Our look at the reproductive cycle of female dogs begins with sexual maturity. Small breeds usually have their first heat at six months of age, medium breeds at 8 to 10 months, large breeds at 10 to 12 months and giant breeds at 12 to 15 months.

A dog may become pregnant during her first heat. Therefore, it’s not necessary to delay spaying until after the first heat if you are not interested in a future litter. In fact, spaying females when they are young, before the first heat, is recommended. We suggest finishing the vaccination protocol for puppyhood and setting an appointment with your veterinarian for the ovarihisterectomy. Besides preventing unwanted pregnancies, this procedure prevents hormonal disorders, tumors of the reproductive tract and mammary glands, or uterine infection (piometra).

If you are interested in breeding your female dog, make sure that the puppies are going to find a home. There is no need for more unwanted puppies. If you are going to breed a small type of dog, it is preferable for the male to be even smaller than the bitch. We suggest an ultrasound or x-ray after day 35 of the pregnancy to determine the number of puppies and whether the future mother will be able to give birth or it is better to coordinate surgery.

Anticonceptive shots are available for dogs and cats. Medroxiprogesterona can be administered every six months as a subcutaneous injection in the inside part of the leg. As a result, the female will not have a heat at all. As with any medication, there are side effects, but if applied at the correct time (not during heat), medroxiprogesterona is usually effective and safe.

Surgery is always the best option if possible. Veterinarians commonly encounter the situation of owners wanting to terminate a pregnancy after seeing their female dog with a male during her heat. There is a medication that will cause reabsorption in the first trimester and abortion in the second and third trimesters. This medication is more risky and personally, we suggest avoiding it. Instead, as soon as the heat cycle is over, coordinate surgery with your veterinarian. Sterilization during the heat is not recommended, however, due to the higher risk of bleeding as the reproductive tract is swollen and more irrigated. In emergency cases, for example a chihuahua pregnant from a 10 kilogram male, surgery has to be done.

The bitch’s reproductive cycle is divided in stages. During proestrous, her vagina usually gets swollen or edematous, and males will be attracted, but she will not accept them yet. It can last from 6 to 21 days, and in the same animal is always the same duration. Oestrous is the real heat, the moment in which the bleeding is less. The vagina is still swollen but not like before. The odor from this liquid may not be as bad and the tan color is more clear than before. It lasts from 4 to 21 days. Diestrous is the pregnancy stage, lasting 63 days. In some cases, a dog has not become pregnant but a pseudopregnancy can occur; it seems like she is pregnant but actually is not. Sometimes, this will just pass on its, or medical treatment may be necessary. Anestrous is the hormonal rest for the female dog. All has stopped until the next heat starts. It can last from five to 12 months.

Remember, if you do not want a litter, spay your female dog soon, just before the first heat. Also, please help us with our clinic’s spay program for stray animals, both dogs and cats. Call us for more information: Hospital Veterinario Cavallini Ph, 2652-9009.