TV4101 - Bovine - Toxic and Infectious Repro Loss

Viral Diseases that can cause pregnancy loss include?

Most common one (put in bold)

I. Bovine Viral Diarrhoea Virus

II. Bovine Herpes-1 Virus

III. Akabane Virus

IV. Bluetongue Virus

V. FMD (Australia is free)

VI. Rinderpest

VII. Parainfluenza

VIII.Pseudorabies

Clinical manifestations by gestational stages

Trimester 1?

1. Early embryonic death (0-28 d)

2. Late embryonic death (28-42 d)

3. Regular or irregular return to oestrus

4. Abortion (> 42 – 90 d)

Clinical manifestations by gestational stages

Trimester 2?

1. Abortion

2. Mummification

3. Maceration

Clinical manifestations by gestational stages

Trimester 3?

1. Abortion

2. Mummification

3. Maceration

4. Abnormal foetus > Dystocia > Retained placenta > Metritis

Clinical manifestations by gestational stages

After trinester 3

1. Stillbirth

2. Weak neonates

3. Susceptible to diseases

4. Poor growth rate

5. Calf mortality

Factors Inducing Abortion?

Severe maternal illness

1. High fever

2. Hypoxia

3. Endotoxemia

Placentitis

1. Release of endometrial PGF

2. Low placental blood supply

3. Leads to foetal stress > foetal death or premature calving

Bovine Viral Diarrhoea in Australia
Agent?
Prevalence in AUS?
Forms of disease?

Bovine Viral Diarrhoea Virus or Pestivirus
Widespread across AUS
Acute transient, persistently infected, mucosal disease

Bovine Viral Diarrhoea in Australia
Acute transient form features?

Animal will mount immune response after infection and clear virus in 10-14 days. (Fever and diarrhoea)

Bovine Viral Diarrhoea in Australia
PI form
How does it ocur?
Result?

Virus cross placenta of non-immune pregnant cows and infect foetus
Foetus may become PI calf that may or may not have any CX

Bovine Viral Diarrhoea in Australia
Mucosal Disease Form
How does it occur?

PI animals infected with non-cytopathogenic virus strain → spontaneously mutates into cytopathogenic form → mucosal disease

Bovine Viral Diarrhoea in Australia

Mucosal Disease Form

CX?

sero-mucoid nasal discharge,

severe erosive lesions in oral & intestinal mucosa, diarrhoea, and death

BVDV Gallery
What is each photo?

Left - incoordination (CNS birth defects in PI calf)
Right - cerebellar hypoplasia

BVDV Gallery

What is each photo?

Left - aborted foetus
Right - Normal calf on left and PI calf on right

BVDV Routes of infection?

Route of infection: Inhalation, Ingestion, Venereal, Transplacental (nasal discharge, saliva, semen, urine, tears, and milk)

Impact of BVDV based on gestational stages

Around breeding?
40-120d gestation in naive cow
120-150d gest
>150 days gest

Around breeding
- Disrupted ovulation and fertilisation, EEL

40-120d
- LEL
- Abortions
- Birth of PI
- Ab -ve and virus positive

120-150d
- Abortions
- Congenital defects
AB +ve with or without virus
Cerebellar hypoplasia and hydrancephaly → prolonged gestation

>150
- Birth of normal calf which may be small and weak
- Has competent immune response
- Ab +ve and virus -ve

BVDV - infeced and born alive calves
Mortality?
Disease?
Growth?
Abnomalities?

1. Increase calf morbidity & mortality

2. Prone to respiratory diseases and profuse diarrhoea

3. May be born blind

4. Poor growth rates

5. Low weight at weaning / yearling

6. Die within < 2 years

7. Overall, reduced productiity and profitability

BVDV: Sampling & Tests

Aborted foetus?

1.Detection of BVDV Antigen

• Foetal tissues – Antigen capture ELISA or PCR

2.Detection of BVDV Antibody

• Pericardial fluid – ELISA

3.Gross pathology

• Developmental defects

4.Histopathology

• Mononuclear cell infiltration in skin, lymphoid, and cerebellar tissues

BVDV: Sampling & Tests

PI calves and cattle

Ear notch tissue sample

• AG capture ELISA

• PCR

• Virus isolation

• IHC

Blood – Serum / Plasma

• AG capture ELIS

• PCR

• Virus isolation

BVDV: Sampling & Tests - Agar test and result features?

