Bovine Infectious Pregnancy Wastage Flashcards

Question 1

Q

Sample Collection

Bacterial / Fungal

Viral

Toxicology

Question 2

Q

BovineVenereal Campylobacteriosis*

Pathogen

Signs

Immune rx

Diagnosis

Control & Prevention

Answer

A

<ul>
<li>CFV (venereal) /(CFF) (non venereal - sporadic abortion/infert)
<ul>
<li>Gram⊖, motile, polar flagellated rod, microaer, extracell, obligate repro tract pathogen, killed by UV</li>
</ul>
</li>
<li>Transmission: Venereally (contam instruments/bedding poss)
<ul>
<li>Indiv bulls vary in suscep - some permanent carrier for life/others resistant
<ul>
<li>1° factor = age-rel depth preput+penile epith crypts
<ul>
<li>Young (<4) crypts underdev'd - inf transient (clearance spont - not immune - can be re-inf)</li>
<li>Older (>4) crypts deeper → microaer envir needed for chr inf</li>
<li>1 study: 5% bulls <4 → PI / 95% bulls >4 → PI</li>
</ul>
</li>
</ul>
</li>
</ul>
</li>
<li>Cow immune rx
<ul>
<li>Cleared ut/oviduct wks-mths</li>
<li>Persists vag 6mths (50% up to 10mths) (IgA ltd opson/phag, CFV altered ag express)</li>
<li>95% elim by end of gest (1-2% permanent vag carriers)</li>
</ul>
</li>
<li>Signs:
<ul>
<li>Endometritis most severe 8-13wks (vaginitis/cervicitis) - most conceive but EEL</li>
<li>Marked ↑returns (reg/irreg - EEL b4/after MRP)</li>
<li>Herd PR - acute inf (40%), chr inf (60-75%), no inf (90%)</li>
</ul>
</li>
</ul>

Diagnosis:similar to T.foetus - investig for both

<ul>
<li>Placenta: NSGL</li>
<li>Fetus: NSGL</li>
<li>Culture (caution false⊖):
<ul>
<li>Immed into transport media + plated/incub w/in 6hrs</li>
<li>Vag wash (rarely ⊕)/preputial wash(↑⊕ than vag)/aborted stomach contents</li>
<li>Examine washing w/ fluor AB test + culture microaer</li>
<li>Max accuracy - sample bull 2x 7days apart</li>
</ul>
</li>
<li>Serology (no measurable serum AB rx - confused by non-path Campy AB rx):
<ul>
<li>Vag mucus IgA ELISA - rapid + persistent rx but CFV/CFF not differentiated (more sensit than VMAT)</li>
<li>Monoclonal AB ELISA - recogn + differentiate CFV/CFF ag = highly sensit/specific</li>
</ul>
</li>
<li>PCR - sensitive, differentiates CFV/CFF</li>
<li>Test breed heifers + examine for inf - rarely practical</li>
</ul>

Prevention/Control:

<ul>
<li>Vacc: prevents + elim's inf cow+bull(30-90 days before breeding starts) - cows again midway through breeding season (AB-rx short-lived) - bull double dose 3weeks apart</li>
<li>Vacc speeds elim - may remain carrer but fert greatly ↑</li>
<li>Bulls streptomycin 20mg/kg s/c + topically 3 consec days</li>
<li>Prevent dz entry,AI,replace w/ virgin bulls+heifers, fencing secure - no shared grazing, vacc</li>
</ul>

Question 3

Q

Brucellosis*

Organism

Transmission

Pathogenesis

Clinical signs

Answer

A

<ul>
<li>Brucella abortus (B. melitensis sheep/goat can → dz cattle)
<ul>
<li>Gram⊖ aerobicfacultative intracell coccobacillus</li>
<li>Cervid, camelid, wild bovidae wildlife reservoir (not bos indicus)</li>
</ul>
</li>
<li>Signs: Abortion (2nd half), RFM, metritis (Bull - orchitis/epididymitis/ASG inf)
<ul>
<li>Most → RFM (Morrocan leather intercotyl thickening +yellow exudate, focal cotyl necrotic), can → puerperal metritis</li>
</ul>
</li>
<li>Intro:carrier. Transmission:ingestion (or MMs) aborted tissue, milk, semen</li>
<li>Pathogenesis:
<ul>
<li>Non-preg - colonises udder + supramamm LNs</li>
<li>Preg - erythritol in plac → rapid multipl → endometritis, placentitis
<ul>
<li>Abortion 48-72hrs after death (some → mummif/macer) (live-born weak/unthrifty/d+)</li>
<li>Ut invol then colonises udder + supramamm LNs → can re-inf plac nx gest</li>
</ul>
</li>
</ul>
</li>
</ul>

