PIG How-To's

How To Identify and Track Treated Animals


Even before there is a need to treat an animal, pork producers should have a plan for the identification of treated animals. This plan should include the type of animal identification that is most appropriate for treated animals in their operation.




Producers must be able to identify treated pigs or groups of pigs from the time they receive the animal health product until the withdrawal time established for that product has elapsed. Regardless of the identification method used, a written record of the treatment should be kept on file for one year after the hogs have been marketed. It is important to remember that unanticipated sales decisions of sows or growing pigs treated with animal health products can cause violative residues.

There is no way to keep meaningful records if animals are not identified, individually or by pen or location. Many producers use some form of identification card (such as a sow card) or building record for tracking animals. When individual animal identification is not practical, an identifiable group of animals (pen/building/site) can be tracked and its records retained until the product’s withdrawal time has elapsed. Regardless of the identification system used, pork producers should develop and train employees to fill, read and understand treatment records of animals that are to be treated, moved or sold.


Methods of identifying treated pigs


The following methods can be used to identify individually treated pigs:

  1. A card that stays with the animal and is retained after the withdrawal period has elapsed. This works best for adults housed individually in a pen or stall.
  2. Paint marks. These are easy to apply and can be used for treatments with short withdrawal times, but may rub off or rub onto untreated penmates. This method is inappropriate for withdrawal times of more than several days.
  3. Tattoos. These are permanent, but depending on the type the tattoo may be hard to apply and difficult to read at a distance.
  4. Ear tags. Tags are easy to see, but may be cumbersome to apply.
  5. Ear notches. These can be recorded on a card to identify treated animals. Notching systems may vary, so caretakers must be familiar with site-specific notching systems


Identifying groups of treated pigs


When treated animals are identified by pen, room or group number, it is important that the entire group remains intact until the withdrawal time has elapsed. Any pig removed from the group should be individually identified and the withdrawal time recorded.


With this form of group identification, each nursery, grower and finisher pen must be uniquely identified in a way that is clear to all caretakers. Descriptions such as “Third pen on the south side;” are not effective as some caretakers may not know which way is south or from which end of the building to count.


Methods of identifying groups of animals may includea card, barn sheet or other visual marking that stays with the group(s) of animals or is retained in the office.


Example of individually animal treatment record

Last Date of Treatment Animal identification Product Name Dose (cc) Route Given By Withdrawal (Days)
10-16 129 LA 200 7 IM John 28
11-29 267 Excede 4.5 IM Mike 14


Example of group treatment record

Last Date of Treatment Animal identification Product Name Dose (cc) Route Given By Withdrawal (Days)
10-16 Barn #3 LA 200 7 IM John 28
11-29 Pen #1 at PIN 345890 Excede 4.5 IM Mike 14


More details and information about how to identify and track treated animals can be found in the PQA Plus™ manual.