Diagnosis and management of pancreatitis

Feline comorbidities: What do we really know about feline triaditis?

PRACTICAL RELEVANCE

Feline triaditis describes concurrent pancreatitis, cholangitis and inflammatory bowel disease (IBD). The reported prevalence is 17-39% in ill referral patients. While the aetiology is poorly understood, it is known to include infectious, autoimmune and physical components. What is not known is whether different organs are affected by different diseases, or the same process; indeed, triaditis may be part of a multiorgan inflammatory disease. Feline gastrointestinal tract anatomy plays its role too. Specifically, the short small intestine, high bacterial load and anatomic feature whereby the pancreatic duct joins the common bile duct before entering the duodenal papilla all increase the risk of bacterial reflux and parenchymal inflammation. Inflammation may also be a sequela of bowel bacterial translocation and systemic bacteraemia.

DIAGNOSTIC CHALLENGES

Cholangitis, pancreatitis and IBD manifest with overlapping, vague and non-specific clinical signs. Cholangitis may be accompanied by increased serum liver enzymes, total bilirubin and bile acid concentrations, and variable ultrasonographic changes. A presumptive diagnosis of pancreatitis is based on increased serum pancreatic lipase immunoreactivity or feline pancreas-specific lipase, and/or abnormal pancreatic changes on ultrasonography, though these tests have low sensitivity. Diagnosis of IBD is challenging without histopathology; ultrasound findings vary from normal to mucosal thickening or loss of layering. Triaditis may cause decreased serum folate or cobalamin (B12) concentrations due to intestinal disease and/or pancreatitis. Triaditis can only be confirmed with histopathology; hence, it remains a presumptive diagnosis in most cases.

EVIDENCE BASE

The literature on feline triaditis, pancreatitis, cholangitis and IBD is reviewed, focusing on histopathology, clinical significance and diagnostic challenges. Current management recommendations are provided. Further studies are needed to understand the complex pathophysiology, and in turn improve diagnosis and treatment.

Management of acute pancreatitis in dogs: a critical appraisal with focus on feeding and analgesia

Knowledge about acute pancreatitis has increased recently in both the medical and veterinary fields. Despite this expansion of knowledge, there are very few studies on treatment interventions in naturally occurring disease in dogs. As a result, treatment recommendations are largely extrapolated from experimental rodent models or general critical care principles. General treatment principles involve replacing fluid losses, maintaining hydrostatic pressure, controlling nausea and providing pain relief. Specific interventions recently advocated in human medicine include the use of neurokinin-1 antagonists for analgesia and early interventional feeding. The premise for early feeding is to improve the health of the intestinal tract, as unhealthy enterocytes are thought to perpetuate systemic inflammation. The evidence for early interventional feeding is not supported by robust clinical trials to date, but in humans there is evidence that it reduces hospitalisation time and in dogs it is well tolerated. This article summarises the major areas of management of acute pancreatitis in dogs and examines the level of evidence for each recommendation.

Practical Interpretation and Application of Exocrine Pancreatic Testing in Small Animals

The pancreas remains a difficult organ to evaluate using laboratory methods alone. No single laboratory test is diagnostic of pancreatitis (chronic or acute) without other diagnostic modalities concurring with the diagnosis or ruling out other diseases. The diagnosis of pancreatitis is particularly difficult in cats, and pancreatitis often occurs with other diseases. The use of pancreatic cytology may be useful in diagnosing both inflammation and neoplasia. Exocrine pancreatic insufficiency (EPI) can be relatively easily diagnosed when clinically manifested by the measurement of trypsinlike immunoreactivity. Diagnosis is more difficult when EPI is subclinical.

Nutritional management of acute pancreatitis in dogs and cats

OBJECTIVE

To review current and emerging nutritional approaches in the management of acute pancreatitis (AP) in people, dogs, and cats, and to provide a framework for further investigation in this field.

DATA SOURCES

Veterinary retrospective studies and reviews, human prospective clinical trials and reviews, and experimental animal studies focusing on nutritional management during AP.

SUMMARY

Nutritional management is an important part of the treatment plan for patients with AP. In human medicine, the general approach for providing nutrition in patients with AP has changed in recent years and favors enteral over parenteral nutrition with an emphasis on early enteral nutrition (EN). Although there are limited data available, there is increasing evidence in the veterinary literature that supports the beneficial role of EN in AP and contradicts previous assumptions about poor tolerance to enteral feeding in this patient population. Parenteral nutrition may be appropriate alone or in combination with EN as a temporary measure in malnourished patients that do not tolerate adequate EN; however, enteral feeding should be attempted first in most cases. Immunonutrition is being investigated for its positive role in modulating pancreatic inflammation and improving gut barrier function in cases of human AP.

