False pregnancy

Intact unspayed female rabbits (does) can undergo periodic false pregnancies, also known as pseudopregnancies. Pseudopregnancies mimic true pregnancies. However, they last only 16-18 days rather than 31-32 days of true pregnancy. The doe will not be receptive to a buck during this time.

Rarely, neutered males may also gather and transport nesting material but with no fur plucking behavior. It usually stops when the rabbit grows older.

Symptoms
Below are symptoms of false pregnancies in rabbits.
 * Pulling fur from abdomen and chest.
 * Making a nest.
 * Developing mammary glands.
 * Aggressively defending nesting site.

Causes
Because rabbits ovulate reflexively in response to sexual stimulation, the proximity of a male, an infertile mating, or mating behavior between two females housed together can stimulate ovulation and result in pseudopregnancy. However, it can also be observed in female rabbits with no contact with other rabbits. Once reflex ovulation takes place, it results in the formation of corpora lutea that secrete progesterone.

Treatment
Although there are anecdotal reports of treating pseudopregnancy in rabbits with hormone preparations, in most cases, treatment is unnecessary as the condition is self-limiting. Repeated false pregnancies can be prevented by spaying or separating rabbits that are stimulating each other.

The nesting behavior usually lasts 1 to 3 days, after which the rabbit will resume normal activities.