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== Clinical Signs ==

=== Clinical Signs ===

Animals suffer from pyrexia, and occasionally a little bit of [[Diarrhoea|diarrhoea]]. The skin is reddened diffusely and bruise-like dark purplish-red blotched may be seen. The intestines maay show mild catarrhal enteritis, becoming fibrinous lower down. The bowel is generally flaccid, reddened and filled with fluid. Ecchymotic and petechial haemorrhages are often see on the serosa and mucosa. There may also be enlarged, haemorrhagic mesenteric lymph nodes and excessive blood-tinged peritoneal fluid. The lungs are collapsed and frothy and the heart is often dilated with ecchymotic haemorrhages. The [[Liver - Anatomy & Physiology|liver]] and kidneys are also flabby and may have subcapsular haemorrhages and may contain small white foci of necrosis known as '''paratyphoid granulomas'''.

Animals suffer from pyrexia, and occasionally a little bit of [[Diarrhoea|diarrhoea]]. The skin is reddened diffusely and bruise-like dark purplish-red blotched may be seen. The intestines maay show mild catarrhal enteritis, becoming fibrinous lower down. The bowel is generally flaccid, reddened and filled with fluid. Ecchymotic and petechial haemorrhages are often see on the serosa and mucosa. There may also be enlarged, haemorrhagic mesenteric lymph nodes and excessive blood-tinged peritoneal fluid. The lungs are collapsed and frothy and the heart is often dilated with ecchymotic haemorrhages. The [[Liver - Anatomy & Physiology|liver]] and kidneys are also flabby and may have subcapsular haemorrhages and may contain small white foci of necrosis known as '''paratyphoid granulomas'''.

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== Diagnosis ==

=== Diagnosis ===

Enteric Salmonellosis shows differences in clinical presentation between species.

** '''Horse''' - acute fatal colitis.  

Affected animals produce acute [[Diarrhoea|diarrhoea]], which causes many deaths by dehydration. The diarrhoea may appear watery and yellow and may be blood- tinged. In some outbreaks, particularly in pigs, chronic low-grade [[Diarrhoea|diarrhoea]] only is seen. Calves usually die in the acute stage of the disease, but may also recover.

** '''Cows''' - lingering febrile [[Diarrhoea|diarrhoea]] with passage of pseudomembranes.  

** '''Calves''' - acute [[Diarrhoea|diarrhoea]] like colibacillosis.

Pathologically enteritis is seen throughout the gut, but is more severe proximally. Inflammation is catarrhal in the [[Duodenum - Anatomy & Physiology|duodenum]]. By the ileocaecal junction enteritis is often fibrinous, sometimes with formation of diptheric membranes on the mucosal surface. The necrotic and fibrinous changes particularly affect the Peyers patches and the caecal and [[Colon - Anatomy & Physiology|colon]]ic lymphoid nodules. These may lead to "button ulcers" in the terminal [[Ileum - Anatomy & Physiology|ileum]] and [[Colon - Anatomy & Physiology|colon]], but these ulcers rupture very rarely. Focal necrosis may also be seen, particularly in the [[Liver - Anatomy & Physiology|liver]], but also in the [[Spleen - Anatomy & Physiology|spleen]]. Histologically, foci show a central zone of necrosis, surrounded by macrophages and lymphocytes- paratyphoid granulomas. Although this indicates the animal has had a systemic incfection, paratyphoid granulomas may be present without showing signs of septicaemia. Enteric cases of salmonella infection nearly always show some evidence of systemic spread. The septicaemic form may relocalise in the gut, resulting in enteric disease.

** '''Dogs''' - acute bouts of [[Diarrhoea|diarrhoea]].  

** '''Cats''' - febrile enterocolitis.  

** '''Pigs''' - septicemia or enterocolitis.

=====Pathology=====  

=== Diagnosis ===

=====Sequelae=====

== Hepatitis ==

**** Salmonella typically produces a broad spectrum of disease.

**** Classically may produce 'button' ulcers, especially in the terminal small intestine and upper large intestine (Ileocaecocolic junction).  

Treatment is mainly supportive with fluids and electrolytes being most important at preventing death by dehydration. Antimicrobial drugs can be given however, the use of antibiotics for salmonella enteritis without septicemia (bacteremia) is controversial as the population of normal intestinal bacterial microflora may be altered as well as the possible development of antibiotic resistance by salmonella organisms. NSAIDs should also be given in order to control pyrexia and for pain relief.

***** Seen particularly in [[Salmonella|Salmonella cholerae suis]] in the pig.

*''Salmonella dublin''

Increasing resistance in the young calf can be accomplished in two ways. One method is to vaccinate pregnant cows in late gestation with a salmonella bacterin vaccine. The pregnant cow will respond by producing increased antibodies to salmonella that will be passed on to the calf through the colostrum. Salmonella bacterins are also helpful in building immunity when salmonellosis is a problem in adult beef and dairy cows. The second method to increase resistance is to supplement the antibodies by administering an antibody solution containing additional antibodies to salmonella.

 

=====Clinical=====

 

== References ==

*severe, often haemorrhagic, inflammation in the [[Ileum - Anatomy & Physiology|ileum]]

*'''paratyphoid nodules''' - pale foci of necrosis in the [[Liver - Anatomy & Physiology|liver]]

Divers, T.J. and Peek, S.F. (2008) Rebhun's diseases of dairy cattle Elsevier Health Scieneces.

Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition), Merial.

NB: small foci of hepatocytic necrosis are often found as incidental lesions at post mortem examination

Radostits, O.M, Arundel, J.H, and Gay, C.C. (2000) Veterinary Medicine: a textbook of the diseases of cattle, sheep, pigs, goats and horses, Elsevier Health Sciences.