ch12.alterationsinsexualfunction Flashcards
Examples of congenital abnormalities in bulls that may lead to inappropriate breeding
persistent penile frenulum
penile deviations
Examples of acquired abnormality in bulls that may lead to inappropriate breeding
penile hematoma caused by rupture of tunic albuginea of bulls
–>paraphimosis, adhesions or sensory nerve damage
What lesions are most commonly seen stallion penis’s?
squamous cell carcinoma
cutaneous habronemiasis
What is the most common lesions in rams penis?
ulcerative posthitis (pizzle rot) caused by Corynebacterium renale
**in rams on a high protein diet
Diseases of accessory sex glands are commonly seen in what spp
bulls
stallions
Vesicular gland adenitis in bulls and stallions is described as
- presence of leukocytes in the semen
- enlargement, induration and lobulation noted on palpation and ultrasound of glands per rectum
Azoospermia can be caused by
bilateral sperm granuloma blockage of the ampullae
Treatment of sperm granuloma
-gentle transrectal message
-low dose prostaglandin or oxytocin admin
-frequent semen collections (dislodge granuloma)
When is puberty achieved in the stallion, bull ram and buck?
stallion: 18 months
bull: 9 to 12 months
ram and buck: 7 to 8 months
Cycle irregularities become evident when?
in the display of irregular estrous cycles
-physiologic, pathologic or artifact
(abnomral interval from one estrus to subsequent estrous)
Common causes of cyclic irregularity in ruminants
erroneous heat detection
endometritis
intrauterine therapy
cystic ovaries
heat stress
leptospirosis
infectious bovine rhinotracheitis
bovine virus diarrhea
campylobacteriosis
trichomnoiasis
embryonic death after maternal recognition of pregnancy
Cystic ovarian follicles are seen commonly in what cattle?
high- yielding dairy cattle during the first months postpartum
Cystic ovarian follicles can result in
-interfer with regular cyclic ovarian activity
-nymphomania– a state pof persistent or frequent heats
-progesterone producing luteal cysts result in absence of estrous behavior and prlonged interestrus interval
At what age do mares stop cycling?
older than 25 years old
Sheep and Goats have a pathologic cause of irregular or prolonged estrous cycles in the consumption of what plants?
phytoestrogens from plants such as clover and alfalfa
Common causes of anestrus in mares
season (fall, winter)
poor heat detection
corpus luteum persistence
diestrus ovulation
pregnancy
early embryonic death after recognition of pregnancy
fetal death after endometrial cup formation
psychological impediments
maternal behavior
A variety of conditions can lead to hypothalamic or pituitary suppression preventing the release of what hormones?
GnRH from hypothalamus
-lack of FSH and luteinizing hormong (LH) by the pituitary
What (most common) conditions can cause hypothalamic or pituitary suppression preventing the release of reproductive hormones?
poor nutrition
heavy lactation
periparturient disease
weight loss
idiopathic condition
What incidence of repeat breeding is considered acceptable for dairies?
10 to 15%
What are pregnancy rates per cycle are between what percentage?
60 to 70%
What percentage of mares lose their pregnancy in the first 4 months of gestation?
5 to 8%
What hormone has been shown to be an important mediator of follicular development, steroidogenesis, oocyte maturation and subsequent embryo development
insulin
Early embryonic death definition
death of a conceptus before organogenesis is complete ( about 55 days in horses, 45 days in cattle, 34 days in sheep)
Abortion definition
to pregnancy loss after the copmletion of organogenesis
Stillbirth definition
refers to the delivery of a nonviable fetus at or near term
When do mares, cows, ewes and does recognize a pregnancy endocrinologically?
mare: 11 to 14 days
cow: 15 to 17 days
ewe & doe: day 12
(fetal) Mummification definition
characterized by fluid reabsorption from a fetus retained in a sterile uterine environment
Fetal mummification is most common in what spp?
spp that are multiparous with CL-dependent pregnancy
(fetal) maceration definition
degenerative changes that occur in a fetus after retention in a nonsterile uterine environment
**may be assoc with significant maternal endometrial damage
Equine herpesvirus-1 abortion is usualy at what month of gestation? and pathogenesis?
after 7 months of gestation
**result of exposure and viremia, with damage to the placental vasculature
Exposure of pregnant mares to EAV may lead to abortion with what time period after initial viral exposure?
