Manifestations And Management of Disease In Neonatal Ruminants p302-338

Question 1

Septicemia is the third most common cause of calf mortality in the US. Behind what 2 other causes?

Answer 1

Diarrhea and respiratory

Question 2

The phagocytic and bacterial killing function of neutrophils (PMNs) is decreased in calves, compared to adults. List some reasons why.

Answer 2

Cortisol levels are increased for the first 10 days of life, depressing neutrophil function
Lymphokines produced by CD4+ cells, IL-2, IL-4 and IFN-gamma are essential to Ag-specific immunity. Cortisol levels also depress lymphocyte proliferation and IL-2 activity

Question 3

This is the most common organism isolated from a calf blood culture.

A) Salmonella
B) Camplobacter
C) Klebsiella
D) E. coli

Answer 3

D) E. coli

Question 4

In regards to neonatal calf sepsis, the interaction between LPS and the immune system triggers and inflammatory cascade. Discuss some results of that cascade.

Answer 4

Production of arachidonic acid metabolites, release of myocardial depressant factors, activation of the complement system

Question 5

What are the most useful parameters for predicting septicemia in calves?

Answer 5

Presence of toxic neutrophils, FPT, focal infection or elevated serum creatinine concentration

Question 6

The CSF is poorly defended against pathogens. Why is this?

Answer 6

Complement is not present in the CSF; there are a minimal amount of specific Abs, which leads to inadequate opsonization of meningeal pathogens

Question 7

Urinary reagent strips can be used to evaluate CSF, stall side. What should glucose levels be in the CSF?

Answer 7

Glucose levels should be trace or positive. If they are negative, this could suggest severe meningitis, or profound hypoglycemia.

Question 8

Calves with acidosis can have two different forms of lactate contributing to their metabolic derangement. What are these forms and where are the coming from?

Answer 8

D-lactate can come from bacterial fermentation of carbohydrates in the GI tract
L-lactate is endogenously produced, generally due to dehydration

Question 9

How can hyponatremia lead to neurologic signs?

Answer 9

Hyponatermia leads to a fluid shift from the ECF to ICF, leading to cell swelling and eventually lysis.

Question 10

How does the IV fluid treatment of hyponatremia differ between hypovolemic calves and normovolemic calves?

Answer 10

Hypovolemic calves need fluid resuscitation first with isotonic saline, to not exacerbate cerebral edema. Normovolemic calves can be treated with hypertonic saline.

Question 11

List 3 ways hypernatremia in calves can occur.

Answer 11

1. Excessive loss of free water, due to dehydration, heat, sweating, water deprivation
2. Iatrogenic administration of IV crystalloids without proper water consumption
3. Excessive intake of sodium without proper water consumption

Question 12

Ruminal bloat is uncommon in calves less than 5 weeks of age. How can bronchopneumonia cause ruminal bloat?

Answer 12

Severe bronchopneumonia can cause swollen mediastinal lymph nodes, compressing the esophagus or compressing/inflammation of the vagus nerve.

Question 13

There are 4 types of gastric ulcers in calves. Describe these types.

Answer 13

Type 1: Nonperforating ulcer - intraluminal hemorrhage is minimal, abomasal wall is not perforated

Type 2: Nonperforating with severe blood loss - a major blood vessel in the submucosa has been eroded

Type 3: Perforating ulcer with local peritonitis - peritonitis localized by fibrin deposition and and the abomasum becomes adhered to the peritoneum, the omentum or surrounding viscera

Type 4: Perforating ulcers with diffuse peritonitis - ulcer perforates and quickly spread throughout the rest of the peritoneal cavity

Question 14

What are some treatments that can be used in calves for abomasal ulcers? Describe their MOA as well.

Answer 14

Antacids - Al(OH)3 or Mg(OH)2 bind bile acids protecting ulcerated areas from bile reflux
Al(OH)3 directly binds pepsin, thus decreasing proteolytic action of pepsin in the stomach

Histamine type 2 receptor antagonists - reduction of acid secretion of parietal cells by selective and competitive antagonism of histamine at H2 receptors on the parietal cells
Cimetidine and ranitidine

Question 15

What are some proposed causes of abomasal bloat in calves?

Answer 15

Addition of course roughage, abomasal bezoars, copper deficiency, various microorganisms i.e. C. perf type A has been isolated

Question 16

What are some causes of delayed abomasal emptying in calves?

Answer 16

High osmolality milk replacers, feeding a large volume in a single daily feeding, poor mixing of milk replacers, offering cold milk, not offering water, erratic feeding schedules

Question 17

What is the treatment for abomasal bloat in calves?

Answer 17

Calf in dorsal recumbency, and trocarization.

Question 18

What is the most common location of intestinal atresia in calves?

Answer 18

Spiral loop of the ascending colon

Question 19

What are some proposed causes of colonic atresia in calves?

Answer 19

Palpation of the amniotic sac before 40 days of gestation, autosomal recessive inheritance in Holstein cattle

Question 20

Where is the most common location of intussusception in calves?

A) Duodenum
B) Jejunum
C) Ileum
D) Ileocecal junction

Answer 20

B) Jejunum

Question 21

Match the pathogenesis of diarrhea in calves with its corresponding pathogens.

Coronavirus, E. coli, Enteric viruses, Protozoa, R. equi, Rotavirus, Salmonella

A) Stimulation of the enteric nervous system
B) Compensatory hyperplasia of the crypt cells
C) Increased intestinal secretions due to stimulation of cyclic AMP or cyclic GMP, calm oculi or protein kinase activity
D) Destruction of absorptive villous epithelial cells

Answer 21

A) R. equi
B) Rotavirus, Coronavirus
C) Salmonella, E. coli
D) Protozoa, Enteric viruses

Question 22

Based on the MOA, and age of animal affected, what cause of calf diarrhea is described?

