17. Diagnostic approach of diarrhoea. Principles of treatment Flashcards
4 types of diarrhoea and categorys?
Diarrhoea is defined as an ↑ in faecal fluidity
Categorised by 4 different pathomechanisms
§ Osmotic diarrhoea
§ Secretory diarrhoea
§ Exudative diarrhoea (↑ Permeability)
§ Dysmotility (Altered peristalsis)
They can be categorised clinically too
§ Temporally: Acute / Chronic
§ Aetiologically: Intestinal / Extraintestinal
§ Anatomically: Small bowel / Large bowel; Diffuse
§ Severity: Acute-Self-limiting / Acute-life threatening
Extraintestinal causes?
EXTRAINTESTINAL CAUSES
Diseases of non-GI digestive organs
§ Pancreas → Pancreatitis; EPI
§ Liver; Bile duct → Cholestasis; PSS
Toxic effect & Metabolic derangements
§ Liver failure; Kidney failure (Uraemia)
§ Endotoxemia (Peritonitis; Pyometra)
§ Addison’s disease
§ Toxins: Drugs (NSAID; Abx); Chemicals; Heavy metals;
Plants
Systemic infection: Distemper; Leptospirosis; FIP; FeLV; FIV
Circulatory failure
§ RS-HF
§ Portal hypertension (PSS)
§ IMHA (Immune-mediated haemolytic anaemia)
Disorders affecting peristalsis
§ Abdominal cavity infections (Peritonitis; Pancreatitis)
§ Hyperthyroidism
Metastatic tumours: Hemangiosarcoma
Signalment?
Clinical signs?
Lab D?
LAB. D
Normally used to exclude extraintestinal causes of diarrhoea
CBC; Biochemistry; Urinalysis
Note the serum albumin level: If it is <20mg/L, it could indicate
protein-losing enteropathy
§ If PLE ✓ → Exclude renal & hepatic causes
§ If PLE ✗ → Exclude EPI (TLI test)
Dogs
§ cPL (canine pancreatic lipase)
§ TLI (trypsin-like immunoreactivity) (to test for EPI)
§ ACTH-test
Cats
§ fPL (feline pancreatic lipase)
§ T4 test (thyroxine level – Test for hyperthyroidism)
§ FeLV
§ FIV
Depending on the severity, therapeutic interventions may be required
which are dependent on lab. D exams:
§ Acid-base § PCV
§ Ionogram § TP
§ Blood glucose § CRP (dogs)
§ Cobalamin § Folate
Causes of cobalamin ↓: EPI; Distal SID; Dysbiosis; SIBO
Causes of Folate ↓: Proximal SID
Causes of Folate ↑: Dysbiosis
Faecal analysis?
FAECAL ANALYSIS
Direct smear & cytology
§ Fresh sample: Protozoa; Parasite eggs
§ Special staining: RBC; WBC; Bacterial
§ Exfoliative cytology of rectum: Neoplasia; Histoplasma
Faecal floatation: Parasites
Bacterial culture
§ Campylobacter spp.; Salmonella spp.; Clostridium spp.
§ Only diagnostic if accompanied with CSx (asymptomatic
carriers)
Faecal antigen testing
§ Viruses: Parvo (ELISA); Corona (PCR)
§ Bacteria: Campylobacter spp.; C. perfringens; C. difficile
(PCR); Clostridium spp. enterotoxins (ELISA)
§ Protozoa: Giardia spp. (ELISA); Tritrichomonas spp.
(PCR)
Inflammatory markers (severity & monitoring)
§ Calprotectin
§ Faecal S100A12
§ Lactoferrin
Diagnostic imaging?
