Female small ruminant infertility and abortion

Question 1

What should you ask/look for on your history and physical examination when assessing a small ruminant females fertility?

Answer 1

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

Question 2

What are some specific diagnostics you should perform during your female BSE?

Answer 2

-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

Question 3

Describe some of the main toxic plants that affect the fertility of female small ruminants

Answer 3

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

Question 4

When does veratrum californium cause cyclopia?

Answer 4

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

Question 5

What toxic plants cause arthrogryposis?

Answer 5

Lupine, locoweed, sudan grass

Question 6

What is the main toxin associated with veratrum californicum?

Answer 6

-aka false hellebore
-contains teratogenic alkaloid (cyclopamine) that is responsible for causing congenital defects in lambs

Question 7

Describe some features of locoweeds

Answer 7

-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

Question 8

Describe some of the clinical features of broomweed toxicosis

Answer 8

-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

Question 9

Which toxins are known to cause many congenital abnormalities such as neural tube defects?

Answer 9

Tobacco, poison hemlock, lupine, sudan grass
-main differential caused by bunyavirus infections

Question 10

What do flixweed and other goitergenic plants cause?

Answer 10

decreased hair, higher birth weights, thyroid hyperplasia

Question 11

What are the nitrate accumulating forages and what do they cause? How do you diagnose?

Answer 11

Sweet clover, Johnson grass, sorghum, lambs quarter, jimsonweed, sunflower, pigweed, oat hay
-cause abortions
***diagnose by measuring nitrate levels in fetal ocular fluid

Question 12

What can ergot alkaloids in fescue cause in small ruminants?

Answer 12

Decreased reproductive efficiency
-affects prolactin production
-increases interval from ram introduction to conception

Question 13

What are the main estrogen producing plants and what do they cause?

Answer 13

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

Question 14

What pharmaceuticals can be associated with abortions and birth defects?

Answer 14

-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

Question 15

Which small ruminant is the most likely to abort from stress?

Answer 15

Goats as they are CL dependent
-young angoras especially susceptible

Question 16

What are the main causes of stress in small ruminants which can lead to abortions?

Answer 16

-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

Question 17

How does nutrition play a role in reproductive success?

Answer 17

-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

Question 18

What does copper deficiency cause in lambs?

Answer 18

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

Question 19

Describe pseudopregnancy

Answer 19

-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

Question 20

What are the potential causes of cystic ovarian disease? what are the main clinical signs?

Answer 20

-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

Question 21

What is the treatment of cystic ovarian disease?

Answer 21

hCG or GnRH

Question 22

What are the main neoplasia’s of the female repro tract?

Answer 22

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

Question 23

What are the main causes of vaginitis?

Answer 23

-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

Question 24

How should you work up abortion cases?

Answer 24

-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)

Question 25

Describe the clinical features of chlamydophila abortus

Answer 25

-zoonotic, gram negative intracellular bacteria causing enzootic abortion (due to development of necrotizing placentitis)
-one of the most common causes of infectious abortion of sheep and goats in the US (up to 60% abortion rates after introduction to naiive flocks)
-can cause buck epididymitis, keratoconjunctivitis, pneumonia, polyarthritis
-transmitted via oro-nasal contact of aborted tissues, vaginal discharge or contaminated neonates (infected females can shed organism 3 weeks after abortion)
-clinical signs include late term abortions, anorexia, vaginal discharge, fresh or autolyzed fetus, weak kids, retained fetal membrane
-diagnosis: placenta should be examined for thickened white, gray, yellow or red cotyledons, aborted kids may have white spots on liver, cytology (of cotyledons for elementary bodies), culture or PCR from fresh placenta, stomach contents, fetal tissue and/or dam serology
-treat with oxytet or tylosin
-management: cull affected females, pre-breeding vaccines, biosecurity

Question 26

Describe the clinical features of coxiella burnetti

Answer 26

-zoonotic obligate, pleomorphic intracellular rickettsial organism
-causes abortion via placentitis in goats (non specific clinical signs), cays, cattle, sheep can be sources of infection
-shed via placenta, uterine fluid, colostrum, milk, urine, feces, semen
-diagnosis: placental lesions (white areas of necrosis and mineralization), serology, PCR/culture/histology from placenta
-treatment: cull animal, doe can develop lifelong immunity but can carry and shed indefinitely

Question 27

Describe the clinical features of campylobacteriosis

Answer 27

-caused by c jejuni and c fetus ssp fetus
-zoonotic gram negative microaerophilic rods
-significant cause of abortion of sheep worldwide
-causes in utero fetal death due to hepatitis, pleuritic, peritonitis. Late gestational abortions, stillbirths, weak lambs seen
-transmitted through infected feces (jejuni), aborted fetuses, placenta (fetus)
-ewes usually develop lifelong immunity but some may shed throughout life
-diagnose through culture with special conditions or serology
-treat with antibiotics (penicillin, streptomycin, teracyclines)- may or may not eliminate carrier state
-prevention with vaccination and biosecurity

Question 28

What are some less common bacterial causes of abortions in small ruminants?

Answer 28

Brucellosis, listeriosis, salmonella, leptospirosis, mollicute, yersinia (sheep-systemically ill), opportunistic bacterial (fusobacterium, ecoli)

Question 29

Describe the clinical features of toxoplasmosis gondii in sheep/goats

Answer 29

-zoonotic, common infectious agent in sheep and goats
-cats are definitive host and shed in feces (dams infected when ingesting oocyst contaminated feedstuff)
-less than 40 days results in embryonic abortion, 40-120 results in fetal mummification, maceration, abortion; greater than 120 results in premature, stillborn weak lambs via NECROTIZING PLACENTITIS
-similar placental lesions to coxiella, brucella and chlamydophila (gray to white cotyledons with focal areas of calcification and necrosis)
-diagnose with PCR, IHC on fresh placenta, serology
-coccidiostats mat reduce incidence of abortions (extralabel)
-biosecurity and prevention are key: fetal membranes and aborted materials not used in diagnostics should be incinerated, kittens and pregnant queens should be kept from pasture and feedstuffs used for feeding pregnant does, spayed queens kept in barns may prevent feral pregnant queens from nesting, keep feedstuff in areas or containers to minimize contamination

Question 30

Describe how family bunyaviridae viruses can lead to abortion

Answer 30

-includes cache valley virus
-causes in utero death through necrotizing non suppurative encephalomyelitis, polymyositis, hydrocephalus, axial skeleton deviations, arthroryposis, anasarca, oligohydramnios
-diagnose through serology and presence of congenital abnormalities (such as arthrogryposis)
-no vaccines available so biosecurity is key (spread by mosquitos and cullicoides)

Question 31

Describe hairy shaker disease in lambs

Answer 31

-caused by border disease
-results in abortions and congenital abnormalities in sheep (cerebellar hypoplasia, hydrancephaly, porencephaly, arthrogryposis)
-similar pathogenesis to BVD
-diagnose through serology from fetal and maternal blood
-prevent through culling infected animals, biosecurity, killed BVD vaccines (no evidence though)

Question 32

Describe the pathogenesis of bluetongue virus

Answer 32

-transmitted by culicoides spp (biting minge)
-infected ewes may become febrile, have vascular endothelial damage resulting in swollen tongue, ears, face (goats rarely develop signs)
-fetal death in utero (wont see placental lesions) is due to hepatic necrosis and hydrancephaly (lambs can be born live and viremic)
-diagnose via viral isolation or PCR from blood, semen, brain, spleen, serology
-vaccine is available but has limited efficacy, fly control/management