Very heavy milkers can experience milk fever after kidding as their bodies try to pull enough calcium from their systems to accommodate the sudden output of large amounts of milk. In milk fever the goat or cow will collapse and only the prompt administration of IV calcium gluconate into the blood stream. we fed alfalfa which has high levels of calcium so never experienced this.
Ketosis is different. It usually happens to an overly fat goat whose body refuses to break down the excess fat to release the energy she needs for milk after kidding. The treatment is similar, get easy to digest nutrients (sugar) into the goat to keep her going until her body adjusts to break down fat reserves. In this instance drenching with propylene glycol is the old treatment. Too high a does given too often can be dangerous. Dosing with bicarbonate of soda along with the propylene glycol is recommended. After the first couple doses of propylene glycol has been given a sweet feed can be given for several days until the doe is properly milking and burning her fat reserves.
I used to keep a gallon jug of propylene glycol available as did other goat breeders just in case. Never had to use it. I wonder if I still have it or if I gave it to another goat breeder when DS2 and 3 sold their herds. By the way, both ketosis and milk fever can occur in any lactating animal who has just given birth.