Hemosuccus pancreaticus, also known as pseudohematobilia or Wirsungorrhage, is a rare cause of hemorrhage in the gastrointestinal tract. It is caused by a bleeding source in the pancreas, pancreatic duct, or structures adjacent to the pancreas, such as the splenic artery, that bleed into the pancreatic duct. Patients with hemosuccus may develop symptoms of gastrointestinal hemorrhage, such as blood in the stools, maroon stools, or melena. They may also develop abdominal pain. Hemosuccus pancreaticus is associated with pancreatitis, pancreatic cancer and aneurysms of the splenic artery. Angiography may be used to diagnose hemosuccus pancreaticus, where the celiac axis is injected to determine the blood vessel that is bleeding. Concomitant embolization of the end vessel may terminate the hemorrhage. Alternatively, a distal pancreatectomy may be required to stop the hemorrhage.

Although there can be various causes of dog pancreatitis, such as drugs, fatty diet, trauma, etc., the pathophysiology is very complex. Pancreatitis can be idiopathic; no real causation factor can be found. Obese animals as well as animals fed a diet high in fat may be more prone to developing acute and chronic pancreatitis. Certain breeds of dogs are considered predisposed to developing pancreatitis including miniature schnauzers, Cocker Spaniels, and some terrier breeds. Miniature Schnauzers as a breed tend toward developing hyperlipidemia, an excess of circulating fats in the blood. The breed which appears to be at risk for the acute form of pancreatitis is the Yorkshire Terrier, while Labrador Retrievers and miniature Poodles seem to have a decreased risk for the acute form of the disease. It is suggested that genetics may play a part in the risk factor. Dogs suffering from diabetes mellitus, Cushing's disease (hyperadrenocorticism), hypothyroidism and epilepsy are at increased risk for pancreatitis. Diabetes and hypothyroidism are also associated with hyperlipidemia. Those with other types of gastrointestinal conditions and dogs who have had previous pancreatitis attacks are also at increased risk for the disorder.

Cystic fibrosis, is a hereditary disease that affects the entire body, causing progressive disability and early death. It is caused by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The product of this gene helps create sweat, digestive juices, and mucus. The name "cystic fibrosis" refers to the characteristic 'fibrosis' (tissue scarring) and cyst formation within the pancreas, causing irreversible damage, and often resulting in painful inflammation (pancreatitis).

There are seven classes of medications associated with acute pancreatitis: statins, ACE inhibitors, oral contraceptives/hormone replacement therapy (HRT), diuretics, antiretroviral therapy, valproic acid, and oral hypoglycemic agents. Mechanisms of these drugs causing panreatitis are not known exactly; but it is possible that statins has direct toxic effect on the pancreas or through the long term accumulation of toxic metabolites. Meanwhile, ACE inhibitors causes angioedema of the pancreas through the accumulation of bradykinin. Oral contraceptives/HRT causes arterial thrombosis of the pancreas through the accumulation of fat (hypertriglyceridemia). Diuretics such as furosemide has direct toxic effect on the pancreas. Meanwhile, thiazide diuretics causes hypertriglyceridemia and hypercalcemia, where the latter is the risk factor for pancreatic stones. HIV infection itself can cause a person to more likely to get pancreatitis. Meanwhile, antiretroviral drugs may cause metabolic disturbances such as hyperglycemia and hypercholesterolemia, which predisposes to pancreatitis. Valproic acid may have direct toxic effect on the pancreas. There are various oral hypoglycemic agents that contributes to pancreatitis including metformin. But, glucagon-like peptide-1 (GLP-1) is more strongly associated with pancreatits by promoting inflammation.

Atypical antipsychotics such as clozapine, risperidone, and olanzapine can also cause pancreatitis.

There are no approved treatments for canine pancreatitis. Treatment for this disease is supportive, and may require hospitialization to attend to the dog's nutritional and fluid needs, pain management, and addressing any other disease processes (infection, diabetes, etc.) while letting the pancreas heal on its own. Treatment often involves "resting" the pancreas for a short period of time by nil per os/nothing per os (NPO)/nil by mouth (NBM), in which the patient receives no food or fluids by mouth, but is fed and hydrated by intravenous fluids and a feeding tube. Dehydration is also managed by the use of fluid therapy. However, a specialist from Texas A&M University has stated "There is no evidence whatsoever that withholding food has any beneficial effect." Other specialists have agreed with his opinion.

