Weight loss and chronic colic

what are the mechanisms of weight loss?

• reduced energy intake due to reduced access - e.g. inappropriate feeding, competition for feed, dental disorders, dysphagia

• reduced digestion, absorption or assimilation of nutrients - e.g. dental disorders so less mechanical breakdown, malabsorption syndromes, liver disease

• physiological increased energy demand - e.g. exercise, pregnancy, lactation, cold

• pathological increased energy demand - e.g. neoplasia, infection, immune mediated, GI renal or effusion losses

• additional mechanisms causing increased energy demand - e.g. chronic pain, stress, cachexia, primary muscle loss, aging (sarcopenia)

what are the most common causes of weight loss?

• dental disorders

• parasitism

• inadequate diet

what is colic?

behavioural manifestation of visceral pain - usually intestinal pain e.g.

• stretch

• inflammation

• ischaemia

• muscle spasm

when is colic considered chronic?

if signs persist for more than 48 hours

when is colic considered recurrent?

if horse experiences shorter periods of colic pain which recur at variable intervals

what are the most common causes of recurrent colic?

• colon displacement

• impaction

• adhesions

• gastric ulceration

• IBD

however most often the cause is not established

what is the most important history to take for recurrent colic cases?

• diet esp if any recent changes

• worming / FWEC (faecal worm egg count)

• any dental problems or quidding

• number and nature of previous colics

if regular 3 weekly colicing, what does this suggest?

ovulatory pain

if colic intervals are getting increasingly shorter, what does this suggest?

worsening of bowel condition

if investigating chronic weight loss, what would we look for in blood and faecal tests?

• specific organ disease - liver enzymes, creatinine, etc

• inflammatory processes - WCC, fibrinogen, globulins

• protein loss - albumin

• hypercalcaemia? - can be indicator of malignancy

• faecal egg count

• ELISA tests for cyathostominosis / tape worm

how should we interpret total protein for chronic weight loss?

often have a decrease in total protein, but may be masked by concurrent dehydration

how should we interpret hypoalbuminaemia for chronic weight loss?

• may be due to loss - GI most common, or due to effusions

• may be due to lack of production - malabsorption, liver disease

how should we interpret hypoglobulinaemia for chronic weight loss?

most commonly due to GI loss

how should we interpret hyperglobulinaemia for chronic weight loss?

suggests chronic inflammatory disease (incl. cyathostomosis)

how should we interpret fibrinogen / serum amyloid A for chronic weight loss?

acute phase proteins, SAA quicker up and down in response to infection

uses of abdominocentesis in chronic weight loss?

perform fluid analysis on peritoneal tap

• nucleated cell count

• protein

• lactate

• cytology

what does this peritoneal US show?

tadpole looking structure = intestine, normal to see the round part, but wouldnt usually see the mesentery (tail of tadpole)

what do we look for on abdominal US?

• position of organs

• intestinal wall thickness

• intestinal lumen diameter

• motility

• any abnormal structures

• signs of peritoneal effusion

what further tests (after blood and faecal tests and US) can be done to investigate chronic weight loss?

• oral glucose absorption test - for small intestine only

• rectal biopsy

• gastroscopy

• (duodenal biopsy) - can’t be done without ex lap

• exploratory laparotomy / laparoscopy

how do you perform an oral glucose absorption test?

• fast overnight

• get baseline blood glucose level

• give 1g glucose per kg BW as 20% solution by nasogastric tube

• keep horse calm

• measure blood glucose every 30 mins

what does oral glucose absorption test results show?

• more than 85% increase in blood glucose = normal

• 15-85% increase in blood glucose = partial malabsorption

• less than 15% increase in blood glucose = complete malabsorption

• results indicate small intestinal absorption

how is a rectal biopsy performed?

• use mare uterine biopsy instrument

• 20-30cm inside rectum

• small piece of mucosa from floor at around 10 or 2 o’clock

• submit for histology

• give antibiotics and tetanus prophylaxis

what are some malabsorption and protein-losing enteropathy syndromes?

