Spay and behaviour in bitches
26th May, 2020
Spaying bitches that become irritable pre season will prevent further directly associated behaviour changes; however, it doesn’t necessarily reduce aggression between bitches. Spaying bitches that suffer with behaviour change related to pseudo pregnancy should prevent further episodes. However, as pseudo pregnancy is not always associated with obvious physical signs, timing must be considered. If the pseudo pregnancy is not definitely over, aggression may persist long term.
Aggression between two entire bitches in the home often begins when one or both bitches reach puberty. Spaying both bitches before puberty may reduce the risk of aggression but there is no guarantee. If aggression is occurring between bitches is only associated with season or pseudo pregnancy spaying BOTH bitches may resolve the aggression but not if the aggression is occurring at other times.
The neutering experience can be extremely traumatic for bitches that are fearful. If a fearful dog or bitch must be neutered then it is best to deal with the fear issues, muzzle train and acclimatise the dog to the veterinary surgery pre-spay. In addition giving pre-med on arrival allowing the owner to stay until the dog is drowsy and allowing a familiar blanket or toy will all help.
Hormone changes after neutering can also increase fearfulness, the rise in levels of FSH and LH in both dogs and bitches is associated with increased reactivity. This generally reduces with time, however, bitches can experience surges of these hormones when they would have had their season. In some bitches spaying can precipitate pseudo pregnancy which can lead to increased fear and anxiety.
Several studies (O’Farrell and Peachey 1990 and Kim et al 2006) have reported increases in reactivity post spay. This may reflect increases in FSH, LH and prolactin mentioned above. It could also reflect the loss of the calming effect of Progesterone. There may also be other effects associated with the loss of oestrogen and progesterone because of their interactions with other hormones and neurotransmitters.
Spaying bitches pre puberty is likely to have beneficial and adverse behavioural effects. It will reduce likelihood of sexually dimorphic behaviours but it won’t necessarily prevent them. In other species, including humans, sex hormones have been shown to play an important role in the development of normal social interaction during adolescence (Schulz 2009).