Vaginal/Uterine Prolapses, Metritis, and Retained Fetal Membranes

Prolapse

Displacement of an organ or tissue from its normal anatomical position, causing it to protrude through a natural body opening

Three major types of prolapse in ruminants

1.) Rectal prolapse

2.) Vaginal prolapse

3.) Uterine prolapse

Rectal prolapse

Protrusion of rectal tissue through the anus

Vaginal prolapse

Protrusion of vaginal tissue through the vulva

Uterine prolapse

Eversion of the uterus through the cervix and vulva following parturition

Timing of rectal and vaginal prolapses vs. uterine prolapse

Rectal and vaginal → Usually before parturition

Uterine → Always after parturition

Why can uterine prolapse only occur after parturition?

The cervix must be dilated and the uterus emptied before it can turn inside out and protrude through the vulva

Appearance of rectal and vaginal prolapses vs. uterine prolapse

Rectal and vaginal → Relatively smooth mucosa Uterine → Visible placentomes on the exposed uterine surface

Placentome

Site of attachment between a maternal caruncle and fetal cotyledon

Which type of prolapse is considered an emergency in ruminants?

Uterine prolapse

Why is uterine prolapse considered an emergency?

Eversion of the uterus places tension on the uterine vasculature, potentially causing vessel rupture, severe intra-abdominal hemorrhage, and death

Why should cattle with uterine prolapse generally be treated on the farm rather than transported?

Movement during transportation may increase tension on uterine blood vessels and increase the risk of vascular rupture

Why are vaginal and rectal prolapses generally not considered emergencies?

They do not pose the same immediate risk of severe hemorrhage as uterine prolapse, although prolonged exposure can cause tissue damage

Four complications of prolonged vaginal or rectal prolapse

1.) Edema

2.) Ulceration

3.) Tissue trauma

4.) Necrosis

Primary cause of rectal prolapse in ruminants

Increased abdominal pressure overcoming normal rectal tone and support

Primary cause of vaginal prolapse in ruminants

Increased abdominal pressure combined with hormonal changes that reduce vaginal tissue support

Three predisposing factors for vaginal prolapse

1.) Late-stage pregnancy

2.) Increased abdominal and pelvic pressure

3.) Hormonal changes affecting tissue support

Primary cause of uterine prolapse in ruminants

Decreased uterine tone immediately following parturition

Three predisposing factors for uterine prolapse

1.) Hypocalcemia

2.) Other electrolyte imbalances

3.) Poor postpartum uterine involution

Why does hypocalcemia predispose cattle to uterine prolapse?

Calcium is required for smooth muscle contraction, so low calcium concentrations decrease uterine tone and allow the uterus to become flaccid

Which types of prolapse have a hereditary component?

Rectal and vaginal prolapses

Why is culling often recommended for breeding animals with rectal or vaginal prolapse?

These conditions have hereditary tendencies and may recur during subsequent pregnancies

Why is culling generally not recommended solely because of uterine prolapse?

Uterine prolapse is not considered hereditary and does not typically predispose the animal to recurrence

Four degrees of vaginal prolapse

1.) First degree

2.) Second degree

3.) Third degree

v4.) Fourth degree

First-degree vaginal prolapse

Vaginal tissue protrudes only when the cow is recumbent and returns to its normal position when she stands

Why might first-degree vaginal prolapse not require correction?

Mild protrusion during recumbency in very late pregnancy may resolve spontaneously when the cow stands

Second-degree vaginal prolapse

The vaginal floor protrudes continuously through the vulvar lips, but the tissue remains relatively healthy

Third-degree vaginal prolapse

The majority of the vagina protrudes through the vulva and the cervix becomes visible

Fourth-degree vaginal prolapse

Severe, often chronic prolapse associated with extensive vaginal protrusion, edema, trauma, and possible necrosis

Which degree of vaginal prolapse is characterized by a visible cervix?

Third degree

Which degree of vaginal prolapse is commonly associated with necrosis? Fourth degree

Sacrococcygeal epidural

Injection of local anesthetic into the epidural space between the sacrum and first caudal vertebra

Why is a sacrococcygeal epidural used during prolapse correction?

It provides regional anesthesia and reduces straining, making the prolapsed tissue easier to replace

Five general steps in prolapse correction

1.) Administer an epidural

2.) Clean the prolapsed tissue

3.) Reduce edema

4.) Gently replace the tissue

5.) Secure the tissue to prevent recurrence

Three methods of reducing edema in prolapsed tissue

1.) Gentle circumferential pressure

2.) Granulated sugar

3.) Hypertonic saline

How do sugar and hypertonic saline reduce edema in prolapsed tissue?

