Читать книгу Animal Behavior for Shelter Veterinarians and Staff - Группа авторов - Страница 139

After estrus, the uterus undergoes the same changes whether the bitch is bred or open. Pseudopregnancy is just as it sounds. The bitch is in diestrus, and her body acts as though it is pregnant even though she is not. As described above, she may build a nest, become protective of toys, and exhibit mammary development. She may become restless, irritable, and/or lethargic. She may undergo contractions and have a liquid discharge. Pseudopregnancy is self‐limiting and generally does not require treatment. If treatment is necessary, the type will depend on many factors: gonadal status of the dog, duration and severity of signs, and the types of signs (physical or behavioral). Treatment regimens have not been well described, and more research is needed on this problem.

Pseudopregnancy can occur in any breed and has been known to occur in bitches as young as 7 months of age and those as old as 10 years of age (Johnston 1986). The incidence of pseudopregnancy is unknown but estimated to be as high as 50–75% by one author (Johnston 1980). In a survey study in the United Kingdom, veterinarians reported seeing 10 cases per year on average (Root et al. 2018). Of greatest concern, 96% reported behavioral changes in these patients without noteworthy physical changes, and 97% reported aggression as one of the behavioral signs (Root et al. 2018). Pseudopregnancy may occur in a gonadectomized bitch three to four days after her ovariohysterectomy (Johnston 1986) if the surgery was performed during the diestrus phase of her cycle and not the anestrus phase. The implications of this, combined with the data from the Root study, should not be ignored. Collecting a vaginal swab for cytology is not difficult or time‐consuming, and many resources exist for aiding in the analysis. Vaginal cytology is routinely used for determining stage of estrous. Performing ovariohysterectomy on female dogs in the shelter without knowing their stage of estrous could result in behavioral changes that are hormonally related. Similarly, if aggression is seen in a recently spayed female with an unknown history, an awareness that it could be related to hormonal changes may affect behavior assessments and any planned interventions, including behavior modification.