Therio - Bovine - Subfertility

drraythe's version from 2017-09-10 02:34


Question Answer
What are 4 examples of conditions which might be considered bovine subfertility?(1) Fxnl Infertility (Anestrus; “Silent heat” & Cystic ovarian Dz)
(2) Repeat breeder cow
(3) Congenital defects of the genital tract
(4) Venereal dzs
What are the 3 conditions which compose fxnl infertility?(1) Anestrus
(2) Cyclic subestrus (“silent heat”)
(3) Cystic Ovarian Dz (COD)
Fxnl infertility is most commonly associated w/ post-partum period due to what 2 things?(1) Hormonal changes (Prolactin? Effect of expression of estrus?)
(2) Stress: onset of lactation, Nutrition (cows often in a neg energy balance), social structures, milking parlor (1st calvers)
True anestrus & delayed puberty is usually czd by what 4 things?(1) POOR NUTRITION
(2) Lactational anestrus (esp. beef, bc she’s w/ her calf)
(3) Heat stress
(4) Anatomical problems eg. Freemartinism
Explain situations which can cz poor/inadequate nutrition & can lead to fxnl infertility?During post-partum period = neg energy balance, during puberty bc still trying to grow…. (65% of adult body mass = puberty)
What would you find on rectal palpation of a cow going through True anestrus/delayed puberty?Small inactive ovaries
How can you try to treat True anestrus & delayed puberty?Address underlying czs eg. Nutrition, & Can attempt to “kick start” cycle w/ estrus synch w/ progestagen (CIDR)
What is Silent heat?Cow has normal ovarian activity in the absence of heat signs
What are 4 czs of silent heat?High incidence post-partum
Management (poor estrus detection, slippery floors)
How might you be able to Dx a silent heat?Rectal palpation (feel active ovaries), ultrasound exam, Milk progesterone test
How can you treat a silent heat?Estrus synch w/ vigorous heat detection or FT-AI
How would you define Cystic Ovarian Dz?1 or more cystic structures on the ovary that Persist for > 10 days & Prevent normal cyclic activity
Who gets cystic ovarian Dz most often? WHEN do they get it most often?Predominantly a Dz in high-producing dairy cows
Highest incidence during the post-partum period
Follicular vs Luteal cysts → what are the walls like for these?Follicular is thin walled (like blisters, remember) & luteal is thick walled
Follicular vs Luteal cysts → which is more likely to have a single cyst?Luteal (although can also be mult.)
Follicular vs Luteal cysts → which hormones are produced by which?Follicular produces estrogens/androgens, luteal produce progesterone
Follicular vs Luteal cysts → CSs of each?Follicular cysts (make estrogens) can cz anestrus,
Virilism (male characteristics)
Raised tail root (long term estrogen)

LUTEAL cysts just cz anestrus
Follicular vs Luteal cysts → how do you Tx each?FOLLICULAR: GnRH, hCG, OvSynch programme, CIDR + PGF programme
LUTEAL CYSTS: induce luteolysis
Follicular vs Luteal cysts → how do these appear on ultrasounds?FOLLICULAR is thin walled & dark inside. LUTEAL has a cobwebby appearance inside
GnRH analogues work how to cz what to happen to the cow?Work on pituitary (the pituitary naturally makes FSH) which czs a new follicular wave to happen, & also (czs pituitary to release LH) which czs luteinization or ovulation (only ovulation if CL present, otherwise just make luteal tissue)
What is used to cz superovulation?Injxns of FSH analogues
How do FSH analogues affect the cow?Czs development of multiple follicles = superovulation