Canine pancreatitis is complex, often limiting the ability to approach the disease.

Eighty percent of cases of pancreatitis are caused by alcohol or gallstones. Gallstones are the single most common cause of acute pancreatitis. Alcohol is the single most common cause of chronic pancreatitis.

A 2009 study which followed 189 patients found no excess mortality despite the increased risk of pancreatic cancer.

The annual incidence of chronic pancreatitis is 5 to 12 per 100,000 persons, the prevalence is 50 per 100,000 persons.

In the United States, the annual incidence is 18 cases of acute pancreatitis per 100,000 population, and it accounts for 220,000 hospitalizations in the US. In a European cross-sectional study, incidence of acute pancreatitis increased from 12.4 to 15.9 per 100,000 annually from 1985 to 1995; however, mortality remained stable as a result of better outcomes. Another study showed a lower incidence of 9.8 per 100,000 but a similar worsening trend (increasing from 4.9 in 1963-74) over time.

In Western countries, the most common cause is alcohol, accounting for 65 percent of acute pancreatitis cases in the US, 20 percent of cases in Sweden, and 5 percent of those in the United Kingdom. In Eastern countries, gallstones are the most common cause of acute pancreatitis. The causes of acute pancreatitis also varies across age groups, with trauma and systemic disease (such as infection) being more common in children. Mumps is a more common cause in adolescents and young adults than in other age groups.

treatment of HP resemble that of chronic pancreatitis of other causes. Treatment focuses on enzyme and nutritional supplementation, pain management, pancreatic diabetes, and local organ complications, such as pseudocysts, bile duct or duodenal obstruction.(PMC1774562)

The cause of pancreatic pseudocyst can occur due to a variety of reasons, among them pancreatitis (chronic), pancreatic neoplasm and/or pancreatic trauma.

Locoregional complications include pancreatic pseudocyst (Most common, occurring in up to 25% of all cases) and phlegmon / abscess formation, splenic artery pseudoaneurysms, hemorrhage from erosions into splenic artery and vein, thrombosis of the splenic vein, superior mesenteric vein and portal veins (in descending order of frequency), duodenal obstruction, common bile duct obstruction, progression to chronic pancreatitis, pancreatic ascites, pleural effusion, sterile/infected pancreatic necrosis.

First described by Smith (1953), and elaborated upon by Cameron et al. (1976), internal pancreatic fistulas can result in pancreatic ascites, mediastinital pseudocysts, enzymatic mediastinitis, or pancreatic pleural effusions, depending on the flow of pancreatic secretions from a disrupted pancreatic duct or leakage from a pseudocyst.

A pancreatic fistula is an abnormal communication between the pancreas and other organs due to leakage of pancreatic secretions from damaged pancreatic ducts. An "external" pancreatic fistula is one that communicates with the skin, and is also known as a pancreaticocutaneous fistula, whereas an internal pancreatic fistula communicates with other internal organs or spaces. Pancreatic fistulas can be caused by pancreatic disease, trauma, or surgery.

Risk factors for pancreatic adenocarcinoma include:

- Age, gender, and ethnicity; the risk of developing pancreatic cancer increases with age. Most cases occur after age 65, while cases before age 40 are uncommon. The disease is slightly more common in men than women, and in the United States is over 1.5 times more common in African Americans, though incidence in Africa is low.

- Cigarette smoking is the best-established avoidable risk factor for pancreatic cancer, approximately doubling risk among long-term smokers, the risk increasing with the number of cigarettes smoked and the years of smoking. The risk declines slowly after smoking cessation, taking some 20 years to return to almost that of non-smokers.

- Obesity; a BMI greater than 35 increases relative risk by about half.

- Family history; 5–10% of pancreatic cancer cases have an inherited component, where people have a family history of pancreatic cancer. The risk escalates greatly if more than one first-degree relative had the disease, and more modestly if they developed it before the age of 50. Most of the genes involved have not been identified. Hereditary pancreatitis gives a greatly increased lifetime risk of pancreatic cancer of 30–40% to the age of 70. Screening for early pancreatic cancer may be offered to individuals with hereditary pancreatitis on a research basis. Some people may choose to have their pancreas surgically removed to prevent cancer developing in the future.

- Chronic pancreatitis appears to almost triple risk, and as with diabetes, new-onset pancreatitis may be a symptom of a tumor. The risk of pancreatic cancer in individuals with familial pancreatitis is particularly high.

