Transcript Infectious calf diarrhea

Definition:
• Calf scours is not a specific disease with a specific
cause, but is actually a clinical sign of a disease
complex with many possible causes. It mainly develops
during the first 30-50 days of life
• Scours occur when normal movement of water into
and out of the digestive tract is disrupted, resulting in
water loss and dehydration. Loss of body fluids
through diarrhea is accompanied by loss of body salts.
This fluid and electrolyte loss produces a change in
body chemistry that can lead to severe depression in
the calf and eventual death.
Etiology:
Noninfectious Scours
• Calves do best under consistent circumstances.
Sudden changes, especially to the feeding program,
Overfeeding, switching milk replacer brands or
changing from a high to a low quality milk replacer
formulation can adversely affect digestion. Ingredient
differences, taste, nutrient and product density can
affect a calf's willingness to drink as well as its
performance. Changes like these should be
evaluated and made gradually
Infectious Scours
Bacterial Agents
1. Escherichia coli: three group can be identified
Enterotoxigenic E. coli, these strains adeher the mucosal
surface of intestine and secret four toxins (enterotoxins,
sidophores, verotoxins and hemolysin), these strains
contain k99 antigen which play the main role in toxin
production.
b. Enteropathogenic E. coli, these strain colonize in small
intetsine, cause diarrhea and not produce enterotoxins.
c. Enterohemorrhagic E. coli, these strains colonize large
intesine, cuases mild dysentry.
a.
• Clinical signs:
• Septicemia:
– E.coli septicemia occurs in calves in the first few days of life.
– It is characterized by an acute generalized infection,
sometimes with diarrhea at the late stage (mucoid feces), with
signs of shock (listlessness, poor response to external stimuli,
tachycardia, coma), often followed by death (in 3-8 h with
fatality of up to 100%).
– In some animal infection become localized causing
polyarthritis, pneumonia and meningitis.
• Diarrhea:
– watery diarrhea followed by dehydration, metabolic acidosis
and death. Calve produce large amounts of foul smelling
pasty or watery feces varying from pale yellow to white in
colour (white scour)and occasionally containing flecks of
blood. Loss of body weight, dehydration
– In very severe case, calves will collapse, demonstrating
weakness, recumbency and hypothermia, progressing to
death possibly with convulsions if not treated
E. coli are everywhere in
manure-contaminated
mud!
Bad conditions > Calf gets
mouthful of E. coli!
Low density, no mud >
Excellent conditions!
Calving on Winter Feedground
High density, lots of
manure > Very poor
conditions!
2. Salmonella species
• The serotypes (serovars) that most commonly cause
salmonellosis in farm animal species are as follows:
– Cattle: S. typhimurium, S. dublin, Salmonella Newport.
– Sheep and goats: S. abortusovis, S. typhimurium, S.
dublin, Salmonella anatum
Salmonella Excretion Routes
Urine
Oronasal
Secretions
Manure
Milk
Bad Practice!
• Clinical signs:
• Septicemic form:
– It is common in newborn calves and showed high fever
(40-42 °C), depression, dullness and death. Newborn
animals that survive from septicemia develop enteritis,
polyarthritis and pneumonia.
• Acute enteritis
– In calves, disease usually occurs between two and six
weeks after birth,
– Fever follows by diarrhea, which was bloodstained and
may contain fibrin and mucus. Eventually, the faeces
become dark brown and watery with an offensive odour
– The calves become very weak and dehydrated and death
usually occurs after five to seven days of illness in
untreated individuals.
• Chronis enteritis
– This form occurs in adult calves, intermittent fever and
intermittent or persistent diarrhea with spots of blood and
mucous
– The sequel of some case of enteric salmonellosis is the
development of ischemia and dry gangrene of extremities
including ear lips, tail tips and limbs from the fetlock down
• Sheep and goats:
• Clinical signs of salmonellosis in sheep are varied and
include general systemic and enteric manifestation and
abortion (in the last 6 weeks of gestation).
• Ewes infected with S. abortus show abortion as the main
sign with unnoticeable pyrexia.
• S. typhimurium and S. Dublin cause enteric and systemic
signs as fever, anorexia, profuse scour, abortion and death
due to septicemia or dehydration.
