Hartpury University Repository

Grant, Rachel

Montrose, V. Tamara

It’s a Man’s World: Mate Guarding and the Evolution of Patriarchy

Davies, Emma

Ennis, Julia

Collins, Richard

Psychological responses of elite young riders to the injury of their horses

Murphy, Katie

Wills, Alison

THE EFFECT OF BODY CONDITION SCORE AND 
BODYWEIGHT ON PEAK GROUND REACTION FORCES IN 
WALKING DOGS
Katie Murphy1* and Alison P. Wills1
1University Centre,  Hartpury, Gloucester, Gloucestershire, GL19 3BE UK
* Katie.murphy21@hotmail.co.uk
Methodology
Introduction
Results
Discussion
Obesity is a common nutritional disease that is estimated to affect a quarter of the canine population [1]. It is well documented that weight may be a risk factor in the
development of a number of canine orthopaedic conditions including osteoarthritis (OA) [2]. OA is a degenerative, progressive and irreversible deterioration of the
joints, resulting in a decreased range of motion, pain and joint swelling [3]. Such conditions can be influenced by a combination of many factors such as diet, weight
and exercise. Research has shown that a reduction in bodyweight (BW) can cause a significant decrease in lameness in dogs suffering from OA [4]. To date, force
plate analysis has not been used to explore and compare the mobility of dogs with different body condition scores (BCS) and BW in a range of breeds. The aim of this
study was to assess the effect of BCS and BW on peak limb ground reaction forces (GRFs) during walking.
A sample population of n = 17 medium and large breed dogs of varying age
(mean 5.30 ± 4.16 years) and a range of BCS (mean 3.06 ± 1.14) were recruited
for this study (Figure 1). The dogs were free from any predisposing
musculoskeletal conditions. Dogs were body condition scored using PFMA
guidelines and the study population were assigned weight categories dependent
on the recommended weight range for their breed. Dogs were lead on a loose
lead over an AMTI force plate (sampling at 500Hz; Figure 2) to record GRFs in
the mediolateral, craniocaudal and vertical plane (Fx, Fy and Fz). Individually,
dogs were walked over the force plate up to fifteen times to attempt to achieve
twelve valid trials. Peak Fx, Fy and Fz GRFs (N) were calculated for all trials for
all dogs. A Spearman's rank test was used to test for a correlation between BCS
and average peak GRFs and a Kruskal-Wallis was used to assess for differences
in GRFs between BW categories. Where significant differences were identified,
post-hoc tests were carried out with the Bonferroni correction applied.
Figure 1. Sample Population
An example of the breeds used in the study sample 
(From top left a Rhodesian Ridgeback, Hungarian 
Visla, Black Lab x Pointer and a Standard Poodle)
There was a moderate negative correlation (R2 = -0.57, p =
0.017) between Fx and BCS, a moderate correlation
between Fy and BCS (R2 = -0.65, p =0.004) and moderate
negative correlation between Fz and BCS (R2= -0.58, p =
