Veterinary Reproductive Health Quiz

Postpartum Period in the Cow

• The postpartum period is the time after calving, involving uterine involution and resumption of the estrous cycle.
• Lochia, a discharge, is typically expelled in the first few weeks after calving.
• Lactation begins, increasing metabolic rate and calcium mobilization.
• Delayed uterine involution can cause discharge to persist for up to 30 days.
• Normal postpartum discharges vary in color from dark brown to red to white.
• Discharge is considered abnormal if it is fetid or accompanied by systemic signs.

Uterine Involution

• Uterine size decreases.
• Uterine tone increases (feeling of lines or strips).
• Fluid in the uterus is absent after 14 days, even in dairy cows.
• Dairy cows typically take 30 days for gross involution, and 45 days for histologic involution.
• Beef cows typically take 21 days for gross involution and 30 days for histologic involution.

Retained Fetal Membranes (RFM)

• Most cows expel the placenta within 6 hours.
• Retained fetal membranes are considered present if the placenta is not expelled within 24 hours postpartum.
• RFM causes detrimental effects on reproductive performance, milk production, health, and culling rate.
• Primary retention is when the placenta does not detach.
• Secondary retention is when the detached placenta is not expelled. Spontaneous expulsion of RFM occurs 5–7 days postpartum, often accompanied by cotyledon proteolysis and caruncle necrosis. Possible reasons for RFM include: a deficiency of collagenase, hypocalcemia (<8mg/dL), deficient polymorphonuclear leukocyte (PMN) migration and phagocytosis, deficiencies in the anti-collagenase system

Risk Factors for RFM and Postpartum Uterine Infections

• Obstetric: Abortion, multiple births, previous retained fetal membranes, Cesarean section, dystocia, advanced age.
• Physiologic: Short gestation periods and low calf weight, calving during summer.
• Hormonal: Prepartum cystic ovarian ablation, abnormal progesterone (P4), estrogen (E2), induced delivery (PGF2α).
• Nutritional: Selenium (Se) and vitamin E deficiencies, feeding hay and corn silage, excess iron.
• Infectious: Brucellosis-positive status.

Treatment of RFM

• Manual removal is generally contraindicated due to the risk of predisposing uterine infections and prolonging the interval until the next ovulation.
• Hormonal therapy: Oxytocin is the preferred ecbolic hormone in the early postpartum period. 20-30 IU 3-4 times daily may be used.
• Antibiotics: Ceftiofur is a preferred antibiotic treatment used to delay the release of RFM by inhibiting putrefaction.

Uterine Infections—Predisposing Factors

• Retained fetal membranes.
• Hypocalcemia and ketosis.
• Dystocia.
• Delivery of twins.
• Overconditioning and underconditioning.
• Large herd size
• Unsanitary calving conditions.
• Traumatic obstetric procedures
• Stress.

Organisms Commonly Associated with Uterine Infection

• E. coli
• Trueperella pyogenes
• Fusobacterium necrophorum and Bacteroides melaninogenicus
• Other coliforms
• Pseudomonas aeruginosa
• Staphylococci, hemolytic streptococci,
• Clostridium spp

Defining Uterine Infections

• Character of uterine discharge.
• Days postpartum.
• Clinical findings.
• Endocrine status.

Metritis

• Severe inflammation involving all layers of the uterus (mucosa, submucosa, muscularis, serosa).
• Primarily occurs during the first week after calving.
• Associated factors include dystocia (difficult birth), RFM, calving trauma, ketosis, and hypocalcemia.

Metritis—Diagnosis

• History of dystocia and/or RFM.
• Decreased milk production.
• Physical exam: Fever, anorexia, and depression.
• Rectal palpation: Distended and flaccid uterus, thickened wall, liquid in lumen, lack of longitudinal lines, fibrin and adhesions.
• Fetid vaginal discharge.
• Blood work: Left shift, severe neutropenia, hypocalcemia, ketosis, increased haptoglobin and substance P.
• Ultrasound is unnecessary.

Metritis—Treatment

• Systemic Antibiotics: Ceftiofur (3G cephalosporin, broad-spectrum).
• Fluid Therapy: Address dehydration.
• NSAIDs (Nonsteroidal anti-inflammatory drugs): Flunixin meglumine (to address inflammation, fever, toxemia; may improve appetite)
• Nutritional Supplement: Supplement with Ca, dextrose, and polyethylene glycol for ketosis.

Endometritis

• Inflammation of the endometrium, not deeper than the stratum spongiosum.
• Occurs after RFM, metritis, mating, artificial insemination, or infusion.

Endometritis—Diagnosis

• Presence of purulent vaginal discharge (PVD) >21 days postpartum.
• Discharge in cranial vagina or ventral commissure.
• Associated with PVD but pus or PMNs may not always be present.
• Affects pregnancy rate and calving intervals.
• May be accompanied by cervicitis and vaginitis.

Endometritis —Clinical/Subclinical

• Clinical: Purulent vaginal discharge.
• Subclinical: (Cytological): Inflammation as evidenced by specific percentage of PMNs in uterine cytology relative to days postpartum. Immunosuppression (low percentage of PMNs and monocytes in peripheral blood).

Endometritis—Diagnosis (cont.)

• Clinical Diagnosis Criteria Discrepancy: Subjective with low sensitivity and specificity.. (e.g., transrectal palpation (TRP), transrectal ultrasound (TRUS), vaginoscopy)
• Transrectal Palpation: Asymmetry of uterine horns, increased uterine wall thickness, or presence of fluid, cervix >7.5cm in diameter.
• Ultrasound: Usefulness inconsistent, particularly for subclinical cases. Limited to detecting small fluid amounts in the uterine horns. Detecting uterine thickness and echogenicity.
• Endometrial Cytology: PMN cell response against pathogenic bacteria. Increases in PMNs in uterine lumen. Can be used to identify cows with endometritis. Useful in identifying subclinical endometritis (given specific criteria).
• Endometrial Biopsy: Increased detail of inflammation (epithelial damage, edema, infiltrates of PMNs and lymphocytes, fibrosis) but costly and less practical.

Endometritis—Treatment

• Antibiotics and PGF2α administration (two doses, 14 days apart).
• P4 and Luteolysis.
• Intravenous infections with oxytetracycline not recommended due to low absorption, and risk of residues in meat and milk.

Pyometra

• Suppurative discharge (pus) in the uterine lumen, associated with prolonged corpus luteum activity and closed cervix.
• Persistent exudate,
• Possibly caused by persistence of corpus luteum, and immune suppression.
• First ovulation after cleaning the uterine bacterial contamination.

Pyometra—Diagnosis

• Transrectal palpation: Thicker uterus wall.
• Ultrasound: Confirms purulent fluid. Suggests variable echogenicity (consistency) of fluid, identifies corpus luteum in an ovary, and rules out pregnancy.

Pyometra—Treatment

• Two doses of PGF2α 14 days apart for inducing luteolysis.
• High success rate of pregnancy after initial treatment.
• 15-20% of cows may require additional treatment.

Minimizing Uterine Inflammation in Cattle

• Identifying herd-specific risk factors (breeding and calving)
• Management strategies include sanitation, nutrition, population density, and stress reduction.

Test your knowledge on key aspects of reproductive health in cows, including conditions like endometritis and pyometra. This quiz covers diagnosis, treatment, and management strategies related to uterine health during and after calving.