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74 Cards in this Set
- Front
- Back
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What are several risk factors for neonatal mortality and morbidity?
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- stress during parturition
- pathogen exposure - colostral transfer |
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When should a newborn calve attain sternal recumbency, stand, suckle?
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- breath within 30 seconds
- sternal recumbency within 15 minutes - stand within 3 hours - nurse within 6 hours if left with dam |
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What other parameters (stand, recumbency, suckle) be assessed to determine if a neonatal calf is healthy?
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- breathing well, spontaneously within 30 seconds
- increased HR above 100 bpm within 10 minutes |
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How much colostral IgG should a calf ingest to ensure adequate passibe transfer of immunoglobulins?
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- 125 grams of IgG1 within 24 hours
- sufficient to produce serum concentration >= 1000 mg/dl (10mg/ml) |
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How is colostrum usually administered to beef and dairy calves?
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- beef: nursed as beef cows have higher concentration of IgG
- dairy: harvest colostrum asap from calving, 1st and 2nd lactation cows and those yielding <10L should not be used for first feeding. feed 3-4 qts or L of colostrum within 6 hours after birth and another 2 12 hours later - 10% BW |
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Name several factors that influence colostral IgG concentration?
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- amount of colostrum produced - high yielding cows produced large volumes of colostrum with lower IgG concentration
- age of cow: cows in 1st and 2nd lactation produce lower IgG than those in 3rd lactation - interval between calving and milking: colostral IgG concentration decreases between calving and milking |
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What are the most commonly used methods to asses passive transfer in neonatal calves?
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- RID, ELISA: time consuming and expensive
- serum total protein - best quantitative screening - sodium sulfate precipitation - effective semiquantitative screening - quick test - expensive nonquantitative - serum GGT - GGT is high in colostrum, not recommended unless doing serum biochemistry |
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Given test results, determine if passive transfer was adequate.
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- RID, ELISA - >1000 mg/dl; 500-100 partial, and <500 failure
- Total Protein - <5.2 mg/dl suggests failure - sodium sulfate - 14% precipitates -> >1500 mg/dl; 16%-> 500-100; 18% <500 mg/dl - quick test: 1 line precipiation ok, 2 lines is a failure - serum GGT: for good transfer 1 day >200; 4 days >100 IU/L; 7 days >75; 10 days > 65 |
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How much milk or milk replacer should a dairy calf consume each day?
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- beef calves nurse so adequate
- dairy calves 10-12% BW dividing into at least 2 feedings - increase by 25% BW during cold weather |
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Differentiate between a high quality milk replacer from a lower quality milk replacer.
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- high quality - 22% protein, 20% fat (at least 10), <0.25% crude fiber
- low quality - higher crude fiber and non milk proteins such as soy - avoid soy early because contains anti-nutritional components such as trypsin inhibitor -> villous atrophy |
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When are dairy and beef cattle usually weaned?
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- dairy - after 8 weeks to prevent delayed rumen development
- considered weaned when daily starter ration is 1 to 1.5 lbs or 1% BW (4-8 weeks of age) - beef calves usually weaned 4-6 months of age |
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Name 6 common causes of diarrhea in calves <21 days of age? What are the typical age of onset for each?
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1) ETEC (<4d)
2) Rotavirus (4-21d) 3) Coronavirus (4-21d) 4) Crypto (5-28d) 5) Salmonellosis 6) Nutritional - most infections involve more than one pathogen or cause |
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Name one common cause of diarrhea for calves > 21 days of age?
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- Coccidiosis
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What are two important virulence factors of enterotoxigenic E.coli?
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1) Bacteria adhere to epithelial cell receptors on small intestinal villi by F5 fimbria
2) Bacteria secrete STa toxin allowing - hypersecretion of fluid and electrolytes (mainly Cl) in crypt cells; inhibit NaCl transporter in luminal membrane; leading to excessive loss of Na, Cl and water in small intestine |
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How do vaccines and oral AB products prevent entertoxigenic E.coli diarrhea in calves?
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- Vaccination of the dams in late gestiation with purified K99 (F5) fimbrial antigen results in presence of Ab to interfere with attachment of ETEC - depends on colostrum ingestion within 6-12 hrs
- vaccination of dams in late gestation with bacterin harvested from ETEC to optimize expression of fimbrial Ag - depends on colostrum ingestion within 6-12 hrs - Oral administration of ETEC fimbrial Ab to calves ASAP (within 12 hrs) - more expensive than vax dams, will decrease severity, mortality, and clinical signs |
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What are the pathophysioloical mechanisms for diarrhea for pathogens other than ETEC?