CONCLUSIONS

The nutritional management of veterinary patients with AP remains challenging. Based on clinical evidence in people, experimental animal studies, and preliminary studies in dogs and cats, the choice of EN over parenteral nutritional support during AP in dogs and cats appears to be beneficial and well tolerated. Optimization of nutritional therapies in dogs and cats including the use of immunonutrition during AP warrants further investigation.

Prevalence and histopathologic characteristics of pancreatitis in cats

Despite the high prevalence of feline pancreatic disease, no detailed description on the histopathologic nature of this disease is currently available in the literature. In this study we characterize the distribution and histopathologic changes commonly found in feline pancreases, correlate the lesions with age and gastrointestinal GI and extra-gastrointestinal disease, and compare the pancreatic lesions in cats with those in humans. The entire pancreas was removed and examined from 115 cats presented for necropsy irrespective of the cause of death. Histologic sections from left limb, right limb, and body were scored for lesions of acute (AP) and chronic pancreatitis (CP) with a scoring system based on similar systems used in human and veterinary literature. The lesions of CP in cats resemble CP in humans, with fibrosis being more prominent than inflammatory changes. Cystic degeneration gradually increased as other lesions of CP were more prominent. A distinct nodular change of zymogen depletion and acinar cell dysplasia not associated with pancreatitis was prominent in 15.6% of the pancreases. Histologically, AP consisted of neutrophilic inflammation associated with interstitial edema and necrosis of mesenteric fat. An overall prevalence of 67%, and 45% in clinically normal animals, was identified. CP was found in 69 (60.0%) pancreases, and 58 (50.4%) had CP only, with a significant correlation between age and occurrence of CP. There was a statistically significant higher prevalence of CP in the left limb in animals with gastrointestinal disease. AP was present in 18 animals (15.7%) of which 7 animals had AP only (6.1%).

Canine and Feline Diabetes Mellitus: Nature or Nurture?

There is evidence for the role of genetic and environmental factors in feline and canine diabetes. Type 2 diabetes is the most common form of diabetes in cats. Evidence for genetic factors in feline diabetes includes the overrepresentation of Burmese cats with diabetes. Environmental risk factors in domestic or Burmese cats include advancing age, obesity, male gender, neutering, drug treatment, physical inactivity, and indoor confinement. High-carbohydrate diets increase blood glucose and insulin levels and may predispose cats to obesity and diabetes. Low-carbohydrate, high-protein diets may help prevent diabetes in cats at risk such as obese cats or lean cats with underlying low insulin sensitivity. Evidence exists for a genetic basis and altered immune response in the pathogenesis of canine diabetes. Seasonal effects on the incidence of diagnosis indicate that there are environmental influences on disease progression. At least 50% of diabetic dogs have type 1 diabetes based on present evidence of immune destruction of beta-cells. Epidemiological factors closely match those of the latent autoimmune diabetes of adults form of human type 1 diabetes. Extensive pancreatic damage, likely from chronic pancreatitis, causes approximately 28% of canine diabetes cases. Environmental factors such as feeding of high-fat diets are potentially associated with pancreatitis and likely play a role in the development of pancreatitis in diabetic dogs. There are no published data showing that overt type 2 diabetes occurs in dogs or that obesity is a risk factor for canine diabetes. Diabetes diagnosed in a bitch during either pregnancy or diestrus is comparable to human gestational diabetes.

Review of feline pancreatitis part one: the normal feline pancreas, the pathophysiology, classification, prevalence and aetiologies of pancreatitis

The cellular mechanisms involved once pancreatitis has been initiated are reasonably well understood. The events leading up to this process are less well established. Much of our current understanding of pancreatitis in cats has been determined from experiments in cats or extrapolated from other species. The normal anatomy and function of the pancreas and a review of the current state of knowledge about the pathophysiology of pancreatitis is discussed. The current prevalence of feline pancreatitis is unknown, but the disease is being reported with increasing frequency. The aetiology of pancreatitis and the types of pancreatic inflammation present in cats is different from other species, such as the dog, a species where the disease is considered more common. Concurrent diseases are often present that may be more serious than the pancreatic inflammation and the treatment of these diseases is often complicated by pancreatitis.