0.016). There was a significant effect of weight category on
Fx (χ2(2) = 6.46, p = 0.040), Fy (χ2(2) = 7.62, p = 0.022) and
Fz (χ2(2) = 6.61, p = 0.035). GRFs were significantly lower in
the overweight group compared to the underweight (p<
0.05).
In this study, dogs classified as overweight with a higher BCS had lower peak forelimb GRFs.
This was an unexpected finding and this effect was observed in Fx, Fy and Fz. It could be
concluded that weight does not negatively impact on the kinetics of overweight dogs, but may
have a detrimental impact on their kinematics. The results could also be explained by the fact
that the overweight dogs were possibly walking at slower velocities than the ideal weight dogs
[5]. This could suggest that velocity was ultimately a confounding factor within the study and
hence analysis of stance time is warranted [6]. It would be beneficial to repeat the study with a
larger, homogenous sample population using an instrumented treadmill to control velocity.
LG
RG
LL RL
Figure 2. AMTI Force Plate 
Above Tarsal
Figure 3. Mean peak GRFs for the three BW categories
Data for all dogs in the three weight categories (underweight, ideal
weight and overweight) and mean peak GRF are shown for the
Fz Vertical forces (BW). Circles represent outliers.
References
1.Impellizeri, J. A., Tetrick, M. A. and Muir, P. (2000) ‘Effect of weight reduction on clinical signs of lameness in dogs with hip osteoarthritis.’, Journal of the American Veterinary Medical Association, 216(7), pp. 1089
2. Johnston, S. A. (1997) ‘Osteoarthritis: Joint Anatomy, Physiology, and Pathobiology’, Veterinary Clinics of North America: Small Animal Practice, 27(4), pp. 699–723. doi: 10.1016/S0195-5616(97)50076-3.
3. Payne-Johnson  et al, (2014) Payne-Johnson, M., Becskei, C., Chaudhry, Y. and Stegemann, M.R. (2014) ‘Comparative efficacy and safety of mavacoxib and carprofen in the treatment of canine osteoarthritis’, 
Veterinary Record, 176(11), pp. 284–284. doi: 10.1136/vr.102397
4. Marshall, W. G. et al. (2010) ‘The effect of weight loss on lameness in obese dogs with osteoarthritis’, Veterinary Research Communications, 34(3), pp. 241–253. doi: 10.1007/s11259-010-9348-7.
5. Voss, K. et al. (2010) ‘Relationships of body weight, body size, subject velocity, and vertical ground reaction forces in trotting dogs.’, Veterinary surgery : VS, 39(7), pp. 863–9. doi: 10.1111/j.1532-
950X.2010.00729.x.
6. Piazza, A. M. et al. (2017) ‘Variance associated with walking velocity during force platform gait analysis of a heterogeneous sample of clinically normal dogs’, American Journal of Veterinary Research, 78(4), pp. 
500–507. doi: 10.2460/ajvr.78.4.500.
1.00
1.25
1.50
1.75
Underweight Ideal Weight Overweight
Weight Category
F
z
 (
B
W
)
Figure 4. Example GRF from three dogs 
Example kinetic data from a single trial from three individual dogs, one from each weight category showing 
mediolateral (Fx), craniocaudal (Fy) and vertical (Fz) GRFs (N). 


