DEAR DR. WELDY’S: We have a menagerie of 4-H animals here at my house including pigs, goats and horses. We had a pig get sick this week and wondered if it might be because of heat stress. What are the symptoms of this and what might we do to prevent it?
DEAR READER: After last winter’s polar vortex, I wasn’t sure we would ever worry about hot weather again. However, these first heat waves of 2014 have reminded me of the stress heat can cause all species. Just like people, animals adapt to certain conditions. In a climate like ours where seasons change distinctly, there is always an adjustment period. When an animals body has to deal with extreme temperatures before it has adapted it causes a great deal of stress. Decreased milk production in dairy cattle, stagnant weight gain in pigs, reproductive issues, and respiratory disease in many species are all examples of what this stress can do. In severe cases heat stress can lead to heat stroke and even prove fatal if not corrected. Since our barnyard animals cant be air conditioned, it is vital that we do what we can to give them as much comfort as possible during a heat wave.
When it comes to these animals cooling down, evaporation is the name of the game. Horses sweat, dogs pant, pigs wallow in water or mud. These are all forms of evaporation cooling. What is the most important thing for evaporation to take place? Air flow and water. Therefore animals need plenty of water to drink and fans to provide air flow when it is hot. Some animals, including pigs (that don’t sweat contrary to popular belief) and cattle may need misters or standing water or mud to wallow in. When it is extremely humid outside this evaporation is diminished making it even more important to watch your animals closely for signs of heat stress or stroke.