Neonatal Diarrhea Flashcards
1
Q
What agents produce diarrhea in neonatal ruminants?
A
- E.coli (ETEC)
- Rotavirus Serogroup A
- Coronavirus Serotype 2
- Cryptosporidium parum
- Salmonella spp (serogroups B, C, D)
- Clostridium perfringens A
- Clostridium perfringens C
- Eimeria spp
2
Q
What is the MOA of E.coli in producing neonatal diarrhea?
A
- STa hypersecretion crypts
3
Q
How is E.coi diagnosed?
A
- Age: 0-3 days
- Test: K99 PCR of Feces
4
Q
What is the MOA of Rotavirus Serogroup A in causing neonatal diarrhea?
A
- Malabsorption (SI, vilous blunting)
- Hypersecretion crypts by NSP4
5
Q
How is Rotavirus Serogroup A diagnosed?
A
- Age: 5-14 days
- Test: RT-PCR on Feces
6
Q
What is the MOC of Coronavirus Serotype 2 in producing neonatal diarrhea?
A
- Malabsorption
- Muco-hemorrhagic enterocolitis (SI & LI)
7
Q
How is Coronavirus Serotype 2 diagnosed?
A
- Age: 5-30 days (up to 5mo)
- Test: RT-PCR on Feces
8
Q
What is the MOA of Cryptosporidium parum in producing neonatal diarrhea?
A
- Malabsorption (SI and LI) by villous atrophy
- PG med hypersecretion in crypts
9
Q
How is Cryptosporidium parum diagnosed?
A
- Age: 7-30 days
- Test: RT-PCR on feces
10
Q
What is the MOA of Salmonella spp (serogroups B,C,D) in producing neonatal diarrhea?
A
- Enteritis (Fibrinonecrotic ulcerative)
- Endotoxemia
- Pneumonia (S. dublin)
11
Q
How is Salmonella spp diagnosed
A
- Age: any
- Test: Culture, PCR
12
Q
What is the MOA of Clostridium perfringens A in causing neonatal diarrhea?
A
- Abomasitis
- Abomasal ulceration
13
Q
How is Clostridium perfringens A diagnosed?
A
- Age: 2-4 mo
- Tests: Necropsy, PCR (alpha beta toxin)
14
Q
What is the MOA of Clostridium perfringens C in causing neonatal diarrhea
A
- Enteritis (hemorrhagic necrotic)
- Enterotoxemia
15
Q
How is Clostridium perfringens C diagnosed?
A
- Age: < 10days
- Test: Necropsy, PCR
16
Q
What is the MOA of Eimeria spp in causing neonatal diarrhea?
A
- Enteritis (SI & LI)
- 95% infections subclinical
- May become chronic
17
Q
What other issues can Coronavirus Serotype 2 cause?
A
- Respiratory disease in older calves
- Lactose intolerance
18
Q
What other issues can Cryptosporidium parum cause?
A
- Zoonotic
- Autoinfection
19
Q
What other issues can Salmonella spp cause?
A
- Systemic disease
20
Q
What other issues can Clostridium perfringens A cause
A
- Colic
- Abdominal distention
21
Q
What other issues can Clostridium perfringens C cause?
A
- Colic
- Tetany
- Opisthotonos
22
Q
How is Eimeria app diagnosed?
A
- Age: >8days
- Test: Fecal float (>5000 oocysts/g)
23
Q
What is the source of Rotavirus Serogroup A?
A
Adult cows
24
Q
What is the source of Salmonella spp serogroups B,C,D
A
coostrum/milk
25
What are the sources of *Eimeria spp*
* Calves (3wks -6mo)
* weaning = stress
26
What is the pathophysiology of neonatal diarrhea?
* Hyper-secretion (crypt) - Bacteria
* Cl, Na, HCO3, K, H2O
* Malabsorption - Viruses
* Destruction of absorptive villous epithelial cells (decreased Na and water absorption)
* Hyperplasia of crypt cells \> secretion
* Increased osmolarity and milk fermentation leading to bacterial overgrowth
* Villi atrophy
* Inflammation Salmonella, Clostridium, coccidia
* Enteritis
* Translocation of bacteria and endotoxins
27
Why does metabolic acidosis occur in neonates with diarrhea?