Agar Gel Immunodiffusion (AGID) Test: Determine recent exposure based on Ab titre

▪ 0: Negative

▪ +1 to +2: Exposed to BVDV, but not within last 12 months

▪ ≥ +3: Infection within last 3-9 months

▪ Won’t detect PI

▪ Won’t detect antibody post-vaccination

BVDV: Sampling & Tests - Milk test and results?

Bulk Tank Milk (BTM) Test – compare the BMT sample Ab against a known positive, resulting in a “sample to positive control” or S/P ratio.

▪ S/P = > 1.00: Active or recent PI exposure, likely lactating PI cattle

▪ S/P = 0.75 to 1.00: Relatively recent BVDV exposure

▪ S/P = 0.25 to 0.75 : Some random or historic BVDV exposure

▪ S/P = < 0.25: Naïve herd and likely free from BVDV

BVDV: Vaccination

Used on who?
Efficacy?
Cost?
Schedule of vax?

1.Whole herd / targeted groups

2.Not 100% effective

3.Approximately $5/dose

4.Requires 2 initial doses followed by annual boosters

BVDV: Prevention & Control

Management of animals

Environment

Closed herd management.

Test & quarantine all new introductions

Vaccinate cattle leaving but later returning to farm

Avoid mixing cattle from different groups

Avoid over the fence contact.

▪ Double fencing

▪ Keep pregnant animal away from

boundary fences

Screen and remove PI animals

Minimise BVDV transfer via fomites

▪ Clean cattle handling, transport, husbandry equipment and protective clothing between different properties / herds / groups of cattle.

BVDV: Prevention & Control

Repro aspects?

Use semen (for AI) form registered / certified

AI centres known to be BVDV free.

Use embryos (for ET) from registered /

certified suppliers known to be BVDV free

Test & confirm ET donors and recipients are

BVDV free.

Bacterial Diseases - Brucellosis in Australia

Agent?
Significance?

Brucella abortus
Zoonotic and notifiable in AUS (gain approval from chief veterinary officer for emergency testing of animal disease)

Brucellosis Gallery

Describe photo

Carpal hygromas

Brucellosis Gallery

Describe each photo

Aborted foetus
Ingesting aborted placenta
Placentitis – Cotyledonary & Intercotyledonary

Brucellosis Gallery

Describe each photo

Unilateral & bilateral scrotal enlargement in rams

Middle - Left: Orchitis & Epididymitis in a ram Right: Normal testicle and epididymis of a ram

Seminal vesiculitis in a bull

First 2 photos technically have brucella ovis as the photos are from ovine species

Brucellosis – ROI

Oral - cont feed and water
Service from brucella infected bulls
AI from brucella infected bull semen
Brucella cont milk machines

Brucellosis - CX in Cows

I. Abortion (> 5 months of gestation)

II. Autolyzed foetus with no gross lesions

III. Still birth > Retained placenta > Metritis

IV. Weak calves (If born alive)

Brucellosis - CX in Bulls

I. Orchitis

II. Epididymitis

III. Seminal vesiculitis

IV. Carpal hygromas

Brucelllosis - Samples used for DX?

Foetal abomasal fluid and lung, placenta, uterine fluids, milk & serum samples

Brucelllosis - DX tests?

For brucella ABs

• Rose bengal test

• Complement fixation test

• Standard agglutination test

Bacterial isolation & identification

Brucellosis - Prevention?

Live attenuated vax - Strain 19 or RB-51

Brucellosis - control

I. Closed herd approach

II. Testing & quarantine of new purchases

III. Bulk milk sample or repeated blood sampling to identify

& remove carriers

IV. Slaughter of positive animals

V. Quarantine during an outbreak

Leptospirosis in Australia
Agent?

Signficance?

*Leptospira hardjo or

Leptospira Pomona or L gryppotyphosa

Severe zoonoses and notifiable in humans in AUS

Leptospirosis in Australia

Shedding?
Environment for organism?

Cattle shed in urine when infected (even for life) or with aborted contents

Moist areas for months b4 infecting humans and cow (floodwaters make it worse)

What can we see from left to right
Affliction?

