Calf diarrhea

Question 1

Calf diarrhea can be classified according to

Answer 1

age.

E.g.
* Neonatal septicemia in first days of life (high mortality)
* 1-4 days old calf diarrhea
* 5-21 days old calf diarrhea
* >21 days old calf diarrhea (high morbidity, low mortality)

Question 2

Main Infectious agents of diarrhea according to stage of life (days from birth). (5)

NB Exam q!

Answer 2

Infectious agents of diarrhea from younger to older animals:

rotavirus
coronavirus
crypto
salmonellosis
eimeriosis

Around 3 weeks old, viral diarrheal agents switch to protozoal.

Question 3

What does this diagram depict?

Answer 3

Hypersecretory diarrhea enterotoxigenic producing e.coli and salmonellosis.

Lots of toxins released in intestinal lumen, you get a hyperosmolar state within lumen which causes fluid to osmotically shift toward higher concentration = hypersecretory diarrhea.

Question 4

What does this diagram depict?

Answer 4

Malabsorptive diarrhea such as in Cryptosporidia, eimeria, viral diarrheas.

Protozoa and viruses damage enterocyte microvilli. Nutrients can’t absorb due to villous damage. Nutrients thus remain in GI lumen, cause diarrhea.

The diarrhea can be bloody due to the GI epithelial damage. The diarrhea can be porridge-like and yellow due to the undigested nutrients it contains.

Question 5

Most important treatment for calf diarrhea?

Answer 5

fluid therapy!

the calves die of dehydration first and foremost. they also suffer from acidosis which is corrected with IVFT.

Question 6

Clinical signs of a calf with diarrhea (other than the obvious diarrhea and dirty backend). (3)

Answer 6

• Depression, weakness, emaciation
• Loss of suckle reflex
• Recumbency, lowering of the body temperature, coma

Question 7

What is colibacillosis?

Answer 7

All infections with e.coli are referred to as such. There are loads of subtypes of e.coli though.

Question 8

Two main types of colibacillosis disease:

Answer 8

• Colisepticemia
  &
• Intestinal colibacillosis

Question 9

Describe Colisepticemia.

Answer 9

Sudden onset, fast death

Is a poor-management disease.

• Occurs during first four days of age (up until 14 days old).
• Weakness, fast HR, dehydration, no fever, loss of suckle reflex; cold extremities, mouth, ears, comatose; diarrhea may
  not occur.
• Primary risk factor is insufficient passive immunity + poor calving-and-keeping hygiene, climatic conditions + insufficient
  navel disinfection.
  – Risk of developing it if IgG <10 g/l
• Survival probability 12%

Question 10

Describe Intestinal colibacillosis.

Answer 10

diarrheal disease in calves: gray, watery, smelly diarrhea; dehydration, weakness, death within few days if not treated.

– Causes diarrhea alone during first 4 days of life.

– In case of co-infection (rotavirus, C. parvum) longer susceptibility period.

– Mild diarrhea to peracute disease
– ETEC – K99 or F5, non-invasive

– Intestinal toxemia with enterotoxins
* causes Hypersecretory diarrhea

Question 11

Diagnosis of Colisepticemia & Intestinal colibacillosis.

Answer 11

Colisepticemia
– Bacteriology – spleen, lung, liver, swabs from exudates, navel, meninges.

Intestinal colibacillosis
– Bacteriology – segments from ileum and
colon (including intestinal content).

Question 12

Three principles of Control against colibacillosis.

Answer 12

1. Lower the infection level in the environment.
   – Clean calving environment.
   – Disinfect the navel immediately after birth.
   – Separate and treat diseased calves immediately.
2. Ensure maximum protection: colostrum feeding and optimal husbandry practices.
   – Dry period feeding
   – Calving supervision
   – Fast colostrum feeding after birth
   – Individual housing, cleanliness of the calf environment, dry, good ventilation.
3. Timely and correct treatment when illness develops.

Question 13

Systemic protection is essential against
E. coli diarrhea, why?

Answer 13

Immunoglobulins need to be present where there is a risk of e.coli bacterial entry - so both in the blood and in the intestinal lumen of a newborn calf (from drinking colostrum).

Question 14

See image, 5-21 days old calf with diarrhea.

What could be the causative agent?

Answer 14

malabsorptive diarrhea

Could be a Mixed infection: rota- and/or coronavirus, cryptosporidiosis + E. coli.

– Due to Lowering of the level of colostral antibodies in the gut lumen to below the protective level.

Question 15

Describe protection against Rota- and coronaviruses. (4)

Answer 15

• Protection against disease depends on the availability of specific colostrum antibodies in the gut lumen.

– Protection is against clinical disease not the infection itself.

– Older calves are resistant due to better developed immunity.