• lymphocytic-plasmacytic enteritis

• eosinophilic enteritis

• granulomatous enteritis

• inflammatory cells in intestinal wall leading to malabsorption and protein loss - diagnosis of exclusion

how do we treat IBD?

• prednisolone

• dexamethasone

• highly digestible diet

• see if responsive to anthelmintics

what are some multisystemic infiltrative bowel diseases?

• multisystemic eosinophilic epitheliotropic disease (MEED)

• systemic granulomatous disease

If IBD is steroid responsive, what are possible diagnoses?

• eosinophilic enteritis

• granulomatous enteritis

• lymphocytic-plasmacytic enteritis

If IBD is non-steroid responsive, what are possible diagnoses?

• eosinophilic enteritis

• granulomatous enteritis

• lymphocytic-plasmacytic enteritis

• alimentary lymphoma

what are differential diagnosis for IBD?

• cyathostomosis

• mixed strongyle infection

• idiopathic

• infiltrative bowel disease

• neoplasia

• lawsonia (foals 3-11 months)

what are the types of equine lymphoma?

• alimentary - generalised or solitary

• cranial mesenteric

• cutaneous

• paraneoplastic syndromes:

  • hypercalcaemia

  • haemolytic anaemia

  • cachexia

what can we commonly see clinically with equine lymphoma?

• fever

• weight loss

• peritonitis

• pleural effusion

• abdominal distension

• intra-abdominal mass palpable per rectum

• hypercalcaemia / haemolysis / cachexia of malignancy

what does this US show?

• islands of abnormal tissue in the spleen

• can’t see distinct borders of spleen

—> possibly lymphoma

what neoplasms do we see in intestines?

• lymphoma

• leiomyoma

• myxosarcoma

• gastric or adenocarcinoma

• melanoma

what bacteria are common causes of chronic intestinal disease?

• Streptococcus equi

• Rhodococcus equi

how to diagnose bacterial chronic infections in intestines?

inflammatory haemogram - neutrophilia, hyperfibrinogenaemia, anaemia

how to treat chronic bacterial intestinal infections?

long term antibiotics

what parasites do we see chronically?

• large strongyle (S. vulgaris) —> verminous arteritis and thromboembolic colic

• small strongyle (cyathostomins) —> submucosal inflammation

• parascaris equorum

what are common haematological changes for parasitism?

• neutrophilia

• hypoalbuminaemia

• hyperglobulinaemia

• NOT eosinophilia

what can equine gastric ulcer syndrome be the cause of?

• poor athletic performance

• recurrent colic / poor behaviour

• weight loss

• bruxism (teeth grinding)

what horses is equine gastric ulcer syndrome common in?

• horses in training (approx 70%)

• highest incidence in thoroughbred race horses

what are the two branches of equine gastric ulcer syndrome (EGUS)?

• equine squamous gastric disease

• equine glandular gastric disease

what part of the horse stomach do we see equine squamous gastric disease?

margo plicatus most common area

also dorsal squamous fundus, greater curvature and lesser curvature

what part of the horse stomach do we see equine glandular gastric disease?

ventral glandular fundus

what causes equine squamous gastric disease?

acid contact with squamous epithelium - pH is usually 5-7

• primary - associated with management factors, rest of GI tract normal

• secondary - due to delayed emptying of stomach after another problem with GI tract e.g. glandular disease

what are risk factors for equine squamous gastric disease?

• performance horses

• diet - high starch, intermittent fasting

• increased stabling

• stress, transport, etc.

what are risk factors for equine glandular gastric disease?

• sports and leisure horses

• exercise more than 4 days a week (but not intensity)

• recently started training

• inflammatory bowel disease

• reduced blood supply to stomach

what medication can be used for gastric ulcers?

omeprazole

• give on empty stomach, give 30-60 min before morning feed

• 4mg/kg for 4 weeks