Diagnosis:

<ul>
<li>Smear (aborted tissue/milk) - Ziehl-Nielson/immunofluor</li>
<li>Gross - firm fetal lung, fine fibrin strands</li>
<li>Serology:
<ul>
<li>Rose Bengal plate test (RBPT) -orig herd screening test</li>
<li>Plate agglut test (PAT) -if ⊖ on bull serum- rpt w/ SP</li>
<li>Milk ring test (MRT) - good for herd - bulk milk</li>
<li>Indirect ELISA -cheap, easy, accurate</li>
<li>Complement fixation test (CFT) - can id acute or chr inf + differ inf/vacc</li>
</ul>
</li>
</ul>

Control:

<ul>
<li>Erad schemes many countries - UK dz-free + most US states</li>
<li>B-free if notifiable, reactors slaughtered, vacc not used, ⊕rate≤0.2% min 2yrs</li>
<li>Id all animals, trace movements, secure boundaries, reg testing, isol+test all abortions<271days</li>
</ul>

Question 4

Q

Leptospirosis*

Organism

Pathogenesis

Clinical signs

Diagnosis

Treatment

Control

Answer

A

Organism:

<ul>
	<li>Host adapted bovine: L. intersr Hardjo (commmon UK) + L. borgpetersenii sr Hardjo (common US)
	<ul>
		<li>Up to 81% herds sero⊕ Hardjo</li>
	</ul>
	</li>
	<li>Non-adapted serovars → dz bovine: L. intersr Pomona (PIG) + L. intersr Copenhageni (RODENT)</li>
</ul>

Pathogenesis: Entry via skin abrasions, MM's eye/nose/mouth, semen, vag fluids (venereal tranm Hardjo common)

<ul>
<li>→ short latent period (5-14days) then bacteremia</li>
<li>Bacteremia 4-5 days thenImmune rx vs leptospires</li>
<li>→ Localise tissues inaccessible by AB:
<ul>
<li>Renal tubules → nephritis (renal dz can be severe) - u+ excr wks/lifelong (main envir contam)</li>
<li>Cotyledons/fetus → abortion/stillbirth/weak, latently inf (ut disch contam up to 8 days)
<ul>
<li>Ut inf 150 days preg, 100 days non-preg</li>
</ul>
</li>
</ul>
</li>
</ul>

Clinical signs:

<ul>
<li>L. hardjo - most no dz but excr in u+ + some → carriers
<ul>
<li>Transient pyrexia, dull, ↓app, mastitis (flabby bag), ↓milk yield</li>
<li>Abortion/stillbirth (3-10%) 6+ wks after acute dz - 4mths→term (usually 6mths+) - can abort w/o clin signs</li>
</ul>
</li>
<li>L. pomona / L. copenhagenii:
<ul>
<li>Acute febrile dz (>40°C), anorexia, icterus, hemoglobinuria, ±mastitis, death poss (esp calves)</li>
<li>Sporadic abortionsor abortion storms (up to 50% L. pomona in 1-6wks)</li>
</ul>
</li>
</ul>

Diagnosis:

<ul>
<li>Placenta - intercotyl tissue oed, cotyledons fawn-colour + flaccid</li>
<li>Aborted fetus - severely autolysed, if interstitial nephritis = pathognomonic</li>
<li>Fetal fluids, kidney, lung (or cow u+) - Leptospira direct id dark field microscopy or fluor AB staining</li>
<li>1° SEROLOGY: Mat/fetal blood → microscopical agglut test (MAT) - gold standard + most widely used
<ul>
<li>Non-host-adapted → high titres - w/ clin signs = dx (BUT can → abortion w/o high titre!)</li>
<li>Adapted - more difficult - active inf → high MAT titres but only for 3mths so ↓ by time of abortion!</li>
<li>∴MAT best for screening herd - interpret titres - active inf vs vacc</li>
<li>When >20% herd sero⊕ or if some titres >1:1600 = active inf present</li>
</ul>
</li>
</ul>

Treatment:

<ul>
<li>Streptomycin (25mg/kg IM) - effective clearing from u+ / ab + vacc -. stop abortion storm</li>
<li>Tetracyclines / amp / amox also 2nd line</li>
</ul>

Control:

<ul>
<li>Hygiene ↓spread from other sp
<ul>
<li>Strict segr from pigs, no pig effluent, rodent control, fence/drain contam H₂O, sheep can excr hardjo</li>
</ul>
</li>
<li>Vacc:
<ul>
<li>Closed herd - vacc all annually / Open herd - vacc all biannually</li>
<li>Vacc - all killed - protects up to 12mths - little to no cross protection btwn serovars (bi,trivalent, pentavalent vacc common - efficacy conflicting data)</li>
<li>May not be $ warranted if Lepto losses low (vacc enforced some area w/ high human inf - NZ90% cows)</li>
</ul>
</li>
</ul>

