Diarrhoea in Adult Cattle

Question 1

What are the common Salmonella serotypes?

Answer 1

S. Dublin and S. Typhimurium

Question 2

What are the clinical signs of salmonella?

Answer 2

• Diarrhoea, often pyrexic/systemically ill
• Other features
  
  • Carrier state
  • Abortions
  • Septicaemia/pneumonia/polyarthritis/ear tip necrosis in calves

Question 3

What is the pathogenesis of salmonella?

Answer 3

• Ingestion
  
  • Faecal-oral route
• Survival in rumen and abomasum
• Colonisation and invasion of intestinal epithelium
• Clinical signs often enteritis but may include systemic signs

Question 4

What is the “salmonella cycle?”

Answer 4

Question 5

What mixed infection is common with salmonella?

Answer 5

F. Hepatica

Question 6

What is the most common cattle source of infection?

Answer 6

• Source of infection for herds is usually bought-in cattle
  
  • Or contaminated feed/pasture/water?

Question 7

How can salmonella infections happen in a clsoed herd?

Answer 7

• Shedding of the organism activated by stress
  
  • Calving, weather, transport

Question 8

How can we diagnose salmonella? (3)

Answer 8

• Can be difficult
  
  • Clinical signs/PM not unique
• Enteritis
  
  • Faecal samples
    
    • Sample prior to antibiotics!
    • PM samples of mesenteric Lnn
• Abortion
  
  • Foetus, placenta
• Infected herds: slurry samples?
• Screen for fluke!

Question 9

How can you treat salmonella?

Answer 9

• Antibiotics important?
  
  • Prevent systemic disease
  • Longer carrier state
  • Select for resistant strains
• Culture and sensitivity important!
• Resistant strains!
  
  • S. typhimurium DT104

Question 10

How can we use antibiotic therapy in adults and calves?

Answer 10

• Adult cattle
  
  • Amoxicillin, Sulphadiazine & trimethoprim (TMPS)
    
    • Systemic route (IM, 5 days)
      
      • Oral antibiotics interfere with rumen flora in adults!
• Calves
  
  • Oral antibiotics pre-weaning
    
    • Will kill all of the good bacteria in the rumen in the adult but in calves they do not have the rumen flora so can be given it orally
  • Consider sensitivity testing results?

Question 11

What vaccine is available for salmonella?

Answer 11

• Dead vaccine available
  
  • Bovivac S: S. dublin and S. typhimurium
  • Licensed in the face of an outbreak
    
    • Serological and colostral immunity
    • 2 doses 21 days apart, whole herd
      
      • Calves from 3 weeks of age
    • Boost prior to calving

Question 12

How can you prevent salmonella? (7)

Answer 12

• Salmonella can persist in environment for years
• Closed herd
  
  • Carrier animals (often calves)
• Disinfection protocols
• Prevent concurrent liver fluke infection
• Wildlife biosecurity
• Feed and pasture contamination
• Clean water source (mains)

Question 13

What is winter dysentery?

Answer 13

Winter dysentery is the term usually given to a characteristic syndrome of diarrhoea and mild milk drop (reduction in yield) almost always seen in groups of animals.

Question 14

What is the aetiology of winter dysentry?

Answer 14

The causal agent is thought to be a coronavirus with a tropism for GI and respiratory tracts

Question 15

What are the clinical signs of winer dysentry?

Answer 15

Self-limiting profuse diarrhoea (usually dark in colour, often described as “explosive”!). Usually accompanied by a reduction in milk yield (often of 10-30%, depending on stage of lactation). Occasionally causes colic in severely affected individuals.

Question 16

What is the epidemiology of winter dysentry?

Answer 16

Extremely infectious, usually spreads quickly within a group/herd. Up to 100% morbidity is common, but mortalities are very rare. Short incubation period (3-7 days).

Question 17

How can you diagnose winter dysentry?

Answer 17

Usually made on clinical signs and history; can look for virus in faeces but also sometimes found in normal animals.

Question 18

How can you treat winter dysentry?

Answer 18

Supportive only; disease process is self-limiting.

Question 19

How can you prevent winter dysentry?

