Objective of the study:

1. Investigate the causes of Inflammatory Bowel Disease (IBD) in dogs that can be controlled by owners.
2. More specifically, the aim of this study was to investigate whether a non-processed meat-based diet (raw) or an ultra-processed carbohydrate-based diet (kibble) as well as environmental factors and their timing of exposure (prenatal/neonatal/ postnatal) may be associated with the development of owner-reported Inflammatory Bowel Disease in adult dogs.

Background on Inflammatory Bowel Disease (IBD):

1. In humans, Inflammatory Bowel Disease (IBD) encompasses a number of specific disease conditions including Crohn’s disease and Ulcerative Colitis. In dogs and cats, IBD is less well defined. IBD appears to be an abnormal immune response to (or because of) an abnormal gut microbiome, on a background of genetic predisposition. As to the cause, there is increasing recognition that environmental factors (such as pollution), diet, drug therapy and stress are strong influences. Symptoms include chronic vomiting, diarrhea, weight loss, or any combination of these signs.

Method of the Study

1. Dogs whose owners participated in the DogRisk study were screened for those who answered the following question: “Has your dog suffered from inflammatory bowel disease (IBD), chronic bowel symptoms, chronic bowel ‘allergies’?” 7,015 participants were eligible for the study. The cases were adult dogs whose owners responded “Yes,” while those who responded “No” were chosen as study controls. These 2 groups of dogs were further divided into 2 additional groups according to how the owners reported that the dogs were fed (either raw or kibble) during 4 early life periods. In other words, owners of adult dogs reported on how those dogs were fed during 4 different puppyhood timeframes.
2. Exposures during four early life periods for every dog were analyzed: prenatal (mother’s diet during gestation), neonatal (the first 3–4 weeks of life, i.e., the lactation period), early postnatal (from 1 to 2 months of age) and late postnatal periods (from 2 to 6 months of age). The study investigated non-modifiable and modifiable risk factors for development of IBD later in life. Non-modifiable risk factors were circumstances that an owner cannot change, such as breed-related genetic predisposition or coat color. Modifiable risk factors include things such as vaccinations or diet which can be controlled by the owner. Among other factors, the investigators compared 2 common dog feeding patterns – a raw diet and a kibble diet.

The Results

1. The results were expressed as Odds Ratios (OR). An OR > 1 means increased risk for developing IBD later in life, while an OR < 1 means decreased risk.
2. The OR for development of IBD when puppies were fed raw during early (1-2 months of age) and late postnatal (2-6 months of age) periods were 0.541 and 0.622 respectively. This means that raw feeding is associated with statistically significantly lower IBD risk later in life as compared to feeding kibble.
3. Kibble feeding during the same 2 periods was associated with a statistically significant higher risk of IBD incidence compared to puppies eating raw. The OR for development of IBD when puppies were fed kibble during early (1-2 months of age) and late postnatal (2-6 months of age) periods were 1.847 and 1.608 respectively.

Why Raw May Help:

1. Consumption of raw food by puppies during the early and late puppyhood periods (spanning 1-6 months of age) was significantly protective against later IBD incidence compared to kibble-fed puppies. In comparison, consumption of dry kibble during the same periods increased the incidence of IBD in adulthood compared to puppies eating raw. Researchers speculate that the connection between raw feeding and a reduced risk of IBD may be in accordance with the hygiene hypothesis (now called the “Old Friends” hypothesis), which proposes that the immune system must be ‘educated’ by early life exposure to normal elements in the environment, to which all animals are exposed and must live with. These environmental triggers include microbes, pollens, molds and even the baby’s own cells.
2. Raw diets change the microbiome which could also influence later immune functions. Also, early diet can permanently modify the adult’s later gene programming (epigenetic programming) in the newborn during its formative early life. In summary, it is thought that raw feeding beneficially educates the young immune system, forms a healthy microbiome, and influences later production of gene products.

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