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ACVN NUTRITION NOTES Peer Reviewed
To Feed or Not to Feed?
CONTROVERSIES IN THE
NUTRITIONAL MANAGEMENT
OF PANCREATITIS
Justin Shmalberg, DVM, Diplomate ACVN & ACVSMR
University of Florida
The American College of Veterinary veterinary nutrition
Nutrition (acvn.org) and Today’s Veterinary • Encourage continuing education for both
Practice are delighted to bring you the specialists and general practitioners
Nutrition Notes column, which provides the • Promote evidence-based research
highest quality, cutting edge information on • Enhance dissemination of the latest
companion animal nutrition, provided by the veterinary nutrition knowledge.
ACVN’s foremost nutrition specialists. The ACVN achieves these objectives in
The primary objectives of the ACVN are to: many ways, including designating specialists
• Advance the specialty area of veterinary in animal nutrition, providing continuing
nutrition education through several media, supporting
• Increase the competence of those veterinary nutrition residency programs, and
practicing in this field offering a wide array of resources related to
• Establish requirements for certification in veterinary nutrition, such as this column.
Pancreatitis is a common clinical condition of RISK FACTORS
both dogs and cats (Figure 1), and significant In most patients, the definitive cause of
research has been devoted to improved diagnostic pancreatitis is unknown. Published risk factors for
1-3 pancreatitis are extensive and include endocrine
identification of the disease.
1-6
However, nutritional management of pancreatitis disease, obesity, breed, and others. The
continues to be guided primarily by the human nutritional factors that are anecdotally reported
literature and clinical experience due to lack of con- to precede episodes in dogs include dietary Learn More
trolled clinical trials. Any nutritional intervention indiscretion and consumption of more dietary fat For more information
in the treatment of pancreatitis is predicated on the than normal for a particular dog. on acute pancreatitis
practitioner distinguishing acute or chronic pancre- In a single retrospective study that interviewed in dogs and cats,
atitis from other causes of gastrointestinal signs. owners of dogs affected by pancreatitis and those read the following
articles from
Today’s Veterinary
Practice, available at
tvpjournal.com:
A Case of Canine
Acute Pancreatitis:
From Diagnosis
to Treatment
(September/October
2016)
Feline Pancreatitis:
A B Current Concepts in
FIGURE 1. Ultrasound images of pancreatitis demonstrating (A) heterogeneous echogenicity in Diagnosis & Therapy
the pancreas of a dog affected by chronic pancreatitis and (B) significant pancreatic enlargement, (January/February
2015)
hypoechoic regions in the pancreas, and adjacent hyperechoic peripancreatic fat in a dog with
acute pancreatitis.
tvpjournal.com | November/December 2016 | An Official Journal of the NAVC | TODAY’S VETERINARY PRACTICE 45
Peer Reviewed ACVN NUTRITION NOTES
presenting with renal disease, factors that were Enteral nutrition by jejenostomy tube
5
more prevalent in the pancreatitis group included: maintained intestinal villous height and
Dietary indiscretion of items in the trash, which mucosal thickness better than parenteral
conferred greatest risk (13× more likely) nutrition in dogs with experimentally induced
Unusual food items consumed prior to 8,9
pancreatitis. However, this information may
presentation (4×–6× more likely) not be relevant to most practitioners, who will
Table scraps given in the preceding week or choose between fasting or enteral support,
generally (2× more likely) rather than intravenous nutrition.
Obesity (2.6× more likely). 3. Feeding during illness helps provide essential
nutrients that affect cellular function. However,
CLINICAL SIGNS Many of these nutrients are present in reserve,
Cranial abdominal pain and nausea are thought to and dogs are more resistant to starvation than
1-3
be characteristic of acute pancreatitis in dogs. humans, with higher rates of fat oxidation at
Dogs with chronic pancreatitis may display 10
vague signs of anorexia, hyporexia, lethargy, or rest.
behavioral changes, and an acute trigger may not Protein catabolism may occur in critical illness
be immediately identified in these patients. despite the presence of adequate caloric intake
11
Cats commonly present with nonspecific signs due to increased protein requirements.
of anorexia and lethargy for both acute and chronic This increased interest in early enteral nutrition
4 is challenged by some who routinely fast animals
disease, which makes detection more challenging. with acute pancreatitis. These clinicians argue
CANINE ACUTE PANCREATITIS that there is no evidence—in naturally occurring
To feed or not to feed? pancreatitis in companion animals—that shows
No objective information is available to determine a favorable effect of nutrition and that assistive
whether fasting is associated with beneficial or enteral feeding, when necessary, adds risk and cost
poor outcomes in dogs with pancreatitis. to treatment of a patient with pancreatitis. It is
Fasting was, and continues to be, a mainstay important to consider, however, that:
of acute pancreatitis treatment by many If enteral tubes are placed inappropriately,
2 aspiration may be a risk, but aspiration due to
veterinarians. placement errors is rare and risk is mitigated
The premise for this approach is to avoid both by documenting negative pressure in a feeding
pancreatic stimulation and premature activation
of zymogens, but these effects have not been
demonstrated in clinical patients receiving KEY POINT: Short-term fasting has not been
nutritional support. associated with poorer outcome in dogs
Many veterinarians relate personal observations with pancreatitis, and the benefits of feeding
that early feeding is associated with increased require additional validation in dogs with
nausea or morbidity, especially in the presence of naturally-occurring pancreatitis.
abdominal pain or severe gastrointestinal signs
prior to feeding.
