Atoll's Technical Tips: Avoiding Heatstroke
It's hot, it's very hot
It is hot.
It is very hot.
How do we keep our sheep well? Here are a few tips for avoiding heat stroke in your flock.
The first advice I offer may seem counterintuitive to anyone who has not studied the thermoregulative properties of wool. That is: do not shear during a heat wave. If it is excruciatingly hot– wait for a cooler stretch. Why? Because wool insulates-- from the cold AND from the heat. The only clinical cases of heat stroke I have treated in sheep have been from those shorn on record hot days. Suddenly, the sheep find themselves without protection from the elements that they have been becoming accustomed to all season long. Additionally, you can time shearing for several weeks before the anticipated hottest time of the year, so there is time to grow some of that protection back. There is good evidence that sheep with at least an inch of wool withstand heat better than those that are shorn closely.
Next, have coolish, clear water available at all times. Keep your water troughs in the shade if possible to keep it from being unpalatably hot and also to keep algae from growing.
Do sheep need shade? After shearing, they do. If they are sick or compromised (pregnant, young, old etc.), they do. At other times– it depends. Every veterinarian I know says absolutely all sheep need access to shade in summer. However, many old time producers I now swear they do fine without. To quote one old-time sheep man from Canada when asked what he uses for shade structures, “the clouds!” Because I am a veterinarian and a shepherd I will split the difference and say: it depends. If you are new to your sheep, to the climate you are in, or to the breed you are raising-- provide shade! You may find at some point that you are raising sheep that don’t need or use it. My sheep seem to only prefer their shelters during mild weather. During extremes of heat, wind or snow, I almost always find them nonchalantly giving passersby a heart attack by standing out in the elements.
Provide a high quality, species-specific mineral mix (which will be an important source of vitamins and electrolytes) close to water and shade so they do not have to move much in extreme heat.
You can implement misters (often sold for porch parties and chicken coops).
In very severe heat you may limit grazing during the hottest parts of the day, turning them out in the early morning or later evening.
Do not handle sheep unnecessarily during extreme heat.
And lastly, as we always say here at Leaning On Our Crooks, the most valuable tool you have is your attention. Monitor, monitor, monitor. And if you see someone acting off, intervene.
How can I tell if my animals are suffering from heat stress?
Open mouth breathing and a rapid respiratory (panting) rate are signs that they are being affected by the weather. The farther out their tongue is, the more severe the stress. An animal in danger may have their tongue completely out and their head down. If an animal has a rectal temperature creeping up to or above 105 degrees-- it is a clear sign they cannot regulate their own temperature any longer. They need intervention or the heat stress can be fatal.
Oh no! I read this too late and my sheep is suffering from heat stress!
Move them to a cool, shaded, well-ventilated area. Get a fan or have multiple fans going. Apply rubbing alcohol to the wool-free skin between their rear legs (not directly on mucus membranes-- ouch!). Do not spray water over wooled areas, as this will actually prevent them from cooling down. Avoid sudden temperature shifts like ice baths or ice water enemas-- these can cause too sudden of a shift and send your sheep into shock. Offer small amounts of water frequently.
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