Traditional energy requirement calculations may not be accurate for small dog breeds, with implications for recommended food intake and early obesity. Presented at the Waltham International Nutrition Science Symposium, Chicago, October 2016.

1. Energy requirements for growth in the Yorkshire terrier
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Introduction
• Appropriate nutrition is a key factor for the optimal
development of growing dogs
• Over or under nutrition during development can
have lifelong health effects on dogs so it is
essential that appropriate food amounts are
offered
• The energy requirements of toy breed puppies
have not been reported and it is unclear whether
feeding guidelines for these dogs should differ
from those determined for larger breeds
• The primary objective of this study was to
investigate the energy requirements of a toy
breed, namely the Yorkshire terrier from 10 weeks
to one year of age
Results
• All puppies remained healthy and at ideal body
condition throughout the trial
• The NRC (2006) equation overestimated the energy
requirements until 20 weeks of age whilst the values
were comparable from 21 to 52 weeks of age
• Energy requirements of Yorkshire terriers were
significantly lower than Labrador retrievers from 10-
29 weeks of age and significantly lower than
miniature schnauzers from 16-25 weeks of age
• Values were comparable after 29 weeks of age
Materials and Methods
• 22 Yorkshire terrier puppies from 8 litters were housed
in pairs at the WALTHAM Centre for Pet Nutrition
• Puppies were offered either a wet (CesarTM puppy
Chicken and Rice) or a dry (Royal CaninTM Yorkshire
terrier Junior) diet
• Food amounts were adjusted weekly to maintain
puppies at ideal body condition (WALTHAM S.H.A.P.E
guide)1
• Health was assessed via clinical assessment and blood
samples analysed for biochemistry and haematology at
3, 6, 9 and 12 months of age
• Predicted energy requirements were calculated by the
NRC (2006)2,3 equation and compared to actual values
• Energy requirements for Yorkshire terriers were
compared to those of Labrador retrievers and miniature
schnauzers housed under the same conditions at
WALTHAM as reported by Brenten et al4
• Data were analysed via a linear mixed effect model
with dog nested in litter as the random effect with an
autoregressive correlation structure
• Comparisons between breeds were performed for each
week using a family-wise error rate of 5%
Discussion
• The NRC 2006 equation for puppy energy
requirements over-estimated the requirements of
this population up to 20 weeks of age
• Data indicate differences in toy, small and large
breed energy requirements for growth before 29
weeks of age
• These observations can be used to suggest a
need for breed or size specific feeding equations
for the calculation of energy requirements during
growth
This work was approved by the WALTHAM Ethics Committee and all housing, care and procedures were in keeping with the requirements of the Animals
(Scientific Procedures) Act 1986.
1. German, A. J. et al. J. Nutr. 136, 2031S-2033S (2006), 2. Blanchard, G., et al, J. Anim. Physiol. Anim. Nutr. 80, 54-59 (1998)., 3. National Research Council (US). Ad Hoc Committee on Dog
and Cat Nutrition in Nutrient requirements of dogs and cats (National Academies Press, 2006), 4. Brenten, T. et al Br. J. Nutr. 111, 2104-2111 (2014)
WALTHAM Centre for Pet Nutrition, Mars Petcare, Waltham on the Wolds,
Melton Mowbray, LE14 4RT, UK
Janet Alexander, Alison Colyer and Penelope Morris
Maintenance Energy
Requirements (Kcal) = 130 x 3.2 x [e (-0.87*(BW observed/BW52weeks)) - 0.1]
Figure 1: The actual energy requirements for growth of 22 Yorkshire terriers (YT) in comparison to those predicted by
the NRC(2006) equation. Data are shown as mean (95% Confidence intervals). * indicates significant difference p<0.05
Figure 2: The energy requirements for growth of 22 Yorkshire terriers (YT) in comparison to those reported for Labrador
retriever (LAB) and miniature schnauzer (MS)4. Data are shown as mean (95% Confidence intervals). a: significant
difference between YT and LAB, b significant difference between YT and MS p<0.05
Labrador
Miniature schnauzer
Yorkshire terrier
Actual
NRC Equation
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