottle,* L.A. Baker, J.L. Pipkin, and D. Parker, West Texas A&M University, Canyon, TX, USA
INTRODUCTION Due to the closing of slaughter plants in the United States, equine carcass disposal has been a recent consideration in the horse industry. Composting is a disposal method that has been successfully implemented in a variety of environments and situations. No data currently exists, however, with regard to any drug residues in compost piles used to dispose of euthanized equines. Researchers observed that eagles have died from eating the carcass remains of euthanized animals left uncovered at a landfill1 . The objective of this study was to determine if the euthanasia drug, sodium pentobarbital, remained in compost material after equine carcasses were composted for 6 mo.
MATERIAL AND METHODS A licensed practicing veterinarian euthanized each equine with a pentobarbital solution (Beuthanasia-D: ScheringPlough Animal Health) according to AAEP Guidelines. All horses used in the trial were euthanized at local veterinary clinics. Immediately after euthanasia, a 5 to 10 cm liver sample was taken. Carcasses were then immediately transported to composting site. Base layer of compost piles were constructed with 45 to 50 cm of waste hay and 5 to 10 cm of horse stall cleanings. The carcass was then placed
415
on the base layer, legs removed directly above the knee and hock and placed beside the carcass in the pile. The carcass was then covered with 90 to 100 cm of horse stall cleanings. Compost piles containing a euthanized equine carcass were replicated eight times. Total length of trial was 334 d. Individual compost piles were mechanically aerated at 90-d intervals. Internal pile grab samples were collected at d 0, 10, 14, 90 and 180. Compost pile temperatures were recorded every hour until 180 d using two continuous HOBO units (Onset Computer Corporation) placed next to the carcass during pile construction. Pile grab samples and liver samples were sent to State of Illinois Department of Agriculture Animal Disease Laboratory (Centralia, IL) for a detection and quantitation of pentobarbital. Composite samples for each pile were obtained at d 10, 14, 90, and 180, making a total of 32 pile grab samples and 8 liver samples. Samples were analyzed using gas chromatography and mass spectrometry [GC/MSD Hewlett Packard 6890 GC with a split/splitless injector and a series 5973 Mass Selective Detector (MSD) and a series 7683 autosampler or equivalent] to determine pentobarbital concentrations in compost and liver samples. In addition, a control sample of shavings material used to build piles containing no pentobarbital was sent to the laboratory to be used as a test blank. Control material was fortified (spiked) by adding the appropriate amount of sodium pentobarbital according to SOP recommendations for detection and quantification of pentobarbital ((Standard Operating Procedure SOP, C.TOX.241.49.1). Analyzed sample pentobarbital concentrations were considered acceptable if amounts were within 30 \%of the fortified test blank concentration.
RESULTS AND DISCUSSION Determination of differences between mean pentobarbitol concentrations at different sampling times was conducted using one-way ANOVA test with a significance level of a ¼ 0.10. There was no significant difference between pentobarbitol concentrations and sampling date (P ¼ 0.686). Quantitative pentobarbital concentrations at d 10, 14, 90 and 180 as well as liver concentrations can be observed in Table 1. Three composite pile samples at d 10 and four samples at d 14 had non-detect values (<0.005 ppm) for pentobarbitol. For data analysis purposes, all non-detect values were assigned the lower detection limit of 0.005 ppm. Due to sampling technique and composting limitations, a homogeneous sample was unattainable at d 10 and 14. At these two sampling times the carcass still remained in the middle of the pile, therefore each sample was taken at different locations around the carcass. At d 90 and 180 the compost piles were aerated and mixed thoroughly allowing for a more homogenized sample. Composite samples from all piles had pentobarbital
414
was not different. Changing the horses from group housing to individual stalls, however, resulted in significant increases in pre-transport concentrations of those stressrelated compounds.
This scar capsule has also been determined to be important in binding with the glass capsule to prevent movement of the microchip after insertion.3 The objective of this study was to characterize the inflammatory response and migration of microchips.