They create an osmotic gradient that draws excess fluid out of swollen tissues

Why should the palms rather than the fingers be used when replacing prolapsed tissue?

Broad pressure distributes force more evenly and reduces the risk of tearing fragile, edematous tissue

Buhner suture

Surgical fixation technique in which a large suture is placed around the vulvar lips to prevent recurrence of vaginal prolapse

Why must a small opening remain when placing a Buhner suture?

To allow the animal to urinate

Why must a Buhner suture be removed before parturition?

The vulvar opening must be large enough to allow delivery of the fetus

Two nonsurgical methods of vaginal prolapse retention in sheep

1.) Prolapse harness

2.) Ewe spoon

Prolapse harness

External device that applies pressure near the vulva to prevent vaginal tissue from protruding

Ewe spoon

Device placed within the vagina to support the vaginal wall and prevent recurrence of prolapse

Why must the uterine horns be fully extended following uterine prolapse reduction?

Incomplete replacement leaves the uterus partially inverted and increases the risk of recurrence

Endometritis

Inflammation or infection limited to the endometrium, or inner lining of the uterus

Metritis

Inflammation or infection involving all layers of the uterine wall, generally occurring postpartum

Pyometra

Accumulation of pus within the uterus, typically occurring during diestrus in a nonpregnant animal

Three major uterine inflammatory conditions

1.) Endometritis

2.) Metritis

3.) Pyometra

Endometritis vs. metritis vs. pyometra

Endometritis → Inflammation of the uterine lining, primarily affecting fertility

Metritis → Inflammation of all uterine layers, generally postpartum

Pyometra → Pus-filled uterus, typically during diestrus

Why can metritis cause more severe systemic illness than endometritis?

Metritis involves the entire uterine wall and may allow infection to spread into the bloodstream

During which reproductive stage does pyometra typically occur?

Diestrus

How does pyometra typically differ between large and small animals?

Large animals → Often relatively healthy despite uterine infection

Small animals → Commonly develop significant systemic illness

Two clinical types of bovine metritis

1.) Toxic metritis

2.) Non-toxic metritis

Toxic metritis (acute puerperal metritis)

Severe postpartum uterine infection associated with significant systemic illness and potentially septicemia

Non-toxic metritis

Postpartum uterine infection associated with mild clinical signs and little or no significant systemic illness

Primary difference between toxic and non-toxic bovine metritis

Severity of systemic illness

Seven important clinical signs of toxic metritis in cattle

1.) Fever greater than 104°F

2.) Anorexia

3.) Depression

4.) Ketosis

5.) Enlarged, fluid-filled uterus

6.) Fetid reddish-brown uterine discharge

7.) Possible displaced abomasum

Characteristic uterine discharge in toxic bovine metritis

Watery, reddish-brown discharge with a very foul odor

Why can toxic metritis cause ketosis?

Severe illness decreases feed intake, resulting in negative energy balance and increased fat mobilization

Why can toxic metritis be associated with displaced abomasum?

Decreased feed intake and gastrointestinal dysfunction associated with systemic illness can contribute to abomasal displacement

Five important bacterial groups associated with toxic bovine metritis

1.) Trueperella pyogenes

2.) Fusobacterium species

3.) Bacteroides species

4.) Coliform bacteria, including Escherichia coli

5.) Clostridium species

Three bacterial groups that commonly act synergistically in toxic metritis

1.) Trueperella pyogenes

2.) Fusobacterium species

3.) Bacteroides species

Bacterial synergism

Interaction between different bacterial species that enhances their ability to establish and maintain infection

Three mechanisms of bacterial synergism in toxic metritis

1.) Production of leukotoxins

2.) Inhibition of phagocytosis

3.) Production of growth factors that support other bacteria

Why does bacterial synergism make toxic metritis more difficult to eliminate?

The bacteria collectively impair immune defenses and promote one another's survival

Which bacterial groups contribute to the characteristic foul odor of toxic metritis?

Anaerobic bacteria, particularly Fusobacterium and Bacteroides species

Primary treatment for toxic bovine metritis Systemic antibiotics

Four important management strategies for toxic bovine metritis

1.) Systemic antibiotics

2.) Nonsteroidal anti-inflammatory drugs

3.) Monitoring rectal temperature

4.) Monitoring feed consumption and milk production

Why are nonsteroidal anti-inflammatory drugs used in toxic metritis?

To reduce pain, inflammation, and fever associated with systemic infection

Why is uterine lavage generally not recommended for bovine metritis?

