m) 9-Dec-13 Flashcards
Potential causes of false positives when measuring progesterone levels for PD in cows?
Measured 21D post service/AI (ideally 24)
- Incorrect timing of AI (AI’ed in dioestrous instead of oestrous, therefore measurement at 21D = second dioestrous)
- Prenatal death (was preg at time of test, then died)
- A luteal (thick walled) cyst producing prog
- Persistant CL (secondary to metritis)
What day can Oestrone Sulphate assay be used as a PD method?
in Cows: Milk of lactating dairy cows.
day 105. From fetal-placental unitIs
Can you differentiate the Corpus luteum of dioestrous from CL of pregnancy on rectal palpation?
NO
PD by palpating for ‘membrane-slip’ is actually feeling for the…
How many days post conception can this method be used?
allantochorion
35th to 40th day of pregnancy
Hypertrophy of the middle uterine artery is known as ____.
How many days post conception?
Fremitus. Do not confuse with pulse of other local arteries.
Middle uterine artery runs in the broad ligament
120 DAYS
At what point in gestation does the uterine ‘disappear’ over the pelvic brim?
From about three to five months of gestation. Due to weight of fetal fluids etc.
Why is diagnosis of pregnancy easier at 8 weeks or before, rather than later?
3-5 months post gestation the uterus is situated well over the pelvic brim therefore out of reach
Ideal time to rectally palpate cows for PD?
42 DAYS.
Why can observing oestrous during pregnancy be a poor/dangerous way of PD?
5% OF PREGNANT cows stand to be mounted (signs of oestrous), if this results in transcervical AI = breach the seal and can terminate the already developing foetus.
Natural insemination= not a problem as bull ejaculates into vagina instead
Why is it not possible to palpate the foetus BEFORE day 35?
Amniotic sac looses its turgidity from day 65.
Two bacteria that cause abortion in sheep
Clamydophila abortus (obligate intracellular pathogen) - outside body known as elementary bodies Campylobacter fetus
Campylobacter fetus veneralis is present asymptomatically on the _______
prepuce of mature bull. Causes catarrhal inflammation of genital tract, endometretis of cow = infertility
Diagnose via sheath washings
Golden period is defined as < __ hours after injury, a contaminated wound may be cleans and closed PRIMARILY without developing an injection
Six hours, a contaminated wound may be cleaned and closed primarily without developing an infection.
Misleading as bacteria have different virulences
Why is prophalactic use of antibiotics not required after the formation of granulation tissue?
Granulation tissue is resistant to infection.
When is delayed primary closure indicated?
Apposition of the skin edges performed 2-5 days after wounding. Indicated for contaminated wounds.
Wound closure in the presence of granulation tissue is known as _____closure
secondary closure.
What is second intention healing?
Disadvantages of this?
Healing by contraction and epithelialisation.
Generally reserved for dirty wounds
COSMETIC; NO HAIR GROWTH
Expensive if many bandage changes, hospital visits, prolonged healing
Wounds made ______ to tension lines will tend to close and have minimal tension
Wounds made PARALLEL to tension lines will tend to close and have minimal tension.
(Wounds perpendicular to tension lines will GAPE and have greater tension)
Deep skin grafts require the incision to be made DEEP to the ______to work as a graft
Cutaneous trunci (deep/subdermal plexus is closely associated to cutaneous trunci)
When doing a tension-releasing Z-plasty the central line of the Z has to be )))))) to the tension lines you are trying to overcome
Parallel to tension lines you want to overcome
A cow that has developed sudden onset fever, dullness and loss of appetite then aborts her calf. The cultures show it is a gram -ve organism. What is it most likely to be?
Salmonella Dublin
Bacteria invade from intestinal tract to blood. Cause a bacteraemia; localise in placenta = placentitis
Which VIRUS’ can cause abortion in cows? How are they spread?
BVDV: Respiratory/ Faecal-oral
BHV: Respiratory
SMV/ Bluetongue: Midges
Two puppies have died suddenly following a brief period of crying/ not feeding. What is the probable pathogen responsible?
Canine herpes virus-1
- Keep puppies warm (virus replicates at lower temperatures)
- Vaccinate the mother
Most common cause of abortion in a cat with enlarged lymph nodes?
Feline leukemia virus. Diagnosis a) dam: antigen test
b) aborted kittens: Immunofluorescence
PRRS and Swine Influenza are both causes of abortion in pigs. How would the diagnostic tests differ?
PRRS: Foetal tissues esp spleen
Swine Influenza: Respiratory samples, nasal swabs
Aborted piglets unlikely to have been infected so virus isolaton normally unsuccessful
Gross pathological differences between a) toxoplasma gondii and b) chlaymophila abortus in sheep
Both cause abortion in sheeo
a) toxoplasma gondii causes strawberry pip lesions in cotyledonary areas
b) Chalymdophia causes thickened intercotyledonary regions (cause of ENZOOTIC ABORTION)
What is the Submission Rate? What is a sensible target for UK herds?
Submission Rate: Percentage of cows identified as being in oestrous and inseminated within a set time period.
Sensible target within 80days: 70%
Sensible target for calving to 1st service?
65 days
What is the most common pathogen that causes abortion in cows? Which month of gestation is this generally seen?
The protozoal pathogen: Neospora caninum
Normally month 5 go 8.
Vertical or Horizonal transmission (ingestion of dog faeces)
Which pathogen is most likely to cause higher return to service rates?
BVDV causes early embro loss so may account for the higher return to service rates
Occular discharge is often the first noticed sign of which pathogen that can lead to abortion in the cow?
