Abortion pathogens Flashcards
How do you differentiate follicular cysts from luteal cysts on ultrasound?
Follicular = thin walled, Luteal = thick walled, >3cm
How can follicular cysts (thin walled) be treated?
Burst
GnRH
Or leave
Should you serve a cow that comes into heat straight after follicular cyst treatment?
No - do not inseminate as cyst may have ovulated (egg old and fertile)
Await next oestrus
What is the treatment for luteal cysts (thick)?
Prostaglandin
If unsure if luteal, progesterone device
What is purulent uterine discharge AFTER 21d postpartum?
Endometritis
What is purulent discharge in the vagina and an enlarged uterus WITHIN 21d postpartum?
Metritis
What is accumulation of purulent discharge within the uterine lumen in the presence of CL and a closed cervix?
Pyometra
What is the treatment for pyometra?
Prostaglandin (PGF-2)
What are the grades of endometritis?
Grade 0 - normal, clear/translucent Grade 1 - flecks of pus Grade 2 - <50% pus or <50ml exudate Grade 3 - >50% pus or >50ml Grade 6 - with odour
What are the grades of metritis?
Grade 1 - enlarged uterus, purulent discharge but no pyrexia/illness
Grade 2 - systemic illness/pyrexia
Grade 3 - toxaemia (cold extremities, dull)
Name some 2 pathogens involved with metritis and endometritis
E. coli
Trueperella pyogenes
Fusobacterium necorphorum
IBR is caused by BHV-1. What may be seen on PME?
Liver necrosis
Are PI cows with BVD antibody and antigen positive or negative?
Antibody negative
Antigen positive
If a cow is infected with BVD in the first trimester (up to 95 days), what happens to the pregnancy?
Foetal resorption/abortion
If a cow is infected with BVD from days 95-120d of pregnancy, what happens?
Immunotolerance
Causes PI calf
If a cow is a infected with BVD from day 120-285 of gestation, what happens?
Seropositive foetus with congenital abnormalities
Or abortion due to placentitis
The UK is now free of Brucella abortus, an intracellular pathogen. How long do cows remain infected for? How does this pathogen cause abortion?
Infected for life
Abortion due to placentitis
Which pathogens can infect pregnant cattle at ANY month of gestation?
BVD
Salmonella
Arcanobacterium pyogenes
Mycobacterium tuberculosis
Trichomonas causes abortion of cattle how far along in gestation?
2-4 months
Neospora causes abortion in cattle that are how far along in gestation?
4-6 months
Brucella abortus causes abortion in cattle that are how far along in gestation?
6-8 months
What abortion percentage should farms aim for?
<5%
40% of bovine abortions are due to infectious disease. Give examples of what may cause non-infectious abortion
Nutritional: deficiency or NEB
Developmental: toxins, trauma, twinning, hormonal problem
At how many days gestation does the foetus have T-cell recognition of self?
90-120d
At how many days gestation does the foetus produce antibodies against BVD, Salmonella dublin and fungi?
BVD = 140d
S. dublin = 165d
Fungi = 200d
Give examples of consequences of the presence of BVD in a herd
Abortion
Lower pregnancy rates
Congenital abnormalities
Mucosal disease
Give examples of how BVD can be controlled
Vaccination before 1st breeding
Test bulls, bought in animals
Test and cull PIs
Avoid co-grazing with sheep
How often is the bulk milk tank screened for Brucella abortus antibodies? How is B. abortus prevented?
Monthly
Vaccination
Apart from Campylobacter causing abortion, what other repro problem can it cause?
Endometritis
C. fetus fetus + C. fetus veneralis
How is Camyplobacter diagnosed in cows?
PCR or culture of:
Preputial wash in bulls
Vaginal mucus aspiration in cows
‘Campy kit’
Where does IBR (BHV-1) remain latent in carriers?
Trigeminal nerve
Recrudesence due to stress
How is IBR diagnosed? How is it prevented?
ELISA or immunofluoresence
Prevent with vaccine - can be used in face of outbreak
Where does Leptospirosis hardjo (zoonotic) reside and how is it excreted?
Kidneys
Excreted in urine (for months-years)
How is Leptospirosis controlled?
Vaccination
Bulk milk antibody testing
L. hardjo is often unapparent as it is in the latent state, but may cause RFM, infections of the repro tract and abortions, still births or weak calves. How is it diagnosed?
Bulk milk Ab testing for presence in herd
Serology
IF or PCR on aborted tissue, blood or urine
Which 2 antibiotics are used to treated Leptospirosis?
Dihydrostreptomycin
Oxytetracycline
Neospora causes abortions at 4-6 months gestation. When are congenitally infected heifers most likely to abort (which pregnancy)?
1st pregnancy
10% abort, 10% weak calf, 80% PI calf
How can Neospora be diagnosed on PME?
Brain histopathology
of foetus
Is there a vaccine or treatment for neospora?
No
What are the 2 ways Neospora is transmitted?
Exogenous - ingesting oocysts
Endogenous - transplacental
How is Neospora diagnosed in adult cows?
Maternal serology - increasing Abs suggests recrudesence
Test calf at birt
How is Neospora controlled?
Keep dogs away from cattle feed and water, don’t allow dogs to eat placentas
Cull sero +ve cows and offspring
Breed to beef bulls
Use sexed semen to get Heifers from uninfected animals
How is Salmonellosis controlled?
Vaccination
How is Trichomoniasis spread?
Natural service (venereal)
Abortion from Trichomoniasis is rare. What clinical signs does Trichomoniasis cause (not in UK)?
Pyometra, endometritis
Poor pregnancy rates
What sample should be taken from a foetus PME to diagnose BVD?
Spleen or thymus
PCR
What sample should be taken from a foetus PME to diagnose Neospora? What test is used to diagnose Neospora in this tissue?
Brain
PCR or histopathology
What sample should be taken from a cow to diagnose Leptospirosis or IBR?
Blood
Serology
What congenital abnormalities does BVD cause in calves?
Microphthalmia
Cataracts
