Approach to Weight Loss Cases

why is weight loss important

Common diagnostic challenge

Can affect ability to perform and/or welfare

May involve multiple organs/systems

Multiple potential causes

Specific diagnosis often difficult and may not be reached

normal weight depends on

-size

-shape/breed/species

-repro status e.g. lactating, pregnancy

-season

-work

how to assess weight

BCS based on amount of fat deposited in specific areas

BCS scoring systems

-9 point henneke (professional) → use in records and collegues

-5 (6) point carroll and huntington (clients)

how to BCS

-hands on as big differences in subcut tissue

-assess horse from all angles

Regional adiposity associated with metabolic syndromes

-KEEP RECORD, photos

-re evaluate every month

what is regional adiposity assoc with

metabolic syndromes like PPID or EMS

henneke BCS

must have definitive answer, no 0.5

-best for notes

carroll and huntington BCS

-best for clients

cresty neck score

allows to be able to comment on marked adiposity in areas while also commenting on low BCS overall which makes good for diagnosis of things like PPID and EMS

regional adiposity in the neck

other ways to track weight

weigh bridges

weight tapes→ approx, not realyl used now, can track this number with trends tho

weight loss

general reduction in body fat from stores

muscle wasting

localised, often affecting specific muscle groups while fat stores remain relatively stable

muscles often affected by muscle wasting

-epaxial

-gluteal

-neck

causes of muscle wasting

NMSK, metabolic, less work

what should be assessed alongside bcs

Muscle condition should be assessed alongside BCS to evaluate muscle mass, independent of fat coverage

Significance: PPID, neuromuscular disorders

basics of history

-how long had horse

-previous meds history

-herd/social dynamics (stress inducing)

focused history questions

-duration of issue

-diet

-deworming

-dentistry work

mechanisms of weight loss

-insufficient consumption

-impaired digestion/absorption

-excessive loss

-increased requirements

-other

insufficient consumption

-detailed diet history (pasture? fibre? hay?)

-visit property to observe living conditions to see how much pasture

-watch eat and whether offered enough

if horse not offered enough, what to do

adjust diet to meet needs of 1.5-2% BW DM a day

if offered enough food, what to do next

-consuming enough?

causes of insufficient consumption

-dental disease esp shear mouth

-dysphagia

-pain

-stress/competition

shear mouth

when the occlusal surfaces are severely sloped on each individual tooth, so that, for example, the lingual side of one maxillary cheek tooth is severely worn down while the buccal side is not.

questions for impaired digestion/absorption

has faecal output been normal?

-amount?

-consistency?

causes of impaired digestion/absorption

Dental problems

Malabsorption (intestinal parasitosis, Lawsonia, sand enteropathy, IBD, etc.)

Liver disease (incl. toxicities)

Delayed gastric emptying?

can you determine increased losses from history

no

causes of increased losses

-protein losing enteropathy

-protein losing nephropathy

-third spacing e.g. peritonitis, pleuritis

third spacing

fluid moving from blood vessels to interstitium

what is needed to do to evaluate increased losses

diagnostics

increased requirements questions

-has work increased like exercise or breeding

-has food availability changed like reduced grazing

causes of increased requirements

-pregnancy/lactation

-adverse weather

-neoplasia

other (metabolic) causes of weight loss

inadequate distribution or muscle atrophy

-PPID

-EMS

-Equine Protozoal Myeloencephalitis

-selenium deficiency

physical exam in weight loss case

-thoracic and abod auscultation

• can hear it just behind xiphoid→ sounds like a seashell (doesnt rule out tho)

-rectal palp

-sand investigation of faeces

-oral exam with speculum

sand investigation

-faeces out, suspended in water and see if sand drops

oral exam

-well sedated

-speculum, head torch, mirrors

what to check on oral exam

-denal pathology

-FB (often wires under tongue)

-masses (SCC)

what can be used to relax the smoot m in a rectal exam, when use it

-first without buscopan then with

• is an anticholinergic, smooth m relaxant

why rectal first without buscopan

assess motility first

why rectal with buscopan

anticholinergic so causes smooth muscle relaxation

palpation findings on rectal

-thickened intestinal walls and colon

-enlarged LNs in retroperitoneal space

-increased motility

haem tests about weight loss

-PCV/TP

-CBC

whta will TP show

protein losing enteropathy

biochem renal profile

-creatinine

-urinalysis

-USG

hepatic biochem profile

-AST

-GGT

-GLDH

-SDH

-bile acids

-bilirubin

biochem of acute phase proteins

-albumin (-)→ acute

-fibrinogen (+)→ chronic

-SAA (+)→ acute

faecal testing

often parasitic burden in young that can cause weight loss

• fewc, pcr

  • fwec dont show red worms → elisa

PCR on faeces

-infectious causes

-more acute than chronic

US show

-FLASH (fast localised abdo sonography of horses)

