Difference between revisions of "Category:Hepatitis, Bacterial"
Jump to navigation
Jump to search
| Line 32: | Line 32: | ||
====[[Bacillary Necrosis]]==== | ====[[Bacillary Necrosis]]==== | ||
| − | + | [[Infectious Necrotic Hepatitis]] | |
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
====Bacillary Haemoglobinuria (Red Water)==== | ====Bacillary Haemoglobinuria (Red Water)==== | ||
Revision as of 14:04, 7 June 2010
Hepatitis, Bacterial
- bacteria can enter the liver through a variety of routes
- direct implantation
- eg foreign body penetration from reticulum
- direct extension from disease in adjacent tissues of supportive peritonitis
- haematogenously
- via the umbilical vein from an infected umbilicus
- via the portal vein in the alimentary tract
- via the hepatic artery in bacteraemias and septicaemias
- via the bile ducts
- direct implantation
- the liver may show microscopic evidence of involvement in a large variety of systemic infections
- these can be accompanied by jaundice
- the changes in the liver are diffuse with many small areas of necrosis surrounded by neutrophils and lymphocytes
- eg Salmonellosis or Listeriosis
Hepatic Abscessation
Bacillary Necrosis
Bacillary Haemoglobinuria (Red Water)
- Clostridium haemolyticum AKA Clostridium novyi Type D
- cattle and sheep
- highly fatal
- similar pathogenesis to C. novyi
- beta toxin produced
- causes hepatic necrosis and intravascular haemolysis
- C. haemolyticum found in soil, poorly drained/wet pastures
- spores found routinely in liver and GIT and faeces of grazing animals in affected pastures
- need disease in liver casing anaerobic conditions to allow bacterial growth and toxin production
- normally associated with Liver Fluke damage
- disease occurs in some areas and some farms - distribution is poorly understood
Clinical Signs
- found dead/sudden death
- IF seen alive
- depressed, reluctant to move, pyrexia, respiratory distress
- red urine (haemoglobinuria) but not consistent
- pale mucous membranes/jaundice
- bloody froth in nostrils
Gross
- post mortem is confirmatory finding
- rapid decomposition of carcass
- organs decomposed
- subcutaneous hameorrhages, odema, emphysema
- blood stained abdominal and thoracic fluid, large quantity and pericardium
- animal is severely anaemic
- may be jaundiced
- red urine in bladder, therefore haemoglobin in urine
- kidneys speckled with haemoglobin
- blood in lungs/trachea
- ischaemic hepatic infarct
- usually a single large necrotic focus in the liver
- area of necrosis, sometimes partially liquefied centre, irregular outline with a hyperaemic edge
Microscopically
- presence of Clostridia post mortem must be interpreted with great caution as they are common post mortem invaders
- FAT for organism
- identification of toxins
- need this for diagnosis
Treatment
- unlikely
- very high doses of penicillin or oxytetracycline
- blood transfusion
Prevention
- vaccination lasts up to 6 months
- liver fluke control
- remove infected carcasses from pasture
NB: Distinguish Red Water from Black Disease! The former will have bleeding out of any orifice while the latter does not
Tyzzer's disease
- Bacillus piliformis
- affects
- mostly laboratory rodents
- possibly foals 1-4 weeks of age
- young immune-compromised pups and kittens
- initial intestinal lesions can be hard to find at post mortem examination
[image from smythes' ppt] wheat sheaf
Leptospirosis
- Leptospirosis icterohaemorrhagica - a septicaemic disease which affects the liver
- puppies
- Leptospirosis is an important spirochaetal group of diseases causing disease in animals and humans (zoonotic)
- Transmission
- via urine of affected animals
- organisms can remain viable for weeks in damp conditions
- method of action
- cause anaemia via intravascular haemolysis
Clinical
- fever
- dehydration
- haemorrhaging from the mucous membranes of the body
Diagnosis
- dark field microscopy on fresh urine is best
Gross
- widespread hameorrhages
- icterus
- pale foci in the liver (not always a constant finding)
- subcapsular and cortical renal haemorrhages
Microscopically
- foci of necrosis
- dissociation of hepatocytes form each other (similar to post mortem change)
- substantial haemosiderin in the Kuppfer cells (from the haemolysis)
- need to use a silver stain or immunofluorescence to demonstrate the organisms in tissues
Salmonellosis
- Salmonella dublin
- calves
Clinical
- fever
- dehydration
- diarrhoea
Gross
- severe, often haemorrhagic, inflammation in the ileum
- paratyphoid nodules - pale foci of necrosis in the liver
Microscopically
- foci of hepatocytic necrosis
- mixed mononuclear inflammatory cell infiltrate
NB: small foci of hepatocytic necrosis are often found as incidental lesions at post mortem examination
Other bacteria causing liver lesions
Mycobacterium tuberculosis
- in all species
- causes granulomas
Actinobacillus equuli
Nocardia species
- dogs
- cause pyogranulomatous foci
Pages in category "Hepatitis, Bacterial"
The following 8 pages are in this category, out of 8 total.