3. Clostridium perfringens Types C & D
 cause enterotoxemia, an acute intestinal infection, and kill
through the production of a systemic toxin. Clostridium
perfringens is normally found in the intestine of cattle and can
survive for months in the soil. Overeating or sudden change of
diet tend to produce indigestion, which slows gut movement,
providing the sugars, proteins and lack of oxygen for rapid
growth of Clostridium perfringens. Wet conditions also seem to
favor this organism
 Clinical signs: Affected calves show uneasiness and strain or
kick at their abdomen. Calves are often found dead without
having shown any symptoms
 Occurance:Usually affects calves less than 10 -14 days of age
• Viral agents:
1. Rotavirus
Rotavirus is a new genus within the family Reoviridae. The
presence of colostral antibodies against rota virus in
lumen of intestine give protection but antibodies in serum
does not protect animals against clinical disease
Viruses of this type can cause scours in calves within 24
hours of birth. It can affect calves up to 30 days of age or
older mainly with 4-14 days of age. Infected calves are
severely depressed. There may be a drooling of saliva and
profuse watery diarrhea. The feces will vary in color from
yellow to green. Abdomen is distended at the right lower
quarter with fluid-filled intestine.
Calves lose their appetite and the death rate may be as
high as 50 percent, depending on the secondary bacteria
present
2. Coronavirus:
Scours caused by coronavirus occurs in calves that are
over 5 days of age.
When the infection first starts in a herd, calves up to 6
weeks of age may scour.
These calves are not as depressed as those infected
with rotavirus. Initially, the fecal material may have the
same appearance as that caused by rotavirus.
As the calf continues to scour for several hours, however,
the fecal material may contain clear mucus that
resembles the white of an egg
3. Herpesvirus (infectious bovine rhinotracheitis)
Herpesvirus type 1 may causes alimentary disease with
mucosal lesion
• Protozoal Agents
1. Coccidia and Cryptosporidia
are found in nearly all cattle populations. These
organisms enter the body through contaminated feed and
water and can lay dormant in manure and soil for up to
one year. Once in the intestine, the oocysts (eggs) release
protozoa that multiply, attach to and enter the cells of the
intestinal lining decreasing digestion and absorption of
feed ingredients
Clinical signs: animals suffer reduced feed consumption,
Acute infections result in diarrhea (often with blood),
depression, weight loss, dehydration, but calves will often
continue to eat
Occurrence: Coccidia have a 21-day life cycle, so it is
unlikely that calves will scour before 18-19 days of age
 Cryptosporidia are typically found in calves from 7 - 21
days of age
 Cryptosporidia are often detected in combination with
rotavirus, coronavirus and E. coli.
Parasitic agents
 It is a parasitic disease caused by heavy infestation of
small intestine by Ascaris worms, it affect calves of 2-5
months.
 It characterized by alternative constipation and
diarrhea, pot-belly and colic. Signs of
bronchopneumonia as cough and dyspnea due to
migration of immature worm through liver and lung.
Most Common Infectious Organisms and the Age of Diarrhea
Organism
Age of Diarrhea
E. Coli
First 3 days
Salmonella
Day 5 – 14
Corona Virus
Day 3 – 7
Roatvirus
Day 3 – 7
Eimeria spp. (coccodiosis)
Cryptosporidium parvum
(parasite)
Day 18 – 19 to 6 months
Giardia spp. (protozoa)
Day 14 – 21
Day 7 – 21
Most Common Non–Infectious Organisms
Under–feeding
Over–feeding
Selenium deficiency
Antibiotic treatment
Other oral treatments
Unknown causes
Pathobiology:
• The common feature of newborn calf diarrhea is the
dehydration, which results whether the cause of the
diarrhea is infectious or nutritional. Therefore, rehydration
by oral and/or parental means is the basis of the treatment
of calf diarrhea
• In young calves, death caused by diarrhea is mainly
attributed to fluid losses, electrolyte imbalances, and
increased excretion of water, minerals and nutrients.
• The total fecal volume in diarrheic calves may be about 40
times than normal.
