Uterus

The uterus (womb) is the central reproductive organ of the female dog, consisting of a uterine body and two long horns in which the puppies develop.

How is the uterus structured in female dogs?

The womb of the female dog differs significantly from the human uterus. It consists of a short central body (corpus uteri) and two horns (cornua uteri) that extend in a Y-shape towards the ovaries.

This horn structure explains why female dogs have multiple births; the fertilised eggs are distributed across both horns. The uterine wall consists of a thick muscle layer (myometrium) and a mucous membrane (endometrium), which changes depending on the cycle phase.

What happens in the uterus during pregnancy?

Birth ends the pregnancy 64 to 66 days after the LH peak, the hormonal starting point of the cycle. The duration therefore varies when calculated from the mating date.

During this time, the placenta forms, enabling the exchange of nutrients, oxygen and waste products between mother and puppies. During birth, the uterine muscles contract rhythmically and move the puppies through the birth canal.

Which uterine diseases occur in female dogs?

Pyometra is the most dangerous uterine disease. The underlying mucous membrane change typically occurs in older or middle-aged unspayed female dogs after they have had one or more non-pregnant cycles.

The disease is progesterone-controlled and begins in dioestrus, the phase after oestrus, which lasts two to three months without pregnancy. A closed pyometra, with no visible discharge, is particularly insidious as it is often recognised only late.

How can you recognise problems with the womb?

Warning signs are increased drinking and urination, lethargy, fever and, in open pyometra, purulent vaginal discharge. Some female dogs also show vomiting or a distended abdomen.

The vet usually diagnoses uterine diseases using ultrasound, which shows fluid accumulations or thickening of the uterine wall. Blood tests reveal signs of inflammation, elevated white blood cells or altered organ values.

When is spaying the best solution?

Spaying removes the ovaries and womb and is the recommended treatment for pyometra, unless the female dog is explicitly intended for breeding.

In acute pyometra, emergency spaying is often life-saving. The procedure removes both the ovaries and the womb, thereby permanently ending the risk of disease. Many vets also recommend spaying healthy older female dogs as a preventive measure.

How does treatment proceed for uterine diseases?

A broad-spectrum antibiotic treatment is necessary in every case and is started at the initial examination. Conservative treatment is only an option if the female dog is explicitly intended to continue breeding; pyometra frequently recurs in the next dioestrus afterwards.