1 to 3 weeks
Does exposure to EAV at breeding cause a mare to abort later in gestation?
no
Mare reproductive loss syndrome defined as
consumption of eastern tent caterpillars (larva of Malacosoma americanum) by mares causes abortion
Diagnosis of mare reproductive loss syndrome (MRLS) is done by
- placental lesions
- culture of characteristic bacteria from fetal tissues
- conformation of inc caterpillar exposure
- diagnostic elimination of other known causes of abortion
in MRLS what are the most common bacterial isolates?
non-beta-hemolytic streptococci
actinobacilli
What infection results in gross lesions easily recognized as brownish, tick and tenacious exudate on the corionic surface?
Nocardioform placentitis: Crosiella equi, Amycolatopsis spp, Stretomyces spp
What Leptospira spp most commonly causes abortion in horses?
Leptospira interrogans serovar Pomna type Kennewicki
Bacterial and fungal abortions in mares are most commonly due to
infections ascending through the cervix, causing placentitis
What is the most common noninfectious cause of equine abortion?
twin pregnancy
In horses with a twin pregnancy, when is the most common time to abort?
after 7 months
Bacterial abortions in ruminants that are a result of hematogenous spread, can be caused by what bacteria?
Brucella abortus
Arcanobacterium pyogenesBacillus spp
listeria monocytogenes
E. coli
leptospira spp
pasteurella haemolytica
What are the most common infectious causes of abortion in ewes?
Campylobacteirosis (vibriosis)- c. eftus and C fetus subsp jejuni
Chalmydia psittaci
Noninfectious causes of abortion in large animsl include
genetic or chromosomal factors
maternal stress
inadequate nutrition
vitamin or mineral deficiencies
ingestion of poisonous plants or other toxins
hormonal factors
environmental factors
physical factors
certain medications
What is the toxic principle of fescue?
ergot alkaloids
**endophytic fungus Epichloe coenophiala
What is the most abundant ergot alkaloid in tall fescue?
ergovaline
Pathogenesis of agalactia iwth fescue toxicosis
Ergovaline- dopaminergic agonist interacts with DRD2 (dopamine type 2 receptors) that inhibits release of prolactin
Besides preventing the release of prolactin, what is another negative side effect of fescue toxicosis?
vasoconstriction
What are problems reported in horses grazing fescue?
altered hormone concentrations
extended gestation
thickened placenta
premature placental separation
placental retention
dystocia
birth of dysmature foals
inc foal and placental weights
agalactia
In addition to lactogenesis, prolactin exerts an effect on
steroidogenesis (estrogens, progesterone, testosterone)
hair growth and sheeding
libido
synthesis of surfactant by fetal lumbs
maturation of fetal adrenal pituitary axis
What two diseases are caused in ruminants due to ergo alkaloids (vasoconstrictive effects)?
Summer slump- warm climates
Fescue foot- cold climates
Definitive diagnosis of fescue toxicosis is made via
identification of the endophytic fungus in forage or seed samples by microscopic exam
What viruses in ruminants can cause severe cerebral lesions in the fetus, resulting in absence of the hypothalamus and pituitary stalk?
Bluetongue virus
bovine diarrhea virus
border diseae virus
When pregnant ewes ingest what plant on the 14th day of pregnancy, that results in fetuses lacking a pituitary gland or malformed hypothalamic stalk?
Veratrum californicum
What is normal gestation length in a mare, dairy cow, beef cow, ewe and doe?
mare: 310 to 374
dairy cows: 275 to 292
beef cows: 271 to 310
ewe: 143 to 155
does: 146 to 155 days
Define dystocia
difficult parturition
Dystocia in mares and ruminants is more likely to be attributable to fetal causes, such as
malpresentation
malposition
malposture
(as opposed to maternal conditions)
What are the 3 stages of parturition?
- Position of the fetus and myometrial contractions
- rupture of the chorioallantois and delivery of fetus
- expulsion of the placenta
Second stage of parturition in the bovine requires what time frame?
1/2 hour to 4 hours
Second stage of parturition in ewe and does occurs in what time frame?
1/2 hour to 2 hours
Dose of caudal epidural anesthesia in mare
1 to 1.25 ml per 100 kg of 2% lidocaine
Retained fetal membranes are pathologically retained in ruminants after what time frame?
8 to 12 hours
The placenta of the ewe and doe are considered retained after what time period?
over 24 hours
Define galactorrhea
abnormal manifestation of lactation (not the secretion of true milk)
**popularly known as witch’s milk