• Dehydration is initially due to plasma losses but later is due
to fluid loss from extravascular compartments. Severe
metabolic changes can occur in calves with diarrhea. If the
disease is progressive, the acidosis becomes more severe,
lactic acidosis develops because of a reduced ability to
utilize lactic acid, and severe hypoglycemia may occur
because of a reduced rate of conversion of lactic acid to
glucose. If extensive fluids are lost, hypovolemia and
shock occur
• Hyperkalemia is most common in dehydrated diarrheic
calves that are severely acidotic. The potassium moves out
of the intracellular space into the extracellular space,
resulting in hyperkalemia. The predominant clinical
finding is bradycardia (heart rate < 90 bpm) in a
dehydrated diarrheic calf. However, hypoglycemia and
hyothermia may be associated with bradycardia in a similar
calf
Prognosis:
 It depends on animal conditions, care received and
virulence of the causative agent. High percentage of
calves will recover with the proper care and treatment.
Diagnosis:
A. field diagnosis:
1. History and epidemiology of the disease
2. Clinical signs
3. Postmortem lesions
B. Laboratory diagnosis:
Samples:
 From live animals; feces, rectal swabs, nasal swabs,
synovial from infected joint, blood and serum.
 From dead animals; parts from liver, gall bladder,
spleen, brain, kidney, lymphnode especially
mesenteric lymphnodes (gall bladder and mesenteric
lymphnodes were proved to the predilection sites for
isolation for salmonellosis).
Laboratory examinations:
Isolation the organism on selective media as McConkey agar for
E. coli, selenit F broth or tetrathionate broth for salmonella or,
Virus isolation on cell culture using fecal filtrate or tissue
suspension.
2. Serological examination: It has diagnostic value to identify
salmonella infected herds, especially carriers.
a) ELISA, it can be used for detection of carrier in case of S.
Dublin in adult cattle.
b) Latex agglutination test; it can be used for identification of
S. enteridis.
c) Indirect hemagglutination test; it use for detection of
salmonella infection in sheep.
d) CFT; it can be used for identification of recent S. dublin
infection.
1.
3. Serological examination, antigen of K99 can be
done by slide agglutination. Also, ELISA, FAT can
be performed on fecal samples.
4. Hematological analysis: leukopenia, neutropenia,
and hyperkalemia.
5. A serological test such as ELISA, is the most
sensitive test for detection of virus (rota and crona
virus) in feces of the infected calve. Besides FAT
and immunodiffusion test.
6. Carrier diagnosis (salmonellosis) : The
recommended procedures for diagnosis of carriers
depends on a combination of fecal culture of all
animals at 7-14 days intervals for 3 examinations
and serological examination such as ELISA.
 Treatment:
1. Fluid therpy:
The fluid therapy is based on isotonic equimolar
mixture of sodium and glucose. the hydration treatment
on the degree of the dehydration
Content
Formula 1
Formula 2
Sodium chloride
20g
25g
Sodium bicarbonate
20g
4.5g
Potassium chloride
6g
3g
Glucose
200g
130g
water
4 liter
4liter
The guide of the estimation of the dehydration degree and the
corresponding base deficit in the diarrheic calves.
Dehydration
degree
1
2
3
Clinical signs
Dehydration
(%)
Calf is standing, skin "tents" for 4
seconds or less, eyes are bright,
oral membranes are moist.
Calf is dull and lying down but
upright, skin "tents" for 5
seconds, eyes are sunken slightly
with a slight gap, limbs are cold,
oral membranes are warm
Calf is lying flat in a coma, skin
stays "tented", eyes are deeply
sunken with a big gap, limbs are
cold, oral membranes are cold
Approximate deficit
base (mEq)*
5
5
7
10
9
15
* Per liter of extra-cellular fluid
volume of hydration therapy is 40 kg x 7%= 2.8 liters of fluid plus allowance for
maintenance requirements (minimum of 100 ml/kg/day).
The maintenance
requirements for a 40 kg calf are 40 kg x 100= 4 liters fluid. Therefore, total
volume of fluid should be given over 3 feedings.
 Bicarbonate should not be added to solutions
containing calcium, such as Lactated Ringer's
Solution, as a precipitate may form. Bicarbonate may
be added to saline solutions.
 Lactated ringer’s solution is the best treatment for
calves with severe dehydration and metabolic acidosis.
