Fundamentally, producing puppies involves combining oocytes (eggs) and sperm. However, there are actually multiple options to accomplish that task. When you’re first getting started, it can be overwhelming to keep track of the lingo, but this article can help!
When discussing methods of insemination, there are two components: the processing of the semen itself (none, chilled, frozen) and the method of insemination (live cover, vaginal insemination, transcervical insemination, surgical insemination). These components are defined below.
Natural (aka live cover) – The original method. Put the dog and the bitch in the same room/yard and leave them to it.
Advantages: often easy and inexpensive
Disadvantages: both animals must be in the same place at the same time, which limits your options for genetic diversity and/or adds logistic challenges of getting them to the same place; additionally, this isn’t always an option if the bitch won’t let him breed her or if there is a significant size difference between the two
Vaginal insemination (aka vaginal AI) – An insemination pipette is inserted past the vulva, into the vagina, and the semen is slowly flushed into the vagina using a syringe. Oftentimes, people will refer to this procedure simply as an “AI” (artificial insemination), probably because our society is afraid of the word vagina.
Advantages: Solves the challenges of live cover
Disadvantages: Does not work well if the semen quality is poor
Transcervical insemination (aka TCI) – A specialized TCI scope or endoscope is inserted past the vulva and through the vagina until the cervix is visualized on the scope’s camera. Then, a catheter is threaded through the scope, through the bitch’s cervix, and into her uterus. Semen is slowly flushed through the catheter directly into the uterus using a syringe.
Advantages: increased litter sizes, especially for lower-quality semen
Disadvantages: this is a technically challenging procedure, so finding a veterinarian with the ability to perform the procedure may be challenging depending on your location; this procedure is also often more expensive
Surgical – The bitch is anesthetized. Her abdomen is surgically cut open with a scalpel blade and the surgeon finds her uterus. The semen is injected directly into the uterus with a needle or catheter and syringe. The surgeon then closes her abdomen with stitches. This procedure used to be relatively common, but with the increasing availability of TCI it is used significantly less.
Advantages: same as for TCI (increased litter sizes, especially for lower-quality semen)
Disadvantages: Ethically questionable. This procedure puts the bitch through a lot for the sake of breeding. Multiple studies have shown that TCI and surgical insemination have the same success rate, and some studies show that TCI actually has better success. There are very few situations (beyond the scope of this article) in which this technique would be recommended.
Side-by-side – The term “side-by-side” means that the male is in the same location as the female. Semen is manually collected from the male and is then transferred to a syringe/insemination pipette. Most of the time, when someone refers to a “side-by-side AI,” they mean that a vaginal insemination is performed after semen collection, but breeding could also be done via TCI (usually people specify by referring to a “side-by-side TCI”).
Fresh chilled, Fresh shipped chilled – The terms “fresh chilled” or “shipped chilled” mean that the semen was collected from the dog and then was mailed/shipped to the location with the bitch. Once the semen arrives, it can be inseminated vaginally or via TCI.
Frozen – Semen is collected from a dog and then mixed with an extender to enable it to be cryopreserved in liquid nitrogen. This dramatically increases the flexibility in timing a breeding cycle as well as the options for taking advantage of genetics separated from the bitch by space or time. Frozen semen can be shipped to the location of the bitch well ahead of breeding so it’s ready and available when she is and semen can be frozen when a male is young and fertile and then used years or decades later, etc. Take a look at this article for a detailed look at frozen semen. Freezing is tough on sperm, so TCI is a must if you’re going to use frozen semen.
In summary, here’s a list of all the methods that can be used for artificial insemination by combining the semen processing techniques with the various insemination methods:
– Live cover
– Side-by-side vaginal AI (aka side-by-side AI)
– Side-by-side TCI
– Fresh chilled/shipped vaginal AI (aka fresh chilled/shipped AI)
– Fresh chilled/shipped TCI
– Frozen TCI
– Fresh chilled/shipped surgical
– Frozen surgical
Each method has its advantages and disadvantages. Generally, the more technologically involved the method, the more potential it has for expanding the genetic opportunities of your breeding program but also the more likely it is to have smaller litter sizes because of the “trauma” endured by the semen. Considering these factors is an important part of responsible dog breeding!