- Diabetes mellitus is a risk factor for pancreatic cancer and (as noted in the Signs and symptoms section) new-onset diabetes may also be an early sign of the disease. People who have been diagnosed with Type 2 diabetes for longer than ten years may have a 50% increased risk, as compared with non-diabetics.

- Specific types of food (as distinct from obesity) have not been clearly shown to increase the risk of pancreatic cancer. Dietary factors for which there is some evidence of slightly increased risk include processed meat, red meat, and meat cooked at very high temperatures (e.g. by frying, broiling or barbecuing).

Among the causes of chronic pancreatitis are the following:

The relationship between etiologic factors, genetic predisposition, and the pace of disease progression requires further clarification, though recent research indicates smoking may be a high-risk factor to develop chronic pancreatitis. In a small group of patients chronic pancreatitis has been shown to be hereditary. Almost all patients with cystic fibrosis have established chronic pancreatitis, usually from birth. Cystic fibrosis gene mutations have also been identified in patients with chronic pancreatitis but in whom there were no other manifestations of cystic fibrosis. Obstruction of the pancreatic duct because of either a benign or malignant process may result in chronic pancreatitis.

Hepatic diseases refers to those affecting the liver. Hepatitis refers to inflammation of liver tissue, and may be acute or chronic. Infectious viral hepatitis, such as hepatitis A, B and C, affect in excess of (X) million people worldwide. Liver disease may also be a result of lifestyle factors, such as fatty liver and NASH. Alcoholic liver disease may also develop as a result of chronic alcohol use, which may also cause alcoholic hepatitis. Cirrhosis may develop as a result of chronic hepatic fibrosis in a chronically inflamed liver, such as one affected by alcohol or viral hepatitis.

Liver abscesses are often acute conditions, with common causes being pyogenic and amoebic. Chronic liver disease, such as cirrhosis, may be a cause of liver failure, a state where the liver is unable to compensate for chronic damage, and unable to meet the metabolic demands of the body. In the acute setting, this may be a cause of hepatic encephalopathy and hepatorenal syndrome. Other causes of chronic liver disease are genetic or autoimmune disease, such as hemochromatosis, Wilson's disease, autoimmune hepatitis, and primary biliary cirrhosis.

Acute liver disease rarely results in pain, but may result in jaundice. Infectious liver disease may cause a fever. Chronic liver disease may result in a buildup of fluid in the abdomen, yellowing of the skin or eyes, easy bruising, immunosuppression, and feminsation. Portal hypertension is often present, and this may lead to the development of prominent veins in many parts of the body, such as oesophageal varices, and haemorrhoids.

In order to investigate liver disease, a medical history, including regarding a person's family history, travel to risk-prone areas, alcohol use and food consumption, may be taken. A medical examination may be conducted to investigate for symptoms of liver disease. Blood tests may be used, particularly liver function tests, and other blood tests may be used to investigate the presence of the Hepatitis viruses in the blood, and ultrasound used. If ascites is present, abdominal fluid may be tested for protein levels.

Pancreatic diseases that affect digestion refers to disorders affecting the exocrine pancreas, which is a part of the pancreas involved in digestion.

One of the most common conditions of the exocrine pancreas is acute pancreatitis, which in the majority of cases relates to gallstones that have impacted in the pancreatic part of the biliary tree, or due to acute or chronic alcohol abuse or as a side-effect of ERCP. Other forms of pancreatitis include chronic and hereditary forms. Chronic pancreatitis may predispose to pancreatic cancer and is strongly linked to alcohol use. Other rarer diseases affecting the pancreas may include pancreatic pseudocysts, exocrine pancreatic insufficiency, and pancreatic fistulas.

Pancreatic disease may present with or without symptoms. When symptoms occur, such as in acute pancreatitis, a person may suffer from acute-onset, severe mid-abdominal pain, nausea and vomiting. In severe cases, pancreatitis may lead to rapid blood loss and systemic inflammatory response syndrome. When the pancreas is unable to secrete digestive enzymes, such as with a pancreatic cancer occluding the pancreatic duct, result in jaundice. Pancreatic disease might be investigated using abdominal x-rays, MRCP or ERCP, CT scans, and through blood tests such as measurement of the amylase and lipase enzymes.

