Sensitivity of commercial scanners to microchips of various frequencies implanted in dogs and cats.
ABSTRACT To evaluate the sensitivity of 4 commercially available microchip scanners used to detect or read encrypted and unencrypted 125-, 128-, and 134.2-kHz microchips under field conditions following implantation in dogs and cats at 6 animal shelters.
Cross-sectional study. Animals-3,949 dogs and cats at 6 animal shelters.
Each shelter was asked to enroll 657 to 660 animals and to implant microchips in 438 to 440 animals (each shelter used a different microchip brand). Animals were then scanned with 3 or 4 commercial scanners to determine whether microchips could be detected. Scanner sensitivity was calculated as the percentage of animals with a microchip in which the microchip was detected.
None of the scanners examined had 100% sensitivity for any of the microchip brands. In addition, there were clear differences among scanners in regard to sensitivity. The 3 universal scanners capable of reading or detecting 128- and 134.2-kHz microchips all had sensitivities > or = 94.8% for microchips of these frequencies. Three of the 4 scanners had sensitivities > or = 88.2% for 125-kHz microchips, but sensitivity of one of the universal scanners for microchips of this frequency was lower (66.4% to 75.0%).
Results indicated that some currently available universal scanners have high sensitivity to microchips of the frequencies commonly used in the United States, although none of the scanners had 100% sensitivity. To maximize microchip detection, proper scanning technique should be used and animals should be scanned more than once. Microchipping should remain a component of a more comprehensive pet identification program.
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ABSTRACT: To evaluate sensitivity of 4 commercially available microchip scanners used to detect or read encrypted and unencrypted 125-, 128-, and 134.2-kHz microchips under controlled conditions. Evaluation study. Microchip scanners from 4 manufacturers and 6 brands of microchips (10 microchips/brand). Each microchip was scanned 72 times with each scanner passed parallel to the long axis of the microchip and 72 times with each scanner passed perpendicular to the long axis of the microchip. For each scan, up to 3 passes were allowed for the scanner to read or detect the microchip. Microchip and scanner order were randomized. Sensitivity was calculated as the mean percentage of the 72 scans for each microchip that were successful (ie, the microchip was detected or read). Results-None of the scanners had 100% sensitivity for all microchips and both scanning orientations, and there were clear differences between scanners on the basis of operating frequency of the microchip, orientation of the microchip, and number of passes used to detect or read the microchip. For the 3 scanners designed to detect or read microchips of all 3 frequencies currently used in the United States, sensitivity was highest for 134.2-kHz microchips and lower for 125- and 128-kHz microchips. None of the scanners performed as well when only a single pass of the scanner was used to detect or read the microchips. Results indicated that use of multiple passes in different directions was important for maximizing sensitivity of microchip scanners.Journal of the American Veterinary Medical Association 01/2009; 233(11):1723-8. DOI:10.2460/javma.233.11.1723 · 1.67 Impact Factor
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ABSTRACT: To characterize animals with microchips entering animal shelters and the process used to find owners. Cross-sectional study. 7,704 microchipped animals entering 53 animal shelters between August 2007 and March 2008. Data for animals with microchips were recorded by participating animal shelters and reported monthly. Of 7,704 animals, strays accounted for slightly more than half (4,083 [53.0%]), with the remainder classified as owner-relinquished animals (3,225 [41.9%]) and other (396 [5.1%]). Of 3,425 stray animals for which animal shelters reported that the owner was found, a higher percentage of dog owners (2,191/2,956 [74.1%]) than cat owners (298/469 [63.5%]) was found. For 876 animals for which the owners could not be found, the main reasons were incorrect or disconnected telephone number (310 [35.4%]), owner did not return telephone calls or respond to a letter (213 [24.3%]), and animal was registered to another group (151 [17.2%]). Of 1,943 animals for which animal shelters contacted a microchip registry, 1,129 (58.1%) were registered in the database. Purebred neutered dogs whose owner information was in the shelter database registry or microchip registry had a higher likelihood that the owners would be found. The high rate for return of microchipped dogs and cats to their owners supported microchipping as a valuable permanent pet identification modality; however, issues related to registration undermined its overall potential. Bundling of microchip implantation and registration, point-of-implantation data registration, use of annual compliance and update reminders, and providing access to all registries are potential solutions.Journal of the American Veterinary Medical Association 08/2009; 235(2):160-7. DOI:10.2460/javma.235.2.160 · 1.67 Impact Factor
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ABSTRACT: Worldwide, invasive species are associated with severe ecological and economic impacts. As a group, reptiles are very successful invaders and in some areas where they have established they are responsible for the decline of native fauna and economic disruptions, whilst also posing a threat to human health. Due to its biogeographical isolation and unique evolutionary history, New Zealand is highly susceptible to invasive species. Importation of reptiles into New Zealand is illegal, however over a dozen species of exotic reptile are legally present in captivity and their risk of establishment is unknown. This study investigates their establishment potential and possible impacts by considering 1) the amount of trade and propagule pressure of species, 2) the degree of climate match between their native range and New Zealand, 3) areas that may be suitable for establishment based on physiological models of incubation and development, 4) their ability to transfer pathogens to native fauna and humans, and 5) overall establishment risk. The red-eared slider (Trachemys scripta elegans; RES) is the most common and easily obtained exotic reptile pet in New Zealand, with over 800 sales per annum. The RES is also the species most regularly released into the wild. Climate matching models in this study were developed to minimise false-negative predictions, to generate a suitability score irrespective of the prevalence of species records (allowing species to be easily compared to one another), and incorporated a weighted multimodel average prediction based on the relative importance of climatic variables to each species. These correlative models indicated that the blotched blue-tongue skink (Tiliqua nigrolutea) had the highest degree of climate match with parts of New Zealand, while the common blue-tongue skink (T. scincoides) had the highest proportion of land area predicted to be suitable for establishment. The other 10 species generally had both low climate match scores and limited areas within New Zealand predicted to be suitable. Mechanistic models focus upon environmental influences on physiological processes of a species, such as development and growth. Degree-day models, combined with soil measurements in potential reptile nesting sites in New Zealand, were utilised to determine if environmental conditions were suitable for the successful reproduction of oviparous exotic reptiles. These models predicted that the New Zealand environment meets the minimum thermal requirements for the incubation of eggs of RES, snake-neck turtles (Chelodina longicollis), and Reeves turtles (Chinemys reevesii). While prevalence of Salmonella in exotic reptiles is higher than that of native reptiles, it is considerably lower than that of exotic reptiles overseas. All serovars identified in this study had been previously reported both in humans and reptiles in New Zealand. The overall risk assessment for 12 species of exotic reptile kept in captivity in New Zealand indicates that blotched blue-tongue skinks and RES pose the highest establishment risk. Blotched blue-tongue skinks are allegedly only present in zoos. Therefore, based on propagule pressure, RES pose the highest establishment risk and efforts should focus on minimising release events and removing feral individuals from the New Zealand environment. In summary, at least eight species of exotic reptile legally traded within New Zealand are predicted to be capable of surviving in a portion of the New Zealand environment and at least three species have the potential to successfully breed in warmer microclimates. However, further research involving climatic tolerances and breeding potential (i.e., soil moisture content, juvenile survival, sex ratio, and predicted climate change) is recommended. Public education and possible regulations imposed on the New Zealand exotic reptile trade may prevent introductions of these species into the local environment and still allow selected species to be enjoyed by the New Zealand public. The methods developed in this study may be easily applied to other species and other geographic regions, allowing investigation into the establishment risk of alien species. This may help guide control and management efforts and help stem the tide of the growing problem of invasive species.