Infectious Bovine Rhinotrachitis (IBR) caused by Bovine-Herpes-Virus-1
Conjunctivitis, URT infection, Vaginitis, Pyrexia, Nasal discharge
Significance of the hormonal influence on immunity in pregnancy
Oestrous: Proinflammatory activity of oestrogen (upreg of T/B lymphocytes in ruminants)
Uterus more susceptible to infection during luteal phase (progesterone
By which mechanism are freemartins formed?
Anastomosis of foetal circulations.
Only a problem if two fetus of different sex, male hormones are passed into female foetus circulation
Defintion of follicular cyst
> 2.5cm (cow) >1cm (sow)
Persistance for >10days without functional CL
Anovulation without luteinisation
No LH peak due to low GnRH receptors
Which type of ovarian neoplasm has a ‘shaggy’ cauliflower like appearance?
It is especially common in the bitch.
Cystadenoma (benign) or Cystadenocarcinoma (maligant)
May spread by implantation on peritoneal surfaces (all ovarian neoplasms)
Why does chronic endometritis commonly lead to persistant CL in the mare and cow?
Endometritis stops the production of prostaglandinF2alpha.
This prevents leutolysis and therefore no cycling
Common pathogens that cause endometritis in the mare
Klebsiella pneumonia (capsule 1,2,5) Taylorella equigenitalis Pseudomonas aeruginosa
Why is pyometra more likely in older bitches?
Cystic Endometrial Hyperplasia often preceeds pyometra.
More cycles (i.e. older dog) = more endometrial hyperplasia
E.coli: brownish exudate
Strep sp: yelllowish exudate
How do predisposing factors for pyometra differ in the cow?
In cow, endometritis/metritis predisposes to pyometra or high progesterone levels do you persistant CL (can be caused by endome/metritis as no pgf2a production)
TREATMENT: No systemic signs, get cow cycling again
c.f. MARES KEEP CYCLING
Most common isolate from pyometra in the sow
Trueperella pyogenes
c.f. Mare: Strep zooepidermicus
At post mortom, a cow with lymphocytosis and carcinoma/ lymphosarcoma of the uterus. WHICH DISEASE has to be considered (and reported)
EBL
Enzootic Bovine Leukosis
Notifiable
How do the CL dependent stages differ in the cow, goat, pig, dogs and horse, sheep and cat?
HORSE, SHEEP, CAT= EARLY PREGNANCY ONLY
All pthers: All of pregnancy
NOTE SHEEP AND COW ARE DIFFERENT
How does stress lead to abortion?
Same way as normally initiates parturition.
Foetal ACTH–> increase placental oestrogens etc
(also maternal illness/ hyperthermia)
Bacterial/Fungal abortions in the mare are mostly ____ infections
Ascending because the cervix doesn’t fully close
Majority of abortions in sheep are due to which pathogen
Chlamydophila (thickened intercotledonary areas)
c.f. with Toxoplasma (next commonest): Strawberry pip cotyledons
DDx for thickened leathery placenta following an abortion
Chlamydophila abortus (thickened oedematous)
or MYCOTIC abortions )Aspergillus fumigatus- ascending infection in mare (leathery placenta covered in exudate)
Associated with poor quality feed.
Brucellosis
Cow abortion at 4 months, that is macerated.
The cow also has pyometra/endometritis.
What is the likely pathogen
Tritrichomonas foetus
Infected at coitus (prepuce of male)
one mars bar is __MJ.
It takes ___MJ to produce 1 litre of milk
1 MARS BAR IS 1MJ
1 LITRE OF MILK TAKES 5MJ
Maintenance of 700kg cow: 72MJ/day
Pregancny (full term) added: 35MJ/day
Which is higher in metabolisable energy
a) cereal grains
b) maize silage
c) hay
d) straw
Cereal= highest
Maize
Hay
Straw (low ME)
Cow voluntary feed intake is lowest around ___
Cow VFI is lowest around CALVING and EARLY LACTATION
What BCS should a cow calf at?
When should BCS be altered?
BCS at calving ideally 3.0
Can alter BCS during LATE LACTATION
Which strain of Equine-Herpes virus causes abortion?
EHV-1 causes abortions and respiratory disease
EHV-3 causes genital pustules but not abortion
EHV-4 respiratory only
A mare has aborted in the last third of her pregnancy. The aborted foetus has lung oedema and multifocal necrosis in liver, lung and spleen.
What is the likely pathogen?
EHV-1 (not 3 or 4)
Covered in muconium? stress
Lung oedema shows was alive at start
The equivalent of BVDV in sheep is known as ____
How do the PI lambs present as neonates?
Border Disease.
Hairy shaker lamb disease.
Present shaking as neonates
The equivalent of BVDV in sheep is known as ____
How do the PI lambs present as neonates?
Border Disease.
Hairy shaker lamb disease.
Present shaking as neonates
Symptoms of porcine circovirus,
How would it be diagnosed?
Porcine Circovirus 2:
Abortions, congenital tremors, porcine dermatitis, multifactorial disease.
HISTOPATHOLOGY
NOT PCR= IT WILL BE THERE!
Antibody detection in free foetal fluids are only useful once the foetus is ______
Immunocompetent
no placental transfer of antibodies
When can progesterone in plasma and milk be used as a method of PD?
21-24 DAYS
non return to oestrous after service is 18-24 days
Presence of placentomes as PD can be palpated from day
Placentomes can be palpated from day 80
(SAME AS FREMITUS which is approx 85days
If palpation is difficult, and you need to know if animal is pregnant, oestrogen sulphate in milk can be used from day
105
but day 120 can palpate foetus!
Progesterone is a test for ______
Non-pregnancy
(at day 24, 99% accurate for PD negative)
but if high progesterone could be re-cycling i.e. not pregnant