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- calf ingest or inhale virus from feces of other calves or dam
- following incubation period 1-5 days virus infects epithelial cells - infected cells are sloughed - villous atrophy - diarrhea is due to maldigestion/malabsorption - osmotic fermentive diarrhea |
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Name 4 enteric pathogens of calves that have zoonotic potential.
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- Crypto
- Salmonella - Giardia - E.coli |
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Why don't producers/veterinarians pursue an eitologic diagnosis in calves with diarrhea?
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- diarrhea causing agents are found in healthy ccalves
- similar risk factors for different pathogents - treatments are similar - mixed infections are common |
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Suggest an appropropriate eitologic test for each of the types of calf diarrhea.
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- ETEC: <4 days; find F5 Ag, need histologic lesions for deffinitive
- Rotavirus: 4-21 days EM feces, ELISA - Coronavirus: 4-21 days, EM of fectes - Crypto: 5-28 days: fecal oocysts - Salmonellosis: fecal culture |
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Make general recommendations for controlling/preventing diarrhea in calves.
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- clean calving and rearing equipment
- expose housing to dry winds and sun - good ventilation - vaccination programs that work - milk or high quality replacer fed to calves <21 days - follow proper biosecurity to limit biocontamination |
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Make specific recommendations for controlling/preventing diarrhea caused by enteric pathogens(eg. vaccines, specific tx, and preventatives)
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- Vaccinate pregnant females -> ETEC (purified K99 E5 antigent), Rotavirus (inactivated), Corona (inactivated)
- If colostrum deprived, vaccinate calf ASAP -> ETEC (Ab against K99, Rotavirus (modified live), Corona (modifed live) - Supportive care for ETEC, Coronavirus, and Rotavirus - Coccidiosis -> control is best prevention by keeping food above floor - Salmonellosis -> supportive A/B and culling, control by preventing fecal contamination - Crypto -> zoonotic |
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Describe the general signs of septicemia and signs associated with localization of bacteria in common sites.
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- major killer of calves < 14 days
- acute, generalized infection to few areas: joints (swollen inflammed reluctant to stand), umbilicus , brain and SC (meningitis - depression, ataxia, nystagmus, padding, seizures, abnormal vocalization), anterior chamber of eye (uveitis) - progressive lethargy, depression, inappetance - DX: history and CS, serum Ig status |
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What treatments are available for septicemic calves?
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- poor prognosis for recovery
- broad spectrum A/B, all extra label such as cetiflur, ampicillin, gentamycin - IV fluids - feed whole milk 12-15% / BW per day - transfuse > 1L blood (not from dam if failure of passive transfer) - NSAIDs extra label |
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Name metabolic derangements that you are attempting to correct when administering fluid therapy in a diarrheic calf.
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- dehydration
- metabolic acidosis/alkalosis - electrolyte disturbance - energy deficiency - SIBO - hypothermia - hypoproteinemia - speticemia |
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When are oral fluids likely to be sufficient to correct dehydration and when IV therapy is needed?
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- oral sufficient if deficiet =< 8%
- IV necessary when >8% deficit |
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What is the daily maintenance requirement for a calf?
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60-80 ml/kg/day - somehow that calculates to 3-4 L per day....
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What type of fluid (osm?) provide the best correction of IV fluid deficit?
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- isotonic
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What rate should isotonic fluids be replaced? Calculate for 50kg calf.
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- rapidly (2-6 hours)
- 80 ml/kg/hr - 80*50 = 4L per hour |
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How can hypertonic saline be used to correct a fluid deficit? How can the duration be extended?
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- If adminstered rapidly enough (4-5 ml/kg over 4-5 mins jugular) it will cause a dramatic increase in plasma osmolality creating an osmotic gradient which draws fluid from the intracellular spaces and GI to the blood stream to rapidly improve CO and peripheral perfusion
- however it must always be given in conjunction with oral isotonic fluids (4L) - the water allows for plasma volume expansion - extend duration by administering hypertonic saline in 6% dextran |
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Calculate the total volume of hypertonic saline needed to correct a deficit in a 50kg calf?
