Chapter 3 - Testing
3.1 Tuberculosis Testing (Updated January 2017)

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1. This section deals with tuberculosis testing procedure only. Information about the disease, bovine tuberculosis, may be found on the CFIA website.

2. Tuberculin skin testing of livestock has been the cornerstone of on-farm active surveillance for the National Bovine Tuberculosis (TB) Eradication Program (NBTEP) for many years. Testing is also applied for the purpose of import, export, entry into semen production centres, and to support disease investigations. The basis of tuberculin testing is the induction of delayed-type hypersensitivity reaction to the intradermal injection of antigenic substances derived from a laboratory strain of Mycobacterium bovis (M. bovis). The hypersensitivity response results in the accumulation of cells and fluid in the dermis which creates swelling at the injection site. In test positive animals, the intradermal skin reaction develops within 24 hours post-injection, reaching a maximum by 48-72 hours, characterized by erythema and swelling, but rarely to the point of induration or ulceration.

3. There are two limitations associated with intradermal tuberculin tests:

  1. Some animals infected with M. bovis fail to respond to the test (false negatives). The number of animals in this category is a measure of the sensitivity of the test; the probability of the test correctly identifying as reactors those animals that are truly infected. False negative responses may be observed for a variety of reasons, including compromised tuberculin quality, improper testing technique, the chronicity and extent of the disease process, or variations in the time of testing in relation to calving and previous tuberculin tests.
  2. Some animals that are not infected with M. bovis react to the test (false positives). The number of animals in this category is a measure of the specificity of the test; the probability of the test correctly identifying as negative those animals that are truly not infected. Most false positive responses are due to the animal having been exposed to antigens similar to, or shared with, those in tuberculin.

4. Sensitivity and specificity are characteristics of the tuberculin skin test itself and are not influenced by the population on which the test is applied (i.e. if the population is TB-free or actually has TB at a given prevalence). However, what is influenced by the prevalence of TB in a population is the probability that a reactor animal is truly infected with M. bovis (the positive predictive value of a positive test result). Positive and negative predictive values are influenced by the prevalence of disease in the population that is being tested. The higher the prevalence in a population, the more likely that an animal that reacts to the tuberculin test actually has the disease, than if the test were performed in a population with a low prevalence.

Tuberculin Procurement, Handling, Storage, Use, and Disposal

5. All tuberculins used in Canada are produced by the Biologics Production Unit of the Canadian Food Inspection Agency (CFIA) Ottawa Laboratory Fallowfield (OLF). Bovine purified protein derivative (PPD) tuberculin, produced by the CFIA, contains 3250 IU in each 0.1 mL.

6. Tuberculin is distributed by district offices to accredited veterinarians. Accredited veterinarians that wish to obtain tuberculin are to contact their CFIA district office who will provide tuberculin upon request free of charge.

7. In light of the short turnaround time for tuberculin, it is unnecessary to stockpile an inventory in anticipation of future needs. Stockpiling leads to unnecessary and increased wastage of tuberculin and contributes to supply shortages.

8. Tuberculin has an expiry date of one year from the time of potency testing, when stored and handled appropriately, but, ideally, should be used within a few months of receipt. Manage tuberculin inventories carefully to avoid their expiry before use. A test performed with expired tuberculin is invalid.

9. Always check the expiry date of tuberculin before use. Do Not Use Expired Tuberculin. A tuberculin test is valid only if carried out prior to, or on the same date as, the expiration date on the bottle. If expired tuberculin is used inadvertently to conduct an official TB test, the test is invalid and will have to be repeated after the appropriate period of time has passed, as required for the particular tuberculin test procedure. Contact immediately the district office for further instructions.