Question 5

Q

Salmonellosis

Organism

Pathogenesis

Clinical signs

Diagnosis

Control

Answer

A

S. Dublin → 80% Salm abortions UK (present some US states)

S. Typhimurium endemic worldwide (not major cause of abortion)

Pathogenesis:

<ul>
<li>Faecal-oral - contam feed/pasture/water</li>
<li>Initial bacteremia, →liver, lung spleen, LNs dam...localises placentomes 6-8d later → pyrexia again</li>
<li>Fetal death + abortion due to placentitis (often only few cases in herd but abortion storm poss)</li>
<li>NB: septicemia → endotoxemia + endog PGF2a → luteolysis + abortion
<ul>
<li>This case fetus/placenta culture negative!</li>
</ul>
</li>
</ul>

Clinical signs:

<ul>
<li>Pyrexia (>40°C), sevre d+, septicemia, ±abortion (abortion us. late preg - may be no other clin signs)</li>
</ul>

Diagnosis:

<ul>
<li>Culture - fetal tissue/plac/ut disch/vag mucus/(feces)
<ul>
<li>Fetal stomach contents/brain → defin dx (BEST)</li>
<li>Dam feces if clin signs - sensit only 38% - intermitt shedding (↑stressed so PP culture ↑chance)</li>
</ul>
</li>
<li>Serology (2nd BEST):
<ul>
<li>Indiv serum more sensit than fecal culture(bulk milk - show presence in herd)</li>
</ul>
</li>
</ul>

Control:

<ul>
<li>Organism secr v short period after abortion (unlike enteric cont/intermitt shedding)</li>
<li>Isol aborting cow until vag disch stops</li>
<li>Dispose of fetus/plac/contam bedding + clean/disinfect</li>
<li>↓ stock density can ↓ spread in abortion storm</li>
<li>Vacc avail (killed)(S. dublin + S. typhimurium) - prevent (w/ hygiene, biosecurity) or use in face of outbreak</li>
</ul>

Question 6

Q

Listeriosis

Organism

Pathogenesis

Clinical signs

Diagnosis

Treatment & Control

Answer

A

Listeria monocytogenes - gram⊕ coccbacillus

<ul>
<li>1º CNS dz (encephalitis sheep+cattle) - incub 5-12d</li>
<li>Cross-inf poss - some symptomless carriers - excr feces+milk</li>
<li>Ubiq in envir - soil/effluent/bedding/feed</li>
<li>Res to drying/sunlight/extreme heat</li>
</ul>

Source: almost always silage (soil cotam or low DM→ inadeq fermentation→ high pH, butyric silage) - ↑ incid winter (obv reasons)

Entry: ingestion or penetr conjunc/resp MMs

<ul>
<li>Predil for CNS + placenta→ placentitis, fetal death + abortion</li>
</ul>

Clinical signs:

<ul>
<li>Abortion usually sporadic - late gest - autolysed, yellow/grey pinpoint necrotic foci liver/cotyl = charac</li>
<li>Cow occas pyrexic around time of abortion</li>
<li>Rare for cows w/encephalitis to abort + VICE VERSA</li>
</ul>

Diagnosis:

<ul>
<li>ID: direct smear/IHC/immunofluor from fetal abomasum/liver/plac orvag disch</li>
<li>Culture = difficult / Serology not used</li>
</ul>

Treatment & Control:

<ul>
<li>If pyrexia/malaise, ab's may prevent abortion</li>
<li>Remove source (silage) 2nd half gest</li>
</ul>

Question 7

Q

Histophilus Somni*

Answer

A

<ul>
<li>Normal gram⊖ inhab genital tract (28% cows, 90% bulls - preputial cavity, SV's)</li>
<li>Diff strains can → systemic dz (septicemia/PA/pneum/pleurisy/meningoenceph) or repro dz</li>
<li>Repro dz: endometritis, cervicitis, granular vulvovaginitis, vulval disch (ddx ureaplasmosis) → EED/abortion or testis degen/orchitis/epididymitis - can be transm venereally
<ul>
<li>Abortion uncommon</li>
<li>Lesions non-specific - acute, non-supp cotyl placentitis</li>
</ul>
</li>
</ul>

Dx: Culture (difficult if overgrowth of contam's)

Tx: Ab's may help, AI w/ extender → ↓incid (bull likely source)

