Answer:
The hormonal cycle of the bitch assumes that pregnancy has occurred after every cycle, whether or not a mating has taken place. She will therefore experience the physiological changes of pregnancy over the next 2 months. She will have an increase in progesterone production, milk production and an increase in appetite. She may even go into mild labour.
The caregiver may notice physical and emotional changes, particularly 8-9 weeks after her last season. She may exhibit a change in preferred diet to blander food, fluid retention, and a wish not to take her usual amount of exercise, and she may hoard toys and treat them as puppies. There may be restlessness, lack of appetite, panting, trembling, whining and nest-building at the time she would have given birth. There may be a degree of aggression to perceived threats. She will usually return to normal after 2-3 weeks, 48hrs after the birth would have occurred.
As this is a physiological occurrence which settles over 2-3 weeks, treatment is rarely needed. If possible try to reduce stimulation of the mammary glands, by reducing stroking and wiping, and not allowing the bitch to lick excessively, as these will increase prolactin release and further milk production.
Occasionally the bitch may become ill, by producing excessive milk, or other problems. She may need treatment to reduce milk production, such as diuretics or hormone treatment. Although some advocate reduced fluid intake to induce dehydration and reduce milk production, others feel that this may be unsafe.
It is rare (but not unknown) for bitches who are spayed (ovariohysterectomised), to exhibit these changes. Although the majority of the hormones are being produced by the ovaries, some are produced in the adrenal glands.