Feline inflammatory bowel disease (IBD), like that in humans, is a group of diseases involving gastrointestinal inflammation both caused by and contributing to GI motility problems, typically presenting as frequent vomiting and/or severe or chronic soft stools or diarrhea (depending on where in the GI tract the inflammation is located). An early warning sign is frequent hairballs - "frequent" being more than once every month or two.
According to Dysbiosis in the Pathogenesis of Pediatric Inflammatory Bowel Diseases, (Comito and Romano, 2012),
"A condition of 'dysbiosis', with alterations of the gut microbial composition, is regarded as the basis of IBD pathogenesis. The human gastrointestinal (GI) microbial population is a complex, dynamic ecosystem and consists of up to one thousand different bacterial species. In healthy individuals, intestinal microbiota have a symbiotic relationship with the host organism and carry out important metabolic, 'barrier,' and immune functions. Microbial dysbiosis in IBD with lack of beneficial bacteria, together with genetic predisposition, is the most relevant conditions in the pathogenesis of the pediatric IBD."
Since this was published in 2012, subsequent work has definitively linked IBD to gut dysbiosis (bacterial imbalance) that creates the inflammation. Technically an autoimmune disease, IBD as seen above was thought to have a genetic component, but recent research has discovered that the process that triggers IBD is actually transmissible. (See information in “Supporting Links” at the end of this document).
There are very few studies in cats, but the two examining the microflora of healthy vs IBD cats found significant differences in gut microflora. (Included in "Supporting Links" at the end of the document).
What Causes Dysbiosis?
In cats, many things can contribute to the development of gut dysbiosis. But notably, a species-inappropriate diet that has ingredients that act as antigens, and also creates changes in the natural pH of the animal likely have an important role. The evidence is only anecdotal at this point, but far too many cats transitioned to a raw diet see their symptoms of IBD (whether vomiting or diarrhea) clear up almost overnight. Notably, the All Feline Hospital notes that they “started trying commercial raw food diets with amazing results.” They further state
"We have had cats with confirmed by biopsy IBD that had severe IBD and significant symptoms that had to be on very high doses of steroids just to have some quality of life. Many of these cats had a complete reversal of signs and symptoms by going to an exclusively raw food diet, and were able to either come off of all medications, or at the very least, drastically reduce their medications."
(Bold, our emphasis)
Basically, whether due to diet, pathogens, over-vaccination, exposure to toxins, overuse of antibiotics, or any combination of these, cats with IBD undergo changes in the structure of the small intestine that set the stage for chronic diarrhea and/or vomiting, malabsorption, gut dysbiosis (the lack of beneficial bacteria) and leaky gut syndrome.
The gut dysbiosis leads to gut inflammation. The inflammation increases permeability of the intestine wall, allowing toxins (rather than just nutrients) to “leak” through the walls into the bloodstream. This triggers an immune response that can ultimately result in what appears as “allergies” and/or other more serious autoimmune disorders. This is why we believe that (appropriate!) diet and (appropriate!) probiotics are the cornerstone of effective IBD management.
Causes of IBD include
- gut bacterial imbalance (“microflora”)
- GI parasites
- Immune system function
- certain drugs
According to Dr. Lyn Thomson, writing at the Feline Nutrition Education Society,
"The main hypothesis for the cause and development of human IBD is that there is a dysregulation of the mucosal immune responses to intestinal microflora and/or dietary antigens. This same abnormal immune response to dietary antigens is often suspected in feline IBD.
…The important point that seems to have been missed is that it is actually the feeding of a species-inappropriate diet that has led to the rise in inflammatory bowel disease in cats and loss of integrity of the gut wall.
By feeding cats inappropriately and not recognising them as obligate carnivores, we have damaged their intestinal tracts… "
Read more: Feline Inflammatory Bowel Disease: Nature and Treatment, Feline Nutrition Education Society (FNES) Lyn Thomson, BVSc DipHom March 09, 2012
Inflammation & Symptoms of IBD
“Inflammatory bowel disease” is as it sounds: a condition where there are high numbers of inflammatory cells present in the lining of the digestive tract. This inflammation causes structural changes in the mucosal lining: in IBD, so many inflammatory cells can accumulate that they cause thickening of the gut lining, interfering with gastrointestinal motility, absorption of nutrients, and sometimes causing significant weight loss.