Keywords: Transport; Cortisol; DHEA
MATERIALS AND METHODS REFERENCES 1. Council of the European Union. Council Regulation No. 1/2005: On the protection of animals during transport and related operations. 2005. 2. Collins MN, Friend TH, Jousan FD, Chen. Effects of density on displacement, falls, injuries, and orientation during horse transportation. Appl. Anim. Behav. Sci. 2002;67:169-179. 3. Gibbs AE, Friend TH. Horse preference for orientation during transport and the effect of orientation on balancing ability. Appl. Anim. Behav. Sci. 1999;63:1-9. 4. Iacono C, Friend TH, Keen H, Martin T, Krawczel P. Effects of density and water availability on the behavior, physiology, and weight loss of slaughter horses during transport. J. Equine Vet. Sci. 2007;27: 355-361. 5. Kusunose R, Torikai K. Behavior of untethered horses during vehicle transport. J. Equine Vet Sci. 1996;7:21-26. 6. Stull CL. Responses of horses to trailer design, duration and floor area during commercial transportation to slaughter. J. Anim. Sci. 1999;77:2925-2933. 7. Toscano MJ, Friend TH. A note on the effects of forward and rear-facing orientations on movement of horses during transport. Appl. Anim. Behav. Sci. 2001;73:281-287. 8. Waran NK., Robertson V, Cuddeford D, Kokoszko A, Marlin DJ. Effects of transporting horses facing either forwards or backwards on their behaviour and heart rate. Vet. Rec. 1996;139:7-11.
Quarter horse mares (n ¼ 18) assigned randomly to 3 groups with 7 in the micro-chipped group, 7 in the dry needle group and 4 as control animals. All of the horses that were microchipped were implanted in the nuchal ligament. Skin temperature, swelling area, and algometer measurements were collected over a 2 week period. The algometer is used to quantify the pressure necessary to induce a pain threshold response.4 The skin temperature measurements were analyzed with nested longitudinal mixed effects ANCOVA with the covariate of outdoor (ambient) temperature. The algometer readings were analyzed with nested longitudinal mixed effects ANOVA. To assess migration, the 7 horses that were microchipped had lateral radiographs taken at 0,1,2,4 and 6 m. All images included a metal marker of known length (for scaling), the microchip and vertebrae 2 and 3. Measurements were recorded from the most cranial portion of the fourth vertebrae to the microchip and analyzed through linear regression.
RESULTS
31656 Health Factors Associated with Microchip Insertion in Horses M.I. Gerber,* A.M. Swinker, W.B. Staniar, J.R. Werner, E.A. Jedrzejewski, and A.L. Macrina, The Pennsylvania State University, University Park, PA, USA
INTRODUCTION Inflammation and migration were two major health concerns of horse owners when weighing the advantages and disadvantages of using microchips. The use of radiofrequency devices as a permanent identification method in horses is being evaluated as the standard method for the National Animal Identification System. Animal identification is the 2nd part of a 3 part registration that also includes premise registration and animal movement tracing.1 When microchips are inserted, the skin damage from the needle immediately initiates a local immune response to address any introduction of bacteria or other disease-causing organisms and to begin repair on the damaged tissues. Further, the chip doesn’t present antigens for the immune system response, but it does cause tissue irritation until a capsule of scar tissue begins to form around the chip.2
The microchip insertion and dry needle did not cause a detectable increase in temperature throughout the 2 week interval. The microchipped horses were more sensitive to the algometer than the dry needle group at 2 h, 1 and 3d post insertion (p < 0.05). The swelling begins 2 h post insertion and resolves by 3d. There was not a detectable difference in swelling area between injected groups. Measurements for migration found no difference between each measurement for each horse over time within a 2 cm margin of error. The marker length was also used to determine the error of measurements and to determine that magnification did not occur.
DISCUSSION The characterization and comparison of inflammatory indicators with microchip insertion can be used to describe to horse owners what is expected during this process. The inflammatory reaction that occurs from the implantation of the microchip is comparable to the dry needle injection. As such, horse owners can expect slight swelling to occur and localized heat at the injection site to increase several degrees between 6 h and 3d post injection. Also, there may be increased sensitivity to that area up to three days after insertion. No movement of the microchip was detected when implanted according to standard protocol.
