In Adult Dogs, Does Feeding a Raw Food Diet Increase the Risk of Urinary Calculi Formation Compared to Feeding a Complete Dry Kibble Diet?
a Knowledge Summary by
Emma Taylor BSc (Hons) 1
Nieky van Veggel MSc CBiol FHEA 1*
1Writtle University College, Lordship Road Chelmsford, Essex, CM1 3RR, United Kingdom
*Corresponding Author (email@example.com)
Vol 3, Issue 2 (2018)
Published: 17 Apr 2018
Reviewed by: Morag Moseley (RVN DMS Cert SAN) and Sue Badger (MEd, Cert Ed, RVN)
Next Review date: 1 Jun 2019
During consultation you are asked by a client if a raw food diet supports the prevention of kidney stone formation in dogs because they have read on an internet forum that a raw food diet is a healthy and natural alternative to kibble that alleviates a number of health issues. The client is now seeking additional advice from you. You decide to explore the available literature that investigates the effect of raw feeding is on urine composition in dogs.
There is currently very little published evidence which studies the effect of raw feeding on urine composition.
The literature search returned 129 records of which 120 records were excluded because they were not related to the PICO. A further 5 records were excluded because they investigated the use of meat-meal with carbohydrate biscuit rather than raw meat, 1 record was excluded as it was non-primary research and 1 record excluded for investigating non-urinary parameters. The study by Dijcker et al., (2012) identified that currently, evidence is undetermined on whether a raw food diet maintains healthy urinary composition parameters or increases the risk or urolithiasis in adult canine dogs. The findings from this paper found that feeding a commercially available dry kibble diet was associated with a high urine calcium to creatinine (Ca/Cr) ratio compared to the raw diet which was associated with a lower Ca/Cr ratio.
Summary of the evidence
|Population:||Dogs aged between 1.3 to 16.1 years of age, 13 female (of which 4 entire), 10 male (of which 4 entire), bodyweight range 12-35 kg.|
|Intervention details:||Treatment group 1 (n = 23): Fed raw food over a 4-week period Treatment group 2 (n = 23): complete and balanced dry extruded feed over a 4-week period. Each diet started with a 3-day gradual diet change, and diets were provided by owners.|
|Study design:||Cohort (study 1) and RCT (study 2) in crossover design
Questionnaire from private owners
Uox and Uca excretion rates and the dietary and animal related factors which are associated with these parameters.
A single urine sample was collected in week 4 of the diet by the owner through natural voiding. Urine sample was divided immediately between a non-acidified vial and an acidified vial containing 2N HCl. Samples were stored at -20 °C until analysis.
Uox was measuring using isotope dilution mass spectrometry, whereas Uca was measured atomic absorption spectroscopy.
(relevant to PICO question):
|Urinary creatinine concentration high in dogs fed raw meat diet (TG1)|
Appraisal, application and reflection
The option to feed a raw diet to dogs has grown in popularity and is now readily available commercially. Historically, there has been concern regarding excessive protein intake and the potential increase of calculi promoting substances such as calcium and uric acid (Robertson et al., 1979). This concern has been steadily increasing (Lulich et al., 1999) which has led to the association of a high protein diet with the increased risk of renal damage (Singer, 2003). Interest in the health benefits of a protein fed diet is increasing, however studies measure the relationship between protein and growth rather than welfare and health. Studies are also based on results from comparatively brief studies of less than 6 months. Furthermore, the majority of research conducted focusing on raw feeding, assesses the transmission rate of zoonotic disease and the risk this poses to human health (Joffe and Schlesinger, 2002; Strohmeyer et al., 2006; Finley, et al., 2006; Lefebvre et al., 2008).
It was noted at the British Small Animal Veterinary Association (BSAVA) 2016 Congress, that standardised information and advice is limited and not easily available to veterinarians, which reduces their ability to advise clients correctly. This lack of evidence-based peer reviewed research was addressed by Goh (2016), who found that advice concerning a raw feed diet often stems from anecdotal evidence only.
There is currently very little published evidence which studies the effects of raw feeding on urine composition and therefore on urinary calculus formation or urinary tract health. Additionally, there is still little evidence-based scientific research and a lack of feeding trials which supports the hypothesis that raw diets are a healthier or more nutritionally balanced than other diets (Michel, 2006; van Veggel & Armstrong, 2017).
|Databases searched and dates covered:||CAB Abstracts (1973-2017), PubMed (1950-2017)|
|Search terms:||(dog OR dogs OR canine OR canines OR bitch OR bitches) AND (raw OR BARF OR 'biologically appropriate raw feed' OR natural OR meat OR 'raw food*' OR 'raw diet*') AND (urine and (composition or analysis or constituent))|
|Dates searches performed:||1st June 2017|
|Exclusion / Inclusion Criteria|
|No limitations regarding study design, setting, sample size or study population were imposed.|
Number of results
Excluded – not related to PICO
Excluded – non-primary research
Excluded – under 1 year of age
Excluded – not complete raw food
Excluded – non-urinary composition
Total relevant papers
Total relevant papers when duplicates removed
The authors declare no conflict of interest.
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