Its benefits are uncertain, and routine lavage is not considered necessary or recommended

Why should retained fetal membranes not be manually removed in cows with metritis?

Forceful removal may damage placental attachment sites and impair uterine healing

Why are intrauterine antibiotic infusions generally unnecessary in toxic metritis?

Systemic antibiotics can adequately penetrate uterine tissues

Why should iodine solutions generally be avoided for treating bovine metritis?

They may negatively affect future fertility

Four important strategies for preventing bovine metritis

1.) Maintain clean calving environments

2.) Practice good obstetrical hygiene

3.) Prevent or manage metabolic disease

4.) Ensure adequate nutrition

Three important clinical findings in non-toxic bovine metritis

1.) Mild depression

2.) Fetid uterine discharge

3.) Possible retained fetal membranes

Why are systemic antibiotics generally unnecessary in mild non-toxic metritis?

The cow has little or no significant systemic illness, so antibiotics may provide limited additional benefit

Why is prostaglandin F2α sometimes used in non-toxic metritis?

It may stimulate uterine contractions and promote evacuation of uterine contents, although evidence of benefit is inconsistent

Why should cows recovering from metritis be reexamined before breeding?

To confirm uterine recovery and reduce the risk of breeding an animal with persistent uterine inflammation

Toxic vs. non-toxic bovine metritis

Toxic → Severe systemic illness, high fever, anorexia, depression, and fetid discharge; systemic antibiotics indicated

Non-toxic → Mild systemic illness and fetid discharge; systemic antibiotics generally unnecessary

Six important clinical signs of metritis in dogs and cats

1.) Fever

2.) Depression

3.) Anorexia

4.) Vomiting or diarrhea

5.) Fetid vulvar discharge

6.) Decreased maternal care

Typical fever associated with metritis in dogs and cats

Greater than 103°F

Why is concurrent mastitis and metritis particularly concerning in dogs and cats?

It raises concern for septicemia and possible spread of infection through the bloodstream

Toxic milk syndrome

Risk of illness in nursing offspring associated with milk from a dam experiencing severe systemic infection and concurrent mastitis

Why may puppies or kittens need alternative feeding when the dam has severe metritis and mastitis?

They may be exposed to harmful bacteria or inflammatory products through the milk

Characteristic bloodwork finding in dogs and cats with metritis

Neutrophilic leukocytosis with a left shift

Why can metritis cause neutrophilic leukocytosis with a left shift?

Bacterial infection stimulates neutrophil production and release, including immature neutrophils, from the bone marrow

Three characteristic ultrasound findings in small animal metritis

1.) Thickened uterine wall

2.) Increased intrauterine fluid

3.) Flocculent material within the uterine lumen

Lochia

Normal postpartum uterine discharge consisting of blood, mucus, and tissue debris

How does normal lochia differ from discharge associated with metritis?

Normal lochia → Expected postpartum discharge without significant systemic illness

Metritis → Often foul-smelling discharge accompanied by fever and systemic illness

Four important treatments for metritis in dogs and cats

1.) Intravenous fluids

2.) Systemic antibiotics

3.) Supportive care

4.) Uterine evacuation when appropriate

Why must oxytocin and prostaglandins be used cautiously in small animal metritis?

They stimulate uterine contractions and may worsen uterine damage or contribute to rupture if the uterine wall is compromised

When may ovariohysterectomy be necessary for small animal metritis?

When severe infection does not respond adequately to medical treatment or uterine damage is significant

Subinvolution of placental sites (SIPS)

Failure of normal regression of placental attachment sites following whelping, resulting in persistent bloody vulvar discharge

Species affected by subinvolution of placental sites

Dogs

Underlying cause of subinvolution of placental sites

Unknown

Why does subinvolution of placental sites cause prolonged bloody discharge?

Placental attachment sites fail to regress normally, allowing bleeding to continue after whelping

Characteristic clinical presentation of subinvolution of placental sites

Persistent bloody vulvar discharge in an otherwise healthy postpartum bitch

Four clinical findings associated with subinvolution of placental sites

1.) Persistent bloody discharge

2.) Normal appetite and behavior

3.) Normal maternal care

4.) Healthy nursing puppies

How long may bloody discharge persist with subinvolution of placental sites?

Beyond 6-12 weeks postpartum, sometimes continuing for 12-16 weeks

Characteristic vaginal cytology finding in subinvolution of placental sites

Persistent trophoblastic cells with a foamy appearance

Approximately _____% of subinvolution of placental sites cases have identifiable trophoblastic cells on vaginal cytology

30-40%

Characteristic abdominal palpation finding in subinvolution of placental sites

Spherical enlargements at placental attachment sites