10. To be reliable, tuberculin must be handled and used according to strict parameters:

  1. Store tuberculin in a cool environment (4°C), and protect from light. Tuberculin exposed to extreme temperatures or to sunlight for more than a few hours is improper for use.
  2. Always pack tuberculin on ice or frozen cold packs during transit.
  3. Use a good aseptic technique when handling tuberculin. To prevent contamination of tuberculin, disinfect the stopper of the vial after peeling back the aluminum seal.
  4. Immediately dispose of any expired tuberculin as follows:
    • Discard directly as biological waste; or
    • Return to the CFIA district office for disposal (only full and unopened bottles)
  5. Please also return any tuberculin which is no longer intended for field use (only full and unopened bottles).

11. Be aware that tuberculin is for use only by trained and qualified accredited veterinarians.

Tuberculin Testing Notes

12. Testing may involve considerable travel time and many hours to process all animals to be tested. To facilitate this process, it is important to prepare in advance to ensure that all materials will be available at the test site.

Syringes and Needles

13. Use 1 ml tuberculin syringe. Only a single dose may be drawn at once. Multiple doses in the same syringe are not allowed.

14. Use a new needle for each animal: 26 gauge, ⅜" long.

15. Be aware that tuberculin syringes may be re-loaded, with a new needle for each animal.

16. Do not pre-load syringes with tuberculin prior to testing under any circumstances.

Test available

17. Tuberculin tests may only be performed by trained and qualified accredited veterinarians as follows:

  1. Caudal fold tuberculin (CFT) test for bovine TB testing in cattle, bison, goats or sheep.
  2. Mid-cervical tuberculin (MCT) test for bovine TB testing in cervids.
  3. Single post-axillary test for bovine TB testing in camelids
  4. Base-of-the-ear tuberculin test for bovine TB testing in swine

18. For accredited veterinarians, training and qualification entails having successfully completed:

  • Review of this section of the Manual with a district veterinarian; and
  • On farm demonstration and practice on live animals with a CFIA veterinarian. The district veterinarian must keep a record in the accredited veterinarian's file regarding the date and place where the injection technique was practised on farm.

19. For accuracy of test results conducted under the NBTEP, it is essential that the same person conduct both the injection-day and reading-day measurements for these tests, other than for exceptional circumstances that make this impossible (unplanned and unavoidable absence).

20. The base-of-the-ear tuberculin test for swine is not an official test for bovine TB under the NBTEP and is only performed under export programs testing for live swine and swine semen. Given the volume of animals that are sometimes tested, the requirements of biosecurity protocols to enter a swine premises and the bovine TB freedom of commercial swine operations in Canada, injection-day and reading-day inspections are to be conducted by the same trained person whenever possible and practical.

Adjunct Activities

21. If the owner or operator plans to medicate the animals (e.g. vaccines, anti-parasitic) while the animals are being handled for TB testing, all medications shall be applied at the time of the tuberculin testing reading, not at the time of tuberculin injection. This facilitates the salvage of carcasses for human food, if animals must be destroyed due to test results or injury, and ensures that the medication does not interfere with the test results.

Test Date

22. The date of the tuberculin test is to be recorded on the report of intradermal test, including both the tuberculin injection date and the reading date. For export purpose and entry into a semen production centre, the test date recorded is the reading date.

23. For the purpose of calculating the interval that has elapsed since a tuberculin test was performed, use the tuberculin injection date.

Caudal Fold Tuberculin (CFT) Test

Preparation

24. The CFT test is the standard official screening test for bovine TB in cattle, bison, sheep and goats at low risk of having tuberculosis.

25. The test involves an intradermal injection of 0.1 mL of bovine PPD tuberculin into either caudal fold, with observation and palpation at 72 hours ± 6 hours.

26. Do not apply the CFT test to an animal that has had a tuberculin test of any kind during the preceding 60 days.

27. Prepare the following equipment:

tuberculin – bovine PPD tuberculin (store in dark at 4°C)
syringes – 1 mL tuberculin syringes
needles – 26 gauge, ⅜" long
absorbent cotton
Form CFIA/ACIA 1524 – Report of Intradermal Test
headlamp or flashlight, if poor lighting

28. Adequately restrain each animal for testing to ensure correct animal identification, proper preparation of the injection site, careful tuberculin injection, and reading of the test result. Do not apply or observe the test without having the animal adequately restrained.