Symptoms of IBD can include
- frequent vomiting or intermittent bouts of vomiting
- regurgitating hairballs more than once every two months
- diarrhea or bouts of diarrhea
- unexplained weight loss
- variation in appetite and/or nausea
Traditional vet protocol for treating the symptoms of IBD include steroids, antibiotics like Flagyl (metronadizole), and/or broad spectrum dewormers – often with little success because these medicines treat the symptoms, they do not address the underlying causes. Many vets also attempt to address diet by recommending novel proteins, hypoallergenic or other “prescription” veterinary diets, but as most commercial diets are replete with potentially problematic ingredients (additives such as carrageenan, guar gum, xanthan gum, etc.) and/or flavorings & preservatives - and the veterinary diets often contain grains, soy, peas, brewer's rice or yeast - many find it impossible to control IBD with those diets.
Feline IBD is best treated with a healing protocol that addresses all potential contributing factors to the inflammation, starting with a minimally processed, fresh food, species-appropriate diet. Healing of the GI tract can only begin by recognizing our cats as the obligate carnivores they are. Feeding them food that supports their proper intestinal pH is imperative to long term healing. Treatment should also include supplement therapy that supports healthy gut flora and immune system regulation. As many vets are not familiar with this approach (or even antagonistic to it), IBD kitty parents often have to rely on each other via Facebook groups and cat forums to see their kitties thrive again.
A Note on IBD vs Intestinal Lymphoma
IBD is almost always a diagnosis of exclusion. Actual diagnosis of IBD involves functional GI testing (ultrasound, endoscopy, and/or biopsy). The only definitive diagnosis is via biopsy – an ultrasound can only see inflammation, not the cause of it. Many people opt not to have biopsies done, and treat the inflammation with a presumption of IBD. There’s nothing wrong with this. But it is important to be aware of a 2014 study published by Dr. Gary Norsworthy and associates. They reviewed the cases of 100 cats with a history of chronic vomiting, weight loss, chronic diarrhea, published in JAVMA (Journal of the American Veterinary Medical Association). This review found that 99 of 100 cats had either IBD (“chronic enteritis”) or neoplasia – most often lymphoma. In fact, 49 cats were found to have IBD and 50 found to have neoplasia (of those 50 with cancer, 46 had lymphoma). The primary difference between cats with IBD and cats with cancer was age at the time of diagnosis: older cats were more likely to have lymphoma. So if your kitty’s IBD has been managed, yet kitty begins to experience unexplained weight loss (B12 and folate levels are normal, hyperthyroidism has been ruled out, kidney disease is not present or has been all along, etc.), please discuss adding leukeran (chlorambucil) and prednisolone to the treatment regimen with your vet. This chemotherapy combo is usually very well tolerated by cats. Given that almost HALF the time in older kitties “IBD” is actually lymphoma, this treatment course may both improve the quality of your cat’s life and add years to your kitty’s life. Of course, this is not a substitute for proper nutrition with homemade food or a balanced raw diet and appropriate IBD management with probiotics that contribute to GI healing. This is for use when kitty is failing despite those steps, especially if they had been working.
More on IBD:
All Feline Hospital: Inflammatory Bowel Disease (IBD)
Feline Inflammatory Bowel Disease: Nature and Treatment, Feline Nutrition Education Society (FNES) Lyn Thomson, BVSc DipHom March 09, 2012
Dr. Becker of Mercola
The Hidden Inflammatory Bowel Disease That Threatens Your Pet's Well-Being 11/2/2010
Feline IBD: The Most Common Cause of Vomiting and Diarrhea in Cats 6/1/2012
The Wrong Way to Treat GI Inflammation 9/24/2012
Article: Norsworthy 2014. Chronic Vomiting in Cats isn't Normal After All. Veterniary Practice News online, published 2014.01.22 04:12 PM
Study: Norsworthy et al. 2014. Diagnosis of chronic small bowel disease in cats: 100 cases (2008-2012). J Am Vet Med Assoc. 2013 Nov 15;243(10):1455-61.
Janeczko et al 2008. The relationship of mucosal bacteria to duodenal histopathology, cytokine mRNA, and clinical disease activity in cats with inflammatory bowel disease. Veterinary Microbiology 128 (2008) 178–193.