Abstracts Vol 29, No 5 (2009)
Therefore, this research indicates that when performed according to standard protocol, microchip insertion is not detrimental to the health of the horse. Keywords: Equine; NAIS; Microchip; Inflammation REFERENCES 1. http://animalid.aphis.usda.gov/nais/ 2. Spire M, Drouillard J, Galland J, Sargeant J. Use of infrared thermography to detect inflammation caused by contaminated growth promotant ear implants. J Am Vet Med Assoc 1999;215;1320-1324. 3. Jansen J, van der Waerden J, Gwalter R., van Roy S. Biological and migrational characteristics of transponders implanted into beagle dogs. The Veterinary Record 1999;145:329-333. 4. Stafford K, Mellor D. The assessment of pain in cattle: a review. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutriton and Natural Resources 2006;1-10.
ACKNOWLEDGEMENTS PSU Horse Barns
31849 Sodium Pentobarbital Residues in Compost Piles Containing Carcasses of Euthanized Equines L.M. Cottle,* L.A. Baker, J.L. Pipkin, and D. Parker, West Texas A&M University, Canyon, TX, USA
INTRODUCTION Due to the closing of slaughter plants in the United States, equine carcass disposal has been a recent consideration in the horse industry. Composting is a disposal method that has been successfully implemented in a variety of environments and situations. No data currently exists, however, with regard to any drug residues in compost piles used to dispose of euthanized equines. Researchers observed that eagles have died from eating the carcass remains of euthanized animals left uncovered at a landfill1 . The objective of this study was to determine if the euthanasia drug, sodium pentobarbital, remained in compost material after equine carcasses were composted for 6 mo.
MATERIAL AND METHODS A licensed practicing veterinarian euthanized each equine with a pentobarbital solution (Beuthanasia-D: ScheringPlough Animal Health) according to AAEP Guidelines. All horses used in the trial were euthanized at local veterinary clinics. Immediately after euthanasia, a 5 to 10 cm liver sample was taken. Carcasses were then immediately transported to composting site. Base layer of compost piles were constructed with 45 to 50 cm of waste hay and 5 to 10 cm of horse stall cleanings. The carcass was then placed
415
on the base layer, legs removed directly above the knee and hock and placed beside the carcass in the pile. The carcass was then covered with 90 to 100 cm of horse stall cleanings. Compost piles containing a euthanized equine carcass were replicated eight times. Total length of trial was 334 d. Individual compost piles were mechanically aerated at 90-d intervals. Internal pile grab samples were collected at d 0, 10, 14, 90 and 180. Compost pile temperatures were recorded every hour until 180 d using two continuous HOBO units (Onset Computer Corporation) placed next to the carcass during pile construction. Pile grab samples and liver samples were sent to State of Illinois Department of Agriculture Animal Disease Laboratory (Centralia, IL) for a detection and quantitation of pentobarbital. Composite samples for each pile were obtained at d 10, 14, 90, and 180, making a total of 32 pile grab samples and 8 liver samples. Samples were analyzed using gas chromatography and mass spectrometry [GC/MSD Hewlett Packard 6890 GC with a split/splitless injector and a series 5973 Mass Selective Detector (MSD) and a series 7683 autosampler or equivalent] to determine pentobarbital concentrations in compost and liver samples. In addition, a control sample of shavings material used to build piles containing no pentobarbital was sent to the laboratory to be used as a test blank. Control material was fortified (spiked) by adding the appropriate amount of sodium pentobarbital according to SOP recommendations for detection and quantification of pentobarbital ((Standard Operating Procedure SOP, C.TOX.241.49.1). Analyzed sample pentobarbital concentrations were considered acceptable if amounts were within 30 \%of the fortified test blank concentration.
RESULTS AND DISCUSSION Determination of differences between mean pentobarbitol concentrations at different sampling times was conducted using one-way ANOVA test with a significance level of a ¼ 0.10. There was no significant difference between pentobarbitol concentrations and sampling date (P ¼ 0.686). Quantitative pentobarbital concentrations at d 10, 14, 90 and 180 as well as liver concentrations can be observed in Table 1. Three composite pile samples at d 10 and four samples at d 14 had non-detect values (<0.005 ppm) for pentobarbitol. For data analysis purposes, all non-detect values were assigned the lower detection limit of 0.005 ppm. Due to sampling technique and composting limitations, a homogeneous sample was unattainable at d 10 and 14. At these two sampling times the carcass still remained in the middle of the pile, therefore each sample was taken at different locations around the carcass. At d 90 and 180 the compost piles were aerated and mixed thoroughly allowing for a more homogenized sample. Composite samples from all piles had pentobarbital