29. Record on Form CFIA/ACIA 1524 the individual animal identification of each animal tested. Acceptable animal identification is as follows: a tag approved (or considered equivalent) under the Livestock Identification and Traceability (TRACE) Program, a Health of Animals (HofA) ear tag, or a registered tattoo.

30. The injection site is the caudal fold, distal to the base of the tail, well away from the hairline, in the center of the fold. Use either the left or right fold, but be consistent. If a lesion is encountered on the caudal fold use the opposite fold and make a note of this change.

Injection

31. Clean the caudal fold with cotton (moistened with water, if necessary). Do not use alcohol to clean the injection site. Note any abnormalities, lesions, or scabs observed in the vicinity of the injection site, recording on Form CFIA/ACIA 1524 to avoid being mistaken for tuberculin responses.

32. Check tuberculin label to confirm type – M. bovis tuberculin has an orange label.

33. Check/confirm the tuberculin expiry date against current date.

34. Disinfect rubber stopper with alcohol after opening aluminium seal.

35. Fill tuberculin syringe to 0.1 mL volume. Only a single dose can be drawn.

36. Raise tail and locate the caudal tail folds.

37. Insert needle into the dermis of the skin on the center line of either the left or right caudal tail fold, distal to the tail base and away from the hair line. Be consistent and use either the right or left caudal fold for all test animals on the farm. Lift the tip of the needle slightly after insertion to ensure it is clearly outlined under the skin. Inject 0.1 mL of tuberculin intradermally and withdraw the needle slowly.

38. View injection site to ensure that the injected tuberculin is visible and palpable as a definite bleb. If not, it indicates that either the needle was inserted too deeply or the dose was inadequate. The administration of tuberculin should be repeated on the opposite side.

39. Discard needle immediately into a sharps container.

Reading

40. After 72 hours ± 6 hours, restrain the animal and confirm its identification.

41. Raise the tail with one hand to slightly stretch the caudal tail folds.

42. Observe and palpate the length of the caudal fold injection site with the thumb and index finger of the other hand.

43. Record the response to the CFT test for each animal on Form CFIA/ACIA 1524) as follows:

  • Negative (Neg.): There is no visible or palpable change in tissue at the site of injection; or
  • Reactor: There is any visible or palpable disturbance in tissue at the site of injection. Contact the district office immediately.

When in doubt regarding the nature of the response to the CFT test, classify the animal as a reactor.

44. Animals classified as reactors on the CFT test are retested by CFIA veterinarians, using the Comparative Cervical Tuberculin (CCT) Test (refer to the CCT test section below).

45. All tuberculin tests are official and must be recorded and reported to a CFIA District office by one of the following methods:

  1. Fully completed Form CFIA/ACIA 1524, including animal information for each animal tested. A copy of the completed Form CFIA/ACIA 1524 is forwarded to the district office responsible of the area where the animals were tested. A copy must also accompany the export health certificate sent for endorsement to the district office (if different from the district where the animals were tested) or the certificate of health for entry into a semen production centre (Form CFIA/ACIA 1634 – Certificate of Health for Entry into a Semen Production Centre or Isolation worksheet and Authorization for Release); or
  2. Partially completed Form CFIA/ACIA 1524 as follows and attach an Animal List.
    1. Complete all parts of Form CFIA/ACIA 1524 (except the animal information section) including the signature block where the accredited veterinarian certified that he/she tested the animals described on date and at location shown.
    2. Attach to Form CFIA/ACIA 1524 a list of animals that were TB tested and found negative. In the animal information section of the Form CFIA/ACIA 1524, insert a statement that reads "The (insert # of animals) (insert species) listed on attached list were tested on the date shown above and at the location shown above with negative results". The accredited veterinarian should sign and date the list.
    3. Any animals with non-negative results must be included in the animal information section of Form CFIA/ACIA 1524.
    4. A copy of the completed Form CFIA/ACIA 1524 and the attached list are forwarded to the district office responsible of the area where the animals were tested. A copy must also accompany the export health certificate sent for endorsement to the district office (if different from the district where the animals were tested) or the certificate for entry into a semen production centre (Form CFIA/ACIA 1634 or Isolation worksheet and Authorization for Release).

