Surgical models and perioperative care in swine

Published on February 11, 2015   48 min

Other Talks in the Series: Animal Models in Biomedical Research

0:00
I'm Michael Swindle. I'm a professor emeritus at the Medical University of South Carolina in Charleston, South Carolina. And I'm going to be speaking about surgically produced models in swine. And then later Dr. McCrackin will conduct the second part of the lecture on perioperative care.
0:21
To start off with, not all pigs are created equal in terms of their growth rates. And for instance, the green pattern here is the growth of a domestic pig, a farm pig, which will grow upwards of 100 to 120 kilos in about four to six months time after birth, as compared to the miniature breeds whose growth curves are down here at the bottom in various colors. And the miniature breeds are made to grow more slowly than the farm pigs, but physiologically they are the same genus and species.
1:02
The four most common breeds of pigs that are used as miniature pigs, on this slide, are the Sinclair, the Yucatan, which comes in both a miniature and a micro variety, the Hanford pig, which grows to be a human sized mini-pig, and then the Gottingen pig, which is used extensively throughout Europe and some in the United States. So those are the four most common varieties of pigs. You can look at the growth chart. You can go to the various websites of the producers and find information on their background.
1:42
This is the housing system we use at our university. We use these raised fiberglass floors. We have an automatic watering system with the spigot in the back of the cage here. And we have feed bowls that are tightly attached to the side of the cage, and we give them toys to play with. We can also house pigs socially so that they have snout to snout contact. The reason we use this system is that we do surgical models. If you house pigs on bedding and fast them for surgery, they will tend in large numbers to eat the bedding, and can develop intestinal impaction from it. Pigs can also be cannibalistic post surgically, and so we do not house them together after they have had surgery. And they're very content with just snout to snout contact, and seeing and hearing other pigs in the room with them.
2:42
To start off with on anesthesia, it's the number one issue to consider in avoiding complications in these surgical protocols. There is no such thing as one anesthesia that's good for all swine protocols. You must match the anesthesia to the type of surgery that you're performing and minimize the effects of the anesthetic on the scientific protocol. If there is any default general anesthetic, it would be the inhalant anesthetics isoflurane or sevoflurane.
3:16
There are reasons to use injectable anesthetic protocols, both for induction of anesthesia, as well as for maintenance during some types of protocols such as imaging and some cardiac protocols. If you use more than one injectable agent, then it changes the physiology. So the physiologic effects of the anesthetics may vary widely the more agents you add. So you need to minimize the number of injectables. And if you're using an injectable protocol, it should be given is a continuous infusion, rather than repeated bolus injections to avoid physiologic discomfort.
3:57
We do not recommend that you give intramuscular injections into swine, because their muscle density is so tight that it is extremely painful, especially if you're using agents like ketamine. We have been using, for decades, subcutaneous injections in the sides of the neck. In this case, what you would do is place a butterfly catheter into the neck. And once the pig walks around and gets over the initial sting of having the needle stick, then you pick up the end of the catheter and inject your tranquilizer or your anesthetic agent. This methodology does not require that the pig be handled by more than one person. And you don't have any kind of distress from grabbing ahold or trying to restrain the pig. It's free to walk around during this particular procedure. And the subcutaneous route is what we recommend for the anesthetics and analgesics.
4:59
Intubation of the pig can be accomplished from a variety of positions. My personal preference is to have the pig placed on its back, as you see in this picture. And the primary issue is that the pig has a lot of diverticula, these folds inside the larynx. And those can give you trouble with the intubation.
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Surgical models and perioperative care in swine

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