How is a roundworm infection diagnosed in dogs and cats?

Diagnosis is usually confirmed with a fecal parasite examination to detect eggs or adult worms. Blood tests and imaging may also be used to assess your pet's overall condition. Follow your vet's instructions for collecting and submitting samples.

Can roundworms be transmitted to humans?

Some pet parasites carry a zoonotic risk, meaning they can potentially be transmitted to people — this is particularly relevant when young children or immunocompromised individuals are in close contact with an infected pet. Practising good personal and environmental hygiene is important; ask your vet for specific prevention advice.

Does my pet need follow-up appointments after treatment?

Yes, follow-up visits and repeat fecal tests are usually recommended to confirm that the deworming treatment has been effective. Your vet will also monitor your pet's weight and overall improvement, and adjust the treatment plan if necessary.

How much do the tests and treatment usually cost?

Costs vary by clinic and region — ask your vet for an estimate before proceeding.

Disease Guide

Roundworms (Ascariasis) in Dogs & Cats: Symptoms, Diagnosis & Deworming Guide [2025]

A common intestinal parasite that is easily treated with deworming medication

Take 1 minute to check the symptoms first

Last updated: 2026/01/06

Pethealthmap Editorial Team

Sources: AVMA, WSAVA, National Taiwan University Veterinary Hospital

When to See a Vet

Seek Emergency Care Immediately

•Persistent severe coughing or difficulty breathing
•Continuous heavy vomiting preventing any food intake
•Obvious dehydration or unresponsiveness requiring emergency care

Schedule a Clinic Visit Soon (within 24–72 hours)

•Intermittent or persistent coughing with breathing still stable
•Bloating, vomiting, or changes in bowel habits lasting several days
•Weight loss or significantly reduced appetite for more than two days

01What symptoms indicate a problem?

Roundworm infections primarily affect the digestive and respiratory tracts, with clinical signs ranging from mild to obvious discomfort.

Weakness, reduced activity, or lethargy
Intermittent or persistent coughing, sometimes with abnormal breathing sounds
Abdominal bloating, vomiting, abdominal discomfort, or changes in appetite
Visible worms or worm segments in the stool or vomit
Weight loss or poor growth rate (especially important to watch for in puppies and kittens)

Seek emergency care immediately if you notice the following symptoms:

⚠️ Persistent severe coughing or difficulty breathing
⚠️ Continuous heavy vomiting preventing your pet from eating
⚠️ Marked dehydration or unresponsiveness — seek emergency care immediately

02How to assess the situation at home — what to watch for and when to go to the emergency clinic

Observing and recording symptom changes at home helps the vet assess disease progression and prioritise appropriate tests.

Log the frequency of coughing episodes, when they occur, and any apparent triggers
Note any changes in alertness, interest in play, and overall activity level
Monitor appetite and track daily food intake
Record bowel movement frequency, stool consistency, and whether any worms are visible
Weigh your pet regularly and track the trend — especially important for young animals
Film coughing or unusual behaviour on your phone to show the vet at the appointment

03How will the vet diagnose this? Common diagnostic tests explained

At the clinic, the vet will combine a clinical examination with imaging and laboratory tests to confirm the infection and assess your pet's overall condition.

Physical examination

assessment of breathing pattern and abdominal palpation

Blood and biochemistry panel

to check for infection or electrolyte imbalances

Urinalysis

to help evaluate metabolic status and kidney function

X-rays

to check the chest or abdomen for abnormalities or secondary complications

Advanced imaging (CT scan) for complex or unclear cases

Fecal parasite examination

to identify eggs or adult worms and confirm infection

04Treatment and aftercare: medications, dietary adjustments, and home care

Treatment centres on deworming, with supportive care and regular follow-up provided as needed.

The vet will prescribe an appropriate deworming medication and treatment course based on the test results
Supportive care such as fluid therapy or nutritional support will be provided when needed
Thorough environmental cleaning and proper disposal of faeces to reduce the risk of re-infection
Schedule follow-up visits and repeat fecal checks as directed by your vet to confirm treatment success
Keep a record of your pet's progress and response; if symptoms do not improve, seek further evaluation

05What to prepare before your vet visit — key information to help the vet identify the cause quickly

Write down when symptoms first appeared and how they have changed over time

Prepare a record of your pet's diet and bowel habits over the past week

Bring a fresh stool sample or any vomited material for testing

List all current medications and supplements your pet is taking

Record a short video on your phone of any coughing or abnormal behaviour for reference

Consider calling ahead to book at a larger clinic or specialist hospital that can perform laboratory testing

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.