Pancreatitis distinct in English Cocker Spaniels
MedWire News: English Cocker Spaniels (ECS) exhibit a histologically distinctive form of chronic pancreatitis (CP) that differs from other breeds in its duct-destructive nature, which is predominantly mediated by T cells, study results show.
Furthermore, the condition was associated with an enlarged, hypoechoic pancreas on ultrasound examination, showing some similarities to autoimmune pancreatitis (AIP) in humans.
Penny Watson (University of Cambridge, UK) and colleagues note that recent pathological investigations suggest chronic pancreatitis (CP) is common in dogs.
"Furthermore, pancreatitis in different breeds has been shown to have different histological appearances, raising the possibility that breed-related differences in etiology may exist," they comment in the Journal of Veterinary Internal Medicine.
In particular, ECS are overrepresented in clinical and pathological studies of CP and appear to show a distinctive clinical and histologic appearance. The authors therefore sought to fully characterise CP in ECS using clinical, clinicopathological, and ultrasonographic investigations.
They enrolled eight ECS dogs and nine other breeds with histologically confirmed CP into the study, recruited over an 8-year period, as well 50 post-mortem non-ECS dogs with CP.
Histological sections were compared using immunohistochemistry with anti-CD3, anti-CD79a, and anti-cytokeratin antibodies, in order to evaluate distribution and type of lymphocytic inflammation and appearance of pancreatic ducts.
Watson et al found that clinical signs were similar in ECS and other breeds; however, the pancreas was enlarged and hypoechoic in four ECS and two control dogs.
In terms of histopathology, ECS had a predominantly interlobular and periductular distribution of fibrosis and inflammation, unlike other breeds such as collies and terriers, which had an intra-acinar pattern of fibrosis.
Some breeds (Boxers, Cavalier King Charles Spaniels, and one Chow Chow) also had an interlobular or periductular distribution of inflammation and fibrosis or both. However, they differed from the ECS by showing ductular hyperplasia even in end-stage disease, whereas ECS showed duct loss.
Immunohistochemistry demonstrated that the focally marked infiltrations of lymphocytes in the fibrous tissue of ECS were predominantly associated with CD3+ T lymphocytes, with sparse but occasional CD79a+ B lymphocytes. This finding contrasted with the other breeds, most of which showed mixed CD3+ and CD79a+ infiltrates in an intralobular location.
Summarising, Watson et al say the findings confirm that "CP in ECS is distinct from CP in other breeds and is notably duct destructive."
They add: "Additional studies are indicated to investigate the pathogenesis, identify noninvasive blood markers of disease, assess the efficacy of immunosuppressive therapy in affected dogs, and identify the genetic basis of the disease."
By Andrew Czyzewski