Incidence of IBD in the present study was found to be 0.1 per cent (33 dogs) out of 30,535 diseased dogs presented to the Small Animal Medicine Unit with various ailments. However,
Arslan (2017) stated that there is no information about incidence for IBD in dogs and cats. This is because, characterisation of many cases remains incomplete and detailed histopathological criteria for the medical diagnosis are needed.
Though there is no apparent age or gender predisposition, IBD is most commonly seen in middle aged and male dogs
(Volkmann et al., 2017). Similarly, in our study 5-10 years of aged male dogs (25/33) were affected. However, the reason for highest prevalence in male dogs might be due to over representation of population and owners preference for male dogs.
The documentation of various breeds such as Non-descript (10/33), German shepherd (8/33), Labrador (5/33), Doberman (4/33), Rottweiler (1/33), Pug (1/33), Lhasapso (1/33) and Dachshund (1/33) in the study well correlated with previous studies
(Volkmann et al., 2017; Heilmann et al., 2018). The high incidence of IBD recorded in non-descript in the present study might be due to over representation of this breed in the study area. It is interesting that two indigenous breeds of Tamil Nadu
viz Rajapalayam and Combai were also documented to have IBD. There is no published data so far that these breeds are affected or predisposed to IBD and future studies should aimed to do research on native breeds.
Clear history is crucial in directing the investigation in diagnosing IBD due to the waxing and waning nature of the disease. Haematochezia (11/33), diarrhoea (7/33) and vomiting (7/33) recorded as major presenting signs in our study were in accordance with
Heilmann et al., (2018). Further, the clinical signs were present for 3 months prior to diagnosis. This delay in the diagnosis of IBD in our study might be due to the owner’s negligence and ignorance towards the disease. The dogs were presented to the hospital only when gastrointestinal signs were severe as the disease progressed. This was further supported by weightloss (6/33) and altered appetite (10/33) reported in the study which refers to the severity of the disease. Pica or altered appetite reported in the study can be an important sign as
Hall and German (2010) opined that the dogs eating grass can be significant signs even in the absence of other signs.
Clinical signs associated with canine inflammatory bowel disease are primarily gastrointestinal symptom
(Roth-Walter et al., 2017). They comprise vomiting, small bowel diarrhoea (loose-watery or melena), large bowel diarrhoea (tenesmus, fresh blood /mucus and urgency), anorexia, weight loss, flatulence and borborygmus and abdominalpain. Similarly, in our study tenesmus combined with haematochezia and mucoid faeces (11/33), vomiting and diarrhea (8/33), watery diarrhoea alone (5/33), vomiting alone (4/33), haematochezia (2/33), melena (3/33), thickened intestinal loops (3/33), weight loss and emaciation (10/33) were recorded (Fig 1). The fecal scoring of 4.5 (very soft) to 5 (very watery diarrhoea) recorded in our study was comparable with the study of
Westermarck et al., (2005) (Fig 2).
Clinical indices utilize scoring systems derived from GI signs alone (CIBDAI) or in combination with laboratory testing (CCECAI) to quantify intestinal activity. CIBDAI and CCECAI supports a preliminary classification of the severity of inflammatory changes, enabling the selection of the appropriate therapy, treatment monitoring and early relapse detection
(Jergens et al., 2003 and
Allenspach et al., 2007). Disease severity based on CIBDAI and CCECAI scores was indicative of moderate IBD in our study. The median CIBDAI score was 7 (range 5-13) and the affected cases were classified as mild (3/33), moderate (18/33) and severe disease (12/33). The CCECAI score was 8 (range 4-13) and was classified as mild (4/33), moderate (17/33), severe (10/33) and very severe (2/33) (Fig 3). Similarly,
Heilmann et al., (2018) recorded moderate form IBD in his study. CCECAI helps to detect whether IBD has progressed to Protein losing enteropathy (PLE)
(Dossin and Lavoue, 2011). In the present study serum albumin levels of the IBD dogs were normal. Even though ten dogs had hypoalbunemia, they had only mild decrease. Further there were no signs of ascites or pedal edema in the affected IBD dogs. This indicates that the IBD dogs in this study have not progressed to PLE.
