What is hepatocellular adenoma?

Hepatocellular adenoma is a benign liver tumor that is more common in middle-aged to older dogs and cats. It often presents with non-specific symptoms or mild gastrointestinal signs. If it is suspected, further imaging or tissue sampling is needed to confirm — speak with your vet.

How is hepatocellular adenoma diagnosed?

Diagnosis typically begins with blood biochemistry and abdominal ultrasound to evaluate the liver. A CT scan or cellular and tissue sampling may be arranged if necessary to reach a definitive diagnosis — your vet will guide the appropriate workup.

When should I seek veterinary care if I notice symptoms?

Seek emergency care immediately if your pet collapses, vomits blood, has black tarry stools, or shows difficulty breathing. For other persistent or worsening signs — such as weakness, refusal to eat, or abdominal distension — arrange a consultation as soon as possible.

What does treatment and follow-up typically involve?

Treatment depends on lesion size and symptoms, and may involve surgery or conservative management. Both approaches require regular blood tests and imaging follow-up; your vet will advise on the appropriate schedule.

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

Hepatocellular Adenoma in Dogs & Cats: Symptoms, Imaging & Care Guide [2025]

Hepatocellular adenoma is a benign liver tumor that is typically solitary and slow-growing. Prognosis is excellent after complete surgical resection, but it must be differentiated from hepatocellular carcinoma.

Take 1 minute to check the symptoms first

Last updated: 2026/01/05

Pethealthmap Editorial Team

Sources: WSAVA, ACVIM, National Taiwan University Veterinary Hospital

When to See a Vet

Seek immediate veterinary care (emergency)

•Sudden coma with no response to sound and unfocused eyes
•Persistent vomiting of blood or black stools with heavy bleeding
•Rapid breathing or marked panting that will not settle

Schedule a veterinary visit soon (within 24–72 hours)

•Persistent frequent vomiting for more than a day with a change in alertness
•Markedly reduced appetite or refusing food for days with weight loss
•Persistently distended abdomen or obvious discomfort when touched

01What symptoms indicate something is wrong?

Hepatocellular adenoma in dogs and cats often presents with non-specific gastrointestinal or behavioural changes; further examination is needed to confirm the cause.

Persistent or intermittent weakness and reduced activity
Recurrent vomiting, or lethargy and dullness following episodes of vomiting
Discomfort or avoidance behaviour when the abdomen is touched
Reduced appetite or obvious refusal to eat
Gradual weight loss or a visibly distended abdomen
If any of the above symptoms appear, arrange a veterinary consultation promptly

Seek emergency care immediately if you notice the following symptoms:

⚠️ Sudden collapse or loss of consciousness with no response to sound or unfocused eyes
⚠️ Persistent vomiting of blood or black tarry stools indicating significant bleeding
⚠️ Rapid breathing or obvious laboured breathing that does not settle

02How should you monitor at home? Key observations and emergency signs

Keeping a detailed record of symptoms and changes at home helps your vet assess the progression, plan investigations, and determine follow-up frequency.

Record the frequency, timing, and appearance of vomiting episodes
Weigh your pet regularly and track any changes over time
Observe and note any changes in alertness and activity level
Record appetite, amount eaten at each meal, and any refusal to eat
Note the colour and frequency of stools and whether blood is present
Use your phone to record videos of vomiting episodes or signs of abdominal discomfort
If symptoms worsen, arrange a veterinary visit immediately

03How will the vet diagnose the condition? Common diagnostic tests

At the clinic, your vet will start with a physical examination followed by blood tests and imaging; sampling may be performed if needed to confirm the nature of the lesion and assess liver function.

A full physical examination to assess overall health and abdominal abnormalities

Blood tests including a complete blood count and liver function biochemistry

Abdominal ultrasound to evaluate liver size, structure, and any lesions

Advanced imaging (CT scan) for precise lesion localisation and extent assessment

Fine-needle aspiration or cytology to obtain a cellular sample

Tissue biopsy arranged when necessary to reach a definitive diagnosis

Referral to a specialist or advanced imaging and treatment may be recommended as appropriate

04What treatment and care are needed after diagnosis? Medications, diet, and home care guide

Treatment strategy is determined by lesion size and clinical signs; regular monitoring of liver function and imaging is required regardless of whether surgical or conservative management is chosen.

Surgical resection or conservative management options are discussed based on the assessment
Medications and supportive care require regular follow-up appointments as directed by your vet
Adjust diet according to veterinary advice and provide necessary nutritional support
Regular blood tests to monitor liver function and biochemistry trends
Follow-up with ultrasound or CT imaging to track lesion changes
Schedule regular check-up appointments during the post-operative period or throughout conservative management
If symptoms change or worsen, return to the vet immediately for re-evaluation

05What should you prepare before the vet visit? Key information to help your vet quickly identify the cause

Prepare a log of when symptoms first appeared, how they have changed, and key dates

Note the frequency of vomiting, what was vomited, and the times it occurred

List all current medications and supplements your pet is receiving

Bring recent weight records if available

Record videos of your pet's activity, vomiting, or abdominal discomfort to show the vet

Bring any previous examination reports or imaging discs if you have them

Consider booking an appointment at a specialist clinic equipped for imaging and biopsy

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.

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