Monitoring CFT Testing: Performance Standard

46. The CFT test has less than perfect specificity (ranges from 97-99%), resulting in a false positive reactor rate in a disease-free livestock population of 1%–3% per year. False positive reactors are an indicator that the test is being performed correctly as they are expected when applying this test in a group of animals without disease.

47. A minimum performance standard exists for all inspectors and veterinarians, including accredited veterinarians who conduct CFT testing. The reactor rate of each accredited veterinarian trained to conduct CFT test shall be monitored and calculated based on the number of cattle or bison test for each one year period. If a reactor rate less than the minimum performance standard of 1% is identified, this will be addressed and appropriate actions taken (i.e. additional training or supervision, audit) and documented. If insufficient cattle/bison are tested in one year for evaluation of compliance with the standard, the period for review will be extended.

48. District veterinarians involved in the evaluation of official services performed by accredited veterinarians are responsible for monitoring reactor rates of accredited veterinarians. Failure to meet the minimum performance standard (i.e. non-conformance) noted during evaluation of accredited veterinarians services will be addressed according to the Procedures Manual – Management of Accredited Veterinary Services – to improve the services provided.

49. Authorization to perform CFT test may be withdrawn for accredited veterinarians where non-conformance to the minimum performance standard cannot be resolved.

Mid-Cervical Tuberculin (MCT) Test

Preparation

50. The MCT test is the standard official screening test for tuberculosis in cervids. The test involves an intradermal injection of 0.1 mL of bovine PPD tuberculin in the mid-cervical area, with observation and palpation at 72 hours ± 6 hours.

51. Do not apply the MCT test to an animal that has had a tuberculin test of any kind during the preceding 60 days.

52. Prepare the following equipment:

tuberculin – bovine PPD tuberculin (store in dark at 4°C)
syringes – 1 mL tuberculin syringes
needles – 26 gauge, ⅜" long
absorbent cotton
electric clippers with #40 head
Form CFIA/ACIA 1524 – Report of Intradermal Test
headlamp or flashlight, if poor lighting

53. Adequately restrain each cervid for testing to ensure correct animal identification, proper preparation of the injection site, careful tuberculin injection, and proper reading of the test result. Do not apply or observe the test without having the animal adequately restrained.

54. Record on Form CFIA/ACIA 1524 the individual animal identification of each animal tested. Acceptable animal identification is as follows: tag approved (or considered equivalent) under the Livestock Identification and Traceability (TRACE) program, a HofA ear tag, a registered tattoo, or an ear tag approved by a provincial regulatory authority for farmed cervids.

Injection

55. Use clippers to clip an area in the mid-cervical region that is approximately 8-cm square.

56. Clean the injection site with cotton (moistened with water, if necessary). Do not use alcohol to clean the injection site. Note any abnormalities, lesions or scabs observed in the vicinity of the injection site, recording on Form CFIA/ACIA 1524 to avoid being mistaken for tuberculin responses.

57. Check tuberculin label for type – M. bovis tuberculin has an orange label.

58. Check/confirm expiry date against current date.

59. Disinfect rubber stopper with alcohol after opening aluminium seal.

60. Fill tuberculin syringe to 0.1 mL volume.

61. Insert needle into the dermis of the skin. Lift the tip of the needle slightly after insertion to ensure it is clearly outlined under the skin. Inject 0.1 mL of tuberculin intradermally and withdraw the needle slowly.

62. View injection site to ensure that the injected tuberculin is visible and palpable as a definite bleb. If not, it indicates that either the needle was inserted too deeply or the dose was inadequate. In such case, the administration of tuberculin should be repeated on the other side of the neck if possible, or at least 15 cm rostral or caudal from the previous injection site.