Physiological (0.9%) saline with up to 5 gm NaHCO3,
50 gm glucose/liter
 Milk feeding to calves with diarrhea is still debated, but
evidence is accumulating that feeding milk to a calf with
diarrhea is unlikely to negatively affect outcome.
 On the other hand, withholding milk from calves with
coronavirus, cryptosporidiosis or salmonella over the long
period it takes for the diarrhea to resolve may result in the
calf starving to death.
 Digestion and absorption of milk or milk replacer may be
maximized in diarrheic calves by feeding smaller but more
frequent milk meals.
 If bicarbonate-containing oral electrolyte solutions are also
being used, they should be given at least 30 to 60 minutes
after a milk meal to minimize their disruption of milk
digestion
 Gut protectants or adsorbents such as Koalin-Pectin
or Bismuth salts are sometimes used as adjunct
therapy for diarrhea. Kaolin-pectin, while it may
improve the character of the stool, has not been shown
to improve fluid and electrolyte imbalances
 Hypothermia can be a significant problem in
diarrheic calves. Oral and intravenous fluids should be
warmed to target body temperature before
administration. Calves with severe hypothermia may
be most effectively warmed by submersion in a warm
water bath
 probiotics:
 Probiotics supplement the intestinal flora with viable
beneficial bacteria and thus create unfavorable
conditions for the growth of enteropathogens, reduce
the occurrence of scours, and are rather a
complementary therapy for resorting balance to
intestinal flora. The currently available probiotics
contain strains of lactobacillus and streptococcus spp.
The minimum effective dose is 108-109 CFU/calf/day.
 Immunoglobulins:
 Gut acting immunoglobulins is one of the most recent
methods of treatment of diarrhea. Immunoglobulins
prepared in egg yolk (IgY) against enteropathogens
can be used as immunotherapy or prophylactic against
intestinal organisms.
 6. Supportive treatment:
 It includes astringents and adsorbents (antidiarrhea),
parasympatholoytics and spasmolytics to counteract
the hyperperistalsis of the intestine.
Control:
 Reduction of the degree of exposure of newborn calves to
infectious agents:
 Proper housing and management of calves:
 Calves should be born in well bedded clean hygienic calving boxes.
 Overcrowding should be avoided, individual pen for each calf or 8 calves of
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approximately of equal age in one unit.
The ground of the pens should be of suitable slopping to permit good drainage
and they should be disinfected periodically once a week.
Feeding and water utensils should be placed away from fecal contamination
and should be cleaned and disinfected after each use.
Immediately after birth the umbilicus of the calf should be swabbed with 2%
iodine.
Calves affected with diarrhea should be removed from the main calf barn if
possible and treated in isolation and don’t return back to group of calves at risk
(>30 days of age).
Prophylactic medication with antibiotic or sulfonamides for first week of life,
injection of Vit A, blood or serum transfusion can be applied if necessary.
 Proper housing and management of dams
 Dams should be placed in good hygienic house with
calving pens.
 Dams should received good balanced ration.
 Movement of heavy pregnant dam should be avoided.
 Prepartum milking should be avoided.
 The perineum and udder of the dairy cow should be
washed shortly before calving.
 Provision of maximum non specific
resistance:
 Optimal nutrition to the pregnant dam should be give in order to
obtain a vigorous newborn animal and adequate quantities of
colostrums.
 Calves should early receive colostrums (50 ml/kg in the first 2 hours
of life). Natural suckling of colostrums from the udder is better
than bucket feeding (calf is able to stand within 20 minutes after
birth and able to suck after 3 hours of birth). The level of the serum
immunoglobulins can be estimated by zinc sulfate turbidity test at
24 hours of age.
 Calves show low serum immunoglobulin level should receive
purified bovine immunoglobulins as 30-50 g inoculated
intravenously, The alternative way is feeding of fermented
colostrums for up to 3 weeks of age to elevate the lactoglobulin in
the intestinal tract, which reduces the incidence of diarrhea.
 Stress factors should be avoided with adequate housing area and
good ventilation.
 Increasing specific resistance of the newborn by
vaccinating the pregnant dam or the newborn:
 The immunization of neonate farm animals against
colibacillosis by vaccination of the pregnant dam or by
vaccination of the neonate. Vaccination is aid to the
good management, but can not compensate the
inadequate management