Combat summer lethargy
24 Jul 2020
By Harbro nutritionist, Dr Vicki Glasgow
Although we and our horses have been in lockdown, I have still been getting the usual summertime queries about horses lacking in energy - these generally come in after a hot spell.
The first thing to check (particularly in the summer when feed levels are cut back) is whether your horse is receiving the full complement of vits and mins.
More often than not, where the feed has been cut back due to a plentiful supply of grass, provision of essential vitamins and minerals has also been cut back.
Simply providing your horse with a supplement will improve energy levels. This can be provided in the bucket feed or as a mineral lick depending on your circumstances.
The next point to consider when trying to tackle lethargy in your horse, is the effect that extra sweating, either due to exercise or just standing in the field can have on your equine friend.
Horses, like humans, use sweating and evaporative heat losses as the main means of cooling down. When a horse sweats it doesn’t just lose water, it also loses a large amount of salts, or electrolytes. The three main electrolytes lost during sweating are sodium, potassium and chloride with some magnesium and calcium also being lost. Electrolytes carry an electrical charge, which enables them to transfer water through cell membranes (in or out).
Thus, their main function is to get the nutrients in to cells and the waste out. They are responsible for the correct functioning of muscles and nerves. It is also crucial that they are present in the correct balance for these chemical reactions to proceed.
Large electrolyte losses will result in complications such as muscle cramping, tying up, thumps and alkalosis.
Sodium is also required as a trigger to the horse to drink. If a horse is low in electrolytes then the trigger to drink won’t be there, which could obviously become a dangerous cycle.
A horse at rest or in light work is not going to sweat as much as a horse in hard work but it will still require some electrolyte supplementation, especially in hot weather.
This can be supplied by providing the horse with a free-access salt block. However, not all horses use salt blocks and if they do they are generally unable to achieve the intake required.
The best way to ensure that your horse is getting its daily requirement for sodium is to add table salt (sodium chloride) to its feed. One tablespoon per day for an average 500kg horse.
The majority of horse feeds don’t contain enough salt for your horse, so it must be provided as an extra. For horses that are in light-medium work and especially if they have been sweating a lot, a third of the salt can be replaced with lite salt (contains potassium chloride).
Ordinary table salt is perfectly adequate for idle horses or those in light work, as forage and feed would contain appropriate levels of potassium.
For horses in hard work and in particular during hot weather, electrolyte losses are significant.
Excessive losses result in muscle weakness and fatigue. Electrolyte supplementation must be able to replenish what has been lost to prevent these problems.
It, therefore, is obvious that large amounts of electrolyte minerals and water must be supplied daily to horses doing long distance work, eventing at higher levels, sweating heavily, and in hot humid conditions.
This should be provided by using a good quality electrolyte supplement. Look for high levels of sodium, chloride and potassium and that it doesn’t contain cheap fillers or very high levels of sugars (some sugar is fine to encourage intake but if there is too much sugar there is no room for the electrolytes!).
Most proprietary electrolytes don’t contain anywhere near enough sodium, so continue to use table salt and top up with the 'fancy' electrolytes. Unfortunately, horses do not store electrolytes from one day to the next, so 'loading' electrolytes for days before competition is of little value and will just increase urine losses.
It is advisable to give an electrolyte supplement a couple of days before an anticipated strenuous competition, during it and for a couple of days after. In the majority of cases, the electrolyte supplement should be provided in the feed to prevent negative effects on water intake if it is added to water buckets.
You can lead a horse to water … but you can’t make it drink! There are some tricks used by top event and endurance riders which will hopefully assist you in keeping your horse’s hydration levels up this summer.
The favourite one is to take along really sloppy sugar beet or just the juice. Most horses will be tempted by this one. Another idea is to flavour your horses water at home with apple cordial, or peppermint (whichever works) a few days before the competition and then use the flavouring when you are at the competition.
Feeding soaked hay or haylage will help, also mixing feed with water is a good way to improve water intake. A high fibre/forage based diet helps with water reserves as the fibre in the horses gut holds a lot of water and research has shown that 20 litres of water can be drawn from the gut to help replenish body fluid levels.
Crucially, remember to always allow your horse access to clean, fresh water.