* Original theories:
* Loss of bicarbonate via the intestines
* Formation of L-lactate secondary to dehydration
* Current:
* D-lactate accumulation
* primarily of GI origin - Rumen acidosis, Neonatal diarrhea
* Age dependent
* young calves with ETEC less academic than older calves with crypto or viral diarrhea
28
Why does neonatal diarrhea present with paradoxical hyperkalemia?
* Extracellular potassium concentration ~2% of total body potassium
* Affected calves have negative potassium balance due to intestinal losses and decreased milk consumption
* Depends on degree of dehydration and the cause of the metabolic acidosis, does _not_ require the presence of acidemia
29
Why does neonatal diarrhea present with Hyponatremia?
* Loss of isotonic fluid through the GI tract is replaced by free water
* Calves with compromised sodium absorption capacity due to severe pathologic changes or an inadequate level of agents that facilitate sodium cotransport
* Hyponatremia results in a fluid shift from the extracellular space to the intracellular compartment and may result in neurologic disturbances, depression, disorientation, and convulsions
30
What are the causes of Hypoglycemia in neonatal calves with diarrhea
* Withdrawal from milk
* septicemia
31
What are the clinical effects of diarrhea?
* Significant fluid & electrolyte losses
* Cardiovascular collapse
* Acidosis:
* fecal loss of bicarbonate
* Endogenous synthesis of L-lactate
* GI bacterial fermentation and synthesis of D-lactate
* Variable amounts of depression
32
What are the risk factors for Neonatal Calf Diarrhea (NCD)
* Dystocia
* calves born from dystocia 2-4x more likely to get sick in first 45days of life
* Dam parity
* risk of diarrhea 3.9x ⇡ in calves born to heifers (1st parity)
* Colostrum management
* Failure transfer of passive immunity
* Anti *E. coli* K99 antibodies in colostrum are low
* Beef cow Management:
* High stocking density in calving pasture
* High pathogen load in environment
* Intensive calf-rearing systems
* 1x daily milk feeding
* Damp bedding
* Feeding mastitic milk
33
How are NCD calves treated?
* Correct dehydration
* Correct metabolic acidosis
* Correct electrolyte abnormalities
* Provide adequate nutrition
34
What is the most common cause of death in diarrheic calves?
Dehydration & metabolic acidosis
35
How should fluids be administered in NCD cases?
* Determined by:
* Mentation-
* alert = oral
* Depressed = IV
* Suckle reflex-
* Strong = oral
* Weak/absent = IV
36
What fluids may be used in NCD cases?
* Sodium bicarbonate
* Polyionic crystalloid
* Dextrose (5%)
37
How is metabolic acidosis corrected?
* mEq HCO3 needed = weight (kg) x base deficit (mEq/L) x 0.6
* more consistent recovery if an alkalinizing agent is used
38
How are electrolyte disturbances In NCD cases corrected?
* Oral electrolyte solutions (OES)
* only 60% absorbed in GI tract
* Must satisfy 4 requirements:
* Supply sufficient sodium to normalize extracellular fluid volume (ECF)
* Provide agents that facilitate absorption of sodium and water from intestine (glucose, glycine, acetate, propionate, citrate
* Provide an alkalinizing agent (acetate, propionate, bicarbonate)
* \>50 mmol/L and high SID ([Na+] + [K+]) - ([Cl-]) at least 60-80
* Provide energy
39
What are the results of neonatal calf diarrhea (NCD)?
* Dehydration
* Metabolic acidosis
* Negative energy balance
* Overgrowth of gram negative bacteria (*E. coli)*
40
Why would calves die from NCD?
* Acidemia
* Septicemia
* Hyperkalemia
* Hypoglycemia
* Hypothermia
41
What are the advantages of OES?
* Administration is easy
* Catheterization (IV) not required
* Correction of dehdration, and acidosis
* Provision of nutrition support
42
What are the requirements of an ideal OES
* Adequate sodium concentration to replace deficit (90-130 mM/L
* Contain agents to facilitate intestinal absorption of sodium and water (glycine, acetate, glucose)
* Provide an alkalinizing agent (acetate, propionate, bicarbonate)
* Provide sufficient energy
* Facilitate healthy gastrointestinal microbiome
43
What IV fluids are used for NCD?
