Moxon, Rachel
(2024)
A prospective study to investigate the impact of neutering bitches prepubertally or post-pubertally.
PhD thesis, University of Nottingham.
Abstract
Contradictory findings in the literature relating to the effects of timing of neutering on bitch behaviour and health make decision-making regarding neutering timing difficult. Most literature that examines the effect of neutering timing has used age rather than the onset of puberty as the primary variable. The aims of this study were to 1) conduct scoping reviews to identify and chart the evidence on the effects of neutering timing in relation to puberty on the behaviour and health of female dogs, and 2) conduct a prospective study to investigate the effects of neutering timing in relation to puberty on physical development, behaviour, progression through an assistance dog training programme and health for female dogs.
The scoping reviews identified only one study that considered behaviour. The study examined behaviour retrospectively and reported no differences between bitches neutered pre or post-pubertally. For health, one study was identified that examined neoplasia. In that case-control study malignant mammary neoplasia was less likely in bitches neutered before puberty. Additionally, six studies were identified that considered urogenital disease related to pubertal status at neutering, and three reported significant results. Two studies presented conflicting results for urinary incontinence, and one study suggested that vulval development may be negatively affected by prepubertal neutering. No studies were found that considered atopic dermatitis, developmental orthopaedic disease or obesity.
For the prospective study, 306 Labrador and Golden Retriever crossbreed bitches were neutered before (at six months of age, PPN, n=155) or after puberty (after the first oestrus, Control, n=151). Data on growth and physical development were collected from assessments conducted at six and 17 months of age. Behavioural data were collected using questionnaires completed at one and three years of age. Data for progression through training and for health were extracted from an electronic database.
PPN bitches had greater changes in height (mean difference=2.039 cm, P<0.001) and smaller changes in vulval size (length: mean difference=−0.377 cm, P<0.001, width: mean difference=−0.221 cm, P<0.001) between six and 17 months of age than Control bitches. At 17-months, more PPN bitches had vulvas that appeared juvenile (P<0.001) and recessed (P=0.005).
Pubertal status at neutering was not associated with behavioural factor scores at one or three years of age, and there was no difference in the number of PPN (n=97) and Control (n=98) bitches that qualified as guide dogs. Examination of health data suggested detrimental associations between prepubertal neutering and musculoskeletal disease and immune disease. Cruciate disease occurred in significantly more PPN (n=11) than Control bitches (n=1; P=0.009). For osteoarthritis (P=0.016) and having at least one musculoskeletal disease (P=0.023) there were significant differences indicated between survival curves. The first diagnosis of atopy was reported at significantly older ages for PPN (3.9 ± 0.6 years) than Control bitches (1.6 ± 0.3 years; P=0.008), and for otitis (P=0.008) there was a significant difference between the survival curves.
Based on the findings presented, neutering after puberty is advised for bitches of the breeds studied, and potentially after 12 months of age based on the work of others.
| Item Type: |
Thesis (University of Nottingham only)
(PhD)
|
| Supervisors: |
England, Gary C. W.
Freeman, Sarah L.
Payne, Richard
Corr, Sandra A. |
| Keywords: |
Dog; Female; Neuter; Health; Puberty; Behaviour: Growth |
| Subjects: |
S Agriculture > SF Animal culture |
| Faculties/Schools: |
UK Campuses > Faculty of Medicine and Health Sciences > School of Veterinary Medicine and Science |
| Item ID: |
78844 |
| Depositing User: |
Moxon, Rachel
|
| Date Deposited: |
11 Dec 2024 04:40 |
| Last Modified: |
11 Dec 2024 04:40 |
| URI: |
https://eprints.nottingham.ac.uk/id/eprint/78844 |
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