63. Discard needle immediately into a sharps container.

Reading

64. Observe and palpate the injection site at 72 hours ± 6 hours post-injection. Good lighting is essential.

65. Record the responses to the MCT test for each animal on Form CFIA/ACIA 1524 as follows:

  • Negative (Neg.): There is no visible or palpable change in tissue at the site of injection; or
  • Reactor: There is any visible or palpable disturbance in tissue at the site of injection. Contact the district office immediately.

When in doubt with respect to the nature of the response to the MCT test, classify the animal as a reactor.

66. Any animal that is classified as reactor on the MCT test is retested by a CFIA veterinarian with the Comparative Cervical Tuberculin (CCT) test (refer to the CCT test section below).

67. All tuberculin tests are official and must be recorded and reported to a CFIA District office by one of the following methods:

  1. Fully completed Form CFIA/ACIA 1524, including animal information for each animal tested. A copy of the completed Form CFIA/ACIA 1524 is forwarded to the district office responsible of the area where the animals were tested. A copy must also accompany the export health certificate sent for endorsement to the district office (if different from the district where the animal was tested); or
  2. Partially completed Form CFIA/ACIA 1524 as follows and attach an Animal List.
    1. Complete all parts of Form CFIA/ACIA 1524 (except the animal information section) including the signature block where the accredited veterinarian certified that he/she tested the animals described on date and at location shown.
    2. Attach to Form CFIA/ACIA 1524 a list of animals that were TB tested and found negative. In the animal information section of the Form CFIA/ACIA 1524, insert a statement that reads "The (insert # of animals) (insert species) listed on attached list were tested on the date shown above and at the location shown above with negative results". The accredited veterinarian should sign and date the list.
    3. Any animals with non-negative results must be included in the animal information section of Form CFIA/ACIA 1524.
    4. A copy of the completed Form CFIA/ACIA 1524 and the attached list are forwarded to the district office responsible of the area where the animals were tested. A copy must also accompany the export health certificate sent for endorsement to the district office (if different from the district where the animal was tested).

Comparative Cervical Tuberculin (CCT) Test (for information purpose only. Not to be performed by accredited veterinarians)

68. It is recognized that the majority of screening test CFT/MCT reactions in Canada are not due to actual bovine TB infection. Follow-up comparative cervical tuberculin (CCT) testing serves to rule out the vast majority of false positive MCT reactions and identify any truly infected animals. The CCT test is performed by trained and qualified CFIA veterinarians.

69. The CCT test involves an intradermal injection of 0.1 mL of bovine PPD tuberculin and 0.1 mL of avian PPD tuberculin in the cervical region and is based on the premise that M. bovis (the agent of bovine TB) is somewhat antigenically distinct from M. avium and other related environmental mycobacterial species. The difference in size of reaction at both sites is used to determine if an animal's reaction to the CFT/MCT test was more likely due to exposure to M. bovis or to the antigens from M.avium or other cross-reactive mycobacteria. An animal exposed to M. bovis will have greater reactivity at the bovine PPD injection site relative to the avian PPD injection site.

70. Animals that are negative to the CCT test are not subject to further disease investigation activities.

71. Any animal that is classified as positive to the CCT test is considered to be a TB suspect and ordered destroyed (with compensation paid) for confirmatory testing. The animal is subject to a detailed post-mortem examination, followed by the laboratory examination of any abnormalities that may be observed, as well as a selection of normal tissues. If the laboratory analyses result in the isolation and identification of M. bovis, disease eradication activities are initiated on the affected premises.

72. For export purposes, although CFT/MCT reactor animals that are subsequently negative to the CCT test are not usually eligible for exportation, their herdmates with a negative CFT/MCT test result may be eligible for exportation. Contact the district veterinarian for more information.