-more of colic exam

pathologies seen on US

-thickening intestine wall

-gastric dilation

-oedema in intestine

-distension of renal pelvis

-distension of biliary tree or changes in echogenicity of liver

what to assess on US

-motility

-wall thickness

-lumen characteristic

how to assess motility on US

-no sedation

-no buscopan

size of SI

<2-3mm

size of LI

<3mm

size of stomach

<5mm

lumen characteristics on us

• large colon should be gas filled → not see it

• colitis→ fluid filled colon

why thoracic US if weight loss

always assess as could be pneumonia as cause of weight loss

what to assess on thoracic US

-pleural surface for bronchopneumonia

-pleural effusion

-adhesions/fibrin tags

signs of bronchopneumonia

-comet tailing

-areas of consolidtion

clinical decision making factors to consider

-age (older=PPID. lymphoma)

-signalment

-chronicity (liver disease, IBD)

-presence of diarrhoea, colic, fever

-regional prevalence (e.g. strongyles, sand)

what test for malabsorption

oral glucose absorption test (OGAT)

oral glucose absorption test prep

-avoid stressors on day

-12 hour fast or only grass hay prior to test but allow water

• nothing high in concentrates

-no sedation

-quiet

why don't sedate with oral glucose absorption test

-alpha 2 agonist cause glucose spike

how to oral glucose absorption test

-admin 1g/kg glucose as 20% dextrose via NGT

-blood samples for glucose at baseline then hourly for 6hr post glucose admin in oxalate flouride tubes

normal response to oral glucose absorption test

-approx doubling of baseline blood glucose at 2 hours post dosing

severely hypoalbuminaemic patients with oral glucose absorption test

-depressed peaks (colon oedema) so peak between 90-150 mins and may only be 60-70% above baseline

partial malabsoprtion on OGAT

15-65% rise

-insignificant and needs retest

-may be due to stress

-can progress in later tests as may show early signs

total malabsorption on OGAT

no greater than 15% rise in blood glucose, poor prognosis

positive OGAT can mean

-IBD

-lymphosarcoma

-chronic enteritis

-parasitic infestation

if worry peritonitis what do

peritoneal fluid analysis

how to collect abdominocentesis

EDTA and plain

EDTA of abdocentesis for

-TNCC

-cytology

-TP

-glucose

-lactate

plain tube from abdocentesus for

culture

interpreting peritoneal fluid

Test	Normal	Abnormal
TNCC	< 5,000 cells/μL	> 5,000 cells/μL – indicative inflammation +/- infection
Cytology	Predominantly non-degenerate neutrophils and macrophages. No bacteria or neoplastic cells	Degenerate neutrophils, reactive macrophages, bacteria (esp. intracellular), neoplastic indicators
Total Protein	< 2.5 g/dL (transudate range)	> 2.5 g/dL – suggestive of exudative process e.g. peritonitis
Glucose	Similar to blood glucose levels	Lower than blood glucose levels – indicative of bacterial process bacteria use up glucose
Lactate	< 2 mmol/L	> 2 mmol/L – indicative of compromised perfusion or ischaemia of abdominal viscera

what can cause ulcers

stress

equine gastric ulcer syndrome

-not often cause of weight loss but can coincide and proliferate

-may indicate stress

diagnosis of equine gastric ulcer syndrome

gastroscopy

common gastric neoplasia

SCC

delayed gastric emtpying

-limit possible feed intake

-indicate intestinal disease

gastroscopy see

-gastric ulcers

-gastric neoplasia

-delayed gastric emptying

-evaluate oesophagus for strictures if history of choke

PPID testing

-basal ACTH

-TRH stim test

hyperthyroidism tests

-total T4/free T4/T3

-TRH basal/stim testing

renal testing

fractional excretion of electrolytes→ shows which part if affected

-look at USG

-chronic interstitial nephritis common from NSAID long term

transendoscopic biopsy

-gastric

-duodenal

partial thickness

manual biopsy

-liver

-rectal mucosa (IBD) → high risk

surgical biopsy

-full thickness and need time off

-midline exploratory celiotomy

-flank lap

-laparascopy

weight loss approach