Question 8

Q

Mycoplasma

Answer

A

Mycoplasma bovigenitalium:

<ul>
<li>Common isolate vag mucus, semen, preputial washes normal cow/bull</li>
<li>May → gran vulvovaginitis, semvesiculitis, testes/epidid inf → ↓semen quality</li>
</ul>

Mycoplasma bovis:

<ul>
<li>Widespread US, UK, Aus but rarely in repro tract normal cows</li>
<li>Resp dz/otitis media/PA calf/mastitis (transm resp/mamm secr)</li>
<li>♂orchitis/sem vesiculitis/↓semen quality (tranm in semen)
<ul>
<li>Vag inf (1mth), ut inf (8mths) → endometritis/salpingitis (even peritonitis)</li>
<li>Abortion - mild-severe placentitis ± fetal bronchopneum</li>
</ul>
</li>
<li>Dx: Culture difficult (high false⊖), serology, PCR (indiv/bulk milk)</li>
<li>Control: difficult - sporadic, few ab's effective, no vacc, closed herd BEST</li>
</ul>

Question 9

Q

Ureaplasma*

Organism

Clinical signs

Diagnosis

Treatment

Prevention

Answer

A

Ureaplasma diversum:(urea-splitting mycoplasma)

<ul>
<li>Common inhab cow vestib/vag - venereal transm or contam semen - likely opportunistic</li>
<li>Acute inf → granules clit+vag walls (gran vulvovaginitis)vulval hyperemia, profuse mucopur disch
<ul>
<li>Purulent lesions resemble IPV (BHV-1)</li>
<li>Endometritis+salpingitis → high EEL + returns or abortion (3rd trimester)</li>
</ul>
</li>
<li>Bull → gran balanposthitis, sem vesiculitis, ↓semen morpho</li>
<li>Dx:
<ul>
<li>Hyperemia + granules</li>
<li>Difficult to culture - PCR BEST
<ul>
<li>Cow: sample active gran vaginits lesions</li>
<li>Aborted tissue: Lung, placentoma, stomach contents, amn fluid</li>
</ul>
</li>
<li>Charac hemorrhagic amnionitis -thickened + opaque, lungs - interstitial necrosis + alveolitis</li>
</ul>
</li>
<li>Tx: Systemic macrolides/tetracyclines</li>
<li>Prevention: Cassou chemise impt to avoid iatrogenic advancement → endometritis + salpingitis
<ul>
<li>No vacc avail</li>
</ul>
</li>
</ul>

Question 10

Q

Chlamydia

Answer

A

C. abortus:

<ul>
<li>Gram⊖ oblig intracell - prob ubiq bovine - many carriers, abortion incid low</li>
<li>Transm - fecal shedding maninly (vag, semen, nasal, ocular, aborted tissue)</li>
<li>Colonise endometr → endometritis + EEL, abortion
<ul>
<li>Incub 5-125 days - some abort same season, other abort next season</li>
<li>Abortion usually >7mths, no dz b4, RFM common (live born weak poss)</li>
<li>Sporadic (ovine enzootic abortion sheep) (human abortion poss)</li>
</ul>
</li>
<li>Bulls clinically normal OR epididymitis/sem vesiculitis/testic degen</li>
<li>Dx: 
<ul>
<li>Gross (like OEA)placenta thickened, leathery, red/white discol+oed
<ul>
<li>Fetal liver enlarged w/ coarse nodular surface, mottled red/yellow</li>
</ul>
</li>
<li>Culture or smear fetal tissues (Giemsa - elementary bodies/inclusions)</li>
<li>MOSTLY ag-detec ELISA or immunostaining or PCR</li>
<li>Serology LACKS SPECIFICITY</li>
</ul>
</li>
<li>Control: Ab's rarely used, hygiene, isol fromaborted mat, vacc sheep only</li>
</ul>

Question 11

Q

Trichomoniasis*

Organism

Pathogenesis

Clinical signs

Immune response

Diagnosis

Treatment & Control

Answer

A

Tritrichomonas foetus:(same organism as T. suis - pig commensal)

