Reproductive System: Spaying

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The Female Reproductive Tract:

The vital part of the female canine reproductive tract is the ovaries, which produces ova or eggs. These eggs initially are produced in the ovaries in an immature form, which need to get mature enough before fertilization.

Once the heat cycle approaches, certain hormones stimulate the maturation of some of the produced ova or eggs in the ovaries. After maturation, these ova or eggs are released through the surface of the ovaries. Ova or eggs are passed into oviducts, which connects the ovaries with the horns of the uterus. Along with the “bridge-function” of oviducts, the fertilization or union of sperm and ova also occurs in the oviducts.

Fertilized eggs are passed into the horns of uterus, which are strong muscular tubes, with a varying diameter and length, depending upon the breed of dog. Mostly, horns of uterus are 4 – 6 inches in length with a diameter of 0.5 - 1 inch. During pregnancy, the length of the horns becomes up to 24 inches with a diameter of 2.5 – 6 inches. Developing embryos mostly reside in the horns of uterus during pregnancy, but in late pregnancy (last quarter), all the fetuses’ line up towards the body of the uterus.

Advantages of Spaying Dogs:

The most common advantage of spaying a dog is to prevent several problems during the heat cycle and issues related with hygiene and behavior. Female dogs may escape and become prone to various risks, increasing the chance of an unwanted pregnancy. A unspayed female dog can attract an influx of male dogs around the home. These male dogs not only cause a disturbance, but also leave various excretory markings around the residence.

Similarly, during the heat cycle, female vaginal blood and secretions may continue dropping for 3 – 14 days. Spaying a dog can help prevent several kinds of mammary and reproductive tract cancerous growths. The malignant form of cancer can be initiated with estrogen, which is one of the primary reproductive hormones. In cases where a female dog is suffering from a uterine infection, cystic problems can occur in the ovaries. Spaying can be an effective way to treat all these conditions.

When to Spay a Dog

The best age to spay a dog depends upon the indication/reason for which a dog is spayed. If a dog is spayed to prevent reduce the chance of mammary and reproductive tract cancer, a dog should be spayed before its first heat cycle. In this context, age below 6 months is suitable to spay a dog.

Similarly, if a dog is only spayed to prevent unwanted litters, such as in a shelter, most have a policy to spay dogs at age of 8 - 12 weeks.

Finally, there is another view point regarding the release of hormones. Since, spaying blocks the release of primary sexual hormones, the growth of spayed dogs may become slower. Therefore, in the context of breeding, a dog should only be spayed after 12 months of age.

Overall, researchers and veterinarians believe that age 3 - 6 months is the most suitable time to spay a dog, since it  just about covers all aspects of the aforementioned indications for spaying a dog.

Methods of Spaying Dogs:

There are two main methods of spaying female dogs. These are:

Non–Surgical Method of Spaying Dogs:

Birth control pills are the only non–surgical method of spaying dogs. These pills contain purified antigens, which are derived from Porcine Zona Pellucida (membrane of unfertilized eggs/ova of pigs), which on oral intake produces specific antibodies in the treated dog. The antibodies help to prevent fertilization or the union of sperm and ova, due to the development of a protective membrane around the ova.

This method only prevents fertilization; otherwise female dogs come into heat normally. This means that this method is not effective if spaying is indicated for treating uterinal infections, health issues and to prevent mammary and uterine cancers. Also, birth control pills can cause adverse reactions. A female dog may experience side effects and several other health issues. This method prevents fertilization in dogs from age 22 months to 7 years.

Surgical Method of Spaying Dogs:

Surgically, dogs may be spayed by two different methods, which are;

Post Surgical Care:

A spayed female dog can be discharged soon after surgery, but it is always recommended that it should be kept in the hospital/clinic for a day or two. Post surgical monitoring is necessary for unusual symptoms or certain reactions caused by visceral surgical wounds. Additionally, to help healing and support health and immunity, several therapeutics including antibiotics, anti-inflammatory drugs, supportive supplements and some natural remedies can be used. This includes products that strengthen the bladder such as Better Bladder Control, help the urinary system function properly such as UTI Free and a behavioral remedy such as Problem Pet Solution.

Disadvantages of Spaying Dogs:

Spaying dogs is widely practiced all over world and has several advantages, but some of disadvantages have been reported as well. Immediate complications of spaying a dog includes post surgical infection, bleeding and problems related with anesthesia. Long term complications includes the risk of developing osteosarcoma (malignant canine bone cancer), cardiac tumors and urinary tract cancers.

Studies also show that spayed dogs have a five (5) times greater chance of developing urinary incontinence and urinary tract infections. Similarly, due to the blockage of hormonal secretions, hormone-response alopecia or hair loss and chances of behavioral complications such as noise phobia and undesirable behavior may develop.