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- use 4-5 ml/kg over 4-5 mins
- 5*50kg = 250 ml needed |
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What should be used to correct an acidosis, orally and IV?
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- oral -> acetate bc bicarb raises abomasal pH and when mixed with milk impairs protein digestion
- IV: NaHCO3 |
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How do you make 1L of isotonic NAHCO3?
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- 13g of baking soda in 1L of distilled water
- need 2L to correct base deficit of an acidemic calf |
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How much bicarb would a 50 kg calf with 10 mEg/L based feficit require?
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- 50kg*0.5*10mEq/L = 250 mEql
- Isotonic NaHCO3 provides 156 mEq/L - need 1.5L for 234 mEq/L |
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What are common electrolyte imbalances?
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- hyperkalemia - treat with IV NaHCO3
- hyperphosphatemic - due to reduced GFR and dehydration - hypernatremia - due to diarrhea |
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What is a high-energy versus a low-energy electrolyte solution?
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- hi: hyperosmotic to the intestinal villus of 600 mosm/L - still do not meet a calf's energy needs
- low: isoosmotic - can lead to severe energy deficit and hypoglycemia |
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What digestive pathogens affect the energy absportion capability of a calf with respect to energy electrolyte solutions?
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- ETEC - no physical damage to villi, so no affect on absorption
- Rotavirus - ablates the villi therefore no capacity to absorp solutions |
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At what age are young ruminants protected by maternal ABs?
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3 weeks to 6 months
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Ruminants between 3 weeks to 6 months frequently do not present with diarrhea except for?
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- Coccidia
- Salmonellosis - Ostertagiasis - Mucosal Diseas (BVD) |
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What age does maternal AB protection dissipate making the animals more susceptible to infectious agents such as those that cause diarrhea?
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6 months to 2 years
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Name two causes of diarrhea in mature aged rumiants?
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- Diet
- Johne's - Salmonellosis - BVD - Winder Dysentery (Coronavirus) - Mo/Secondary Cu Deficiency - amyloidosis - MCF |
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Match the onset/severity with the likely cause of diarrhea:
acute, mild transit - severe and transiet - sever and fatal - chronic and insidious --> with Johnes, MD, BVD, Winter Dysentery |
BVD - acute, mild and transient
Winter Dysentery - severe and transiet MD - sever and fatal Johne's - Chronic and insidious |
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What clinical signs are commonly associated with BVD?
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- diarrhea +/- blood
- fever - decreased food intake - decreased milk production - +/- oral erosions and blunting of oral papillae |
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What age group are most commonly affected with BVD?
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- juvenile, however it can spread to callte of any age in unprotected herds
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How is BVD spread?
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direct contact with secretion - nasal, oral or genital
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What secondary complications can arise from BVD?
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- main cause of economic loss due to BVD
- immunosuppresion - leads to respiratory disease - hemorrhage (uncommon) - fetal diseases and death (reproductive failure <100d; congenital defects 60-180d; PI < 125d with PI calves later; seropositive >180 d) |
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How is a diagnosis of acute BVD made?
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- clinical signs
- seroconversion or rise in AB titer at 4 weeks - isolation from whole bloody buffy coat - viremic stage - PCR - detection of BVD antigen (isolation, fluresscent, IPO test, PCR on secretions, necropsy lesions) |
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How is a diagnosis of PI made?
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- ear punch and IPO
- virus isolation from buffy coat on 2 occasions 3-4 weeks apart - virus isolation from serum on 2 occasions - Antigen capture ELISA on serum on 2 occasions |
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How is BVD controlled?
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- identify and cull PI animals in herd
- testing incoming animals for PI and isolating until results ready - vaccinate heifers (dairy and beef) and cows (beef) one moont or more before pregnancy with MLV - calves <6 mo vaccinate then again after 6 mo due to inferferecne from material ab |
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T/F In well-vaccinated herds, a PI will not shed enough virus to overwhelm the protection afforded by vaccination and cuase disease in other cows.
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False - the PI shedding can overwhelm
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What is the sequela to BVD?
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MD with specific conditions
- acute and fatal 5-7 days - no treatment, euthanasia |
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What are the specific conditions necessary for a BVD to progress to MD?
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- must be PI calf <125 days
- exposed to non cytopathic exogenous virus (AG) or more likely a mutation of non cytopathic virus - cannot mount an effective immune response - cytopathic lesions must be severe |
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What are clinical signs of MD?