Left - White spotted kidneys; non-pathognomic
Middle - Icteric mm from haemolysis

Right - Photosensitisation from liver damage

Leptospirosis

Describe each of these photos

Left - Leptospira bacteria under silver staining
Right - Urine contaminated stagnant water - the ideal environment for leptospirosis

Leptospirosis - ROI

Contact via intact mm (nose, eyes, and

mouth ) or abraded skin to..

• Piss cont feed, pasture, soil, water

• Aborted foetus cont environment

Leptospirosis - CS in cows?

Abortion storms >5 months gest
Mastitis → milk drop or agalactia

Photosensitisation

Leptospirosis - CS in calves?

I. High fever

II. Hemolytic anemia > Icteric mm

III. Hemoglobinuria > Reddish-brown urine

IV. High mortality rates

Leptospirosis - TX?

Oxytetracycline, Penicillin, Amoxycillin, Tilmicosin, or

Ceftiofur

Leptospirosis – Pathognomic lesions?

No pathognomic lesions - White spotted kidneys in infected cattle

Leptospirosis - samples for DX?

Urine

Serum

Whole aborted foetus and membranes

Fresh or fixed foetal brain, liver, spleen & kidney

Leptospirosis - DX tests?

I. Bacterial isolation & identification (Difficult)

II. Histopathology – Silver stains < foetal tissues

III. Dark filed microscopy < foetal fluids

IV. PCR or FAT or MAT > to detect Ag in foetal tissues

V. Maternal serology using MAT

Leptospirosis - Prevention and control?

Leptospira vaccine

I. Closed herd approach

II. Testing, Vaccinating & Quarantine of new purchases

III. Good biosecurity measures in place

IV. Bulk milk ELISA for screening

Listeriosis in Australia
Agent?
Significance?

Listeria monocytogenes

Zoonotic - serious illness in humans (mostly immunocompromised ones)

Listeriosis in Australia

Infect humans how?

Via raw milk or raw foods of plant origin that contaminated by manure from infected or shedding cattle

Listeriosis in Australia

Environment for oranism?

Soil, water, and animal faeces

Poorly fermented or spoiled silage is the breeding ground due to low acidity

What can we see here?
Affliction?

Left - soiled silage (low acidity is breeding ground for Listeria)
Middle - Facial paralysis and head tilt → Encephalitis/Meningitis (Listeriosis)

Right - Loss of coordination and circling → Encephalitis / meningitis (Listeriosis)

LISTERIOSIS

What can we see here?

Affliction?

Left - foetal hepatitis (non-pathognomic) with white-yellow foci
Middle - aborted autolytic foetus (mostly 3rd trimester abortions)
Right - Corneal opacity (rare)

LISTERIOSIS

Listeriosis - ROI

Oral → contaminated silage (poorly fermented or spoiled) → bacteria to other organs inc brain (i.e. encephalitis)

Listeriosis - CX in cows

Sporadic abortions (>5 months)

Abortion storms/stillbirths (rare)
Neuro signs from encephalitis (rare)
Retained placenta → metritis → fever and anorexia
Septicaemia (rarE)

Listeriosis - CX - Neruo?

. Loss of coordination & circling

II. Head tilt & facial paralysis

III. Salivation & difficult to eat

IV. Depression and lethargy

Listeriosis - TX

Oxytetracycline or Penicillin

Listeriosis - Pathognomic Lesions?

No pathognomic lesions

Leads to suppurative placentitis

Pinpoint white to yellow foci (may present) in the liver

Listeriosis

Samples for DX?

CSF from affected cows

Whole aborted foetus and placenta

Fresh or fixed foetal brain, liver, spleen & kidney tissues

Listeriosis - DX tests

I. Bacterial isolation & identification – Gram staining

II. Immunohistochemistry – Using Listeria antibodies

III. Histopathology – look for placentitis & foetal hepatitis

IV. PCR – For Listeria antigens

Listeriosis - PX and control?

NO VACCINE

Avoid feeding poor quality silage

Campylobacteriosis Gallery

Describe each photo

Older bulls > deep preputial crypts > more bacteria

Preputial scrape or wash – sample collection

Early embryonic loss – no heartbeat + disintegrated

Campylobacteriosis (Vibriosis) in Australia

Agent?
Aka?
Bulls vs cows/heifers in infection

Campylobacter fetus subsp. venerealis

Also called Vibriosis

Bulls – Asymptomatic carriers

Cows/heifers – Acquire immunity following

infection but it lasts only for < 15 months

Campylobacteriosis – ROI

HX?