Management of canine diabetes

The majority of diabetic dogs appear to have a form of type 1 diabetes analogous to the latent autoimmune diabetes of adults (LADA) in humans. Evidence of acute or chronic pancreatitis occurs in about 40% of diabetic dogs. Blindness caused by cataract formation eventually occurs in the majority of diabetic dogs and is not dependent on glycemic control. Insulin is the mainstay of therapy for diabetic dogs, and a conservative approach to insulin therapy is crucial. Most diabetic dogs require twice-daily dosing with lente or NPH insulin to adequately control their clinical signs. The diet fed should primarily be palatable and nutritionally balanced. Improved glycemic control may be achieved in some dogs if the diet contains increased insoluble fiber.

Review of feline pancreatitis part two: clinical signs, diagnosis and treatment

In the past decade pancreatitis has become recognised as a significant disease in the cat. Chronic, mild pancreatitis is often associated with more commonly diagnosed diseases such as inflammatory bowel disease or cholangitis/cholangiohepatitis. Furthermore, acute pancreatitis with similar complications to those seen in dogs is now diagnosed more frequently in cats. Unfortunately, the clinical signs and clinicopathological findings in cats with pancreatitis are often non-specific and vague. The lack of specific signs often results in a diagnosis being made only when the veterinary surgeon has a strong index of suspicion for pancreatitis and vigorously pursues that diagnosis. Pancreatitis is an important disease in cats, has been implicated as a potential cause of diabetes mellitus, and when present complicates the treatment of diabetes and other intra-abdominal diseases in cats.

Clinical indications for use of fresh frozen plasma in dogs: 74 dogs (October through December 1999)

OBJECTIVE

To document reasons for use of fresh frozen plasma (FFP) in dogs and determine variables that apparently triggered the decision to use FFP.

DESIGN

Retrospective study.

ANIMALS

74 dogs.

PROCEDURE

Medical records of dogs that received FFP at a veterinary teaching hospital during a 3-month period were reviewed.

RESULTS

The 74 dogs underwent 144 transfusion episodes (TE; a TE was defined as 1 day of transfusion therapy) and received 252 units (120 ml/unit) of FFP. Fresh frozen plasma was administered to provide coagulation factors (67 TE), albumin (91), alpha-macroglobulin (15), or immunoglobulins (19); for some TE, multiple clinical indications were identified. Variables that apparently triggered the decision to administer FFP included active hemorrhage with or without prolongation of coagulation times, low total plasma protein concentration, persistent vomiting associated with pancreatitis, and sepsis. Mean doses of FFP for each indication were between 8.5 and 9.4 ml/kg (3.9 and 4.3 ml/lb). Small dogs were generally given higher doses (mean dose, 13.9 ml/kg [6.3 ml/lb]) than large dogs (mean dose, 5.1 ml/kg [2.3 ml/lb]). Fifty (68%) dogs were alive at the time of discharge from the hospital.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that FFP plays an important role in the care of critically ill dogs. Because the supply of FFP is limited, guidelines for when administration of FFP may be clinically useful should be developed.

Evaluation of serum feline trypsin-like immunoreactivity for the diagnosis of pancreatitis in cats

OBJECTIVE

To evaluate serum feline trypsin-like immunoreactivity (fTLI) concentration and results of abdominal ultrasonography, CBC, and serum biochemical analyses for diagnosis of pancreatitis in cats.

DESIGN

Prospective study.

ANIMALS

28 cats with clinical signs compatible with pancreatitis.

PROCEDURE

Serum fTLI concentrations were determined, and abdominal ultrasonography, CBC, and serum biochemical analyses were performed prior to histologic evaluation of pancreatic, hepatic, and intestinal specimens. On the basis of histologic results, cats were categorized as having a normal pancreas (n = 10), pancreatic fibrosis with ongoing inflammation (9), pancreatic fibrosis without inflammation (4), and acute necrotizing pancreatitis (5). Serum fTLI concentrations and results of CBC, serum biochemical analyses, and histologic evaluation of hepatic and intestinal specimens were compared among groups.

RESULTS

Significant differences in serum fTLI concentrations or any hematologic or biochemical variable were not detected among the 4 groups of cats. Median serum fTLI concentrations were 51 micrograms/L (range, 18 to 200 micrograms/L) in cats with a normal pancreas, 32 micrograms/L (range, 12 to > 200 micrograms/L) in cats with pancreatic fibrosis and ongoing inflammation, 124 micrograms/L (range, 36 to > 200 micrograms/L) in cats with pancreatic fibrosis without ongoing inflammation, and 30 micrograms/L (range, 24 to 84 micrograms/L) in cats with acute necrotizing pancreatitis. We detected a high prevalence of concurrent hepatic and intestinal tract disease in cats with pancreatitis.

CONCLUSIONS AND CLINICAL RELEVANCE

In cats with clinical signs of pancreatitis, serum fTLI concentration is poorly associated with histopathologic diagnosis.

