Calf Diarrhea Flashcards by Marin Low

T or F, the specific agent causing scours in calves is very important to determine to solve the problem

False! specific agent is less important than risk factor triggers

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what are the 3 aspects of the epidemiology of neonatal calf diarrhea?

pathogen, host, environment

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true or false: calf scours is NEVER an individual animal problem

true! treating an individual and not asking about the rest of the herd is malpractice

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list some causes of diarrhea in calves (there are a ton of these bestie just do your best)

ETEC (K99) or other E coli
salmonella
clostridium perfringens type C
campylobacter jejuni
rotavirus
coronavirus
totavirus
cryptosporidium
eimeria
giardia
yeast
nutritional

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what exactly is nutritional scours?

when the calf receives poor quality milk replacer or inappropriate replacer mixing
if there’s sudden dietary changes
over feeding

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true or false: calves with nutritional scours have systemic signs

false, they should not be systemic, should be bright and alert, and should resolve in a few days

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the most important pathogen causing diarrhea in calves less than 5 days old is ______

enterotoxigenic E coli (ETEC)

most common strain is F5/K99

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why is it important to find virulence factors to confirm a diagnosis of ETEC?

because E coli is prevalent in fecal culture, but we don’t know if its specifically F5/K99, so we need to make sure! If a test comes back positive for E coli but we dont know the specific E coli, it may not actually be what is causing the diarrhea

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how does a calf usually get ETEC? pathogenesis?

ingested from the environment, attaches to the intestinal epithelium and really likes the ileum, then spreads to the duodenum and produces toxins causing a secretory diarrhea. EPITHELIUM REMAINS IN TACT

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_____ typically infects 5-15 day old calves, but can infect younger and older ones too

rotavirus

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pathogenesis of rotavirus infection causing diarrhea

adult cattle and older calves excrete the virus into the environment, the calf ingests the virus from the environment, virus kills the villous enterocytes and reduces absorptive surface area causing a malabsorptive diarrhea. also toxin induced secretory diarrhea

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rotavirus targets the ________ , which means ____

mature villar cells

the developing/immature cells quickly replace and there is minimal epithelial damage and it quikcly resolves

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true or false: rotavirus often results in coinfection

true

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clinical signs of rotavirus

profuse watery diarrhea, dehydration, depression, weakness, hypoglycemia

high morbidity and low mortality

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which virus is similar to rotavirus but infects slightly older calves and causes more severe disease?

coronavirus

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which virus causes winter dysentery in adults associated with BRD?

coronavirus

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coronavirus typically infects calves that are how old

5-21 days old

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coronavirus targets what cells?

crypt AND villous enterocytes, which means worse maldigestive and malabsorptive diarrhea

crypt loss=prolonged illness and more severe acidosis and dehydration

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which has higher mortality, coronavirus or rotavirus? why?

coronavirus because it infects the crypt and villous enterocytes. rotavirus just infects the villous cells

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which bacteria causing diarrhea in calves is provincially reportable?

salmonella enterica subsp enterica

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which salmonella serovar causes systemic disease in young and adult cows, and which serovar causes acute diarrhea and outbreaks in calves less than 2 months old?

S. dublin: systemic disease, young and adults
S. typhimurium: acute diarrhea, outbreaks less than 2 months of age

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which diarrhea pathogen infects calves usually before 28 days of age, and can cause a chronic carrier state?

salmonella enterica

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You go see a set of calves that are 20 days old, all with a transient fever, dullness, anorexia, malodourous diarrhea with some mucus and blood, and are a little cold. When talking with the farmer, you also found one calf dead on the ground. What pathogen are you worried about

salmonella

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how does salmonella cause disease? why does diarrhea develop?

it invades the intestinal mucosa and multiplies in lymphoid tissue and can evade host immune systems leading to systemic disease

diarrhea develops due to inflammatory response to an infection

a farmer has had a few calves with diarrhea suddenly die, and you do a necropsy and find intestines with fibrin deposits, blood everywhere, and lots of liquid. the mesenteric lymph nodes are also enlarged. what pathogen do you think caused this?

salmonella

which diarrhea pathogen is characterized by the following: - very zoonotic and very common - lots of subclinical infection - infect calves 8-14 days old

cryptosporidium parvum

pathogenesis of crypto diarrhea

causes villous atrophy and disruption of the epithelial barrier causing inflammation-->malabsorptive diarrhea

which diarrhea pathogen is characterized by the following: - high infection rate with low case fatality - infects calves older than 21 days old

coccidosis/eimera

clinical signs of coccidiosis in calves

diarrhea, dysentery (mucus and blood), tenesmus, painful abdomen

pathogenesis of coccidosis diarrhea

exfoliation of intestinal mucosa causing diarrhea and possible hemorrhage

list the diarrhea pathogens from infecting youngest cows to infecting oldest cows using your pneumonic: "every cat runs, climbs, & catches silly grey antelopes, crikey!"

