As Ketu mahadasha comes for 7 years. The position of Ketu will decide the exact effect of this mahadasha. Ketu is a shadow planet that represents salvation, higher knowledge, real happiness, pilgrimage places, travels etc. As Ketu does not have a head part, so Ketu thinks with heart and gives spiritual satisfaction. As the mind is not attached to Ketu, so Ketu works selflessly in the field of charity & spirituality. It gives a sense of detachment from the outer world & generates attachment to the inner world.
In Ketu mahadasha, the native gets detached from his/her family, either for work or any other reason. Depending upon the position of Ketu, it forces the native to live alone or make him move out of his country. Ketu mostly chooses Arabic countries for work. In this way, it creates a sense of isolation which pushes one to go deeper inside.
Badly placed Ketu may lead to divorce & Nicely placed Ketu can give you good opportunities for new adventures.
As a dog is a pure soul, so Ketu loves dogs. So good Ketu makes you love dogs while bad Ketu makes you afraid of a dog. Good ketu inspires one to keep a dog at their home, especially when ketu mahadasha starts.
Ketu is the starting of life as it rules Ashwini nakshatra which itself means a new beginning. The soul in this world, represents stage of a child when he has started his journey, who has not been contaminated yet, with no thought, no impurity, and no desire.
The starting of Ketu mahadasha could be difficult but the ending of Ketu could be good.
The most common Anter Dasha where you find yourself all alone would ketu-ketu, ketu-saturn, ketu-moon or ketu-rahu.
The effects of ketu mahadasha also depend or vary from chart to chart. Depending upon the sign, nakshatra, houses, and ketu mahadasha results will vary.