In adult horses, you will be wasting money and helping to build parasite resistance to the drug you are using. In foals, you may need to deworm monthly but you have to be sure to use an appropriate drug each time rather than using a single drug.
For Howrse: At least once a month, however this is not appropriate in real life.
This depends upon the climate, soil condition and parasite load the environment the horse is kept on. In most places, if you deworm every other month you are pretty safe.
dewormer medicine, look in the local tack shop
Deworm the dog and make sure he/she does not eat anything from outside or any table food.
nope
It is importnt to de worm your horse every other month.
It is recommended to deworm horses every 6-12 weeks, depending on the type of dewormer used and the horse's individual needs. Consult with your veterinarian to determine the best deworming schedule for your horse based on factors such as age, health, and living conditions.
http://ezinearticles.com/?Worming-Your-Horse&id=519530
The moon phases would change.
To keep your horse healthy and the others around 'em. They are due sometimes every month, ask your local vet.
The first saturday of every month...
My mare goes into heat every 2 weeks, i think thats normal.