Winter is slowly arriving here too - the first snow has fallen and the temperatures, although not yet far, are already in the minus range from time to time. The majority of horses, unless they are kept in robust open stables, have to spend most of the day in the stable or on the sand paddock at this time of year.

Does The Weather Determine The Right Time To Deworm?

Anyone who keeps their horses in their own stable and/or takes care of the stable management themselves will know that the last worming treatment of the year is due in winter. The time window for this worming treatment is quite wide and falls in the months of October, November and December. The reason for this long period is the development cycle of the gasterophilinae, which depends on the climate and weather conditions during the summer months. The ideal climate for the gasterophilinae is warm and dry - this is when it develops best. In such weather during the summer, the winter worming treatment should be administered earlier, i.e. as early as October. If the summer is rainy, the development of the gasterophilinae is delayed.

It is therefore sufficient to deworm the horses in November or December, whereby December should not be exceeded under any circumstances. However, it is also important that horses are not wormed too early, i.e. only when all the larvae have hatched and been ingested by the horse, as otherwise there is a risk that larvae that hatch later will only be ingested after worming and can then develop unhindered in the horse. It is common practice to deworm after the first frost.

Gasterophilinae larvae - a danger to mucous membranes

A heavy infestation with gasterophilinae larvae can lead to inflammation of the mucous membranes of the mouth, changes in the pharynx, inflammation of the stomach and intestinal mucous membranes and even stomach ulcers, as the larvae bore through the skin and mucous membranes.

The active ingredients ivermectin, trichlorphone and moxidectin can be used to effectively combat stomach worms. When deworming, it is important to ensure that the worming treatment is administered according to the horse's weight and is not underdosed, as this can lead to resistance to the active ingredients.

So if you haven't yet administered the winter worming treatment this year - don't panic, it's not too late.

More on the topic

You can find lots more information about feeding horses with stomach problems on our Feeding horses with stomach problems page.  

Horses with stomach problems need additional support. It is important to know which feed is suitable for your horse and which should be avoided.