Lecture 8 Flashcards
What is a volvulus
Twisting on its mesenteric axis Up to 720 rotation
What is torsion
Rotation along length of long axis
What doe volvulus and torsion cause
Vascular obstruction, ischaemic injury, infarction Mesenteric oedema, congestion, haemorrhage, necrosis
What can intestinal disorders cause in horses
Colic, intestinal rupture and death
What are the intestinal disorders in horses
Intestinal volvulus/torsion of horses Pedunculated lipomas of horses Renospenic entrapment in horses
Where does intestinal volvulus/torsion of horses commonly occur
Left dorsal and left ventral colon ar diaphragmatic and sternal flexure
Where does predunculated lipomas of horses commonly occur
Wrap around intestinal mesentery or intestine and causes intestinal ischaemia and strangulation
Where does renosplenic entrapment of horses commonly occur
Left dorsal displacement of left dorsal or ventral colon between spleen and left body wall
What are some intestinal disorders
Large intestinal and caecal rupture Intestinal diverticula Muscular hypertrophy of ileum
What causes large intestinal and caecal rupture
Post-parturient mares Causes include: impaction, anaesthesia, rectal palpation
What causes intestinal diverticula
Mucosal epithelial lined cavities - May extend through all layers to serosa - May rupture -> peritonitis
What is muscular hypertrophy of ileum
Tunica muscular hypertrophy - Incidental or can cause impaction and rupture
What is an example of an intestinal intoxicant
- Ingested irritants - Corticosteroids - NSAIDS
What can ingested irritants cause
Lesions in mouth, oesophagus, stomach and intestine - Haemorrhage and inflammation - Ulceration and sloughing of mucosal lining
Why do corticosteroids cause ulceration and perforation of GIT
- Reduced cell turnover and dealt healing - Decreased mucous production - Increased gastrin and hence acid production, reduced PGs
What causes NSAIDS to caused erosion, ulcers haemorrhage and necrosis
Detect contact (orally) and reduced protective PG synthesis
Parasite causing vascular disorder in intestines of horse
Strongylus vulgaris
Explain the migration of strongyles vulgaris
- 3rd stage larvae are ingested and moult to 4th stage larvae in intestines - Migrate through small arterioles to the wall of cranial mesenteric artery
What do strongyles vulgaris cause
Sever arteritis and aneurysms -> thrombosis and thromboembolism -> intestinal infarction
What is lymphangiectasia
dilation of lymph vessels
What is lacteal dilation
Results in diminished lymph adsorption by lacteals in the lamina propriety
How do animals get congenital lacteal dilation
Developmental disorder of lymphatics
How do animals get acquired lacteal dilation
Idiopathic secondary to lymphatic obstruction
What are the diseases of intestinal epithelium: absorptive enterocytes
Virus - rotavirus, coronavirus Bacteria - brachyspira hyodysentariae Parasites - coccidia
What do diseases of the absorptive enterocytes cause
Loss of enterocytes -> villous atrophy Maldigestion and malabsorption (osmotic diarrhoea)
What are the diseases of intestinal epithelium: undifferentiated crypt cells
Viruses - parvovirus Radiation
What does diseases of undifferentiated crypt cells cause
Loss of the cells capable of rapid mitosis -> impaired regeneration of epithelium
What are disease of microvilli and glycoalyx largely responsible for
Large surface area and enzymes of digestion and absorption
microvilli and glycoalyx: what does maldigestion and malabsorption cause
Osmotic diarrhoea
What are the diseases of the lamina propria
Inflammation Necrotising processes Vascular changes and lymphagiectasia
What does inflammation causes to the lamina propriety
Dense cellular infiltrations can cause diarrhoea - Johne’s disease (cattle) - Canine histolytic ulcerative colitis (boxer dogs) - Inflammatory bowel disease
Disease of lamina propria: where is necrotising processoccuring
Necrosis of GALT and overlying epithelium - BVD - Rhodococcus equi
What are vascular changes and lymphangiectasia secondary to
Obstruction
What is inflammation the the small intestines called
Enteritis
What is inflammation the large intestines called
Colitis
What is inflammation the the caecum called
Typhlitis
Torsion of large colon
Pedunculated lipoma
Pedunculated lipomas and intestinal strangulation
Diverticula: horse caecum
Acute necrohemorrhagic enteritis
Tiger striping: dog colon
Verminous arteritis: cranial mesenteric artery
Infarction
Ascites and emaciation caused by lymphangiectasia
Lymphangiectasia of jejunum: dog
Lymphangiectasia of jejunum