Answer 19

None really commonly used; standard biosecurity measures likely to reduce risk of outbreak but very hard to control once established. Usually “burns itself out” over the course of a couple of weeks, but very important to differentiate from other causes (e.g. salmonellosis!).

Question 20

Other than winter dysentry,name 7 other causes of diarrhoea (9)

Answer 20

• Johne’s disease (separate lecture, GIL2)
• Liver fluke (Liver disease lecture, GIL2)
• GI parasites (various sessions, GIL2)
• Coccidiosis (Calf scour lecture, GIL2)
• BVD (acute infection or mucosal disease; separate lecture, GIL2)
• Babesiosis (LCB2)
• Malignant catarrhal fever (NEU2)
• Clostridial disease (separate lecture, GIL2)
• Endotoxaemia (where diarrhoea is really just a clinical sign, e.g. mastitis, metritis, peritonitis; covered in relevant modules)

Question 21

Which of these are group problems? Individual? Individual and group problems?

Answer 21

Question 22

What questions do you ask when there is a diarrhoea outbreak on a farm?

Answer 22

Question 23

How do we approach the clinical exam of a cow with diarrhoea?

Answer 23

• General: pyrexic, dull, anorexic, recumbent
• Assess GI:
  
  • weight loss, abdominal pain, colic, oral cavity: erosions,
  • rectal exam (careful!): assess repro tract, kidney, rumen fill, peritonitis
• Assess CRS: scleral injection, tachycardia (may be associated with pneumonia)
  
  • Scleral injection is referring to blood shot eyes, which may relate to high BP
• Asses MSK: polyarthritis
• Asses NEU: meningitis

Question 24

How do you examine cow diarrhoea?

Answer 24

Colour and odour

• Dark and foul smelling (occult blood)
• Pale and pasty (rumen acidosis)
• Watery (endotoxaemia)
• Air bubbles (Johne’s)
• Mucus, fibrinous casts (Salmonella)
• Fresh blood

Question 25

What is the diagnostic plan of a cow with diarrhoea?

Answer 25

* **History** * **Clinical exam** * Faecal samples? * Bloods? * PM? * Response to supportive treatment?

Question 26

What is the treatment plan for a cow with diarrhoea?

Answer 26

* **Supportive treatment** * Remove from current feed * Transfaunation: rumen fluids from another co * *Direct pump from one cow to another* * *Replacing microflora in sick animal* * Introduce good quality hay * promote rumen contractions, reduce gut transit time * Absorbents such as kaolin? * Fluids (oral, IV) * NSAIDs * Antibiotics?

Question 27

What rumen supplements can we give?

Answer 27

* Proprietary powders e. g. ProRumen™, Vetrumex™ * Add to water and give as drench * Several products * Sold over the counter * Large list of ingredients! * Yeasts, vitamins, lactobacilli, minerals, sugars etc. * No evidence but may help

Question 28

**What is the differential diagnosis for acute diarrhoea in cows? (9)**

Answer 28

* Salmonellosis * Endotoxaemia * Winter dysentery * BVD * MCF * Ruminal acidosis * Simple indigestion * Abomasal ulcer * Poisoning

Question 29

What is the differential diagnosis for chronic diarrhoea in cows? (4)

Answer 29

* Johne’s disease * Fluke * GI parasites * Nutrition

Question 30

You somehow get a job at the Orchard Veterinary Group in Somerset in the heart of cow and cider country. You receive a telephone call at Sunday at 08:00 am from a worried Holstein-Friesian dairy herd manager at Upper Hayes farm. He says that several of their cows are suddenly developing severe projectile diarrhoea- “that really stinks”. He states that some cows have had severe, watery diarrhoea since yesterday afternoon. He feels that the diarrhoea is most severe in the 20 cows in one group that have all just finished calving and are being kept together in a loose straw yard. You visit the farm and confirm the manager’s description of case signalment, attack rate and general symptoms. You have a mild hangover remaining from having too much scrumpy on Saturday night so you forget the practice camera. You therefore take a picture of the worst affected cow with your mobile phone, see picture. You put on gloves and collect samples of the diarrhoea from 3 cows and diagnostic blood samples (EDTA and clotted) from these 3 affected cows. You find an appropriate package to send them in, and the diagnostic APHA form supplied. You send these blood and faeces samples to the APHA lab for testing. **Are these the appropriate samples for tests and procedures for diagnosis and why?**