ECRCCSGAC E coli, C perfingens, rotavirus, coronavirus, crypto, salmonella, giardia, attaching and effacing e coli, coccidia

best diagnosgtic for calf diarrhea is

a fresh carcass (acute and untreated) and/or feces from live (acute and untreated)

important things to remember when collecting necropsy samples for investigating diarrhea in calves? are there special considerations for culture vs viral isolation?

collect various samples of the gut, cut lengthwise and put in formalin, also collect from major organs and an ear notch to check for BVDV for culture: tie off loops of each section of bowel and mesenteric LN and submit fresh in separate labelled bags for virology: fresh feces OR tires off loops of bowel in separate bags for parasites: feces for float and FAT for crypto/giardia for mineral/toxicology: liver fresh or frozen

what is septicemia?

inflammatory response to bacteremia or endotoxemia resulting in systemic signs, usually E coli. high fatality rate and requires aggressive therapy.

what are clinical signs of septicemia?

severe depression, tachypnea, anorexia, hyperemia of mms, injected sclera. as it progresses, weak pulses and cold extremities

calves usually get septicemia in 2 ways, what are they?

calves less than 2 weeks old with failure transfer of passive immunity calves with neonatal calf diarrhea involving bacterial translocation of the gut

septicemia can be mistaken for pneumonia because...

it causes metabolic acidosis (which also happens in pneumonia)

describe mild, moderate, and severe dehydration findings for calves

mild (6-8% dehydrated): slightly depressed, 2-4mm of eyeball recession, and 1-2 sec skin tent moderate (8-10% dehydrated): depressed, 4-6mm eyeball recession, 2-5 second skin tent severe (10-12% dehydrated): comatose, 6-8mm eyeball recession, 5-10 second skin tent

based on the dehydration table we have to memorize @%^##&*@&#*@#^@&^# >:( , which calves need IV fluids and which ones dont?

for mild dehydration, they don't need it, but moderate and severe dehydration calves need it

mentation is relative to the level of ____

acidemia

what kinds of things are associated with acidemia?

inability to stand, weakness, ataxia, poor suckle reflex, and a slow palpebral reflex

what acid base derrangement do scouring calves get?

metabolic acidosis loss of bicarb in the feces, decreased renal excretion of H+ ions, poor perfusion=lactate

why is D-lactate is produced by bacteria?

as a result of maldigestion and malabsorption of carbohydrates in the gut

what are the components of individual calf treatment for diarrhea? use "remember, cats prefer tuna my wanker"

replace fluids/electrolytes correct acid base imbalances provide energy support treat the bacteremia/septicemia mitigate pain warm body to ideal temp

we should give IV fluids when the calf is ____% dehydrated

8 or more

when are oral electrolyte solutions a good option for calves with diarrhea?

in calves with normal mentation, <6% dehydrated, and HAS a suckle reflex

you are treating a calf with diarrhea and you decide to go with OES. The owner asks what you should do about giving the calf milk. you say...

alternate milk feedings with OES and spread it out thru the day. DO NOT withhold milk! they need the energy!

when are IV fluids indicated for calves?

if >8% dehydrated, if the calf cannot stand, or if the calf has a weak or absent suckle reflex

how do you calculate how much IV fluids to give to the calf?

replacement fluids: % dehydrated x body weight ongoing losses: usually 2-4 L a day maintenance requirements: 50ml/kg/day

what are the IV fluid options?

isotonic saline: slightly acidifying (probs not) isotonic sodium bicarb: alkalinisation effect LRS: most scouring calves have lactic acidosis so some say to avoid this P-LYTE: affordable and closest to physiologic values :)

how do you correct for acid base imbalances by adding bicarb to IV fluids?

add bicarb to IV fluids using this equation: bicarb requirement=body weight kg x base deficit in mEq/L x 0.6

besides adding bicarb to IV fluids, what other options are there for correcting acid base imbalances?

there is isotonic saline with bicarb in it 1.3% solution: can give 10% of isotonic bicarb over 3-4 hours hypertonic saline (doesn't correct acidemia) hypertonic bicarb 8.4%: 5-10ml/kg over 10 minutes

if you are using hypertonic solutions to correct acid base derrangement, what do you need to remember?

allows follow up with additional fluids like OES or IV

how do you provide energy support in a calf with neonatal diarrhea?

can give dextrose IV. it is non alkalinizing and it is not sufficient on its own due to lack of sodium add 5-10% to other solutions

true or false: popular oral sulfa boluses are not recommended for bacteremia/septicemia for calves with diarrhea

true, dont use them!

which calves should you be giving antibiotics to and what are your options?

calves that exhibit systemic signs of illness AND/OR have blood or mucus in the feces ceftiofur, ampicillin for salmonella: amoxocillin, TMS, cefitofur, but usually need culture and sensitivity

what is the drug Halofuginone for?

an anti-protozoal solution that can reduce clinical signs of crypto

what NSAIDs should you use for these calves with diarrhea?

meloxicam or flunixin