73. For the CCT test to work properly, it must be applied at specific times after a screening CFT/MCT test, which in some circumstances requires a waiting period. Although this can be inconvenient for some individual producers, the delay is preferable to the possibility of missing infected animals which could spread disease. The CCT test may be applied as follows:

  1. up to 10 days following the injection of tuberculin for the CFT test (cattle and bison only);
  2. for the purpose of exportation to the USA only, the CCT test may also be performed on a cervid reactor to the MCT test up to 10 days following the injection of tuberculin for the MCT test, in order to qualify herdmates for export if the CCT is negative;
  3. at least 60 days following the injection of tuberculin for the CFT test (cattle, bison, goats, sheep); or
  4. at least 60 days following the injection of tuberculin for the MCT test (cervid).

All subsequent CCT test re-tests must be conducted at intervals of not fewer than 60 days.

Single Post-Axillary Test for Camelids

Preparation

74. A post-axillary intradermal tuberculin test is a standard test for tuberculosis in New World (llama, alpaca) and Old World (camels) Camelidae. Although this test is not validated for use in a domestic TB program, the post-axillary intradermal tuberculin test is performed in Canada under live animal export and import programs. Use the test procedures in this section, unless the export health certificate stipulates otherwise.

75. The test involves intradermal injections of 0.1 mL of bovine PPD tuberculin into the skin, posterior to the axilla and elbow of the animal, with observation, palpation, and measurement at 72 hours ± 6 hours post-injection.

76. Response to this test is determined by a relatively small change in skin thickness; therefore, it is imperative that a regimented approach is taken in applying the test. Measurements are influenced by the skin tension (related to animal positioning and restraint); by the amount of pressure applied to the skin by the callipers, and by the size of the skin fold picked up for measurement. Make every effort to standardize these conditions for both injection and reading.

77. Note: Do not apply this test to an animal that has had a tuberculin test of any kind during the preceding 90 days.

78. Ensure that this test is performed by a trained and qualified accredited veterinarian, subject to the requirements of the importing country.

79. Prepare the following equipment:

tuberculin – bovine PPD tuberculin (store in dark at 4°C)
syringes – 1 mL tuberculin syringes
needles – 26 gauge, ⅜" long
absorbent cotton
electric clippers with #40 head
callipers
Form CFIA/ACIA 1524 – Report of Intradermal Test
headlamp or flashlight, if poor lighting

80. Record the individual animal identification of each animal tested on Form CFIA/ACIA 1524. Acceptable animal identification is as follows: a HofA ear tag, a registered tattoo, or a microchip number, if a reader is available.

Injection

81. Adequately restrain each animal for testing to ensure correct animal identification, the proper preparation of the injection site, accurate pre-injection measurement, careful tuberculin injection, careful palpation, and accurate post-injection measurement.

82. Prepare the injection site by clipping an 8-cm square area on the lateral aspect of the chest wall in the axillary region near the point of the elbow.

83. Clean the injection site with cotton (moistened with water, if necessary). Do not use alcohol to clean the injection site. Inspect and palpate the intended injection site, recording any abnormalities, lesions, or scabs that are observed in the vicinity of the injection site on Form CFIA/ACIA 1524 to avoid being mistaken for tuberculin responses.

84. Prior to injecting the tuberculin, lift the fold of skin in the center of the injection area, apply the callipers to the fold, adjust the callipers just until they grip the skin but can still slip off the fold, slip the callipers off the fold, and read the calliper measurement to the nearest 0.5 mm. Record the measurement on Form CFIA/ACIA 1524.

85. Note: Perform a single calliper measurement at the injection site. Only if a problem is encountered with this measurement is the first measurement discarded and the entire process repeated. Repeated measurements will "flatten" the skin.

86. Draw 0.1 mL of bovine PPD tuberculin into the syringe. Inject the tuberculin intradermally into the center of the injection area, lifting the tip of the needle slightly after insertion to ensure it is clearly outlined under the skin. Inject 0.1 mL of tuberculin intradermally and withdraw the needle slowly.