• Observed in calves less than 3 d old
• If concurrent infection with rotavirus, observed in calves 7-14 d old
• Two virulence factors: fimbriae and enterotoxins (LT and STa, STb)

A) ETEC
B) AEEC
C) STEC
D) EPEC

Answer 22

A) Enterotoxigenic E. coli

Question 23

Based on the MOA, and age of animal affected, what cause of calf diarrhea is described?

• Observed in 2 d-4 wk old calves
• Cytotoxic damage to the intestinal mucosa by a Vero or HeLa toxin that induces a mucohemorrhagic colitis, with petechial or ecchymotic hemorrhages

A) ETEC
B) AEEC
C) STEC
D) EPEC

Answer 23

B) Attaching and effacing E. coli

Question 24

Based on the following, what cause of calf diarrhea is described?

• Induction of severe inflammation of the bowel mucosa leading to dysentery and passage of mucous and fibrin casts
• Infects salivary glands and is shed in saliva and nasal secretions
• Immunity changes rapidly during the first 3 months of life

A) E. coli
B) Salmonella
C) Clostridium
D) Camplyobacter

Answer 24

B) Salmonella, with typhimurium causing the most clinical disease

Question 25

Based on the following, what cause of calf diarrhea is described?

• Not a common pathogen causing neonatal calf diarrhea
• Clinical disease due to management issues allowing proliferation of bacterial within the GI tract
• Type A is associated with acute hemorrhagic abomasitis
• Type B not commonly associated with neonatal diarrhea in calves

A) C. difficile
B) C. perf
C) Rotavirus
D) Salmonella

Answer 25

B) C. perf

Clostridium is a natural habitant of the calf GI tract
C. difficile has recently emerged as a pathogen in human and veterinary medicine, but the role as a primary pathogen has not been established

Question 26

Based on the following, what cause of calf diarrhea is described?

• Observed in calves 5 d - 2 weeks of age
• Most common cause of neonatal diarrhea in calves
• Targets villous enterocytes, leading to shedding of infected cells, and replacement with immature squamous and cuboidal cells from the crypts, thus villous blunting
• Serogroup A most common in calves, serotype B is most common in lambs
• Stable in fresh water; stable in feces for up to 9 months

A) BVDV
B) Coronavirus
C) Rotavirus
D) Torovirus

Answer 26

C) Rotovirus

Question 27

Based on the following, what cause of calf diarrhea is described?

• Observed in calves 5 days-1 month of age
• Results in muco-hemorrhagic enterocolitis
• Affects small and large intestine
• Destruction of colonic ridges in spiral colon
• Replication occurs in surface epithelium, along distal half of the villi = stunting and fusion of the villi and decreased absorption abilities
• Often self-limiting use to crypt cells not being affected

A) BVDV
B) Coronavirus
C) Rotavirus
D) Torovirus

Answer 27

B) Coronavirus

Question 28

Based on the following, what cause of calf diarrhea is described?

• Causes diarrhea and thrombocytopenia
• Calves also have oral ulcerations on the hard and soft palate

A) BVDV
B) Coronavirus
C) Rotavirus
D) Torovirus

Answer 28

A) BVDV

Ulcerations must be distinguished from papular stomatitis; BVDV ulcers do not have zones of epithelial proliferation as seen in papular stomatitis

Question 29

Based on the following, what cause of calf diarrhea is described?

• Type 1 and Type 2 (zoonotic)
• Infected 1-4 weeks of age, with clinical signs 4-14 days
• Invasion of the superficial mucosa, but stays extraplasmocytic due to invagination of the host cell membrane
• Epithelial destruction and mild-moderate villous atrophy with microvillous shortening and destruction
• Increased mucosal prostaglandin secretion, leading to crypt secretion of chloride and bicarbonate

A) Salmonella
B) Clostridium
C) Giardiasis
D) Cryptosporidium

Answer 29

D) Cryptosporidium

Fecal-oral transmission of encysted sporulated oocyst

Question 30

What does bradycardia indicate in a diarrheic calf?

Answer 30

Hypothermia, hyperkalemia, hypoglycemia

Question 31

How can an isotonic solution of sodium bicarbonate be made?

Answer 31

13 grams of baking soda mixed with 1 L of water, provides 156 mmol/L of bicarb

Question 32

What is normal venous pH, bicarb and a base excess for calves?

Answer 32

pH 7.34
Bicarb 30 mmol/L
Base excess 5 mmol/L

Question 33

If a calf is acidotic and dehydrated, the base deficit can be corrected by administering what type of sodium bicarb?

Answer 33

Hypertonic 8.4% sodium bicarb at 10 ml/kg over 8 minutes

Must give isotonic fluids, orally, simultaneously

Question 34

What’s the best form of oral alkalinizing agent and why?

A) Acetate
B) Bicarb
C) Lactate
D) Citrate

Answer 34

A) Acetate - excellent alkalinizing ability, does not interfere with milk clotting in the abomasum

Bicarb binds to hydrogen ions directly, but reduces milk digestive lite and interferes with normal clotting of milk
Citrate binds calcium and interferes with normal clotting of milk in the abomasum

Question 35

What can be given to dams, prior to calving, to protect calves against ETEC?

Answer 35

6 and 3 weeks prior to calving, dams vaccinated with Abs against F5 (K99) Ag afford protection to calves against ETEC. HOWEVER, field trials have shown low efficacy, bc a single dose only has a short period of protection. Endemic farms should consider proper use of the vaccine