Transmission?

History of exposure to outside bulls/cows, recent introductions, shared grazing

Venereal transmission or AI using semen collected from

infected bulls or contaminated collection / AI tools

Campylobacteriosis - CX in cows

I. 10% perm infert – due to oviduct

obstruction after inf

II. EEL → may return to heat

III. Occasionally (4 - 7 months) abortions

IV. Develop immunity – may conceive later in the breeding

season

V. Inc interval from calving to conception

VI. Prolonged inter-calving interval

Campylobacteriosis - TX?

Oxytetracycline or Erythromycin

Campylobacteriosis - Samples for DX?

Cows/Heifers – Vaginal swab

Bulls – Preputial wash or scrape

Placenta – Intercotyledonary

Campylobacteriosis - DX tests?

I. Vaginal mucus

a. Bacterial culture & identification – IHC/DFM

b. IgA ELISA (Low specificity)

II. Preputial sample

a. PCR – 3 tests, one week apart for high sensitivity and

specificity

Campylobacteriosis - Prevention and Control?

Vax herd esp bulls - 2 doses, 4 wks apart
I. Closed herd approach

II. Test & cull older carrier bulls (> 5 Y old)

III. Purchase only younger & virgin bulls

IV. Avoid contact with stray bulls and cows

Vax new bulls b4 introducing for breeding

Protozoal Diseases

Includes? Put more common occuraances in bold and the ones that cause sporadic abortions occaionally in itlaics

I. Trichomoniasis

II. Neosporosis

III. Toxoplasmosis

IV. Theileriosis

Trichomoniasis (Trich) in Australia

Agent?
Aka?

Infections diffs in cow/heifer/bulls?

Tritrichomonas foetus

AKA trich
Bulls - Asympto carriers
Cows/Heifers - transient infection with acquired immunity <6 months

Describe photos from L-R
What is the affliction?

Left - preputial scrape/wash - sample collection
Middle - Epithelial crypts of preputial lining of 5Y bull
Right - Tritrichomonas foetus

Trichomoniasis

Describe photos from L-R

What is the affliction?

Left - Tritrichomonas foetus – Placentitis

Middle - Dead disintegrated foetus
Right - Post-coital pyometra

Trichomoniasis

Trichomoniasis – ROI
HX?
Transmission?

History of exposure to outside bulls/cows, recent introductions, shared grazing

Venereal transmission or AI using semen collected

from infected bulls or contaminated collection / AI tools

Trichomoniasis - CX in cows
Abortions and Disease aspects?

I. Post-coital pyometra***

II. Early embryonic death

III. Occasionally (< 5 months) abortions + edematous

placenta (due to placentitis)

IV. Develop immunity – may conceive later in the

breeding season

Trichomoniasis - CX in cows

Interval and rates aspects?

CX in bulls?

V. Increased interval from calving to conception

VI. Prolonged inter-calving interval

VII. Reduced pregnancy & calving rates

Bulls asympto carriers

Trichomoniasis - TX?

NO Approved Rx available currently

Trichomoniasis - Samples used for DX?

Cows/Heifers – Vaginal swab

Pyometra cow – Uterine sample

Bulls – Preputial scrape or wash

Foetus – Abomasal fluid & Placenta

Trichomoniasis - DX tests?

I. Vaginal mucus / Uterine sample / Foetal abomosal

▪ Histology – H&E stain

▪ Immunofluorescent test (IFT)

▪ Immunohistochemistry (IHC)

II. Preputial sample

▪ PCR – 3 tests, one week apart for high sensitivity

and specificity

Trichomoniasis - Control?

I. Closed herd approach

II. Test & cull older carrier bulls (> 5 Y old)

III. Restrict breeding to bulls of < 5 Y old

IV. Purchase only young & virgin bulls

V. Avoid herd contact with stray bulls and cows

VI. Cull or segregate non-pregnant and aborted cows

VAXX not available in AUS

Neosporosis in Australia

Agent? Features?
Significance?

Neospora caninum - protozoa
Causes ~20-30% of abortions in both dairy and beef cattle in AUS

Neosporosis in Australia

ROI
Horizontal version

Ingestion of feed contaminated with dog faeces

that has Neospora oocysts

Neosporosis in Australia

ROI

Vertical Transmission features?

