Pathology of the alimentary tract III

Question 1

What are the congenital abnormalities of the intestine?

Answer 1

• stenosis
• atrisia
• megacolon
• aganglionosis

Question 2

What is stenosis?

Answer 2

• narrowing of the intestinal lumen
• caused by compression by tumous, granulomas, abscesses
• or hyperplasia of intestinal mucosa

Question 3

What is atresia?

Answer 3

• occlusion of the intestinal lumen - caused by an anomalous development of intestinal wall
  
  • A.coli
  • A.ani
  • Segmental atresia - if a segment of the bowel is missing or completed occluded - due to lack of ep development between the 2 continuous parts

Question 4

Causes of atresia?

Answer 4

• malpositioning of foetus
• mechanical lesion to vessel in part of gut
• vascular accidents
• ischaemia

Question 5

What is Megacolon?

Answer 5

• large, faeces filled colon
• congenital - fewer ganglion cells in mesenteric matrix
• acquied - A.ani, damage to innervation

Question 6

What is Aganglionosis>

Answer 6

• congenital lack of ganglion cells in enteric plexus

Question 7

What is Merkels diverticulum persistence?

Answer 7

• remnant of the omphalomesenteric duct
• should disappear in 1st trimester

Question 8

What can block the intestine?

Answer 8

• physical
  
  • foreign bodies
  • enteroliths
  • impaction
  • stenosis
• Functional
  
  • grass sickness
  • paralytic ileus
  • feline dysautonomia

Question 9

How do obstructions cause death?

Answer 9

• toxaemia
• shock
• dehydration
• starvation

Question 10

Gross lesions due to obstructions?

Answer 10

• distended abdomen
• dilation proximal to blockage
• empty after/ collapsed
• perforation
• congested/ infarcted area

Question 11

What are the classifications for displacement of the intestine?

Answer 11

• eventration
• displacement
  
  • strangulation
  • mesenteric volvulus
  • intrussusception
• hernias

Question 12

What is Intussesception and what are the causes?

Answer 12

• telescoping of the intestine
• intussuscepten - trapping segment
• intussusceptum - trapped
• causes - altered motility, peristalsis, foreign body, peritonitis, enteritis

Question 13

What herniations occur?

Answer 13

• internal
  
  • Foramen of Winsloe
  • mesenteric tears
  • retrosplenic ligaments
• External
  
  • scrotal
  • umbilical
  • perineal
  • diaphragmatic

Question 14

What is inflammation of the SI and rectum called?

Answer 14

SI = enteritis

rectum = proctitis

Question 15

What part of the villi do enteritis causing viruses target?

Answer 15

• rotavirus - upper 2/3
• coronavirus - middle and tip
• parvo - botoom - crypts, peyers patches
• BVDV - all + PPs

Question 16

How does rotavirus cause atrophic enteritis?

Answer 16

• faecal-oral infection
• viral replication
• necrosis and sloughing of epithelium
• release of viral particles
• loss of enterocytes
• villous atrophy
• impaired absorption and digestion
• diarrhoea

Question 17

Enteritis (atrophy to necrotising) - what causes it?

Answer 17

• parvovirus
• panleukopaenia (cats)
  
  • causes intestinal segmental lesions
  • crypt necrosis
  • villous atrophy hyperplasia
  • lymphoid necrosis
  • bone marrow necrosis
  • fatal cerebellar necrosis

Question 18

What causes haemorrhagic/ necrotising enteritis?

Answer 18

• C.perfringens
• sudden death in well nourished animals

Question 19

What is lymphoplasmacytic enteritis?

Answer 19

• lymphoplasmacytic fluid in lamina propria
• dog/cat
• villous atrophy, crypt dilation, ep necrosis
• lymphoma

Question 20

WHat is granulomatous enteritis caused by?

Answer 20

• Johne’s disease
• granulomatous inflam - lamina propria
• cerebroid appearance of mucus

Question 21

What is fibrino-necrotising enteritis?

Answer 21

• salmonellosis
• bacterial toxins -> vasculitis -> focal intestinal infarcts -> button ulcers