Some practitioners, nutritionists, and internists
advocate early enteral nutrition in dogs with acute
episodes of pancreatitis because:
1. A large body of evidence from human critical
care medicine supports decreased morbidity and
mortality associated with early enteral nutrition
2. While evidence for early enteral nutrition in
dogs is comparatively sparse:
Early enteral nutrition accelerated recovery
in dogs with parvoviral enteritis, with food
administered by nasogastric tube irrespective of FIGURE 2. Radiographs should confirm place-
7 ment of nasoenteral tubes; this lateral radio-
whether dogs were vomiting or regurgitating; graph shows a nasogastric tube placed in a cat
however, the significance to older dogs and with the distal tip clearly evident in the stomach.
those with pancreatitis remains unclear.
46 TODAY’S VETERINARY PRACTICE | An Official Journal of the NAVC | November/December 2016 | tvpjournal.com
ACVN NUTRITION NOTES Peer Reviewed
tube, absence of a cough when sterile saline is Resting energy requirement (RER) can be
given via the tube, radiographic confirmation estimated in 2 ways:
(Figure 2) of correct placement, or even 0.75
1. 70 × (BW ) = RER (kcal/day)
kg
12
capnography. 2. [30 × (BW )] + 70 = RER (kcal/day)
kg
The expense of feeding dogs with severe acute The first formula is the more accurate of the 2
pancreatitis amounts to a small fraction of the equations, while the second is an approximation of
overall care (< 5%), but these costs could be RER for dogs weighing 5 to 25 kg. Body weight
significant if the owner’s budget is limited. should always be entered in kg.
In the absence of evidence specific to canine If partial intolerance to enteral nutrition is
pancreatitis, practitioners should evaluate the risks present, it is likely that a lesser amount provides
of enteral feeding in the context of the patient’s some benefit in maintaining absorptive surface
overall clinical picture. Dogs with intractable area of the intestines. Illness factors, which increase
vomiting or regurgitation, in normal body calculated RER, should not be used as the available
condition, or those with owners who have financial literature suggests that such values overestimate
limitations may tolerate a period of fasting without 17
calories needed in hospitalized patients.
any clinically relevant adverse effects. Animals may require assistive enteral feeding.
Syringe feeding is not recommended due to
KEY POINT: Maintenance of enteral nutrition the practical inability to deliver full nutrient
appears beneficial in humans with critical illness requirements with this method and the risk of
and is likely worth the time and effort of inter
- food aversion and aspiration.
vention—when risks of feeding the patient are Nasoesophageal and nasogastric tubes are often used
low—until additional studies are performed. in management of canine and feline pancreatitis.
Esophagostomy tubes are generally reserved for
Enteral or parenteral feeding? severe chronic pancreatitis in dogs, or in cats
Enteral nutrition in humans with pancreatitis may with concurrent morbidities that make the need
prevent bacterial translocation, metabolic and for continued supportive feeding likely.
electrolyte complications of parenteral feeding,
immune system impairment, villous atrophy, and What should the patient be fed?
13
reduced mortality. However, human guidelines Commercially available low fat enteral diets
also suggest that parenteral nutrition should be (Table 1) may best be reserved for patients that
considered: have been discharged from the hospital or those
If nutrition is indicated due to prolonged or that are severely hyperlipidemic.
anticipated anorexia
When enteral nutrition is either contraindicated TABLE 1.
