Volume 29, Issue 2 (4-2022)
RJMS 2022, 29(2): 1-11 |
Back to browse issues page
Research code: 123456
Ethics code: 1234567
Clinical trials code: 12345678
Download citation:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:
Mohammadi P, Kazemi D. Behavioral and Hormonal Changes Following Ovariohysterectomy in Dogs. RJMS 2022; 29 (2) :1-11
URL: http://rjms.iums.ac.ir/article-1-8866-en.html
URL: http://rjms.iums.ac.ir/article-1-8866-en.html
: General Doctor of Veterinary Medicine, Faculty of Veterinary Medicine, Tabriz Branch, Islamic Azad University, Tabriz, Iran , divar71@yahoo.com
Abstract: (653 Views)
Bakcground & Aims: Ovariohysterectomy refers to the surgical procedure involving the complete excision of the ovaries and uterus. This technique is primarily employed for the sterilization of animals. Such procedures are conducted under the guidance of licensed veterinarians, with the primary aim of preventing reproduction in animals (1). The practice of spaying and neutering is associated with beneficial outcomes for both the behavior and long-term health of pets. While ovariohysterectomy typically leads to an immediate and total cessation of sexual behaviors in female dogs, there remain inquiries regarding the nonsexual behavioral modifications linked to this surgical intervention, particularly concerning hormonal and behavioral shifts (2). Notably, hormonal alterations, including heightened levels of catecholamines and cortisol following anesthesia, surgery, and postoperative discomfort, are components of the neurohumoral stress response. Despite its limitations, cortisol is widely acknowledged as a prevalent marker of stress. Furthermore, research indicates that serotonin concentrations in dogs are inversely correlated with aggression and impulsivity. Additionally, castrated male dogs exhibit lower plasma or serum testosterone levels compared to their intact counterparts. In terms of behavioral modifications, it is posited that the owners' comprehension of their dogs' behavioral challenges, alongside veterinarians' readiness to address these issues, may influence the frequency and nature of cases presented to veterinary practices and referred to medical facilities over time (3). A multitude of studies has investigated the demographics of age, sex, and breed in relation to behavioral problems and diagnostic communication among dogs. Despite the importance of this topic, there is a paucity of research specifically addressing the effects of ovariohysterectomy on the behavioral and hormonal changes in dogs. Consequently, this study seeks to investigate the implications of ovariohysterectomy on the behavioral and hormonal alterations observed in female dogs.
Methods: The present study included a cohort of 12 female dogs, divided equally into an experimental group and a control group, all of which were privately owned. The ages of the dogs ranged from 2 to 5 years, with an average age of 3.1 ± 0.73 years, encompassing a variety of breeds. Ovariohysterectomy was performed using a surgical approach that involved a 2 cm incision in the retro-umbilical region, facilitated by a snook hook for ovarian access. Simultaneously, orchiectomy was executed employing prescrotal techniques. To assess behavioral modifications in the dogs, their owners were surveyed via a questionnaire at the time of the female dogs' sterilization and again two months post-surgery. Owners of the control group, which consisted of unsterilized dogs, were also subjected to two interviews, mirroring the experimental group’s process. The questionnaire comprised 40 items pertaining to the dogs' behaviors over the preceding month, addressing aspects such as aggression (toward owners, visitors, and other dogs), fear, activity levels, biting tendencies, reactions to separation from their owners, wandering behaviors, and elimination patterns (1,3). To evaluate hormonal fluctuations in the dogs, urine samples were collected naturally on two separate occasions by the owners: on the morning of the surgery and four weeks thereafter. These samples were obtained during the first morning walk and prior to the first meal. The urine was then transferred into dark-colored tubes containing 3.2 M HCl (150 µl/ml) to enhance stability through acidification, thereby creating optimal conditions for serotonin analysis. Data analysis was performed utilizing an independent t-test.
Results: The mean surgical duration for the experimental group was recorded at 7.24 ± 1.85 minutes, while the control group had a mean duration of 7.26 ± 1.95 minutes. This difference was not statistically significant (P < 0.05). The average age of participants in the experimental group was 3.08 ± 0.74 years, compared to 3.11 ± 0.78 years in the control group, with no significant difference noted (P < 0.05). Additionally, at the conclusion of the surgical procedures, there was no significant difference in temperature between the two groups (experimental group: 37.02 ± 0.49 °C, control group: 37.0 ± 0.60 °C) (P < 0.05). All dogs underwent successful sterilization without any complications. The recovery period was brief, lasting less than two days, and owner satisfaction was reported to be high. Notably, aggression scores among female dogs in the experimental group showed a significant increase in the post-test (after surgery) compared to the pre-test (before surgery) (t=5.33, P=0.011). Furthermore, the analysis revealed significant differences in the levels of serotonin, cortisol, testosterone, and progesterone between the pre-test and post-test within the experimental group, indicating a marked decrease in the concentrations of these hormones following surgery (P < 0.050).