87. View injection site to ensure that the injected tuberculin is visible and palpable as a definite bleb. If not, it indicates that either the needle was inserted too deeply or the dose was inadequate. In such a case, the administration of tuberculin should be repeated on the other side.

88. Discard needle immediately into a sharps container.

Reading

89. Observe and palpate the injection site in good light at 72 hours ± 6 hours after the injection to locate the point of greatest response. Note that, in camelids, response at the injection site is frequently diffuse. The response can also be highly variable.

90. Lift the fold of skin in the area of greatest response or, if there is no area of greatest response, in the centre of the injection area and measure the thickness of the fold with the same callipers used on the injection date and in the same manner as on the injection date, to the nearest 0.5 mm. Record the measurement to the nearest 0.5 mm, on Form CFIA/ACIA 1524.

91. Note: Perform a single calliper measurement at the injection site. Only if a problem is encountered with this measurement is the first measurement discarded and the entire process repeated. Repeated measurements will "flatten" the skin.

92. Subtract the pre-injection measurement from the post-injection measurement, and record the difference on Form CFIA/ACIA 1524. This value is the "skin thickness difference value."

93. Interpret the "skin thickness difference value," according to applicable export or import requirements. If interpretation is not specified, classify the animal's TB test result as follows and record on Form CFIA/ACIA 1524:

  • Negative (Neg): There is no visible or palpable reaction at the injection site, and "skin thickness difference value" is less than 1.5 mm; or
  • Reactor: There is a visible or palpable reaction at the injection site, or "skin thickness difference value" is equal to or greater than 1.5 mm. Contact immediately the CFIA district office.

94. All tuberculin tests must be recorded and reported to a CFIA District office by one of the following methods:

  1. Fully completed Form CFIA/ACIA 1524, including animal information for each animal tested. A copy of the completed Form CFIA/ACIA 1524 is forwarded to the district office responsible of the area where the animals were tested. A copy must also accompany the export health certificate sent for endorsement to the district office (if different from the district where the animals were tested); or
  2. Partially completed Form CFIA/ACIA 1524 as follows and attach an Animal List.
    1. Complete all parts of Form CFIA/ACIA 1524 (except the animal information section) including the signature block where the accredited veterinarian certified that he/she tested the animals described on date and at location shown.
    2. Attach to Form CFIA/ACIA 1524 a list of animals that were TB tested and found negative. In the animal information section of the Form CFIA/ACIA 1524, insert a statement that reads "The (insert # of animals) (insert species) listed on attached list were tested on the date shown above and at the location shown above with negative results". The accredited veterinarian should sign and date the list.
    3. Any animals with non-negative results must be included in the animal information section of Form CFIA/ACIA 1524.
    4. A copy of the completed Form CFIA/ACIA 1524 and the attached list are forwarded to the district office responsible of the area where the animals were tested. A copy must also accompany the export health certificate sent for endorsement to the district office (if different from the district where the animals were tested).

Base-of-the-Ear Tuberculin Test for Swine

Preparation

95. The base-of-the-ear intradermal tuberculin test is the standard test for tuberculosis in swine carried out under the Artificial Insemination Program and for the purposes of live-animal export.

96. Unless the importing country specifies different procedures and/or interpretation, use the procedures and interpretation set out in this section.

97. The test involves an intradermal injection of 0.1 mL of bovine PPD tuberculin into the skin at the base of the ear, with observation and palpation at 48 hours post-injection.

98. Note: Do not apply this test to an animal that has had a tuberculin test of any kind during the preceding 60 days.

99. Ensure that this test is performed by a trained and qualified accredited veterinarian, subject to the requirements of the importing country.

100. Prepare the following equipment:

tuberculin – bovine PPD tuberculin (store in dark at 4°C)
syringes – 1 mL tuberculin syringes
needles – 26 gauge, ⅜" long
absorbent cotton
Form CFIA/ACIA 1524 – Report of Intradermal Test
headlamp or flashlight, if poor lighting

101. Sufficiently restrain each pig for testing to ensure, correct reading of the animal identification, careful tuberculin injection, and proper reading of the test result. The method of restraint used can be modified according to the temperament and the weight of the pig. Avoid applying or observing the test without having the animal adequately restrained.