English

The effect of body condition score on peak ground reaction forces in walking dogs

Oxley, James Andrew

Bowen, Jon

McBride, Anne

Owner perceptions of the effects of fireworks on rabbits and guinea pigs

Knox, Gareth

De Martin Silva, Luciana

Draper, Stephen

Lee, Sarah

Legge, Thomas

Engaging students and employers as partners: a connected approach to curriculum development

Fernandes, John

Internal Loads, but Not External Loads and Fatigue, Are Similar in Young and Middle-Aged Resistance-Trained Males during High Volume Squatting Exercise

Knowles, Laura

Farrell, Mary

The Effects of Personality upon Breeding Success 
in Humboldt Penguins (Spheniscus humboldti)
Laura Knowles, Mary Farrell and V. Tamara Montrose
Animal Welfare Arena, Hartpury University, Hartpury, Gloucester, GL19 3BE, United Kingdom
ZSL London Zoo, Regent's Park, London, NW1 4RY, United Kingdom
Tamara.Montrose@Hartpury.ac.uk
Methods
Introduction Results
References
Study Site and Study Sample: Personality profiles were
created for 30 individual Humboldt penguins (15 pairs) housed
in the Penguin Beach enclosure at ZSL London zoo. Pairs were
randomly chosen from within the colony (n=84).
Personality Assessment: Personality was assessed using
keeper questionnaires considering interactions with
conspecifics and human-animal interactions, novel object
testing (via three separately presented novel objects: bamboo
wind chime, glitter ball and an abacus; Figure 1) and
behavioural observations. Each individual was observed for a
total of two hours over a two-month period via continuous focal
sampling.
Reproductive Success Assessment: Breeding success was
assessed in terms of number of eggs laid, number of eggs
hatched and number of chicks fledged. Data on breeding
success were obtained from the Zoological Information
Management System (ZIMS) for 2014-2017.
Statistical Analysis: Principal component analysis was used to
create personality dimensions, and individuals were rated as
high/low on each dimension. Chi square tests were then used
to determine if there was an association between each
personality dimension and reproductive success.
Principal component analysis revealed three components of
personality, labelled dominant, sociable and shy toward people,
which explained 70.9% of the total variance.
There was a moderately strong association between sociability
and reproductive success (Cramer’s V = .208, x2(2) = 11.039,
p=.004) and a small association between shyness and
reproductive success (Cramer’s V = .187, x2(2) 8.872, p=.012).
There was no significant association between dominance and
reproductive success. Penguins with low sociability and high
shyness toward people tended to show greatest reproductive
success (Figure 2 and Figure 3).
These findings suggest that personality can affect breeding
success in Humboldt penguins and is a factor that should be
considered in captive breeding programmes. Less sociable
penguins with low sociability and penguins that were shy toward
people tended to show greatest reproductive success.
This coincides with the wild population where Humboldt penguin
nests were more successful when located away from humans
(Ellenberg et al, 2006), and where less sociable individuals may
better cope with mate-separation during the rearing period (AZA
Penguin Taxon Advisory Group, 2014).
Interventions such as providing nest boxes throughout the
enclosure and away from public access, as well as reducing
keeper disturbance through nest checks may be beneficial in
enhancing reproductive success in captive Humboldt penguins.
Discussion
Humboldt penguins (Spheniscus humboldti) are a vulnerable
species commonly kept within UK zoological collections (ZIMS,
2018). However, in captivity, their breeding success is half that
of their wild counterparts (Mason, 2010).
Past research has tended to focus on determining optimal
breeding conditions (e.g. Blay and Cote, 2001), however
personality may also be a determinant of breeding success
(Schuett, Dall & Royle, 2011; Martin-Wintle et al, 2017).
The aim of this study was to determine whether personality
affects breeding success in captive Humboldt Penguins.
Figure 2: 
Sociability and 
reproductive 
success
Figure 3: 
Shyness 
toward 
people and 
reproductive 
success
Figure 1: Novel object testing using an abacus
AZA Penguin Taxon Advisory Group. (2014). Penguin (Spheniscidae) Care Manual. Silver Spring, MD: Association of Zoos and Aquariums.
Blay, N. & Cote, I.M. (2001). Optimal conditions for breeding captive Humboldt penguins (Spheniscus humboldti): A survey of British Zoos. Zoo Biology, 20, 545-555.
Ellenberg, U., Mattern, T., Seddon, P.J & Jorquera, G.L. (2006). Physiological and reproductive consequences of human disturbance in Humboldt penguins: The need for species-specific visitor management. Biological Conservation, 133, 95-106.
Martin-Wintle, M. S., Shepherdson, D., Zhang, G., Huang, Y., Luo, B. & Swaisgood, R. R. (2017). Do opposites attract? Effects of personality matching in breeding pairs of captive Giant Pandas on reproductive success. Biological Conservation, 207, 27-37.
Mason, G. J. (2010). Species differences in response to captivity: stress, welfare and the comparative method. Trends in Ecology and Evolution, 25, 713-721.
Schuett, W., Dall, S. R. X. & Royle, N.J. (2011). Pairs of Zebra Finches with similar ‘personalities’make better parents. Animal Behaviour, 81, 609-618.
ZIMS (2018) Zoological Information Management System. Retrieved from http://zims.Species360.org.


The Effects of Personality upon Breeding Success in Humboldt Penguins (Spheniscus humboldti)

Hernández-Martinez, Jordan

Cisterna, Diego

Ramírez-Campillo, Rodrigo

Álvarez, Cristian

Guede-Rojas, Francisco

Castro-Sepúlveda, Mauricio

Moran, Jason

Association of maximal voluntary isometric handgrip strength with age, gender and handedness in older people

Bearman-Brown, Lucy

Howse, Jennifer

Badman-King, Alexander

Animals on Prescription: The Effect of Animal Handling Sessions on Student Wellbeing in a Further and Higher Education Establishment

Saunders, Rebecca

Public perception of wild boar (Sus scrofa) in the Forest of Dean, UK

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