Ritchie, L.E. 2008. Molecular Characterization of Intestinal Bacteria in Healthy Cats and a Comparison of the Fecal Bacterial Flora between Healthy Cats and Cats with Inflammatory Bowel Disease (IBD). MS Thesis, Texas A&M.
Desai et al 2009. Characterization and quantification of feline fecal microbiota using cpn60 sequence-based methods and investigation of animal-to-animal variation in microbial population structure, Vet Microbiol 2009 May 28;137(1-2):120-8.
JF Garcia-Mazcorro and Y Minamoto 2013. Gastrointestinal microorganisms in cats and dogs: a brief review, Arch Med Vet 45, 111-124 (2013).
Honnafer, Minamoto, Suchodolski 2014. Microbiota alterations in acute and chronic gastrointestinal inflammation of cats and dogs, World J Gastroenterol. 2014 Nov 28; 20(44): 16489–16497.
Suchodolski et al. 2015. The Fecal Microbiome in Cats with Diarrhea, PLoS ONE 10(5): e0127378. doi:10.1371/journal.pone.0127378.
Ghosh et al. 2004. Probiotics in inflammatory bowel disease: is it all gut flora modulation? Gut. 2004 May; 53(5): 620–622. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1774052/
Peña et al. 2005. Probiotic Lactobacillus spp. Diminish Helicobacter hepaticus-Induced Inflammatory Bowel Disease in Interleukin-10-Deficient Mice, Infect Immun. 2005 Feb; 73(2): 912–920. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC547020/
Article: Chow & Mazmanian 2010. Caltech Biologists Link Gut Microbial Equilibrium to Inflammatory Bowel Disease http://www.caltech.edu/content/caltech-biologists-link-gut-microbial-equilibrium-inflammatory-bowel-disease#sthash.2URwr4FP.dpuf
Study: Chow J and Mazmanian SK 2010. A pathobiont of the microbiota balances host colonization and intestinal inflammation. Cell Host Microbe. 2010 Apr 22;7(4):265-76. http://www.ncbi.nlm.nih.gov/pubmed/20413095
Article: Elinav et al, Yale News 2011. Immune System Malfunction May Trigger Inflammatory Bowel Disease. http://news.yale.edu/2011/05/12/immune-system-malfunction-may-trigger-inflammatory-bowel-disease
Study: Elinav et al. 2011. NLRP6 inflammasome regulates colonic microbial ecology and risk for colitis. Cell. 2011 May 27;145(5):745-57. http://www.ncbi.nlm.nih.gov/pubmed/21565393
Comito , D and Romano C. 2012. Dysbiosis in the Pathogenesis of Pediatric Inflammatory Bowel Diseases, Intl. Jour of Inflammation Vol 2012, Article ID 687143, 7 pages. http://www.hindawi.com/journals/iji/2012/687143/
Denizot et al 2012. Importance of Bacteria as Trigger in Inflammatory Bowel Disease. J Gastroint Dig Syst 2012, S8. http://www.omicsonline.org/importance-of-bacteria-as-trigger-in-inflammatory-bowel-disease-2161-069X.S8-003.pdf
Article: Khounlotham et al, Emory News 2013. Immune system compensates for 'leaky gut' in IBD susceptibility. http://news.emory.edu/stories/2012/09/immune_system_compensates_for_leaky_gut/
Study: Khounlotham et al. 2013. Compromised intestinal epithelial barrier induces adaptive immune compensation that protects from colitis. Immunity. 2012 Sep 21; 37(3): 563–573. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3564580/
Article: Winter et al, UC Davis Health System News 2013. Scientists find key to growth of "bad" bacteria in inflammatory bowel disease. http://www.ucdmc.ucdavis.edu/publish/news/newsroom/7462
Study: Winter et al 2013. Host-Derived Nitrate Boosts Growth of E. coli in the Inflamed Gut. Science 8 February 2013:
Vol. 339 no. 6120 pp. 708-711. http://www.sciencemag.org/content/339/6120/708
Article: Silva et al 2013, University of Arizona News. Putting the Brakes on Inflammation. http://uanews.org/story/putting-the-brakes-on-inflammation
Study: Silva et al. 2013. T Cell-Derived Protein S Engages TAM Receptor Signaling in Dendritic Cells to Control the Magnitude of the Immune Response, Immunity Volume 39, Issue 1, p160–170, 25 July 2013. http://www.cell.com/immunity/abstract/S1074-7613(13)00277-X