Plasma and urinary trypsinogen activation peptide in healthy dogs, dogs with pancreatitis and dogs with other systemic diseases

OBJECTIVE

To determine the specificity and sensitivity of plasma and urinary trypsinogen activation peptide (TAP) concentrations in diagnosing pancreatitis in dogs.

DESIGN

Retrospective analysis of clinical cases.

PROCEDURE

Dogs were classified into three groups: healthy animals, dogs with confirmed pancreatitis and dogs with nonpancreatic disease, which clinically or biochemically resembled pancreatitis. This last group was further subdivided into dogs with renal and those with nonrenal disease. The plasma and urinary TAP concentration was determined by a competitive enzyme immunoassay. Clinical cases additionally had serum trypsin-like immunoreactivity concentration measured, as well as radiography and ultrasound of the abdomen and further diagnostic procedures. Nonparametric analysis of variance (Kruskal-Wallis test) was performed using Statistix 4.0 program.

RESULTS

There was a wide range of urinary TAP concentration in healthy dogs (mean 52.30 nmol/L, standard deviation 55.25) that made interpretation of urinary TAP concentrations difficult in the other groups. There was a narrow reference range for plasma TAP (mean 2.67 nmol/L, standard deviation 0.93). Plasma and urinary TAP concentrations, as well as urinary TAP to creatinine ratio, were all increased in dogs that died with necrotising pancreatitis. Values were not increased in mild, interstitial pancreatitis. Increased plasma TAP concentrations were also present in dogs with severe renal disease.

CONCLUSION

Plasma TAP concentration is a good prognostic indicator in naturally occurring pancreatitis in dogs. The failure of TAP to increase in mild pancreatitis, and the increase present in severe renal disease, suggests its measurement has limited application as a sole diagnostic tool for canine pancreatitis. Further investigations are required in order to explain the large variability of urinary TAP concentration and the presence of circulating TAP in healthy dogs.

Diagnosis and management of peritonitis

Peritonitis is a clinical syndrome rather than a definitive diagnosis and, as such, the underlying cause must be identified. Many potential causes exist, and peritonitis may be classified as primary or secondary, local or diffuse, acute or chronic, or according to the causative agent. Peritonitis is one of the most common initiators of the systemic inflammatory response syndrome faced by the small animal practitioner. Because systemic inflammatory response syndrome is such a devastating disease process, aggressive stabilization, rapid definitive diagnosis, and prompt surgical and medical treatment are vital for optimizing outcome.

Gastroduodenal intussusception in a young dog

A 21-month-old German shepherd crossbreed presented with a nine-month history of intermittent vomiting, anorexia and melaena interspersed with periods of clinical normality. Investigations suggested recurrent pancreatitis and the vomiting resolved with supportive therapy but recurred two weeks later. Abdominal radiographs revealed evidence of an intermittent abdominal mass which, on ultrasonography, had the typical appearance of an intussusception. At laparotomy, a gastroduodenal intussusception was found obstructing the pancreatic and bile duct outflows with perforation of the duodenal wall. The dog was euthanased. Postmortem examination and histology showed no obvious cause for the intussusception but confirmed pancreatic involvement. This is believed to be the first case of gastroduodenal intussusception reported in an animal.

Evaluation of three pancreas specific protein assays, TLI(trypsin-like immunoreactivity), PASP (pancreas specific protein) and CA 19-9 (glycoprotein) for use in the diagnosis of canine pancreatitis

Three radioimmunoassays (RIA) for the pancreas specific proteins TLI, PASP and CA 19-9 were evaluated in serum from normal control dogs (n = 40) and dogs with pancreatitis (n = 20). Statistically significant differences (P < 0.05) were found for serum TLI and PASP levels between the control and pancreatitis groups. However, only 3/20 dogs with pancreatitis had serum TLI concentrations greater than the highest concentration in control dogs. Concentrations of PASP in serum were higher in 15/20 dogs with pancreatitis than in the control dogs. The magnitude of the increase in concentrations of PASP in pancreatitis was small in the majority of cases. Thus these assays are of limited clinical value in the diagnosis of pancreatitis. There was no cross-reactivity with dog serum in the CA 19-9 assay.

Use of blood and blood components in canine and feline patients with hemostatic disorders

Therapy with blood and blood products related to hemostatic disorders in small animal practice is reviewed. Administration of platelet rich plasma and platelet concentrates in thrombocytopenia or thrombopathia is discussed. Vascular purpuras, vasculitis, and vascular inherited defects are also considered. Inherited coagulation disorders are summarized and the therapeutic choices in treating these disorders are also proposed. In addition, acquired coagulation disorders are briefly reviewed.