Weight loss Flashcards
Mechanisms of weight loss
Reduced intake
Reduced digestion, absorption
Increased lossess
Increased requirements
Reduced intake
Inappropriate feeding, unable to obtain, dental disease, dysphagia (strangles), pain, gatric disease (must be severe)
Reduced digestion, absorption, assimilation of nutrients
Dental, malabsorption syndromes (cyathostominosis- hypoalbuminaemia, diarrhoea, inflammatory)
Liver disease
Intestinal disease - may also cause chronic diarrhoea
Infiltrative bowel diesease - inflammatory or neoplastic infiltrates
Increased losses
Protein losing enteropathy - cyathostominosis, large strongyles
Rarely protein losing nephropathy, but severe if so
Sequestration to body cavity - pleuritis, peritonitis
Increased requirements
Preganancy, lactate, sepsis, neoplasia
History for weight loss
Diet (specifics), parasite control, age, activity, length of weight loss, dental, diarrhoea, inappetance, colic, type of pasture - other horses?
Physical exam
Muscle waste - head, cervical, epaxial
Oedema - ventral, limbs
Faecal staining on hindquarters
HR, abnormal lung sounds, GI motility
Dental
Faeces, parasites, sand grass
Neutrophilia
more common with parasite infection
Eosinophilia
Parasite, general inflammation
Anaemia
Chronic disease
Inflammatory markers
SAA - acute
Fibrinogen - 4-8h after initial inflammation
Total protein decrease
Hypoalbuminaemia
Hypoglobulinaemia
Masked by concurrent hypovolaemia
Albumin - GI more common than renal, effusions (peritoneal, pleural), liver - rare
Globulin - GI loss
Total protein increase - Hyperproteinaemia
Hyperalbuminaemia - chronic inflammatory - inc. cyathostominosis
Hyperglobulinaemia - infection, inflammation, neoplasia
Oral glucose test
Withhold food overnight
1g/kg 10-20% solution by nasogastric solution
Keep calm - insulin increase with stress
Blood glucose should double in 90 minutes and decrease with insulin response
Limitations - does not only assess SI function - small amount absorbed in LI
Delayed flat curve - delayed gastric emptying, poorly starved
Intestinal ultrasound
SI thickness
LI thickness
SI >4mm abnormal
LI >6mm abnormal
GI biopsy methods
Transendoscopic
Rectal - retroperitoneal
Useful for eosinophillic proctitis
Relies on extensive pathology
SI - Intestinal causes of weight loss
Chronic inflammatory bowel disease - CIBD
Granulomatous enteritis - GE
Eosinophilic enterocolitis
Lymphocytic plasmacytic enterocolitis
Granulomatous enteritis
SI
Rare
Unknown cause - hypothetical inflammatory reaction to intestinal bacteria, any breed, age, sex
Lymphoid and macrophage infiltration (lamina propria), ileal villus atrophy
Eosinophilic enteritis
SI and LI
Eosinophilic infiltration – unknown cause, suspected nematode infection hypersensitivity, young TB and SB
MEED - Multisystemic eosinophilic epitheliotrophic disease – other organs involved
DEE – diffuse eosinophilic enterocolitis – all SI and LI
IFEE or IFEC – idiopathic focal eosinophilic enteritis/colitis – segmental SI or LI lesions
Lymphocytic plasmacytic enterocolitis – LPE
SI
Increasingly common
Lymphocyte and plasma cell infiltration – lamina propria
Unknown cause – suspected to precede intestinal lymphoma
Proliferative enteropathy
SI
Lawsonia intracellularis – intracellular bacteria in crypts of epithelial cells of jejunum and ileum
Weanling foals 3-8 months
Individual or outbreak
Close proximity to pigs
Overcrowding, feed change, antibiotic use, mixing foals, weaning
LI - intestinal causes of weight loss
Parasite infection
RDC – right dorsal colitis
Sand enteropathies
EE – eosinophilic enteropathy
Large strongyles
- Strongylus vulgaris – important and pathogenic
- Strongylus edentates
- Strongylus equinus
Migration through intestinal wall
- 4th stage larvae
- Affects myoelectrical activity
- Infiltration with inflammatory cells, oedema and haemorrhage – increased secretion, decreased absorption of nutrients
Colic or diarrhoea but can be chronic weight loss
Small strongyles
Migration of L4 through mucosa of SI
Period of hypobiosis in large colon
Mass emergence of larvae – mucosal injury, ulceration, inflammatory rection
- Diarrhoea – increased secretion secondary to granulomatous inflammation. Significant protein loss
RDC – right dorsal colitis
LI
PGE2 PGI 2 – maintain blood flow, increase mucus secretion, water, bicarb, cell turnover
- NSAIDs inhibit PG production
Right dorsal ulcerative colitis
- PBZ common cause – intermittent colic, diarrhoea, weight loss
Sand enteropathy
Ingest sand – sacculation accumulation of ventral colon – inflammation and damage to colonic mucosa – diarrhoea, weight loss – impaction colic
Hepatic weight loss causes
Clinical signs from hepatic failure - >75% must be damaged
Theiler’s disease, acute hepatitis, or serum associated hepatitis
Ragwort poisoning
Cholangiohepatitis
Cholelithiasis
Weight loss – anorexia, abnormal metabolism
Colic, diarrhoea, ascites
- Hepatic swelling, portal hypertension, altered microflora, abnormal bile acids
Anorexia - Altered behaviour from hepatic encephalopathies
Theiler’s disease, acute hepatitis, or serum associated hepatitis
Associated to equine blood products
Equine parvovirus – associated - Vertical transmission, biting fleas, nasal transmission
Equine Hepacivirus – cannot be ruled out as cause
Ragwort poisoning
Pyrrolizidine alkaloid toxicosis
Plants or feed (hay or pellets) – green plant not palatable so unlikely to eat in field)
Cholangiohepatitis
Ascending bacterial infection – Salmonella, Klebsiella, E.coli
Sepsis – systemic spread into liver
Cholelithiasis
Stone formation in biliary ducts/obstruction
Abdominocentesis
Colour, protein (refractometer), lactate (>2.5mmol/l) – double systemic bacterial production
WBC
Faecal test
Only adults produce eggs – larvae cause more damage no eggs. Encysted don’t produce eggs. US might see Ascarids burden in weanling
- PCR – proliferative enteropathy – Lawsonia. Intracellularis
- Chronic Salmonella – PCR and culture
Signs of liver disease
Non specific – depression, anorexia, weight loss, colic, icterus, fever, photosensitive, hepatic encephalopathy (circling, walking compulsively, head pressing)