<ul>
<li>Obligate venereal pathogen, faculanaer,3 ant flag, undulating membr 1 side - phase contrast/dark field x100-x400
<ul>
<li>Killed by drying/high temp/UV, survives freezing</li>
</ul>
</li>
<li>Source: Bulls mainly (asymp carriers - lifelong)- naive herd common for close to 100% inf rate (↓incid young bulls - crypts)</li>
<li>Pathogenesis: colonises ut, cx, vag → mild e'metritis, vaginitis, vulval/ut oed
<ul>
<li>Fert ok butEEL (30-50d) +irreg returns, some abortions2-4mths</li>
</ul>
</li>
<li>Signs: Huge ↓fert w/ ↑returns, ↑ICI, ↑culls for fert, pyometra + EEL suggestive (inf bull → 30-90% cows infected)
<ul>
<li>Mucopur disch common, pyometra 10% (voluminous, odorless, grey/white)</li>
</ul>
</li>
<li>Immune rx cow: AB-med (IgA+IgG) - devels over mths (3-22mths heifer)
<ul>
<li>∴series of returns then suffic immunity - carry to term</li>
<li>Immunity only lasts 15mths - suscep at subseq pregs</li>
<li>Occas → PI = reservoir</li>
</ul>
</li>
<li>Dx:Easier than Campy - live T. foetus
<ul>
<li>Samples from ♀vag disch/♂prepuce/aborted material (plac or abomasum BEST)90-95% inf bulls ⊕culture (3 successive cultures weekly intervals detects 99.5% of inf bulls)</li>
<li>Suction on syring+pipette while scraping preputial fornix ± saline → centrifuge → dark-field</li>
<li>Care - fragile - degen rapidly - culture in Diamondmedium - sample culture every 48hrs for 10 days(InPouch TF system too)</li>
<li>22-37°C + microscopy - directly w/ InPouch (sensit 95% InPouch+Diam)</li>
<li>PCR can differentiate T.foetus from fecal trichomad contaminants</li>
</ul>
</li>
<li>Tx:cull carrier bulls - inf permanent (metronidazole/trichostatin effective but no lic)</li>
<li>Control:AI most effective + effic, herd measures as w/ Campy
<ul>
<li>Use only 2yo bull - likely ↓incid but not elim</li>
<li>Vacc (killed) - TriGuard (US) 2x4wks apart 4wks pre-breeding season, annual boost</li>
<li>Dz not prevented - ↓incid + duration → ↑CR + ↑calving rate</li>
<li>Conflicting data re: protection of bulls - may ↓colonisation of preputial epith</li>
</ul>
</li>
</ul>

Question 12

Q

Neosporosis

Organism

Life cycle

Transmission

Clinical signs

Diagnosis

Treatment + Control

Answer

A

Neospora caninum:

<ul>
<li>Protozoan - dog (maybe fox/coyote) defin host (encephalomyelitis)</li>
<li>LIFE CYCLE: Dog ingest tissue cysts → shed unsporulated oocysts feces → sporulate in envir (resistant) → intermed host (dog/grazing animal/bird)ingests sporulated oocysts → sporozoites released GI tract + penetr cells → tachyzoites - divide rapidly - tissue damage → spread to various tissues (neural, MØ, fibroblasts, endothelium, hepatocytes, placenta) → bradyzoites (tissue cysts) - 1° neural → bradyzoites eaten by defin host (mainly fetus/placenta w/ tissue cysts)</li>
<li>Vertical transm = main route bovine inf
<ul>
<li>Endog trans - react of tissue cysts in PI → placenta → sporadic abortions</li>
<li>Exog transm - 1° horiz inf of preg cow → placenta → abortion outbreak if herd naive</li>
</ul>
</li>
<li>Clinical signs:
<ul>
<li>Abortion any time >3mths (5-7 mths)
<ul>
<li>Repeated abortions some indivs</li>
<li>Storms (up to 40%) - either simult horiz expos of naive herd OR inf (e.g. BVD) → suppr immunity</li>
</ul>
</li>
<li>If fetus immuno-competent when inf → live, congen-inf calf
<ul>
<li>∴ reabs/mummif/autolysis/stillbirth/live-born clin signs or no clin signs but chr inf</li>
<li>Congen-inf heifer likely transm vertically - 75-90% offspring congen-inf too</li>
</ul>
</li>
<li>Endemically-inf herds - sporadic abortions - not catastrophic</li>
<li>Horiz-inf cows either abort or live uninf/congen-inf calves - depends on immune status + timing of inf</li>
<li>Most live-born congen-inf calves clinically normal (can be underweight +/or neuro signs)</li>
</ul>
</li>
<li>Dx: Combo of serology, IHC + histopath
<ul>
<li>Fetus - mod-severe autolysis
<ul>
<li>IHC of fetal brain/spinal cord = tissue cysts</li>
<li>Non-supp lesions brain (focal encephalitis), myocardium, skel m.</li>
<li>Non-supp multifocal necrotic foci cotyl</li>
<li>PCR fetal tissues + colostrum(doesn't confirm caused abortion)</li>
</ul>
</li>
<li>Serology: Immunofluo AB test (IFAT) + ELISA avail
<ul>
<li>Widespread sero⊕ cows so does not confirm recent inf</li>
<li>Fetal serology = definitive dx of neospora inf
<ul>
<li>NB: sero⊖ does not rule it out (early fetus not immuno-comp)</li>
</ul>
</li>
<li>Live-born calves - pre-colostral serum = sample of choice</li>
</ul>
</li>
</ul>
</li>
<li>Treatment + Control:
<ul>
<li>No effective tx + no vacc</li>
<li>Control difficult due to vert transm (sero⊕ 'immune' cows can still abort)
<ul>
<li>↓ vert transm - sero⊕ to breed for slaughter only - not replacem's</li>
<li>Test + cull - avoid intro sero⊕ to breeding herd
<ul>
<li>If % sero⊕ rel low - cull all - prevents vert transm (hi value-ET)</li>
</ul>
</li>
<li>↓horiz transm - break life cycle - prevent access to contam feed/water, dispose aborted mat/placenta immed, prevent dog/wild carnivore access to cattle feed or aborted mat, rodent control</li>
</ul>
</li>
</ul>
</li>
</ul>

