17b: Cow Infertility & Abortions

Primary cause of pathologic anestrus in dairy cows

Cystic ovaries

Primary cause of pathologic anestrus in beef cows

Pyometra or mummified/macerated fetus

When are we more likely to see cystic ovaries in beef cows

In superovulated donor cows

Normal rate of cystic ovarian disease in a dairy herd

10%

What happens to most cystic ovaries in dairy cows

Resolves within 45 days after parturition

Types of cystic ovarian diseases that don’t resolve after 45 days

• Follicular cysts

• Luteal cysts

• Cystic CL

Type of ovarian cyst that is non pathologic

Cystic CL

Follicular cyst v luteal cyst

Follicular cysts usually come in multiples and are thin walled, while luteal cysts usually come as 1-2 and have thicker walls from partial luteinization

Definition of an ovarian cyst in cows

Persistent anovulatory follicle that is >30 mm

T/F: ovarian cysts can be dynamic

True

Causes of ovarian cysts

• Decreased or unsynchronized GnRH release

• LH surge at the wrong time

• Problem with FSH or LH receptors

• High glucocorticoids right before ovulation → problem with LH release

Conditions that can predispose a cow to cystic ovaries

• High milk production

• Winter

• Nutrition: low energy, fat

• Estrogenic molds

• Genetics

T/F: pathologic ovarian cysts in cows are anovulatory

True

Diagnosis for cystic ovaries

US

Findings on palpation that may help differentiate between pathologic cysts and a cystic CL

• Pathologic cysts → anovulatory → decreased uterine tone

• Cystic CL → ovulatory → increased uterine tone

Physical exam findings that may indicate ovarian cysts

High tail head (increased E₂ → muscle relaxation)

CS of follicular cysts

• Anestrus or repeat heat cycles

• Multiple, thin walled cysts

• Flaccid and edematous uterus

CS of luteal cysts

• Anestrus

• One or two thin walled cysts

• Flaccid and edamtous uterus with thick walls

Treatment for cystic ovaries if there is lots of luteal tissue

Prostaglandin

Treatment for cystic ovaries if there is not a lot of luteal tissue

GnRH or LH product to luteinize ± P₄ for 2 weeks prior ± prostaglandin afterward

Once you have treated a cystic ovary and the cow is in heat what should you do

Please breed her to prevent the cysts from recurring

Types of cysts that may not respond well to GnRH alone

Chronic cysts

T/F: it is imperative that we diagnose cystic CLs

False, they ovulate and keep cycling

Typical presentation of a cow a pyometra

Closed pyometra but not septicemic

Palpation/US findings consistent with pyometra in a cow

Enlargement of one or both horns and a CL

DDx for pyometra

Pregnancy

When does pyometra often happen

One cycle after calving

Common causes of pyometra in dairy cows

• Retained fetal membranes

• Postpartum metritis

Common causes of pyometra in beef cows

• Post coital pyometra

• Tritrichomonas fetus

Treatment for pyometra in cows

Lyse the CL with 1-2 doses of prostaglandin

Fetal mummification

Sterile fetal death followed by autolysis

Demographic for fetal mummification and why

Feedlot heifers; those with unknown pregnancies get vaccinated upon arrival to the feedlot

Palpation findings associated with fetal mummification <4 mos gestation

Will feel like a mass

Palpation findings associated with fetal mummification >4 mos gestation

You will feel the fetus but no placentomes or fluid

DDx for hard mass in the uterus

Mummification or LSA

Diagnosis for fetal mumification

• Hx of failure to calve

• Anestrus

• Palpation of mass or fetus

• US

When is it more effective to treat mummification medically

<5 mos

Treatment for fetal mummification <5 mos old

Prostaglandin x2

Treatment for fetal mummification >5 mos old

• Moisten the uterus, repeated prostaglandin, E₂ or PGE₂ to dilate the cervix

• C section

Why do later mummifications respond less to medical treatment

The fetal-placental unit is defective