The most common questions about the reproduction of bitches

At what age do bitches have their first heat?

It is impossible to set a specific date for the presentation of the first heat of the bitches. As an average date, we could say that they usually have their first heat between six and nine months of age, but if their appearance does not take place between these dates, we should not be surprised, since there are a large number of factors that make these data only approximate and reference:

• The breed: heat appears earlier in small breeds and later in large breeds.
• Environmental conditions: more incidence at the beginning of spring and autumn.
  – The presence of other females: a group of females will tend to unify the display of heat.
• The administration of certain drugs: certain drugs can alter the normal cycle of a female.

In principle, we can be calm until the bitch is eighteen months old, since there is the possibility of not showing heat before this date. If after this time there are still no signs of heat, we should go to our trusted Veterinarian; he will study the possible causes of this absence of jealousy (impuberism) of our pet.

We must also take into account that not in few occasions the females have their first, even their first jealousy, without visible manifestation (silent jealousy)
Generally, the first heat (and the following) can be identified by the change in the animal’s behavior, the increase in size of the genital area (vulvar edema) and the hemorrhagic losses; the latter and the edema of the vulva are usually more intense in the first heat than in later heats.

How often are bitches in heat?

The heat develops in a period of an average duration of about fifteen days (between eight and twenty); during this period we must be alert in the event that the hemorrhagic losses last more than twenty-one days, in this case there may be a problem in the reproductive system and professional assessment is essential. We can consider normal the appearance of heat every six months (between five and twelve), although the most important thing is that heat is regular, either every five, every seven, or every twelve months.

How is the sexual cycle of bitches?

The sexual cycle of bitches has four phases:

• Proestrus: it is the initial phase of the cycle that begins with the bleeding and the “attraction” of the males without allowing them to mount. It usually lasts an average week, but varies from 3 to 21 days.
• Estrus: is the stage in which mating occurs. It usually lasts about 7 days, but varies from 2 days to three weeks.
• Right-handed: ovulation has already occurred in this phase. It lasts about two months and during this period there may be:
  • Gestation: in case an effective mating has taken place.
  • Pseudopregnancy: if there has been no mating and the typical hormonal variations of “pseudopregnancy” or psychological pregnancy arise.
  • A normal start-rest period.
• Anestrus: it is the actual rest of the sexual cycle. The ovaries are inactive.

Why is there bleeding during heat?

The bleeding is due to the action of a hormone with a main function in proestrus and estrus: ESTRADIOL. Due to its action, there is a greater supply of blood to the genital apparatus and a greater dilation of the vessels. This causes an outflow of blood through these without there being a break.

Why does the bitch attract males?

By a pheromone that accompanies bleeding. The main canine pheromone is the methyl ester of parahydroxybenzoic acid; males can detect the scent of this suggestive pheromone up to several kilometers away.

How can we avoid jealousy and unwanted pregnancies in female dogs?

We can act against these situations with two types of measures:

• Pharmacological measures: consists of periodically administering drugs that act by “interrupting” hormonal mechanisms; they can be given orally, being of short duration, or injectable, with a longer duration.
  We must bear in mind that they are temporary measures and that pharmacological treatments can have side effects, and we must be very clear that they should never be used before our animal’s first heat.
• Surgical measures: these are the definitive measures, both for the animal and for the owner; We can divide them into two types of techniques:
  • Sterilization techniques: respect hormonal activity and prevent reproductive capacity:
    • Tubal ligation: tying and cutting the fallopian tubes.
    • Hysterectomy: remove the horns and cervix.
  • Castration techniques: prevent hormonal and reproductive capacity:
    • Ovariectomy: removal of both ovaries.
    • Ovariohysterectomy: removal of the ovaries and uterus.

Faced with so many possibilities, let’s consult with our veterinarian which is the most appropriate option for our dog.