Calf diarrhea Flashcards
Calf diarrhea can be classified according to
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)
Main Infectious agents of diarrhea according to stage of life (days from birth). (5)
NB Exam q!
Infectious agents of diarrhea from younger to older animals:
rotavirus
coronavirus
crypto
salmonellosis
eimeriosis
Around 3 weeks old, viral diarrheal agents switch to protozoal.
What does this diagram depict?
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.
What does this diagram depict?
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.
Most important treatment for calf diarrhea?
fluid therapy!
the calves die of dehydration first and foremost. they also suffer from acidosis which is corrected with IVFT.
Clinical signs of a calf with diarrhea (other than the obvious diarrhea and dirty backend). (3)
- Depression, weakness, emaciation
- Loss of suckle reflex
- Recumbency, lowering of the body temperature, coma
What is colibacillosis?
All infections with e.coli are referred to as such. There are loads of subtypes of e.coli though.
Two main types of colibacillosis disease:
- Colisepticemia
& - Intestinal colibacillosis
Describe Colisepticemia.
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%
Describe Intestinal colibacillosis.
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
Diagnosis of Colisepticemia & Intestinal colibacillosis.
Colisepticemia
– Bacteriology – spleen, lung, liver, swabs from exudates, navel, meninges.
Intestinal colibacillosis
– Bacteriology – segments from ileum and
colon (including intestinal content).
Three principles of Control against colibacillosis.
- Lower the infection level in the environment.
– Clean calving environment.
– Disinfect the navel immediately after birth.
– Separate and treat diseased calves immediately. - 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. - Timely and correct treatment when illness develops.
Systemic protection is essential against
E. coli diarrhea, why?
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).
See image, 5-21 days old calf with diarrhea.
What could be the causative agent?
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.
Describe protection against Rota- and coronaviruses. (4)
- 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.
Protection against viruses depends on
the presence of specific colostral antibodies in the gut lumen.
Diagnosis of viral causes of calf diarrhea.
- 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.
Control of diarrhea-causing viruses.
- 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.
Describe Vaccination in order to control diarrhea-causing viruses.
- 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!
Describe Cryptosporidium spp. disease.
- 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!!!
Diagnosis of cryptosporidium spp.
– 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.
Pathogenesis of cryptosporidium spp. caused disease.
– 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
Control of cryptosporidium spp.
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
Best disinfectant aginst crypto?
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.
