When it comes to pregnancy in pets, sometimes it’s hard for clients to wait… 

They want to know right away whether there are puppies/kittens present… how many there are… and if the babies are doing OK.

It’s understandable—whether this is a professional breeder or a pet parent who’s decided to proceed with a litter, the arrival of new puppies and kittens is an exciting time.

There are a few ways to check for pregnancy in dogs and cats. Each method has its own pros and cons, which you can explain to your clients to help set up realistic expectations and develop a plan that best suits their pet’s needs.

Early pregnancy checks may include…

Abdominal palpation

• This method of pregnancy detection can yield information as soon as 3-4 weeks into the 9-week pregnancy.

• Abdominal palpation has been used by vets for many years—and can often result in the detection of fetal “bumps.”

• However, this method isn’t always accurate. There are plenty of things that could render palpation inconclusive. For example, in large breeds or overweight dogs, palpation is more difficult. 

Relaxin testing

• Testing for the relaxin hormone—a hormone unique to pregnancy—can be performed as soon as 20 days into gestation. 

• This test gives your client a very important “yes or no” answer—and helps to distinguish between true pregnancy versus pseudopregnancy—but it doesn’t provide information on how many fetuses are present.

The next test to consider is an abdominal ultrasound. 

Canine and Feline Abdominal Ultrasound

The procedure of abdominal ultrasound in veterinary medicine involves examining the internal organs of dogs and cats. To begin the ultrasound study, transverse scanning is performed to locate the urinary bladder and colon, with the uterine body positioned between them.

Once the uterine body is identified, the scan is directed cranially towards each kidney, following the uterine horn towards the ovary. Along this path, each fetus can be identified by its appearance as a round, fluid-filled gestational sac.

Compared to other imaging methods like X-rays, abdominal ultrasound offers several advantages in veterinary practice.

One significant advantage is the ability to confirm pregnancy several weeks earlier than X-rays. Typically, an ultrasound is performed around 30 days into the pregnancy, although it's possible to detect a pregnancy as early as 20 days. At 30 days, it becomes easier to detect fetal heartbeats.

In addition to early pregnancy detection, ultrasound provides other valuable benefits for veterinarians, including:

1. Counting the number of puppies or kittens: The ideal time for this is between 30 and 35 days of pregnancy. After 50 days, the uterine horns may overlap, making it more challenging to accurately count the fetuses.

2. Assessing fetal viability: Ultrasound can confirm the presence of viable fetuses by detecting their heartbeats or movement.

3. Predicting gestation duration: Measurements of fetal size or certain anatomical structures can help estimate the gestation duration.

Another advantage of abdominal ultrasound in veterinary practice is its ability to involve clients in the process. Unlike X-rays, clients can be present during the ultrasound, allowing them to witness the heartbeats of the puppies or kittens.

This experience enhances the bond between the client and their pet, as well as strengthens their connection to the veterinary practice.

However, in the later stages of pregnancy, X-rays also play a valuable role in veterinary medicine. X-rays provide more information when the fetuses have developed significant skeletal structures, usually around 45 to 55 days after breeding.

At this stage, a single set of X-rays is safer for the fetuses compared to earlier in the pregnancy.

Radiographs (X-rays) are particularly useful for:

1. Confirm the fetal count.

2. Assessing the size ratio between the fetal skulls and the pelvic canal. This information helps in planning for potential dystocia and the need for a C-section.

As a veterinary practitioner, you have various diagnostic tools at your disposal to detect and monitor a healthy pregnancy in dogs and cats.

By utilizing the best combination of methods, you can reassure your clients along the way, and increase the chances of a healthy delivery of puppies or kittens!

Written by: Dr. Tammy Powell, DVM