Question 13

Q

Sarcocystis

Answer

A

<ul>
<li>V rare abortion cause bovine</li>
<li>Carnivore = defin host - sporozoites shed in feces</li>
<li>Intermed host ingests sporozoites → sarcocysts in muscle</li>
<li>Sarcocystis abortionindisting from neospora abortion
<ul>
<li>Need IHC or PCR</li>
</ul>
</li>
</ul>

Question 14

Q

BVD*

Organism

Transmission

Pathogenesis

Repro Failure

Diagnosis

Control

Answer

A

Organism:

<ul>
<li>Pestivirus (Flaviviridae family contains classical swine fever + border dz)</li>
<li>BVDV-1 = worldwide / BVDV-2 = mianly US (both have CP + non-CP strains)</li>
</ul>

Transmission:

<ul>
<li>Resp (also ut/abortion/u+/milk/feces/semen/saliva/embryos)</li>
<li>Close contact needed - nose-nose or sex</li>
</ul>

Pathogenesis:

<ul>
<li>Inf naive → transient viremia (most no clin signs) ↑T/↓app/d+/dull/immunosup → recover few days
<ul>
<li>If preg → transplac inf of fetus...depending on timing...
<ul>
<li>→ EED/abortion/live or stillborn ± congen defects/PI/sero⊕ immune</li>
</ul>
</li>
</ul>
</li>
</ul>

Repro fail:

<ul>
<li>Only in naive + PI's bred to recently inf/PI bull/semen- not in sero⊕ (immune)</li>
<li>Inf pre-mating→day 30: conception fail + ↓embr devel (impaired fol/ooc func, ↓LH surge, suboptimal ut envir) (oocytes can be BVDV⊕ - PI dam always→PI calf)</li>
<li>Inf day 30-150: resorp (day 30-40), mummif, abortion
<ul>
<li>Day 80-150 → congen defects (ocular/CNS)</li>
</ul>
</li>
<li>If survives non-CP inf day 18-125 - immunotolerant → PI (most</li>
<li>Fetal death + abortion poss ANY STAGE (most common 1st tri)
<ul>
<li>Expelled autolysed/mummif/fresh
<ul>
<li>Usually autolysed dt time btwn inf+abortion (days-2mths)</li>
</ul>
</li>
</ul>
</li>
<li>Inf day 150+: calf born immune regardless of strain (immunocompetent) dt cont ag challenge</li>
<li>Trojan cow: non-PI cow carrying PI fetus (AB titre signif↑ vs av sero⊕ cow)</li>
</ul>

Diagnosis:

<ul>
<li>Aborted/malformed fetus: virus isol/IHC/PCR from lung/lung/spleen/thymus</li>
<li>± Hyperkeratosis of skin</li>
<li>Herd: bulk milk ELISA for BVDV ag or PCR - detect PI dt high virus shed</li>
<li>Serology: widespread sero⊕ - long-lasting (historical) + difficult to diff vacc
<ul>
<li>'Sentinel animals' - young (9mths) - pre-vacc serology can = recent expos = present on farm</li>
<li>Precolostral serology all calves</li>
<li>Bulk milk - high AB = PI likely</li>
</ul>
</li>
</ul>

Control:

<ul>
<li>Closed herd - test all incoming for virus/ag + ensure no cow carrying PI enter</li>
<li>BVDV-free semen / avoid contact other ruminants / id+cull PI's (main reserv)</li>
<li>Vacc - mod live + killed avail</li>
<li>NB:Bulls can maint testic inf beyond initial viremia - >3 yrs!
<ul>
<li>∴ vacc all bulls w/ CP mod-live at least 28days b4 breeding - boost as necessary</li>
</ul>
</li>
</ul>

