Female small ruminant infertility and abortion Flashcards
(32 cards)
What should you ask/look for on your history and physical examination when assessing a small ruminant females fertility?
History: duration of heat, interestrus intervals, reaction to male, breeding/kidding history
Physical exam: body condition, mammary gland conformation, determination of polled vs horned phenotype, external genitalia evaluation (anogenital distance, size of clit, vulvular abnormalities), clear AI speculum or endoscope to evaluate vagina and cervix
What are some specific diagnostics you should perform during your female BSE?
-Transabdominal ultrasound to examine the uterus
-transrectal ultrasound for a more in depth analysis of uterus and to assess ovarian structures
-bloodwork: inhibin B, progesterone, testosterone to assess for granulosa cell tumors
Describe some of the main toxic plants that affect the fertility of female small ruminants
Fusarium (found in moldy corn and wheat): produces estrogenic substances causing a decreased lambing/kidding percentage
Clovers: estrogen like substance can cause cystic hyperplasia of cervix and hydrops uteri
Ponderosa pine: causes last trimester abortions, stillbirths
When does veratrum californium cause cyclopia?
When it is ingested from day 12-14 days of gestation
-if between 0-10 days causes failure to implant, 12-34 causes motor nerve paralysis, 22 to 20 causes cleft palate and 25 to 36 causes hypoplasia of metacarpal and tarsal bones
-exposure also can cause maldevelopment of the fetal pituitary gland leading to prolonged gestations, abnormally large fetuses, increased incidence of dystocias
What toxic plants cause arthrogryposis?
Lupine, locoweed, sudan grass
What is the main toxin associated with veratrum californicum?
-aka false hellebore
-contains teratogenic alkaloid (cyclopamine) that is responsible for causing congenital defects in lambs
Describe some features of locoweeds
-members of genera astragalus and oxytropis
-causes abortions, birth of small weak lambs and bent legs in newborns
-effects seen in as high as 75% of exposed ewes
-the toxin affects the fetal-placental unit leading to delayed placentation, decreased placental vascularization, fetal edema, altered development of cotyledons
Describe some of the clinical features of broomweed toxicosis
-caused by ecbolic toxic (triterpenoid saponin)
-ingestion causes abortions and birth of small weak premature lambs
-also causes GI upset, hematuria, and death
-mainly affects arid regions of the western US
Which toxins are known to cause many congenital abnormalities such as neural tube defects?
Tobacco, poison hemlock, lupine, sudan grass
-main differential caused by bunyavirus infections
What do flixweed and other goitergenic plants cause?
decreased hair, higher birth weights, thyroid hyperplasia
What are the nitrate accumulating forages and what do they cause? How do you diagnose?
Sweet clover, Johnson grass, sorghum, lambs quarter, jimsonweed, sunflower, pigweed, oat hay
-cause abortions
***diagnose by measuring nitrate levels in fetal ocular fluid
What can ergot alkaloids in fescue cause in small ruminants?
Decreased reproductive efficiency
-affects prolactin production
-increases interval from ram introduction to conception
What are the main estrogen producing plants and what do they cause?
Clovers and alfalfa
- cause infertility, irregular/prolonged heats, vaginal prolapse, cystic glandular hyperplasia of the cervix and uterus, enlarged teats, innapropriate lactation
-some reports of uterine inertia and dystocia
What pharmaceuticals can be associated with abortions and birth defects?
-chlorpromazine
-phenylbutazone
-corticosteroids (in late pregnancy)- more of a concern in sheep as they are placental dependent (can result in parturition cascade)
-anthelmintics in benzimidazole class (albendazole, netobimin, parbendazole, cambendazole) given in first trimester can lead to fetal abnormalities
-phenothiazine and levimasole anthelmintics given in the final months of gestation can lead to abortions
Which small ruminant is the most likely to abort from stress?
Goats as they are CL dependent
-young angoras especially susceptible
What are the main causes of stress in small ruminants which can lead to abortions?
-predator attacks, severe weather changes, shearing
Heat stress: decreases reproductive ability and causes fetal wastage, early embryonic losses, abortions, stillbirths
-decreased water intake, obesity, exercise intolerance and fatigue all contribute
-prevent by shearing, providing shade, keeping animals in good BCS, providing trace mineral salt and water access
How does nutrition play a role in reproductive success?
-poor body condition suppresses libido and contributes to embryonic loss, decreased fetal growth, depressed placental growth, fetal mummification and birth of weak young
-over conditioned dams susceptible to hepatic lipidosis and pregnancy toxemia in late gestation
-deficiencies in vitamin A, E, selenium, copper, manganese and iodine are related to irregular estrous cycles and abortion (fetal wastage between 90-120 days gestation)
-flocks grazing on plants that are members of the Brassica family and animals of certain breeds are more susceptible to iodine deficiency
What does copper deficiency cause in lambs?
Enzootic swayback
-lambs normal at birth but develop hindlimb paresis or paralysis within a few weeks
-caused by dystrophic myelination of white matter in the spinal cord
-lesions begin developing during gestation
-no cure-focus on gestating ewes/does
-pigmy goats most susceptible
-copper supplement ewes with caution, consider interactions with other minerals
Describe pseudopregnancy
-very common, up to 3-5% in dairy goats
-also known as mucometra, hydrometra or “cloud burst”
-diagnose with history and ultrasound (will see anechoic fluid in uterus with no cardinal signs of pregnancy, bloodwork shows high P4, anestrus, behavioral signs of pregnancy)
-caused by prolonged luteal phase, treat with PGF2 alpha
-associated with out of season breeding and overuse of hormone manipulations
-may result from early embryonic loss or spontaneous abortion
-pathologic causes: cervical adhesions from dystocia, neoplasia
What are the potential causes of cystic ovarian disease? what are the main clinical signs?
-more common in goats. Owners may note short cycles or nymphomania, follicles >12 mm may be considered cystic
-use of superovulation protocols, phosphorus deficiency, feeding of estrogenic compounds
What is the treatment of cystic ovarian disease?
hCG or GnRH
What are the main neoplasia’s of the female repro tract?
Ovary: tumors are rare but granulosa cell tumors most common- can see nymphomania, virilism, innapropriate lactation. Ultrasound may show enlarged ovary that is either solid or cystic, contralateral ovary devoid of structures and lacks CL. Bloodwork may show elevated testosterone or estradial. Treat with ovariectomy or cull
Uterine: leiomyosarcomas, adenocarcinoma, leiomyofibroma
-treat with uterectomy, cull/euthanasia
What are the main causes of vaginitis?
-Orf (contagious ecthyma) should be ruled out first
-caprine herpes virus (causes vulvovaginitis and balanoposthitis, but can cause abortions)
-granular vulvovaginitis can be caused by mycoplasma, acheloplasma spp, trueparella pyogenes, staph. Treat with vaginal lavage and NSAIDS
-ectopic mammary tissue is another differential (causes vulvar swelling before parturition). can benign neglect or remove surgically
How should you work up abortion cases?
-clinical signs: return to estrus, unobserved abortion or observation of blood tinged vaginal discharge
-fairly common in sheep and goats (up to 5%), usually sporadic
-epidemiologic investigation should be similar to that in cattle (history, physical exam, fetal/placental exam, maternal serology)