102. Record the individual animal identification of each animal tested on Form CFIA/ACIA 1524. Acceptable animal identification can be found under module 2.1 Identification of Livestock

Injection

103. The tuberculin injection site in swine is the dorsal surface of the ear, slightly anterior to the base. Use either the left or right ear, but be consistent.

104. Clean the dorsal surface of the base of the ear with cotton (moistened with water as necessary). Do not use alcohol to clean the injection site. Note any abnormalities, lesions, or scabs observed in the vicinity of the injection site, recording on Form CFIA/ACIA 1524 to avoid being mistaken for tuberculin responses.

105. Check tuberculin label to confirm type – M. bovis tuberculin has an orange label.

106. Check/confirm the tuberculin expiry date against the current date.

107. Disinfect rubber stopper with alcohol after opening aluminium seal.

108. Fill tuberculin syringe to 0.1 mL volume.

109. Standing to one side of the pig, insert needle into the dermis of skin at the base of the ear. Lift the tip of the needle slightly after insertion to ensure it is clearly outlined under the skin. Inject 0.1 mL of tuberculin intradermally and withdraw the needle slowly.

110. View injection site to ensure that the injected tuberculin is visible and palpable as a definite bleb. If not, it indicates that either the needle was inserted too deeply or the dose was inadequate. In such case, the administration of tuberculin should be repeated on the other ear.

111. Discard needle immediately into a sharps container.

Reading

112. Observe and palpate the injection site at 48 hours post-injection. Good lighting is essential.

113. Unless the importing country has stipulated a different interpretation, record the response to the test on Form CFIA/ACIA 1524 as follows:

  • Negative (Neg.): There is no visible or palpable change in tissue at the site of injection; or
  • Reactor: There is an appreciable visible or palpable disturbance in tissue at the site of injection. Notify the CFIA district office.

114. No ancillary comparative skin testing is available. Whenever a porcine animal is classified as a reactor, an investigation must be undertaken by CFIA to identify any contact that the reactor may have had with ruminant animals since its birth. If any such contact is identified, the ruminant animal herd must be investigated and tested by CFIA employees.

115. The fate of a reactor porcine animal is determined by the standards of the program under which the animal was tested, and may include retesting the reactor after at least 60 days or removing the animal from the semen production centre or export shipment.

116. All tuberculin tests are official and must be recorded and reported to a CFIA district office by one of the following methods

  1. Fully completed Form CFIA/ACIA 1524 including animal information for each animal tested. A copy of the completed Form CFIA/ACIA 1524 is forwarded to the district office responsible of the area where the animals were tested. A copy must also accompany the export health certificate sent for endorsement to the district office (if different from the district where the animals were tested) or the certificate of health for entry into a semen production centre (Form CFIA/ACIA 1634 or isolation release document); or
  2. Partially completed Form CFIA/ACIA 1524 as follows and attach an Animal List.
    1. Complete all parts of Form CFIA/ACIA 1524 (except the animal information section) including the signature block where the accredited veterinarian certified that he/she tested the animals described on date and at location shown.
    2. Attach to Form CFIA/ACIA 1524 a list of animals that were TB tested and were found. In the animal information section of the Form CFIA/ACIA 1524, insert a statement that reads "The (insert # of animals) (insert species) listed on attached list were tested on the date shown above and at the location shown above with negative results". The accredited veterinarian should sign and date the list.
    3. Any animals with non-negative results must be included in the animal information section of Form CFIA/ACIA 1524.
    4. A copy of the completed Form CFIA/ACIA 1524 and the attached list are forwarded to the district office responsible of the area where the animals were tested. A copy must also accompany the export health certificate sent for endorsement to the district office (if different from the district where the animals were tested) or the certificate of health for entry into a semen production centre (Form CFIA/ACIA 1634 or isolation release document).
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