When Drought Affects Your Horse’s Pasture


Periods of excessive rain and drought will always cycle through the seasons. When drought affects your horse’s pasture, you must care for your land and horse.  Never fear, you can make some changes to get through dry spells and alleviate horse pasture drought concerns. 


Table of Contents

Horse pasture drought concerns
How drought affects your horse’s health
Help your pasture survive a drought
Help your horse’s health during a drought
What happens after rain?
Jump to video and shopping 

Horse pasture drought concerns


Storing energy for the future


  • When grass is threatened or stressed, it responds by hoarding starches and sugars. These non-structural carbohydrates supply energy to the plant for future growth and reproduction. Drought is a stressor, and pasture will react by increasing the stored sugars in the plant.


  • Some grass will become dormant, and the sugars and starches remain high despite its brownish color. The bottom few inches of a grass leaf collect those sugars. Incidentally, this makes the base of the plant more delicious and can quickly lead to overgrazing.



  • Drought will thin a pasture rapidly, the perfect moment for weeds to shine and grow. Typically, weeds don’t need as much water as grasses, so they take advantage of the extra sunlight and breathing room to thrive.


  • There are two main problems with weeds – they can overtake a pasture as grass flounders and are sometimes toxic to horses. Case in point, the buttercup. Horses largely ignore this bitter and toxic, but adorable, flower unless the buttercup is the last remaining snack.


skinny bay horse grazing on short drought pasture





  • Overgrazed pastures create a few problems for grass. First, the weeds. Then, horses and other grazing animals may damage the roots and the plant with their hooves. These factors can slow pasture regrowth, not to mention the amount of mud possible when rains do happen.


  • Ideally, it would be best to let overgrazed pastures rest. When the grass has come back to about 6 inches in height, it’s more likely to do well when horses are re-introduced.

Loss of fiber


  • Hay and horse pasture are huge sources of fiber for your horse – until it’s not. Droughts cause the volume, and quality, of pasture (and therefore fiber) to decline.


  • The lack of fiber in pasture during drought leaves horses hungry, needing more chewing time, and more likely to eat fencing and weeds. Or even their buddy’s tail.

Nitrate imbalance


  • Drought-afflicted grass will have increased nitrate levels. While this is more likely to affect cows and other ruminants, horses may be at risk of nitrate toxicity. This risk increases if a horse’s drinking water already has high nitrates.


  • Signs of nitrate toxicity in horses include colic, diarrhea, and other digestive issues.

How drought affects your horse’s health


  • Aside from toxic weeds and nitrate toxicity, horses grazing on struggling pastures have other problems to dodge.

Sand colic


  • As grass gets thinner, and hoofprints dig up the earth, a horse may eat more sand and grit than they would otherwise. Sand colic occurs when the ingestion of sand creates roadblocks and blockage in a horse’s digestive system.


  • And contrary to popular belief, you can not accurately gauge this by doing a fecal float test. This test only tells you IF sand is passing through your horse’s digestive tract. If you don’t see sand in the trial, your horse could still have some that is not passing. Or, you see sand passing, but you won’t know how much remains inside your horse.  More on how to *halfway* test for sand in your horse here.  


herd of horses grazing on brown pasture

There’s not much to munch on here.




  • Laminitis is the biggest risk to grazing horses on drought-riddled land. The stress of the drought causes the sugars and starches in the plant to spike.


  • Horses get into trouble when larger volumes of sugars land in the hindgut rapidly. Think about the pony busting into the feed room. When that happens, a chain reaction of events can lead to laminitis and founder.


Help your pasture survive a drought




  • If possible, irrigation is an option. It may be easier to water smaller paddocks than larger ones, and this is not always an option.  If you clean water thoughts and buckets regularly, pour the dirty water onto smaller, more damaged areas.  Using a wheelbarrow helps if you water with buckets.



  • The type of grass in your pasture will dictate what horse-friendly fertilizer you could use. Your local ag extension office is a great resource for this information.


manure spreader putting compost on the fields

Mowing and fertilizing helps drought-stricken grass.


Keep mowing


  • While it seems counter-intuitive, you can mow to keep the weeds at bay. This also chops some weeds off before they can seed for future weeds. The goal is to adjust the height of the mower deck to save the grass but chop the invaders.

Top seeding with a cool-season grass


  • Some climates support top-seeding with grasses, like cool-season grasses, that can help fill in gaps during a drought. Usually, these are best planted in the late summer or fall, but past seasons of drought in your area may dictate a better time.

Help your horse stay healthy during a drought


Feed more long-stem forage


  • Supplement any missing fiber with hay. This may add dollars to your feed bill, but it’s better than a vet bill. Using hay nets and other slow feeders makes hay last longer, giving your horse more chewing time.


  • If you toss hay into the pasture, and your horses go for that first, it’s a good sign that the grass isn’t giving them the fiber they crave.

Add vitamin and mineral supplements


  • You may need to supplement your horse with vitamins and minerals during a drought. The perfect example is vitamin E, which is plentiful in the pasture but is gone in hay after a week. Your vet and equine nutritionist can help you decide the best supplements for your horse during a drought. The best combo might resemble what you add during winter’s dormancy.


horse in field wearing a greenguard grazing muzzle

Muzzles protect your horse and your fields. 


Grazing muzzles


  • Sometimes our horses still need to graze – for movement, socialization, and digestive health. Grazing muzzles protect your horse’s digestive system and help prevent over-grazing. Muzzles temper the amount and speed of sugars and starches entering the hindgut, which is especially important for horses at high risk of laminitis.
  • Muzzles are nothing more than a wearable hay net that keeps your horse snacking and moving.

Utilize dry lots


  • The other end of the spectrum is using dry lots. Dry lots provide movement and time with other horses. Your pastures can rest and avoid over-grazing. Slow feeders are great here, too, you can add several around the lot to encourage movement.


What happens when rain breaks the drought?


  • Along with a huge sigh of relief, rain after a drought has a few possible hiccups to contend with.


  • First, it’s the mud. Then the grass kicks into its normal growing cycle, using all stored sugars. In many ways, your pasture has another spring bloom.


  • Ideally, you can wait until the grass has grown a few inches before allowing a regular turnout schedule. Your horse may need to acclimate to the new richness and volume of grass – another good time to use grazing muzzles and structured turnouts, perhaps some dry lot time too.



go shopping button for horse products


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Safety break-away halter for grazing muzzles.



The best muzzle in the land. Also in raspberry, blueberry, and black colors.

Use code 15PROEQUINE for a lovely discount!


This slow feeder for pellets and grains helps your horse take his time eating. 

Another style of slow feeder for pellets and grains


A boredom-busting horse toy that fills with hay



Horsemen’s Pride Amazing Graze Treat Toy


Slow feeder hay bag


Another style of hay bag

Small opening hay net

Traditional slow feeder with smaller openings


Round bale hay net

A ration balancer


A basic vitamin and mineral supplement



Another brand of vitamin and mineral supplement




Thank you!