Mucosal dz:

<ul>
<li>Mutation of non-CP in PI → CP →mucosal dz
<ul>
<li>Usually sporadic unless large no PI's → trans of CP from 1 to others</li>
</ul>
</li>
</ul>

NB: CP strain cannot → transplacental inf or PI

Question 15

Q

Bovine Herpes Virus 1*

Transmission

Clinical signs

Diagnosis

Control

Answer

A

BHV-1 - worldwide

<ul>
<li>BHV-1.1 → resp dz, conjunctivitis + abortion</li>
<li>BHV-1.2 → venereal dz (vulvovaginitis + balanoposthitis)</li>
</ul>

Transmission:

<ul>
<li>Shed by MM's resp/conjunc/venereal - inf bedding/sniffing perineum/contam semen/aborted mat</li>
</ul>

Clinical signs:

<ul>
<li>Latent period 10-20 days - resp dz short dur - IPV several weeks
<ul>
<li>Viral shedding resp/genital 14 days (latent carrier intermitt for life)</li>
</ul>
</li>
<li>Inf pustular vulvovaginitis (IPV):
<ul>
<li>Acute onset 24-48hrs after venereal transm - more severe heifer</li>
<li>Labiae swollen, tender, cong / red mucosal vesicles → pustules → ulcers</li>
<li>Mucopur vulval disch - minor→copious</li>
<li>Speculum - so sore cd epidural helpful</li>
<li>Discomfort, swishing tail, dys/strang/pollakiuric</li>
<li>±pyrexia, ±resp dz, ±↓milk yield</li>
<li>Acute phase subsides 10-14 days</li>
<li>Remember check bull - signs dramatic if affected</li>
</ul>
</li>
<li>Abortion: (resp subtype, not from IPV)
<ul>
<li>Most sporadic (storms poss), ±resp dz before abortion</li>
<li>From 4wks+ (4-8mths)</li>
<li>Interval inf (abortifacient strain) → expuls variable (few days → term deliv stillborn/inf calf) - may reside long period in plac b4 inf fetus (interval fetal inf → expuls ≤7 days)</li>
<li>Highly autolysed (occas mummif), RFM common</li>
<li>Some stillborn, occas live-born - die soon</li>
</ul>
</li>
<li>Infertility:
<ul>
<li>Inf around breeding → poor fert / AI inf semen → poor PR</li>
<li>IU inoc → localised endometritis, necrosis luteal + ovar parenchyma (necrotic fols), P4 prodn↓ that cycle + subseq cycle</li>
<li>Impedes sperm binding ZP / direct invasion embr cells → EED</li>
</ul>
</li>
</ul>

Diagnosis:

<ul>
<li>IPV lesions charac (ddx ureaplasma gran VV)</li>
<li>Vag swab/preput washing/semen in VTM</li>
<li>Aborted fetus - severe autolysis highly suggestive (liquefactive necrosis entire renal cortex / focal necrosis liver), serosang fluid body cavities, ±placental oed - charac intranuclear inclusion bodies + cell lysis
<ul>
<li>IHC or PCR</li>
</ul>
</li>
<li>Paired serology little value dt time to abortion (titre may have ↓)</li>
</ul>

Control:

<ul>
<li>IPV - isol + suspend natural service → spont recovery</li>
<li>Vacc + biosecurity - mod live + killed (heifers vacc >6mths b4 service then annually)
<ul>
<li>Preg - killed only (mod live may → abortion - disputed)</li>
<li>Bulls - care w/ vacc - sero⊕ may be rejected for sale - reg semen collec + testing better</li>
</ul>
</li>
</ul>

Question 16

Q

Bovine Herpes Virus 4

Answer

A

<ul>
	<li>Worldwide</li>
	<li>Specific tropism for endometrial cells</li>
	<li>Usually → subclin inf but can → repro dz:
	<ul>
		<li>Endometritis</li>
		<li>Vulvovaginitis</li>
		<li>Abortion</li>
		<li>Metritis</li>
	</ul>
	</li>
	<li><strong>Dx:</strong> PCR</li>
</ul>

Question 17

Q

Bluetongue Virus

Organism

Clinical signs

Diagnosis

Control

Answer

A

Bluetongue virus = non-contag, vector-borne (worst summer - ↑culicoides midge)

