Why Does My Veterinarian Recommend an Ultrasound?
When a pet is unwell, veterinarians may recommend diagnostic tests such as bloodwork, radiographs, or ultrasound. For owners, it can sometimes be confusing to understand why additional testing is necessary, especially when bloodwork has already been performed or previous X-rays appeared normal.
Ultrasound is a valuable diagnostic tool that allows veterinarians to examine internal organs and structures without surgery.
At Lonsdale Place Veterinary Clinic, we believe understanding what an ultrasound can reveal helps pet owners make informed decisions about their animal's medical care.
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What Is an Ultrasound?
Ultrasound is a medical imaging technique that uses high-frequency sound waves to create pictures of structures inside the body.
A small handheld device called a transducer sends sound waves into the tissues. These waves are reflected back at different rates depending on the tissues they encounter.
A computer uses this information to generate images that can be viewed in real time.
Unlike X-rays, ultrasound does not use ionizing radiation.
It is generally a safe, non-invasive procedure and can provide detailed information about many soft tissues and organs.
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What Can an Abdominal Ultrasound Detect?
Abdominal ultrasound allows veterinarians to examine structures such as the liver, gallbladder, spleen, kidneys, urinary bladder, stomach, intestines, pancreas, and other abdominal tissues.
It can help identify abnormalities involving:
Organ size or shape
Changes in tissue appearance
Masses, nodules, or cysts
Abnormal fluid accumulation
Urinary tract abnormalities
Thickening of the intestinal wall
Certain foreign bodies or gastrointestinal obstructions
Ultrasound can also be used to guide the collection of fluid or tissue samples when further investigation is necessary.
However, not every abnormality detected on ultrasound provides a definitive diagnosis. Additional laboratory testing or tissue sampling may still be required.
North Vancouver Vet
Why Would My Pet Need an Ultrasound if Bloodwork Is Normal?
Bloodwork provides valuable information about organ function, blood cell populations, and metabolic processes.
However, normal bloodwork does not guarantee that all internal organs are structurally normal.
For example, an animal may have a localized mass, abnormal intestinal thickening, or another structural change without significant abnormalities on routine blood tests.
Ultrasound evaluates the appearance of organs rather than relying solely on indicators of function.
For this reason, bloodwork and ultrasound often complement one another.
North Vancouver Vet
How Is Ultrasound Different From X-Rays?
Although both techniques provide images of internal structures, they have different strengths.
Radiographs (X-rays) are particularly useful for evaluating bones, overall organ size, certain foreign materials, and patterns of gas or fluid within the body.
Ultrasound provides more detailed information about many soft tissues, internal organ structure, and fluid-filled areas.
For example, an X-ray may show that an abdominal organ appears enlarged, while ultrasound may help determine whether the organ contains a mass, cyst, or other abnormality.
However, ultrasound waves do not travel well through air or bone. This limits their usefulness for examining certain structures.
In some situations, both imaging techniques are recommended because each provides information the other cannot.
North Vancouver Vet
When Might a Veterinarian Recommend an Ultrasound?
An abdominal ultrasound may be recommended when a pet has:
Persistent or unexplained vomiting
Chronic diarrhea
Unexplained weight loss
Abnormal liver or kidney values
Abdominal discomfort
An abdominal mass detected during examination
Unexplained fluid accumulation
Urinary tract concerns
Symptoms that have not been explained by initial testing
Ultrasound can also be used to monitor previously identified abnormalities and assess changes over time.
North Vancouver Vet
Does My Pet Need to Be Sedated?
Many dogs and cats can undergo abdominal ultrasound without general anesthesia.
The procedure is generally not painful, although gentle pressure from the ultrasound probe may cause temporary discomfort in animals with sensitive abdomens.
Some pets may require mild sedation if they are particularly anxious, uncomfortable, or unable to remain still.
More invasive procedures, such as certain tissue biopsies, may require additional sedation or anesthesia.
The appropriate approach depends on the individual pet and the purpose of the examination.
North Vancouver Vet
How Should I Prepare My Pet for an Ultrasound?
Preparation depends on the type of ultrasound being performed.
For many abdominal examinations, the veterinary team may recommend withholding food for a period beforehand to reduce stomach contents and intestinal gas.
A reasonably full urinary bladder may also be helpful when evaluating certain urinary structures.
Clipping a small area of fur is usually necessary because ultrasound waves do not transmit effectively through trapped air within the coat.
Ultrasound gel is then applied to improve contact between the transducer and the skin.
Always follow the specific preparation instructions provided by your veterinary team, particularly if your pet has diabetes or another medical condition that affects feeding.
North Vancouver Vet
Can Ultrasound Diagnose Cancer?
Ultrasound can identify masses and other suspicious abnormalities, but it cannot reliably determine whether a mass is benign or malignant based on appearance alone.
Some cancers and non-cancerous conditions can produce similar imaging findings.
A fine-needle aspirate, biopsy, or other diagnostic procedure may be necessary to identify the underlying disease.
Likewise, a normal ultrasound does not completely exclude every possible medical condition.
North Vancouver Vet
Final Thoughts
Ultrasound is an important diagnostic tool that allows veterinarians to investigate internal structures in greater detail without exploratory surgery.
When combined with a physical examination, bloodwork, and other appropriate tests, ultrasound can provide valuable information that helps guide medical decisions.
If your pet has unexplained symptoms or has been recommended for diagnostic imaging, the team at Lonsdale Place Veterinary Clinic can explain the purpose of the examination and discuss which diagnostic options may be most appropriate for your pet.
