Table of Contents

Fetal Maceration in Animals

Fetal Maceration is the failure of an aborting fetus to be expelled due to uterine inertia in a dilated cervix, when invaded by bacteria causing autolysis of soft tissues and putrefaction leaving the mass of fetal bones within the uterus.

Maceration may occur at any stage of gestation in all species but very often in cows.

In cows, the fetal maceration which occurs after third month of gestation when fetal bones are fairly well developed and infected through bacterial agents results in death and septic metritis of pregnancy follows, fetal emphysema develops in 24 – 48 hours and in 3 to 4 day maceration begins. If fetal death occurs before ossification of bones, complete microbial digestion of fetus occurs followed by pyometra.

When death of fetus occur due to bacterial or viral infections, there may or may not be regression of corpus luteum.

The parturient phenomenon is initiated but the abortion is incomplete due to incomplete dilatation of the cervix. The fetus undergoes microbial digestion in the fluid of the uterus till the bones remains.

Etiology

The causative organisms are normally those found in the uterus. The microorganisms get a favourable environment due to patent cervix and optimum temperature and rapidly multiply. Sometimes the fetal bones penetrate the uterine wall and cause severe damage to the endometrium.

The uterine wall will be thick and heavy with a large and hard cervix with fetid discharge from genitalia resulting from severe degenerative and sclerotic changes in the endometrium is observed.

In multipara, maceration of early embryos and fetus gets reabsorbed or expelled with the placenta and normal co-twin at parturition.

Etiological factors causing fetal maceration are:

Organisms like trochomoniasis and vibriosis present or which invade the genital tract cause infection and pus formation.
Uterine interia, improper dilatation of cervix and birth canal that fails to evacuate the fetal content after the occurrence of fetal death.
Fetal emphysema and maceration associated with uterine torsion during gestation.

Clinical Signs

Intermittent straining for several days accompanied by a foul fetid, reddish-grey vulvar discharge
Rise in temperature
Anorexia
Decreased milk yield
Occasionally diarrhoea may be present

On rectal examination, metallic sound or gritty feeling due to sliding movement of bones on each other after complete maceration of fetus.

In long standing cases:

No straining
Cervix is usually quite contracted
No elevated pulse and temperature
No anorexia
Fetid and mucopurulent discharge from vulva
Metallic sound or gritty feeling on rectal examination

Treatment

Fetal maceration diagnosed at middle period of gestation will be responding promptly as it is being treated as early case. Use of estrogens at the dose rate of 80-100 mg per animal can be used for cervical relation and extraction of fetus with gradual traction.

Oxytocin should not be administered because it increases the contractibility of the uterus and if some bones are left even after manual removal, these penetrate the uterus and cause peritonitis etc.

Large doses of antibiotics should be given parenterally as well as intra uterine preferably oxytetracycline for 5 days.

For intrauterine therapy, 4-8 boluses of terramycin are dissolved in 30 to 40 ml of water.

Cephalexin is also beneficial; 4.5 gm powder is dissolved in 60 ml of water and infuse in uterus for 4-5 days.

Supportive Therapy

Vit A for restoration of endometrial epithelial cells.
Tonophosphan and vitamin B complex for 3-5 days.
Fluid therapy: in severe condition, toxaemia cause septic shock and lactic acidosis. Therefore the cow needs to be balanced with isotonic, alkalizing multiple electrolyte infusion in larger volumes.
Until the cervix is relaxed enough or the fetus is macerated sufficiently to effect its removal entirely or in pieces without injury to the cow.
With this type of treatment, the danger of excessive traction or embryotomy causing lacerations or rupture of the cervix and uterus is avoided.
Because the uterus and its contents are relatively small, the development of septic metritis and severe toxemia is prevented by supportive therapy.
Cesarean section should be considered as a last resort in the cow.
Cow should not be rebred for at least 3-4 months, and the outlook for her reproductive life is guarded.

Prognosis

Prognosis is poor and treatment in cow is difficult and the future breeding life is questionable.

The longer the condition has existed the greater the damage to the endometrium and poorer the prognosis. Even laparohysterotomy is difficult because of the deep embedding of bones in the endometrium and its infected contents.

Torsion of the uterus will also cause fetal emphysema and maceration leading to a local perimetritis or even rupture the uterus and may slough through the abdominal floor into the rumen or into the rectum leading to systemic failure.

In multiparous animals hysterectomy may be performed depending upon the circumstances in the case of dogs and cats after confirming by either abdominal palpation or radiography.