Pancreatic pseudocysts are sometimes called false cysts because they do not have an epithelial lining.The wall of the pseudocyst is vascular and fibrotic, encapsulated in the area around the pancreas. Pancreatitis or abdominal trauma can cause its formation. Treatment usually depends on the mechanism that brought about the pseudocyst. Pseudocysts take up to 6 weeks to completely form.

As the number of published cases of AIP has increased, efforts have been focused on defining AIP as a distinct clinical and pathologic entity and toward developing some generally agreed upon diagnostic criteria and nomenclature. Terms frequently encountered are autoimmune or autoimmune-related pancreatitis, lymphoplasmacytic sclerosing pancreatitis, idiopathic tumefactive chronic pancreatitis, idiopathic pancreatitis with focal irregular narrowing of the main pancreatic duct, and non-alcoholic duct destructive chronic pancreatitis. There are also a large number of case reports employing descriptive terminology such as pancreatitis associated with Sjögren’s syndrome, primary sclerosing cholangitis, or inflammatory bowel disease. Some of the earliest cases were reported as pancreatic pseudotumor or pseudolymphoma.

The most reliable test for EPI in dogs and cats is serum trypsin-like immunoreactivity (TLI). A low value indicates EPI. Fecal elastase levels may also be used for diagnosis in dogs.

In dogs, the best treatment is to supplement its food with dried pancreatic extracts. There are commercial preparations available, but chopped bovine pancreas from the butcher can also be used (pork pancreas should not be used because of the rare transmission of pseudorabies). Symptoms usually improve within a few days, but lifelong treatment is required to manage the condition. A rare side-effect of use of dried pancreatic extracts is oral ulceration and bleeding.

Because of malabsorption, serum levels of cyanocobalamin (vitamin B12) and tocopherol (vitamin E) may be low. These may be supplemented, although since cyanocobalamin contains the toxic chemical cyanide, dogs that have serious cobalamin issues should instead be treated with hydroxocobalamin or methylcobalamin. Cyanocobalamin deficiency is very common in cats with EPI because about 99 percent of intrinsic factor (which is required for cyanocobalamin absorption from the intestine) is secreted by the pancreas. In dogs, this figure is about 90 percent, and only about 50 percent of dogs have this deficiency. Cats may suffer from Vitamin K deficiencies. If there is bacterial overgrowth in the intestine, antibiotics should be used, especially if treatment is not working. In dogs failing to gain weight or continuing to show symptoms, modifying the diet to make it low-fiber and highly digestible may help. Despite previous belief that low-fat diets are beneficial in dogs with EPI, more recent studies have shown that a high-fat diet may increase absorption of nutrients and better manage the disease. However, it has been shown that different dogs respond to different dietary modifications, so the best diet must be determined on a case-by-case basis.

One possible sequela, volvulus (mesenteric torsion) is a rare consequence of EPI in dogs.

Drinking alcohol excessively is a major cause of chronic pancreatitis, which in turn predisposes to pancreatic cancer. However, considerable research has failed to firmly establish alcohol consumption as a direct risk factor for pancreatic cancer. Overall, the association is consistently weak and the majority of studies have found no association, with smoking a strong confounding factor. The evidence is stronger for a link with heavy drinking, of at least six drinks per day.

Periampullary cancer is a cancer that forms near the ampulla of Vater, an enlargement of the ducts from the liver and pancreas where they join and enter the small intestine.It consists of:

1. ampullary tumour from ampulla of Vater,

2. cancer of lower common bile duct, and

3. duodenal cancer adjacent to ampulla.

4. carcinoma head of pancreas

It presents with painless jaundice which may have waxing and waning nature because at times the sloughing of the tumor tissue relieves the obstruction partially.

In humans, the most common causes of EPI are chronic pancreatitis and cystic fibrosis, the former a longstanding inflammation of the pancreas altering the organ's normal structure and function that can arise as a result of malnutrition, heredity, or (in the western world especially), behaviour (alcohol use, smoking), and the latter a recessive hereditary disease most common in Europeans and Ashkenazi Jews where the molecular culprit is an altered, "CFTR"-encoded chloride channel. In children, another common cause is Shwachman-Bodian-Diamond syndrome, a rare autosomal recessive genetic disorder resulting from mutation in the SBDS gene.

Early signs of abnormality include polyhydramnios (an excess of amniotic fluid), low birth weight, and feeding intolerance immediately after birth.