Are you anticipating the pitter-patter of an upcoming litter? Congratulations! But, before you start choosing names or shopping for tiny collars, you should confirm your pet’s pregnancy and fetal health through diagnostic imaging at Groves Veterinary Clinic.

Like human medicine, pregnancy detection and monitoring in pets are important to ensure healthy fetal development and minimize unexpected challenges during the birthing process. Groves Veterinary Clinic provides reproductive support services to help you care for your expectant pet’s health from breeding to delivery. 

When should a pregnant pet be evaluated?

By knowing what to expect when your pet is expecting, you can anticipate their needs and reduce their complication risks. Preparing for a litter can seem daunting, but our knowledgeable team will walk you through your pet’s prepartum care and provide resources so you will be ready for the tiny new arrivals.

The average gestation period for cats and dogs is approximately 63 days, or about two months.  If your pet was intentionally bred, you should know the few-days range when they should give birth and schedule their veterinary care accordingly. However, if your pet’s history is unknown (e.g., a recently rescued stray), your veterinarian can provide a rough estimate based on the pet’s physical examination. Although not every expectant pet will require each of the following steps, they provide helpful information about your pet’s pregnancy.

  • 21 to 23 days post-breeding — At this time, pregnancy can be confirmed by a blood test or ultrasound imaging, with ultrasound the preferred method, because false-negative blood tests are possible.
  • 23 to 35 days post-breeding — Between three and five weeks, the developing fetuses can sometimes be palpated through an abdominal examination.
  • 55 days post-breeding — The fetal bones are mineralized and visible on X-rays by about this time.

Why we recommend imaging and evaluation for pregnant pets

Your female pet’s girth size, milk production, and appetite are not reliable pregnancy predictors, and a wait-and-see approach can endanger your adult pet’s life, increase delivery complication risks, and compromise fetal health. Diagnostic imaging is a safe, easy, and reliable way to perform the following actions: 

  • Confirm diagnosis — Imaging differentiates between false pregnancy (i.e., pseudocyesis), alternative abdominal swelling causes (e.g., tumor or fluid in the abdomen), and pregnancy.
  • Determine fetal viability — Imaging literally illustrates fetal development and position.  Ultrasound can determine whether each fetus can survive outside the uterus by assessing heart rate and screening for abnormalities. 
  • Determine litter size — X-rays can help determine a fetal count after day 55 by showing the skulls and spines. Accurate fetal counts help the pet owner and veterinarian know how many little ones to expect at the time of delivery.
  • Identify potential delivery challenges — By determining the pregnant pet’s pelvic structure, as well as fetal size and position, the veterinarian can plan for the safest delivery (e.g., natural birth versus surgical Cesarean section).

X-rays versus ultrasound—selecting the best option for your pet

Because radiography and ultrasonography offer unique advantages and disadvantages, your veterinarian may recommend one over the other. Here’s a breakdown of the differences between X-rays and ultrasound for pregnancy evaluation: 

  • X-rays — Our state-of-the-art digital radiography (i.e., X-ray) equipment produces a two-dimensional, high-resolution, still image of your pet’s uterus and abdominal cavity. However, like a camera snapshot, radiographs are restricted to capturing only one moment in time, and some fetuses may therefore be obscured or hidden behind their littermates or other internal structures. 

Although X-rays are economical for assessing litter size and planning for potential reproductive challenges (i.e., dystocia), they do not measure fetal health or viability. Fetal bones do not mineralize until the pregnancy’s final stages, so  X-ray use is limited to day 55 post-breeding and later.

Also, X-rays expose unborn fetuses to radiation, so despite low long-term health risks, we limit exposures to one or two views (e.g., the pet on their side and, if necessary, on their back) to guard against adverse effects.

  • Ultrasound — Ultrasonography is safe for early, repeated use, and is considered the gold standard for pregnancy evaluation. Ultrasound, which can be used to detect developing embryos as early as three weeks after breeding, uses painless and harmless sound waves to create dynamic (i.e., moving) two-dimensional computerized images, and can measure uterine blood flow and fetal heartbeats, and scan for abnormalities that may predict future problems.

Despite ultrasound’s safety, this method is considered inferior and inaccurate for determining precise fetal counts. The dynamic real-time image display that is superior for determining fetal viability also makes miscounting fetuses more likely. Fortunately, an X-ray on or around day 55 post-breeding easily overcomes this problem.

Pregnant pets require close monitoring and regular assessment to ensure the mother and offspring stay healthy. Whether you are planning to breed your pet or are currently caring for an expectant dog or cat, let Groves Veterinary Clinic be your trusted resource for veterinary care, guidance, education, and support. Contact our team for more information about the reproductive care services available at our clinic, or to schedule a pre-breeding or pregnancy exam.