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- anorexia, depression, skin erosions, sever mucosal erosions, profuse diarrhea or dysentery
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How is MD diagnosed?
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- clinical signs and necropsy findings
- virus can be isolated from buffy coat or serum or tissues |
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What is meant by biotype and genotype?
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b: cytopathic and non
g: 1a, 1b, 2 |
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What are the GI and non-GI manifestations of BVD?
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GI: diarrhea, +/- blood, decreased feed intake, decreased milk production
non-GI: abortion, immunosuppresion, congenital defects, PI calves, hemorrhage |
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What stage is BVD likely to produce reproductive losses, congenital defects, PV or healthy immune calves?
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- abortion - first 100 days
- congenital defects 60-180d - PV less that 125 d - healthy immune calves > 180d |
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What animals are susceptible to MD?
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Those exposed to BVD in untero prior to a non-cytopathic strain < 125 d followed by another exposure to another exogenous non-cytopathic strain or mutated strain
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What samples can be submitted to daignose acute BVD in live or dead cattle and what tests are required?
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- necropsy: Ag, titer, virus in tissue, depletion of lymphocytes in Peyer's Pathces
- serum, whole blood buffy coat |
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Recommend vaccination programs for dairy and beef cattle against BVD
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- vaccinate with MLV - heifers (dairy and beed) and cows (beef) more than one month prior to breeding - need a protective immunity prior to pregnancy
- vaccinate calves <6 mo then booster after 6 mo of age to deal with maternal AB interference |
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What diagnostic tests distinguish acute BVD from persistent BVD?
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- immunoperoxidase - ear punch
- virus isolation, then again 3-4 weeks later - PCR on serum for persistent 3-4 weeks again - PCR on tissues for acute BVD - Antigen capture ELISA on serum on 2 occasions for persistence |
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Name several diagnoses for mucosal disease?
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- MCF
- FMD - Vesciular stomatitis - Blutetongue - BVD - epizootic hemorrhagic disease of white tailed deer |
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Which common ruminant species carries MCF virus that can expose cattle?
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- sheep
- Ovine herpesvirus-2 |
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Name some clincal signs that distinguish MCF from mucosal disease caused by BVD?
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- enlarged LN
- Hematuria - CNS signs - Keratoconjunctivitis |
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What form of salmonellosis is most common in cattle?
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Subclinical
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What are the clincal signs of salmonella enteritis?
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Peracute - may precede diarrhea, distinguish from mastitis, metritis, pregnant cows may abort
Acute - fever, anorexia, dehydration, diarrhea (blood casts mucus), tenesmus, anemia Chronic - chronic or intermittent diarrhea, ill thrift |
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How is salmonella diagnosed?
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Fecal culture and PCR
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What species of Salmonella is host adapted to cattle and commonly shed in milk?
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S. dublin
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List major risk factors for salmonellosis in ruminants and describe some control measures for each.
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- Risk - stressful event
- Intermittent fecal shedding - Prevent contamination of feed and water - Biosecurity measures |
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What age and type of cow is usually affected by winter dysentery?
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Cows greater than 2 years of age - dairy cows
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What are the clinical signs and causative agent of winder dysentery?
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- Coronavirus
- Acute, profuse, transient diarrhea often dark and bloody with no fever and deacreased milk production |
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What environmental and housing conditions predisposed to winder dysentery?
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- Crowding and stress
- Housing and tie stalls are greater rish than housing in freestalls - its a winder disease |
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What is the eitiologic agent associated with Johne's?
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mycobacterium avium paratuberculosis
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Describe the pathogenesis and clinical signs of Johne's
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- infected in first few months of life
- ingestion of organism that colonizes in ileum, cecum, and ileocecal LN - leads to granulomatous enteritis and lymphadenitis - before clinical signs, organism is shed in feces as well as spreads via MP to mammary glands testes, uterus (shed in milk, semen, transplacental infection) - incubation is 1.5-2yrs Animals are either: - not clinical and not shedding (most) - shedding (light or heavy) but not clinical - shedding and clinical (tip of iceberg) CS: chronic diarrhea (normal in color except small rum may be pale), progressive weight loss, excellent apatite, not febrile - protein losing enteropathy with ventral edema and hypoALB - thickened bowel wall |
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What are the gross and histopathologic lesions associated with Johne's
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Gross - thickened bowel wall
HP - granulomatous enteritis and lymphadenitis |