* Lactated Ringers (LRS)
* Readily available
* Corrects dehydration and electrolyte abnormalities
* Weak alkalinizing ability. Requires hepatic metabolization which takes a long time
* LRS considered _poor alkalinizing_ agent for NDC
* Isotonic sodium bicarbonate
* No commercially available form, must be made (13g/L of baking soda or 155mEq/L bicarbonate)
* _Strong alkalinizing agent_, does not require hepatic metabolization
* Requires IV catheterization, restraint and monitoring
* Hypertonic saline
* Commercially available
* Shifts fluid from GI tract into extracellular fluid space
* **Combined with OES results in rapid plasma volume expansion (corrects dehydration)**
* Increases:
* Cardiac output
* Mean arterial pressure
* Glomerular filtration
* IV catheter not required can be given off the needle
* 4ml/kg given as rapid IV infusion
* **Does not correct academia**
* requires oral electrolyte with alkalinizing agent
* Hypertonic sodium bicarbonate
* Newer, not as cheap as hypertonic saline
* Increases plasma volume and corrects acidosis
* 5-10 ml/kg as an IV fluid bolus (over 5 min)
* Should follow up with OES
44
What factors are considered when selecting a fluid type for a neonate with diarrhea
* Suckle strength
* Standing/recumbent
* Hydration status
45
How is hydration status assessed in calves
Eyeball recession
1.6 x eyeball recession in mm = % dehydration
46
When is just OES (oral electrolytes) used in neonates with diarrhea? (standing, suckle, dehydration)
* Standing, Suckle Present, Minimal dehydration (\<6%, eyeball recession ≤3mm)
* OR
* Standing, Suckle Absent, Minimal dehydration (\<6%, eyeball recession ≤3mm)
47
When is IV hypertonic saline and OES used for neonates with diarrhea (Standing, suckle, dehydration)
* Standing, Suckle Absent, Dehydration ≥6%, eyeball recession \>3mm
48
When is IV Sodium Bicarbonate used in neonates with diarrhea
* Calf _Recumbent_, Suckle Absent
* Volume of fluids will be determined by hydration status, depression score, or laboratory data
49
How is the Base deficit estimated in a neonate with diarrhea?
50
How are losses restored and maintenance fluids calculated for IV fluids in a neonate with diarrhea?
51
How is 1.3% Sodium bicarbonate made for IV?
* 8.4% NaHCO3 solution (available commercially)
* Add 156ml to 1L sterile water
* Volume 1st solution (V1) x concentration 1st solution [C1] = V2x[C2]
* (X)[8.4%] = (1000ml)[1.3%] ⇒ X = 156 ml
* Laboratory Grade (USP) NaHCO3 powder
* 156mEq/L = 13g powder/L
* To 1L sterile water add 13g powder
* To 1 gallon add 52g powder
52
What common fluid therapy mistakes are made when treating NCD?
* Diarrhea not ID early enough
* Volume/duration of fluid therapy to low/short
* Administering oral fluids when calf needs IV fluids
53
How is nutritional support given to calves with NCD?
* Milk/replacer should _not_ be suspended 100%
* smaller volumes (5-7% BW) at higher frequency (every 4-6hrs)
* Provides energy
* Intestinal healing
* 2.5 - 5% dextrose solution within IV fluid therapy
54
When should antibiotics be used for NCD?
* There are increased coliform #s in the SI regardless of the diarrhea etiology
* Leads to Bacteremia (~80% g(-) (*E.coli)*
* Frequency of bacteremia is sufficiently high that treatment of severely ill calves should include antibiotics
55
What antibiotics are ineffective at treating NCD?
* Oral Antibiotic (penicillin, neomycin, ampicillin, tetracycline)
* Increase Diarrhea
56
What Antibiotics are effective for NCD?
* Oral amoxicillin trihydrate 10mg/kg PO q12hr
* Reduced mortality and duration of diarrhea
* Parenteral antibiotics (ampicillin, ceftiofur)