<ul>
<li>Endemic W USA - domestic/wild ruminants - mainly sheep/deer

<ul>
<li>Cattle impt reservoir host - prolobged viremia w/o clin signs
<ul>
<li>Also transmin semen (also blood transfusion)</li>
</ul>
</li>
</ul>
</li>
<li>Clinical signs: rare in cattle
<ul>
<li>Occas cross placenta
<ul>
<li>Inf <100 days→ abortion/mummif/stillbirth</li>
<li>Inf later → ↓ effect on fetus -viremic live-born (weak+ataxic - dummy calf dthydraencephaly + cerebral cysts)or PI</li>
</ul>
</li>
</ul>
</li>
<li>Diagnosis:
<ul>
<li>Aborted fetus: CNS lesions</li>
<li>Virus isol/PCRfrom fetal blood/spleen/lung/brain</li>
<li>Serology = maternal exposure</li>
</ul>
</li>
<li>Control: Live attenuated vacc avail → good protection</li>
</ul>

Question 18

Q

Mycotic Abortion

Organism

Diagnosis

Pathogenesis

Diagnosis

Treatment/Control

Answer

A

Fungal invasion plac + common cause abortion(US～22% of inf abortions)

<ul>
<li>Usually sporadic (can be up to 10% some herds)</li>
</ul>

Aspergillus fumigatus most common cause worldwide

<ul>
	<li>Poor quality hay/silage/bedding, esp confined housing</li>
	<li><strong>Pathogenesis:</strong>
	<ul>
		<li>Hematog spread from GI/resp tract → placentomes</li>
		<li>Abortion when placenta can no longer support preg 4-9mths (7-8mths)</li>
		<li>Freq fetal inf too (skin+ lungs) - may be live-born inf</li>
	</ul>
	</li>
	<li><strong>Dx: </strong>
	<ul>
		<li>Lesions characteristic:
		<ul>
			<li>Whole/part placenta discol grey-yellow/red-brown
			<ul>
				<li>Intercot areas thickened, wrinkled, leathery</li>
			</ul>
			</li>
			<li>25-33% charac skin lesions - grey-white thickened patches (like ringworm)</li>
			<li>Fetal bronchopneum common</li>
		</ul>
		</li>
		<li>Histopath: Fungal hyphae in placenta (liver/lung/brain)</li>
		<li>Culture: ltd use due to contaminants</li>
	</ul>
	</li>
	<li><strong>Tx /Control:</strong>
	<ul>
		<li>No practical tx
		<ul>
			<li>Avoid mouldy feed/bedding</li>
		</ul>
		</li>
	</ul>
	</li>
</ul>

Question 19

Q

Foothill Abortion

(Bovine Epizootic Abortion)

Organism

Clinical signs

Diagnosis

Control

Answer

A

<ul>
<li>Deltaproteobacterium - gram⊖

<ul>
<li>Essential vector = argasid tick (California/Oregon/Nevada)</li>
</ul>
</li>
<li>Abortion seasonal - 3-4mths after tick exposure - crosses plac - inf fetus
<ul>
<li>Inf 60-140 days for fetal dz to occur - 3-4mths later</li>
<li>Most abortions 3rd trimester (sporadic - storm poss) → stillborn</li>
<li>Live-born weak calves poss (unknown if early inf → EED)</li>
</ul>
</li>
<li>No other clinical signs in cow - immune after abortion</li>
<li>At risk = 1st calvers or replacements from argasid tick-free area</li>
<li>Diagnosis:
<ul>
<li>Lesions aborted fetus charac:
<ul>
<li>↑ size LNs, spleen, liver / ↓ thymus size</li>
<li>±petechial haem mouth/tongue/thymus/LNs</li>
<li>Lack of hair apart from above eyes, lesions around lips</li>
</ul>
</li>
<li>Histopath confirm: Initially lymphoid hyperplasia then acute necrosis lymphoid organs</li>
<li>PCR -organism not id'd but PCR aborted mat confirms gene presence</li>
</ul>
</li>
<li>Control: Ensure cattle exposed to ticks before preg</li>
</ul>

Question 20

Q

Bovine Leucosis

Answer

A

Bovine Leucosis Virus: Retrovirus

<ul>
	<li>Uncommon cause abortion - most carriers asymptomatic</li>
	<li>Neoplastic process - lymphoma</li>
	<li>Multifocal lymphomatous masses
	<ul>
		<li>Can affect uterus → diffuse variable thickening myometrium
		<ul>
			<li>Friable ut wall, nodules in vag too</li>
		</ul>
		</li>
	</ul>
	</li>
	<li>Transmission vertical - req's cell transfer (calving, sx, dehorning etc also)
	<ul>
		<li>Not by ET</li>
	</ul>
	</li>
	<li>No vacc avail</li>
	<li>Test and cull</li>
</ul>

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Bovine Infectious Pregnancy Wastage Flashcards

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