Dogs are prone to internal and external parasites.  Routine treatment is recommended for fleas and worms.  It is best to discuss treatment with your vet as there is such a wide selection of preparations on the market it would be impossible to recommend one.

Adding Garlic and Brewers Yeast to the food will deter fleas and worms.   Certain Essential Oils are anti parasitic and can be used in the dilution of five drops to fifty millilitres of water. 

Ticks can be a problem especially in areas where there have been sheep.  Do not try to remove by pulling as the tick has two pincers that penetrate the skin like two hooks.  There are various solutions such as Red Thyme essential oil and Flea Spray that can be applied to the parasite before removing it, by doing this the body will shrivel up and the whole thing can be turned anti clockwise and removed. 

If the head is left in a cyst may form, then veterinary advice will be required.