Question Answer
Is repeat breeding a herd or individual problem?Individual -- if it IS a group problem, Check bull / semen used for AI / Inseminator / heat detection
How do you define repeat breeder?A cow (heifer) that appears to have a normal genital tract, but fails to conceive after repeated (3+) inseminations
4 main reasons you might have a repeat breeder as an individual?(1) Endocrine disturbances
(2) anatomic abnormalities
(3) Uterine environment
(4) Genetic abnormalities of the embryo
What are some endocrine disturbances that might cz a repeat breeder cow?Delayed ovulation? = aged oocyte. Heat stress??
What are possible anatomic abnormalities that could lead to a repeat breeder cow?Non-patent Uterine Tube?, adhesions
What are some examples of when the uterine environment can lead to a repeat breeding cowSubclinical Endometritis
Campylobacter/Trichomoniasis Infxn
Endometrial fibrosis
Damage to cervix
How common are genetic abnormalities of the fetus w/ cows? If there were, what would the COW be considered?Very uncommon, but would lead to a repeat breeder
What are the 4 main reasons you might have repeat breeders as a group?(1) Natural service w/ infertile/sub-fertile bulls
(2) Artificial insemination (technique, timing of insemination, poor semen quality)
(3) Nutritional deficiencies
(4) Environmental temperature
What are 3 congenital defects that can lead to fxnl infertility?(1) Freemartinism
(2) White Heifer Dz
(3) Poor vulvar confirmation
What kind of problem is white heifer dz, & what are the problems this Dz czs in the cow?A congenital defect leading to a persistent hymen, Segmental aplasia of the tubular genital tract, Uterus unicornis, double cervix
What problems does poor vulvar conformation lead to which can cz fxnl infertility?Pneumo- or uro- vagina (congenital defect)
**WHICH is a VENEREAL Dz -- Campylobacter fetus fetus or campylobacter fetus venerealis?Venerealis (duh)
What problems does campylobacter fetus fetus cz?Czs ABORTION BUT NOT INFERTILITY. It is NOT a venereal dz, but rather a GIT inhabitant
What type of organism is Campylobacter fetus venerealis?Gram-neg short, curved rod or spiral
explain the pathogenesis of Campylobacter fetus venerealisMaintained in preputial crypts of bulls (who show no CSs) (venereal dz)- → Spread by natural service or AI → Czs (transient) Endometritis, which Results in EED (hence needing rebreeding) or Occasional abortion
How does Campylobacter fetus venerealis affect the cows? (Short term? long term?)Most cows rid themselves of Infxn & go on to conceive, but Some cows will remain chronic carriers & be a source of Infxn in following breeding season
How does Campylobacter fetus venerealis affect the BULLS? (Short term? long term?)Younger bulls usually rid themselves of Infxn, but Older bulls (>3 yr) usually remain permanently infected (where it lives in the crypts of their preputium to infect mates)
What are the CSs of Campylobacter fetus venerealis in COWS? In BULLS?In cows, you will see Lengthened estrous periods/irregular estrus periods, repeat breeders, abortion (not as common). For BULLS, there are no CSs
How can you Dx Campylobacter fetus venerealis in COWS?Check Cervico-vaginal mucus during estrus or following abortion
How can you Dx campylobacter fetus venerealis in BULLS? (Explain details)Sheath scraping/Sheath wash that must be done 3 times w/ weekly intervals (low sensitivity of test). Place sample In phosphate buffered saline (PBS) on ice to be shipped to the lab w/in 24h for culture or IFAT (Immunofluorescent Antibody Testing)
Which dz do you do sheath scrapings for?Campy fetus venerealis (lives in preputium of bulls asymptomatically)
How do you treat COWS for campy fetus venerealis?Postpone breeding period for 60-90 days to allow immunity to develop. Cows w/ clinical abnormalities should be culled.
How do you treat BULLS for campy fetus venerealis?Double dose of vaccine w/ a 4 wk interval (most bulls), & can + streptomycin
What are some ways you can control/prevent campy fetus venerealis?TEST bulls BEFORE the breeding season! Cull all pos animals. You can Vx, keep a closed herd, keep fences in good repair, & only use virgin bulls
What kinda organism is Tritrichomonas fetus?Flagellated single-cell protozoan
Explain the pathogenesis of tritrichomonas fetus in the cowMaintained in preputial crypts of bulls → Spread by natural service or AI or iatrogenically → Czs (transient) Endometritis/pyometra → Results in EED Occasional abortion
Does tritrich or campy cz the possible pyometria?TRITRICH
What is usually the end result of tritrich Infxn in COWS?Most cows rid themselves of Infxn & go on to conceive (immunity lasts +/- 15 mos). Some cows will remain chronic carriers & be a source of Infxn in following breeding season
What is usually the end result of tritrich Infxn in BULLS?Younger bulls usually rid themselves of Infxn, Older bulls (>3 yr) usually remain permanently infected
What are the main CSs of tritrich in COWS?Irregular estrous cycles / Repeat breeders, (abortion), PYOMETRA ← unique
What are the CSs of tritrich in BULLS?Asymptomatic, Sometimes mild Balanoposthitis
What are signs that there may be a herd problem w/ tritrich?Many pregnancies at a younger than expected age (czs irreg estrous cycles)
*How do you Dx tritrich? Who do you wanna test?Check the BULLS w/ Sheath scrape/Sheath wash for 3 times at weekly interval. Use PCR or in-pouch culture medium
How do you usually treat COWS for tritrich?Cows generally recover spontaneously
How do you usually treat BULLS for tritrich?Costly, labor-intensive & has a high rate of complications. Can use Dimetridazole per os, but can kill rumen critters (& lead to rumen stasis & thiamine deficiency), Metronidazole i/v, Administer w/ course of ABx (Micrococcus spp. In preputium inactive compound) (Diminazene topically in preputium?)
What are some ways to control tritrich?Vx of cows is partially efficacious, TEST bulls BEFORE the breeding season, Cull all pos animals/keep a closed herd/Keep fences in good repair/ Only use virgin bulls. Consider state regulations
If you notice there is a tritrich outbreak, what should you keep in mind as a vet?Consider state regulations - some states have these
Campy vs tritrich → any differences in xmissin?Both via venereal spread, tritrich can also be iatrogenic
Campy vs tritrich → any differences in Tx?Campy has 2 Vxs w/in 4 wks for bulls, tritrich Tx is controversial (for cows, both is that they will clear on their own)
Campy vs tritrich → any differences in prevention/control?Tritrich is Vx of cows ONLY.
(Granular Vulvovaginitis...usually czd by? what do you usually see w/ this problem?)Various mycoplasma & ureaplasma’s isolated. Can be present w/o any CSs, or can see: Heifers hold tails up & urinate frequently (due to vaginitis), Papules found in the vagina & vestibulum, Similar lesions may occur on penis & preputial mucosa of bulls. Abortion/infertility (Endometritis, salpingitis). XMSSION via coitus/AI