Final Answer:
Toxocara canis can be transmitted to puppies from the mother through the placenta or through the mother's milk during lactation.
Step-by-step explanation:
Toxocara canis is a species of roundworm that commonly infects dogs. Puppies can acquire the infection from their mother in two main ways. Firstly, during gestation, Toxocara canis larvae can migrate through the placenta, leading to prenatal transmission from an infected mother to her unborn offspring. Secondly, postnatally, transmission can occur through the mother's milk during lactation. The larvae present in the milk can be ingested by the nursing puppies, establishing an infection in the gastrointestinal tract.
In summary, Toxocara canis transmission to puppies from the mother can occur both during gestation through the placenta and postnatally through the mother's milk.