The Mean S.E values of routine and special blood parameters of control and IBD dogs are given in Table 1. Haematological analysis revealed decreased haemoglobin and packed cell volume with no significant change in the total erythrocyte count. Anaemia (decreased haemoglobin, packed cell volume and total erythrocyte count) was observed in three IBD dogs. Leukocytosis, neutrophilia and monocytosis were the other change recorded. These changes were comparable with
Ristic and Stidworthy (2002). They suggested that chronic gastrointestinal blood loss may result in non regenerative iron deficiency anaemia and leukocytosis was related to stress and chronic inflammatory disease.
The biochemical changes such as elevated alkaline phosphatase and mild hypoalbunemia ((albumin 1.5-1.99 g/dL in ten dogs) in the present study were similar to previous studies
(Jergens et al., 2010 and
Heilmann et al., 2018). Elevated alkaline phosphatase may reflect liver damage secondary to the intestinal inflammation and uptake of toxins through the damaged intestinal mucosa and are of no direct consequence
(Hall and German, 2010).
Elevated serum CRP levels, reduced serum cobalamine values and hypofolataenemia of IBD dogs were similar to previous studies by
Jergens et al., (2010) and
Heilmann et al., (2018). Definite hypocobalanemia was seen only in 10 cases while other IBD dogs had values within the normal range (normal range 225 - 860 ng/l). Serum concentrationlevels of cobalamin and folate can allow for localization of the inflammation. Serum levels decreased together can indicate malabsorption and, thus, be a marker for inflammation while either hypocobalaminemia or hypofolatasemia are consistent with distal or proximal small intestinal disease respectively
(Berghoff and Steiner, 2011). In our study eventhough the IBD dogs showed signs of colitis (haematochezia), the decrease in cobalamin and folate indicated the involvement of small intestine which was also evident in histopathology.
The proportion of IgA+ CD21+ PBMCs was significantly lower in dogs with IBD (median 4.59%, range 0.87-16.28%) compared to control animals (median 31.44 %, range 22.44–46.67%) (Fig 4) which was similar to
Maeda et al., (2013). This may due to a failure of IgA class switching.
CIBDAI was correlated with CRP and cobalamin and was found that it had significant positive correlation with serum CRP and significant negative correlation with serum cobalamin.
Jergens et al., (2003) stated that CRP was described as a marker of disease severity in dogs with chronic enteropathies, because serum CRP concentrations were indirectly correlated with CIBDAI and histologic scoring. He stated that as the severity of the disease increased decrease in the serum cobalamin values was observed. Mucosal disease in the ileum commonly reduces expression of the cobalamin + intrinsic factor complex receptor. This in turn, reduces the mucosal uptake of cobalamin in the ileum, leading to a reduced serum cobalamin concentration.
In the present study three dogs died and were observed to have diffuse IBD with very severe form of disease.
Jergens et al. (2003) recorded the death of dogs having severe intestinal disease. Further these dogs in our study had elevated CRP, decreased cobalamin and folate.
Jergens (2004) opined C-reactive protein has consistently been found to be the most useful disease activity marker for IBD in human patients.
Allenspach et al., (2007) has shown that serum cobalamin also is very important for prognosis in dogs with chronic enteropathies and low serum cobalamin is also been correlated with a poor prognosis in dogs with chronic enteropathy.
Allenspach (2013) opined that if serum concentration of cobalamin is below the reference interval, the risk for later euthanasia increases by a factor of 10.
Batt (2009) suggested that decreased serum cobalamin can be indicative of distal small intestinal damage and when accompanied by low serum folate, is suggestive of diffuse and potentially relatively severe disease affecting the proximal and distal small intestine ones. Hence, from the present study it was concluded that CIBDAI, serum levels of CRP, cobalamin and folate could be used as prognostic indicator.