14
or not well tolerated. Fat Content (g/1000 kcal) of Veterinary
The optimal route of enteral nutrition has Therapeutic Diets Labeled for
15
not been defined in humans or animals. While Management of Pancreatitis
veterinary guidelines for parenteral nutrition have DIET DRY CANNED
been extrapolated from human guidelines, the
pathophysiology of small animal pancreatitis cases Low Fat Kangaroo Maintenance 22 24
may be quite different, as well as prognosis and (raynenutrition.com)
16
response to parenteral nutrition. Prescription Diet i/d Low Fat 20 23
(hillspet.com)
KEY POINT: Enteral nutrition is generally Veterinary Diet Gastrointesti- 19 18
associated with more favorable outcomes nal Low Fat (royalcanin.com)
in humans and possibly in dogs when Veterinary Diets EN 31 44
compared with parenteral nutrition. Gastroenteric
(proplanveterinarydiets.com)
Veterinary Diets HA Hydrolyzed 26/32 n/a
How much is too much? (Vegetarian/Chicken)
Dogs with pancreatitis should eventually achieve (proplanveterinarydiets.com)
their estimated resting energy expenditure when Veterinary Formula Intestinal 29 45
feeding is appropriate and elected. Plus Low-Residue (iams.com)
tvpjournal.com | November/December 2016 | An Official Journal of the NAVC | TODAY’S VETERINARY PRACTICE 47
Peer Reviewed ACVN NUTRITION NOTES
TABLE 2. Similar outcomes have been reported in
Fat Content & Energy Density of Selected Liquid Diets dogs receiving parenteral nutrition for acute
pancreatitis and in those receiving early enteral
DIET FAT PROTEIN KCAL/ML nutrition, but dogs fed parenterally had
(g/1000 kcal) (g/1000 kcal) 18
increased catheter complications.
CliniCare Liquid Diet (abbottnutrition.com) ≥ 50a ≥ 80a 1 The provision of complete parenteral nutrition
Ensure Plus (abbottnutrition.com) 31 37 1.5 solutions is often difficult in practices not
Intensive Care HDN (emeraid.com) 48 85 ≤ 1.36 equipped with a fully staffed emergency and/
or critical care unit or in those without previous
b a a
Rebound Liquid Diet (virbacvet.com) ≥ 60 ≥ 60 0.84 experience with these formulations.
Sustain HDN (emeraid.com) 61 73 ≤ 1.34
Vivonex Elemental Formula 7 42 1 Long-term Nutritional Assessment &
(nestlehealthscience.us) Recommendations
a. Estimated from guaranteed analysis Dogs with acute pancreatitis may fully recover, and
b. Manufacturer does not recommend for constant rate infusion may not display any histologic features or clinical
signs of chronic disease. In such cases, a diet
Initiation of therapeutic diets during acute illness otherwise optimal for the pet’s age and health can
has been hypothesized to risk food aversion to eventually be fed.
the diet offered, and only a limited number of fat- Once the patient is discharged:
restricted diets are available on the market. If the patient received a low fat diet during
Dogs fed a fraction of normal maintenance hospitalization, slowly transition the animal to
energy requirements tolerate a moderate the previous or intended maintenance diet.
fat “sacrificial” maintenance diet during Do not make this transition until the owner has
hospitalization, in my experience. verified the patient is eating well and clinically stable
Liquid veterinary-specific enteral diets are after discharge. There are often no contraindications
available (Table 2): to extended administration of a low fat diet.
Veterinary-specific diets are usually higher in Discontinue food transition and reevaluate
fat than human formulas but are complete and recommendations if there is any evidence of
balanced. lethargy, hyporexia, or abdominal pain.
Human enteral diets may be used for short-term Owners should be counseled to avoid the risk
feeding as they are lower in fat but are generally factors highlighted at the beginning of this
also lower in protein and essential nutrients, article (eg, significant abrupt food changes,
making them inappropriate for long-term use ingestion of trash, table scraps, obesity).
without detailed analysis. CANINE CHRONIC PANCREATITIS
Liquid diets are generally required for Low fat, no fat, or normal fat?
nasoenteral tubes. The evidence for dietary fat restriction in chronic
Elemental diets are liquid diets designed for canine pancreatitis is based on clinical impression
humans. The name “elemental” refers to a basic and the published management of relatively few
mixture of simple nutrients, such as free amino cases. The lack of prospective controlled clinical
acids or small peptides, simple sugars, and low trials assessing fat tolerances in dogs with acute
amounts of dietary fat. These diets tend to be more or chronic pancreatitis has resulted in a range of
expensive per calorie than all other common diets, recommendations.
and are not complete and balanced
for long-term feeding. However, TABLE 3.
they may be beneficial if an animal Published Maximal Dietary Fat Concentrations Suggested
has concurrent food hypersensitivity. for Use in Dogs with Pancreatitis
Standard parenteral nutrition 20
solutions can be given in the event Villaverde C 2012 All dogs: 24 grams fat per 1000 kcal
a,b
of severe acute pancreatitis. Hand M et al Obese dogs: 25 grams fat per 1000 kcal
21 a
There is no evidence parenteral 2011 Non-obese dogs: 38 grams of fat per 1000 kcal
2 a
lipid emulsions increase pancreatic Xenoulis PG et al All dogs: 25 grams fats per 1000 kcal
release of proteases or worsen a. As estimated from dry matter percentage given
prognosis. b. Obese dogs = BCS ≥ 7/9
48 TODAY’S VETERINARY PRACTICE | An Official Journal of the NAVC | November/December 2016 | tvpjournal.com
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