• Normally the excretion of the pathogens
  increases around calving, vaccination of pregnant dams reduces that.

Question 16

Protection against viruses depends on

Answer 16

the presence of specific colostral antibodies in the gut lumen.

Question 17

Diagnosis of viral causes of calf diarrhea.

Answer 17

• Identification of viral antigen in the feces of acutely infected calf.
  – Fluorescence-antibody test – tissue samples
  – ELISA
  – PCR
• Feces collected during the first 24 h after the onset of the disease when it comes to viruses.
  – Virus excretion during the early phase of the disease
  – Coronavirus cytolytic → difficult to isolate in chronically infected animals.
• Investigate for rota, coronavirus, bacteria and cryptosporidia.
• Measure calf immunoglobulin levels from blood.

Question 18

Control of diarrhea-causing viruses.

Answer 18

• Lower the environmental infection dose by:
  – Clean the calving environment between
  calvings.
  – Separate calf immediately from the
  mother.

– Individual pens cleaned and disinfected.
– Feed calves from individual teat-buckets.
– Separate diseased calf immediately from the healthy calves.

– Stocking density
– Feeding the colostrum/fresh cow milk of
vaccinated dams during the risk period

Image: vaccines don’t reduce diarrheal disease morbidity that much but they reduce severe disease which in turns reduces mortality.

Question 19

Describe Vaccination in order to control diarrhea-causing viruses.

Answer 19

• Vaccination of late pregnant animals.
  – Normally there are sufficient amount of antibodies in colostrum of first and second milkings.

– Milk antibody level drops suddenly below the protective level 24-48 h after calving.

– Vaccination increases antibody level and those persist longer in the colostrum.

– Feed calves fresh cow milk up to 2-3 weeks of age.

– Attention to the environment concurrently!

Question 20

Describe Cryptosporidium spp. disease.

Answer 20

• Unicellular protozoal parasites
• Diarrhea from day 3 until the end of 3 weeks of age. Reinfection risk high! Thus, hygiene is super important in order to clear away infectious diarrhea.
• Cryptosporidium parvum is zoonotic!
  – Disease can develop in immunodeficient people.
• Very low Infectious dose, only 10-30 oocysts!
• Colostral immunity is not protective against the disease.
• Monoinfection rarely causes death.
• Low dose induces immunity, high dose causes the disease!!!

Question 21

Diagnosis of cryptosporidium spp.

Answer 21

– Fecal samples

– Crypto is Smaller than Eimeria spp., difficult to find with flotation test.
* thus Staining or immunological tests are helpful.

– Intermittent oocyst excretion
* Multiple sequential fecal samples from single animal are needed.

– Spreading oocysts starts on the day of clinical disease and stops few days after the end of clinical signs.

Question 22

Pathogenesis of cryptosporidium spp. caused disease.

Answer 22

– Incubation period is short due to already sporulated oocysts.

– No clinical disease in adult cattle.

– C. parvum affects distal small intestine and colon.

– Causes Malabsorption syndrome

– Recovered calves will not spread the parasite for a long period.

– Age-related immunity
– Immunity in recovered calves

Question 23

Control of cryptosporidium spp.

Answer 23

Keeping-management to reduce infectious dose.
– Clean calving environment
– Separate calves immediately from the mother and calving pen
– Separation of diseased calves, hygiene
(Employees important transmitters of the disease within farm)

– Clean+wash+disinfect dry surfaces, before introducing new animals
* crypto has Resistance to many disinfectants
– Oocysts are sensitive to high temperatures and drying
– Cresole containing disinfectants

– Frequent cleaning of pens of diseased calves (autoinfection!)
– Good colostrum management
– Keep calves in warm, dry climate
– Attention to rodents and pets in farms

Question 24

Best disinfectant aginst crypto?

Answer 24

Cresol containing disinfectants

(virkon is not that effective against crypto in farm environments)

Cresols are used to dissolve other chemicals, as disinfectants and deodorizers, and to make other chemicals.

Question 25

Treatment against crypto?

Answer 25

Halofuginone lactate
(products Halocur, Halagon, Kryptozan etc.)

• Administration after feeding in 7 first days of life.
• First administration immediately after first colostrum feeding!
• Incidence of diarrhea might reduce/appear later.

Question 26

Eimeriosis is mostly a problem in…?
What does the diarrhea look like?

Answer 26

• Over 3-week old calves
• Usually a problem in calf group pens
• Grey, watery diarrhea (though consistency can differ)

Question 27

Coccidiosis Pathogenic species to cattle: (5)

Answer 27

– Eimeria zuernii
– E. bovis
– E. ellipsoidalis
– E. alabamensis
– E. subspherica

First two are especially pathogenic and require intervention if found in high numbers in many animals.

