Hypoluteoidism in Bitches: Clinical Signs, Diagnosis and Treatment

Hypoluteoidism is a condition in bitches characterized by insufficient production of progesterone by the corpora lutea after ovulation.

Plasma progesterone concentrations begin to rise prior to the onset of standing heat and decline to basal levels immediately prior to parturition. The first 6 to 7 weeks of diestrus are usually associated with progesterone concentrations of  50 ng/ml.

If the progesterone concentration is below 1.0 ng/ml, either the bitch never ovulated or the corpora lutea have failed to synthesize and /or secrete progesterone. Serum progesterone concentrations above 2-4 ng/ml should be sufficient to maintain pregnancy.

If the progesterone concentration is less than 2 ng/ml, the amount of progesterone secreted may be insufficient to maintain pregnancy and abortion or fetal resorption may result. If fetuses are observed on abdominal ultrasonography early in gestation, abortion or fetal resorption should become demonstrable with repeated ultrasound examinations.

Clinical Signs

Hypoluteoidism in bitches is characterized by infertility or early pregnancy loss. Affected dogs may not show obvious signs initially, but they often fail to conceive or experience abortion or fetal resorption during early gestation.

Diagnosis

The diagnosis of hypoluteoidism is typically made through the measurement of plasma progesterone levels.

Any bitch diagnosed as having an infertility problem should be evaluated with a plasma progesterone concentration 10 to 20 days after termination of standing heat and then once or twice weekly thereafter. These studies should be completed in conjunction with evaluation by abdominal ultrasonography.

Treatment

Treatment for hypoluteoidism involves the careful use of progesterone supplementation to address luteal insufficiency. Synthetic progesterone is often administered to support pregnancy, but this should only be done with caution due to potential risks such as pyometra or fetal abnormalities.

Regular monitoring of serum progesterone levels is essential to ensure the supplementation is effective in maintaining pregnancy. If progesterone therapy is started, it is important to track the dog’s progress and adjust the treatment as necessary to avoid complications.