LAM3.12: Weight Management and Malnutrition

Malnutrition def

Provision of diet w/ deficiencies, excesses, or imbalances of nutrients or total energy intake.

Starvation def

Severe malnutrition that can be acute (extreme restriction) or chronic (not quite enough calories to meet needs long term)

Obesity def

accumulation of excessive quantity of adipose tissue that may impair health

Ration-balancer def

AA, vitamin, mineral products to ensure appropriate micro and macro-nutrients are provided.

Weight loss is multifactorial, but often includes (2)

imbalance between energy supplied and energy expenditure.

commonly comorbidities in older horses.

Figuring out the cause of chronic weight loss is often done mechanistically (4)

Decreased feed intake.

Malabsorption/increased protein loss.

Increased nutrient use/demand.

Loss of mm. mass.

Basic R/O for chronic weightloss (6)

Nutrition.

Dentition.

Parasite.

Pain.

Loss - failure to absorb or retain.

Increased demand.

Step 1 of a chronic weight loss work-up

Good hx including detailed diet eval, housing/management info, and historical/concurrent dzs.

Diet eval includes (3)

Inadequate provisions of feedstuffs (difference in flake sizes).

Poor quality feed.

O's perception of amount and quality v. actual.

Energy requirement: Most horses can

meet energy requirements w/ good quality forages alone - should form the basis of the diet.

EXAM: Mature horses daily DM intake

2-2.5% of their BW

Forage minimum per day

1.2% of their BW in forage/d

Maintenance requirement depends on

Age.

Environment.

Individual digestive.

Metabolic efficiency.

PE for weight loss assessment should specifically include

BCS noted in MR.

PO exam.

Weight loss: Lab Data - Minimum (6)

CBC.

Chm.

Fibrinogen.

SAA.

Fecal Float.

U/A.

Weight loss: Lab Data Specialized Testing (11)

Gastroscopy.

Rectal.

U/S.

Biopsy - rectal or duodenal.

Rads.

OST.

Vit E/Selenium.

Fecal PCR.

ACTH/TRH

M. biopsy.

Ab tap.

First step, on the scene tool in eval weight loss

Abdominal U/S.

Your tx plan will be based on

your findings and the O's desire to pursue tx and finances.

Categories of P's based on bloodwork (4)

No abnormalities in CBC/chem.

Changes in leukocytes +/- anemia - inflammation/infection.

Abnormalities of plasma proteins - hypo or hyperproteinemia.

Specific organ dysfxn - kidney or liver.

Refeeding Syndrome occurs

w/in 3-5d

Mechanism of refeeding

Increases glucose which leads to insulin secretion, stimulation of glycogen/fat/protein synthesis, and electrolyte influx.

Electrolyte disturbances w/ refeeding syndrome (3)

Hypophosphatemia.

Hypokalemia.

Hypomagnesemia.

Abrupt refeeding results in

death of severely starved horses in about 3d.

Physical effects of Re-Feeding Syndrome (5)

M. weakness.

Neurologic dysfxn.

Cardiac arrythmias - cardiac dysfxn.

Hematologic abnormalities - hemolysis and WBC dysfxn.

Edema.

Who is at risk for refeeding syndrome (4)

BCS <3/9 and unknown diet hx.

Fasting >10d regardless of BCS.

Weight loss >10% BW in <2m.

Other concurrent dzs.

Prevention of refeeding syndrome

Refeed slowly - small gastric volumes.

Progression of Slow Refeeding (4)

Water and lytes.

Enteral or slurries.

Good quality forage and concentrates.

If thriving - feeding >100% DER.

calculation of daily energy requirement

1st use resting energy requirement (RER) x current BW (kg).

Then over subsequent 7-10d, increase to (MER) x Ideal BW.

RER in horses

22-23 kcal/kg/d.

MER

30-36 kcal/kg/d

Progression of refeeding (3)

Start w/ 25-50% RER.

Increase to 100% of RER at ~3d.

Subsequent 7-10d - MER x ideal BW divided into 4-6 meals.

Re-feeding syndrome tx (5)

IVF.

PO electrolytes.

IV AA.

Lots of nursing care.

Assisted enteral feeding - tube.

Prognosis for starvation cases

Loss of 40% of optimal BW are likely to progress to recumbency.

45-50% of BW is lost (50-55% of optical) makes survival unlikely.

Most starvation cases will die if

unable to rise for 72h.

Overall mortality of severely malnourished horses

14-20%

Time to return to normal BCS

6-10m.