Conclusion: The findings of this study offer valuable insights into the impact of ovariohysterectomy on various behaviors and hormonal levels in dogs. This knowledge is crucial for veterinarians as it aids in formulating recommendations regarding the ovariohysterectomy of dogs and enables them to effectively counsel pet owners on the behavioral implications associated with this procedure (4,5). Sterilization is associated with the risk of certain behavioral changes. There is a risk of excessive appetite. More importantly, there is a risk of increasing the domineering aggression towards family members. This risk is higher in puppies under one year old who show some aggression. The present study may be important for power analysis in future studies and therefore serves as important reference material (1,2). More studies are needed to assess why and what effect it might have on each dog. Therefore, our findings provide further evidence that testosterone originates mainly from the ovaries of dogs. Also, in the present study, progesterone levels decreased significantly four weeks after gonadectomy. Plasma progesterone levels have been reported to be lower in spayed dogs of both sexes (5).
Methods: The present study included a cohort of 12 female dogs, divided equally into an experimental group and a control group, all of which were privately owned. The ages of the dogs ranged from 2 to 5 years, with an average age of 3.1 ± 0.73 years, encompassing a variety of breeds. Ovariohysterectomy was performed using a surgical approach that involved a 2 cm incision in the retro-umbilical region, facilitated by a snook hook for ovarian access. Simultaneously, orchiectomy was executed employing prescrotal techniques. To assess behavioral modifications in the dogs, their owners were surveyed via a questionnaire at the time of the female dogs' sterilization and again two months post-surgery. Owners of the control group, which consisted of unsterilized dogs, were also subjected to two interviews, mirroring the experimental group’s process. The questionnaire comprised 40 items pertaining to the dogs' behaviors over the preceding month, addressing aspects such as aggression (toward owners, visitors, and other dogs), fear, activity levels, biting tendencies, reactions to separation from their owners, wandering behaviors, and elimination patterns (1,3). To evaluate hormonal fluctuations in the dogs, urine samples were collected naturally on two separate occasions by the owners: on the morning of the surgery and four weeks thereafter. These samples were obtained during the first morning walk and prior to the first meal. The urine was then transferred into dark-colored tubes containing 3.2 M HCl (150 µl/ml) to enhance stability through acidification, thereby creating optimal conditions for serotonin analysis. Data analysis was performed utilizing an independent t-test.
Results: The mean surgical duration for the experimental group was recorded at 7.24 ± 1.85 minutes, while the control group had a mean duration of 7.26 ± 1.95 minutes. This difference was not statistically significant (P < 0.05). The average age of participants in the experimental group was 3.08 ± 0.74 years, compared to 3.11 ± 0.78 years in the control group, with no significant difference noted (P < 0.05). Additionally, at the conclusion of the surgical procedures, there was no significant difference in temperature between the two groups (experimental group: 37.02 ± 0.49 °C, control group: 37.0 ± 0.60 °C) (P < 0.05). All dogs underwent successful sterilization without any complications. The recovery period was brief, lasting less than two days, and owner satisfaction was reported to be high. Notably, aggression scores among female dogs in the experimental group showed a significant increase in the post-test (after surgery) compared to the pre-test (before surgery) (t=5.33, P=0.011). Furthermore, the analysis revealed significant differences in the levels of serotonin, cortisol, testosterone, and progesterone between the pre-test and post-test within the experimental group, indicating a marked decrease in the concentrations of these hormones following surgery (P < 0.050).
Conclusion: The findings of this study offer valuable insights into the impact of ovariohysterectomy on various behaviors and hormonal levels in dogs. This knowledge is crucial for veterinarians as it aids in formulating recommendations regarding the ovariohysterectomy of dogs and enables them to effectively counsel pet owners on the behavioral implications associated with this procedure (4,5). Sterilization is associated with the risk of certain behavioral changes. There is a risk of excessive appetite. More importantly, there is a risk of increasing the domineering aggression towards family members. This risk is higher in puppies under one year old who show some aggression. The present study may be important for power analysis in future studies and therefore serves as important reference material (1,2). More studies are needed to assess why and what effect it might have on each dog. Therefore, our findings provide further evidence that testosterone originates mainly from the ovaries of dogs. Also, in the present study, progesterone levels decreased significantly four weeks after gonadectomy. Plasma progesterone levels have been reported to be lower in spayed dogs of both sexes (5).
Type of Study: Research |
Subject:
veterinarian
Send email to the article author