Answer 30

* Yes, they are the correct samples * Faeces: to culture Salmonella * Blood: to detect exposure or presence of the pathogen (antibodies, antigens) * The samples come back positive for *Salmonella dublin*

Question 31

You somehow get a job at the Orchard Veterinary Group in Somerset in the heart of cow and cider country. You receive a telephone call at Sunday at 08:00 am from a worried Holstein-Friesian dairy herd manager at Upper Hayes farm. He says that several of their cows are suddenly developing severe projectile diarrhoea- “that really stinks”. He states that some cows have had severe, watery diarrhoea since yesterday afternoon. He feels that the diarrhoea is most severe in the 20 cows in one group that have all just finished calving and are being kept together in a loose straw yard. You visit the farm and confirm the manager’s description of case signalment, attack rate and general symptoms. You have a mild hangover remaining from having too much scrumpy on Saturday night so you forget the practice camera. You therefore take a picture of the worst affected cow with your mobile phone, see picture. You put on gloves and collect samples of the diarrhoea from 3 cows and diagnostic blood samples (EDTA and clotted) from these 3 affected cows. You find an appropriate package to send them in, and the diagnostic APHA form supplied. You send these blood and faeces samples to the APHA lab for testing. **What information do you consider to help you understand and manage this disease on farm?**

Answer 31

Salmonella epidemiology * Identify source of infection * Assess risk of further spread * –On farm * –Off farm * Identify predisposing factors * Assess any zoonotic risk

Question 32

You somehow get a job at the Orchard Veterinary Group in Somerset in the heart of cow and cider country. You receive a telephone call at Sunday at 08:00 am from a worried Holstein-Friesian dairy herd manager at Upper Hayes farm. He says that several of their cows are suddenly developing severe projectile diarrhoea- “that really stinks”. He states that some cows have had severe, watery diarrhoea since yesterday afternoon. He feels that the diarrhoea is most severe in the 20 cows in one group that have all just finished calving and are being kept together in a loose straw yard. You visit the farm and confirm the manager’s description of case signalment, attack rate and general symptoms. You have a mild hangover remaining from having too much scrumpy on Saturday night so you forget the practice camera. You therefore take a picture of the worst affected cow with your mobile phone, see picture. You put on gloves and collect samples of the diarrhoea from 3 cows and diagnostic blood samples (EDTA and clotted) from these 3 affected cows. You find an appropriate package to send them in, and the diagnostic APHA form supplied. You send these blood and faeces samples to the APHA lab for testing. **What are the most likely sources of infection? (6)**

Answer 32

* Animals recently purchased * Other animals: Feral cats, wild birds, rodents, foxes * Contaminated feed and water: slurry spreading on pasture * Contaminated buildings * Shared equipment (e.g. vehicles) * Personnel

Question 33

**Salmonella infection does not always lead to clinical disease; what factors play a role? (6)**

Answer 33

Factors influencing Salmonella infection * Serotype: B (typhimurium), C (newport), D (dublin), E (anatum) * Virulence * No of organisms * Prior exposure * Stress * Animal: age , immunity, nutrition Salmonella can survive well in certain environments; about 200 days in pasture and soil, at least 27 days in manure (S. dublin) and 286 days for S. anatum. In dry feces S. dublin can be present for over a year.

Question 34

What can we do to control salmonella?

Answer 34

* Identify source * Avoid introducing potentially infected animals by maintaining a closed herd. Quarantine all introduced stock for at least four weeks. * Source new stock from other farms with high health status and not markets. * Avoid shared bulls and communal grazing areas. * Isolate sick animals in dedicated isolation boxes and not calving boxes. * Clean and disinfect buildings between occupancies. Provide good drainage and waste removal. * Maintain good fences to prevent straying of neighbouring stock. * Ensure that milk from ill cows (or cows that have been in contact with such cows) is not fed to calves. * Protect all feed stores from vermin including birds. * Only spread slurry on arable land wherever possible. Leave all grazing land at least three weeks after spreading slurry. * Insist visitors have clean boots and disinfect before entering and leaving the farm premises. * Treat infected animals * Vaccination