The above species are:
* Host-specific
* No cross-immunity against species
* Risk factors are overcrowding, dirty, humid environment, fecal contamination of the feed.
– Cold is a stressor!

Question 28

Describe Coccidiosis survival in the environment.

Answer 28

• Oocysts must sporulate in the
  environment.
  – Humid, colder climate (12-32˚C) oxygen-rich environment facilitates sporulation.
• In favorable conditions oocysts will survive up to 2 years in the environment.
  – High temperature, and desiccation limits them.
  – They can Withstand -7… -8˚C up to 2 months.
  – -30˚C destroys oocysts
• May sporulate in humid haircoat contaminated with manure.

Question 29

What do these graphs show you?

Answer 29

Eimeria oocysts do not immediately begin to be excreted in feces when diarrhea is present. There is a slight delay. (left side image)

E. alabamensis diarrhea will stop and then only then you will find oocysts in the feces. (right side image)

Question 30

Answer 30

Clinical eimeriosis

blood due to damaged epithelium of GI tract

Question 31

Diagnosis of coccidia.

Answer 31

• Oocyst count over 5000 in 1 g of feces is counted as important BUT…
• Negative oocyst finding during clinical disease may occur.
  – Oocysts appear in feces 2-4 days after the start of clinical signs.
  – Take fecal samples from several animals in the group, not just single samples from diseased animals.

Question 32

Review control of eimeriosis.

Answer 32

Question 33

Treatment of coccidiosis.

Answer 33

• Toltrazuril 15 mg/kg
  (tol-tra-zuril)
  (Baycox, Cevazuril etc.)

administered once; 10 days after letting calves out to the pasture; no effects on extracellular parasites → enables them to develop immunity

– Treat before start of the clinical signs

Question 34

Eimeriosis vs coccidiosis.

Answer 34

Eimeriosis refers to infections caused by Eimeria species, which are protozoan parasites.

Coccidiosis is a broader term that refers to parasitic infections caused by Eimeria species as well as other coccidian parasites like Isospora and Cryptosporidium.

Question 35

Describe Salmonellosis causative agent in calves.

Answer 35

• Most commonly in calves aged 4-28 days.
• Gram- , facultative intracellular
  – Host-specific: S. Dublin in cattle! (but Finland is S.Dublin free)
  – Common in humans and animals: S. Typhimurium etc.
• S. enterica serovar Typhimurium – enteritis in <2 months old calves
• S. enterica serovar Dublin – older youngstock, adult cattle

Question 36

Describe Salmonellosis clinical disease in calves.

Answer 36

• Fever, lethargy, anorexia, diarrhea (mucus, blood)
  – Hypersecretory diarrhea, damage of the intestinal epithelium
• From peracute septicemia to subacute carrier status
• Abortion, early embryonic death due to acute endotoxemia and shock
• Mortality
• S. Dublin is more invasive – meningoencephalitis, septic arthritis, septic
  physitis (may accompany enteric disease)
• S. Dublin also cause of a respiratory disease in weaning-age calves.

Necrosis of distal limbs!

Question 37

What age group of calves is affected by salmonellosis?

Answer 37

• Most commonly in calves aged 4-28 days.

Question 38

Distal limb necrosis is sometimes described to be characteristic of what calf infection?
Necropsy findings in it?

Answer 38

infection with Salmonella dublin

Necropsy findings:
Can also see fibrin deposits in SI of calves.
Catarrhal hemorrhagic enteritis in calves.

Question 39

What GI tract lesion is considered to be pathognomonic for acute enteric salmonellosis in calves?

Answer 39

ulcerated bile ducts in the gall bladder

Question 40

Diagnosis of salmonellosis in calves.

Answer 40

– S. Dublin spreads intermittently
– Cultures are the best for serotype and antibiogram.

– Fecal cultures
* S. Dublin has a long latent carrier stage.
* Ideally Repeated fecal samples 14 days apart.

– S. Dublin: cultures of the feces, TTA or lung tissue.

– Repeated serology (Ab level remains higher in persistently infected cattle).

– Carcass: samples from the ileum, colon, caecum, mesenterial lymph nodes.

– Cultures from the lung tissues in case of lung pathology.

– May not find any abnormalities in the intestines in peracute cases!

– Necropsy material is the best in acute stage animals.

Question 41

Which calf disease tends to strike before 4 days old?

Answer 41

e.coli (ETEC)

so septecemia and intestinal colibacillosis

Question 42

Which calf disease tends to strike between 4 and 21 days old?

Answer 42

rota and corona viruses

Question 43

Which calf disease tends to strike between 4 and 28 days old?

Answer 43

cryptosporidiosis

Question 44

Which calf disease tends to strike after 7 days old?

Answer 44

salmonellosis

Question 45

Which calf disease tends to strike from 21 days old?

Answer 45

eimeriosis