Most common more critical method

▪ Passing of Neospora oocysts from infected

pregnant cows to their foetus via placenta

▪ Maintain the infection in herd

Neosporosis - CS in cows
Abortion aspects

I. Sporadic or storm of abortions

II. Abortion is possible anytime during gestation but often

between 4-7 months

Neosporosis - CS in cows
Dam aspects that cause abortions

III. Seropositive dams 3-7 times higher risk of abortion

than seronegative dams

IV. Seropositive dams can abort during subsequent

pregnancies

V. Immunosuppressed dams can allow dormant Neospora

to be activated during pregnancy – leading to abortion

Neosporosis - CS in calves (from vertical transmission)

▪ Majority of infected calves show NO clinical signs

▪ If abnormalities present in calves, then:

▪ Underweight

▪ Unable to stand

▪ Flexed or hyper-extended limbs

▪ Lack of coordination

▪ Decrease sensory perception

▪ “Pop-eyed” (exophthalmos) & asymmetry eyes

▪ Birth defects like hydrocephalus

▪ None of these signs are pathognomic for neosporosis

Neosporosis

TX?

Prevention?

No approved TX available
Vax nt available in AUS

Neosporosis - DX

Samples used?

Dams – serum sample

Aborted foetal tissues & placenta (< placentitis)

Neosporosis - DX

Tests?

I. Serum sample – ▪ Positive Ab titres indicate exposure but not sufficient to confirm Neospora is the cause of abortion

II. Aborted foetal tissues and placenta

▪ Histopathology

▪ PCR or ELISA or Immunohistochemistry

Neosporosis - Control
Dogs?

Dog-to-cow transmission

▪ Reducing wild dog/fox population in extensive grazing farming

▪ Prevent contamination of pasture & feed by dog faeces

▪ Prevent farm dogs scavenging aborted foetuses

▪ Aborted foetuses, dead calves, placentas – buried or

burned or disposed properly

Neosporosis - Control

Calf?

Prevent cow-to-calf transmission

▪ Not including infected cows in the breeding herd

▪ Not breeding replacement heifers from infected cows

Blood test to determine infected cows or calves (for

culling but expensive) or as pre-purchase testing.

Toxoplasmosis

Agent?
Signficance?

TX?

Toxoplasma gondii

Zoonoses (pregnant women)

Ingestion of feed contaminated with cat faeces that has

Toxoplasma oocysts

What is this?

Describe each photo

Toxoplasmosis

Pepperoni pizza like cotyledonitis – classical appearance due to Toxoplasma. (Intercotyledonary area is normal)

Cats transmit disease by shedding oocysts in faeces

Toxoplasmosis

DX?

Control?

Diagnosis based on histopathology or FAT on

aborted foetus & placenta

Control cat population in farms and avoid

cont of feed with cat faeces.

Describe each of these photos
What disease?

Top - Bush tick (Haemophysalis longicornis)

Bottom - Theileria orientalisorganism

Theileriosis

Theileriosis

Agent?

Significance?

Bovine Anaemia caused by the Theileria orientalis

Group (BATOG) - infects through the bite of Bush tick (Haemophysalis longicornis)

Getting more clinical important recently in AUS

Theileriosis

CX?

▪ Anaemia

▪ Red urine

▪ Jaundice

▪ Anorexia, lethargy & depression

▪ Pregnant animals may abort or premature birth due to high fever and anaemia

Theileriosis

Control & prevention

▪ Bush tick (Haemophysalis longicornis) control – by acaricides

▪ Quarantine of introductions for 30 days

▪ Avoid stress and stock movements during late term pregnancies

▪ Avoid moving non-exposed cattle to endemic areas

Toxic Causes include?

I. Mycotoxicosis

II. Ponderosa pine needle

III. Nitrate/Nitrite poisoning

Mycotoxicosis

Causative organisms?

Repro outcomes?

Control?

▪ Aspergillus sp.***

▪ Mucor sp. **

▪ Mortierella sp.

▪ Rhizopus sp.

▪ Candida sp.

▪ Absida sp.

Late term abortions, premature births, retarded growth in liveborn calves

▪ Good ventilation

▪ Avoidance or removal of mouldy feed

Describe photo
What is affliction?

Necrotic Placentitis – leads to asphyxia of the foetus

Mycotoxicosis