Animal Technician Jacqueline Schwartz of Halifax, Nova Scotia’s Dalhousie University
works with pigs in the research laboratory

Not surprisingly, pigs abhor being restrained, so it can be difficult to work with them in the research setting. They are very sensitive and become stressed easily. Therefore, I developed a swine conditioning and training schedule with the goal of decreasing or even avoiding the stress they may experience due to procedures performed during a study.

Socialized pigs at Dalhousie University enjoy being petted and scratched by their caretakers in the laboratory. Tamara Godbey

When the pigs arrive at our laboratory, they are very shy and afraid because they have had little contact with people. We place them individually in prepared pens with food and water and leave them undisturbed until the next morning, so that they may settle into their new homes. Socialization begins on the second day.

As a first step, I patiently habituate the new pigs to my presence until they no longer try to stay at a “safe” distance. I sit quietly on the floor of the pen at the opposite end and let the pig learn that I am harmless. Initially, I avoid making any eye contact because I get the impression that the animals feel intimidated when I look straight at them during this early stage of the conditioning.

Age is a very important factor in determining how long the “warming up to me” phase will take. The very young pigs socialize quickly, probably because their curiosity is stronger than their fear when meeting a strange-looking two-legged animal. The relatively old, very large pigs also have little problem socializing with me, presumably because their body weight advantage “tells” them that they have nothing to fear from this weak human being. The middle-aged pigs are more of a challenge. It can require quite a bit of time to overcome their mistrust, but patience usually pays off.

When I know for sure that the pig has adapted to my presence, I start moving slowly in a semi-seated position in the direction of the pig, but stop whenever the animal shows any sign of fear. I avoid abrupt movements and speak softly so that the animal becomes used to my voice. If the pig appears to be frightened, I carefully move away, wait at a distance, and approach again after the animal has calmed down.

We will be in close proximity for a few minutes before I slowly move away and leave the pen. I repeat these maneuvers for several days, with short sessions in the beginning, followed by progressively longer sessions as the animal begins to accept me. Sooner or later, curiosity wins and the pig will make contact with me. I usually wait until it is the pig’s idea and not mine, so that the animal can initiate contact and hence is in control of the situation. A pig who seeks contact with me is “socialized” and gives the impression of feeling completely at ease when I am around.

Specific training may begin once the pig is comfortable being touched by me, which all “socialized” pigs seem to enjoy thoroughly. They typically lean into my hand or fingers while I rub or scratch them. Once a pig finds out how nice it is to be touched, he or she will often settle down in your lap for a good old scratching.

When petting or scratching a pig, I pay special attention to areas where injections will be given, such as the rump and the back of the neck. I pat the animal firmly on these areas on a daily basis. An injection using a butterfly needle can be given during a petting session, without any ado. The animal may rub the injection site against the fence, but usually will return quickly for more attention. During petting sessions, I am on the floor with the pig. This would not be a safe idea with very large pigs. I have found that they can easily be distracted with a good back scratch or a bowl of treats while I stand safely beside them.

When training a pig, I pay special attention to his or her tail and handle it frequently. In the beginning, the animal is suspicious of having a part of the body touched without being able to see what I am actually doing, but this initial phase of apprehension is quickly overcome. Most pigs actually enjoy having their tail manipulated—especially when I rub the head of the tail. Once a pig allows this contact, anal temperatures can be obtained easily during a good rump or belly scratch.

I also give attention to any body part that will receive a bandage after a surgical procedure. When I take extra time to rub and scratch those areas beforehand, removing or changing a bandage can be accomplished without unduly disturbing the pig. Additionally, I first socialize with pigs assigned to a study that requires frequent eye ointment applications, rubbing my index fingers gently over the pig’s eyes regularly during our petting sessions. Later, when I treat the pig, he or she will show no resistance when I part the upper and lower eye lids with the gentle pressure of my fingertips to apply the ointment onto the eye.

Pigs adore food. This circumstance makes oral drug administration a relatively easy procedure under the condition that the animals are well-socialized and trusting. I disguise oral drugs in jam or peanut butter, depending on the individual pig’s preference, and offer the mixture. It sometimes takes a little coaxing, such as touching the roof of the pig’s mouth with a mixture-coated finger, so that the animal gets the taste of the nice jam or peanut butter and then consumes the mixture without any further reservation. Usually, however, a pig will spontaneously eat the mixture out of a bowl immediately!

I have had the good fortune to work with pigs from the same facility for the last 22 years. It has been very rewarding to repeatedly experience the ease with which a trust-based bond with the animals can be established—and to make use of this bond by conditioning the pigs to calmly cooperate, rather than fearfully resist, during common research-related procedures. With compassion and patience, stress and distress reactions can usually be avoided, and the pigs’ welfare thereby enhanced.

New Book Focuses on the Third “R”

Taking Better Care of Monkeys and Apes: Refinement of Housing and Handling Practices for Caged Nonhuman Primates, a new book by AWI Laboratory Animal Advisor Viktor Reinhardt, reviews literature on the refinement of traditional housing and handling practices for nonhuman primates living in cages alone, in pairs or in trios. Traditional practices often expose animals to unnecessary distress—a problem that is both an ethical and a scientific concern. The reaction of distress is a sign of impaired well-being, as well as an uncontrolled variable that increases statistical variables.

Fortunately, professional and scientific journals document that housing and handling practices for caged nonhuman primates can be refined, without undue labor and expenses, in such a way that distress responses are minimized or avoided when basic ethological principles are applied. With a little bit of good will and earnest concern for animal welfare and scientific methodology, the systematic implementation of refinement for caged nonhuman primates is a practical option.

A free copy of the book is available for individuals at research facilities, and additional copies are available for the cost-price of $3.00. If you are interested, please send a request by mail or email to AWI.