Relieving painful practices
Sept. 13, 2013
Dr. Temple Grandin
On the farm, a major welfare concern is painful practices such as castration and dehorning. At the Australian Veterinary Association Conference in Cairns, Australia, Peter Windsor from the Univ. of Sydney presented exciting findings on a product that can be used to relieve pain after castration and dehorning. His product would make it much more practical to provide pain relief after castration or dehorning of beef cattle and sheep.
A major disadvantage of local anesthetics for beef cattle is that it takes 10 to 15 minutes for an injection of local anesthetics to numb the area. On a dairy, a two-step procedure is easy to do because the calves are kept in small pens. On a beef ranch, a two-step procedure would cause additional stress from handling the animals twice. In a dairy, it is easy to handle the calf a second time because it is already restrained in a small pen. On a ranch, a wild calf would have to be caught twice. In Australia, the Bayer Company has won formal drug approval for use of this pain-relief product on various livestock.
The secret to creating a local anesthetic that can be applied at the time of the surgery was mixing two local anesthetics with a gooey, sticky gel. The mixture also contains an antiseptic and epinephrine, which helps reduce blood loss. The gel was the secret to its success because after the product is applied, it sticks to the cut surfaces and stays on.
Three measurements of pain relief were recorded – thermography (which is how hot the wound is), a pressure test and rate of healing. The gel improved all of these measurements. The product requires no skill to apply and it is applied with a device that looks like a drenching gun with a short nozzle. The livestock industry needs to work on getting this gel approved in the US.
Fear vs. discomfort
Jan Bowers discussed the need to differentiate different types of distressful sensations so that better treatments can be devised. There is fear, the feeling of being sick and in pain. Pain has two dimensions – acute pain and inflammatory pain. Inflammatory pain may be a response to an anti-inflammatory drug such as Meloxicam.
Fear and the feeling of being sick are two different things. Normally, animals that receive a shock in a certain location will avoid entering that place. This is called contextural conditioning. Contextural conditioning will occur if cattle are handled roughly the first time they go in a corral. They may resist going back into the “bad” place in the future because it was associated with a painful experience.
The nasty feeling of being sick is not subject to contextural conditioning. When either an animal or person has fever and chills, they want to rest and get away. In the wild, it would be counterproductive for an animal to avoid a safe hiding place when it got sick. Contextural conditioning in this situation would cause it to be more likely to get eaten by predators. This shows that the feeling of being sick is very different than fear.
Dr. Temple Grandin operates Grandin Livestock Systems Inc., Fort Collins, Colo., and is a faculty member in the animal science department at Colorado State Univ.