What symptoms in dogs and cats should raise concern about a tumor?

Common signs include persistent weight loss, changes in appetite, recurrent vomiting or diarrhea, and decreased energy. If you notice any of these, have your pet examined by a veterinarian.

What tests are typically done when a tumor is suspected?

Common diagnostics include a blood panel, X-rays, abdominal ultrasound, and where necessary cytology or tissue biopsy to identify the source and extent of disease.

What can I record at home to help with diagnosis?

It helps to track vomiting episodes, diarrhea (frequency, timing, appearance), daily water intake, litter box habits, and weekly weight. Photos or short videos are also very useful for your vet.

Does finding a tumor always mean surgery is needed?

Not necessarily. Treatment depends on the tumor type, location, and the pet's overall health. Options may include surgery, medication, or supportive care — discuss the best approach with your vet.

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

Tumors in Dogs & Cats: Symptoms, Diagnosis & Care Guide [2025]

Hydronephrosis is a condition where urine outflow obstruction causes the renal pelvis to dilate. Common causes include stones, tumors, or congenital abnormalities. Relieving the obstruction early can help preserve kidney function.

Take 1 minute to check the symptoms first

Last updated: 2026/01/05

PetHealthMap Editorial Team

Sources: ACVIM, WSAVA, National Taiwan University Veterinary Hospital

When to See a Vet

Seek emergency care immediately

•Sudden collapse, unresponsiveness, or inability to stand
•Repeated vomiting or vomiting blood multiple times with poor alertness
•Difficulty breathing or open-mouth panting that cannot be calmed

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

•Significantly decreased appetite with multiple days of not eating and weight loss
•Obvious change or abnormality in bowel or urinary habits
•Notably reduced activity level or excessive lethargy beyond normal

01What symptoms indicate something is wrong?

Tumors and endocrine-related conditions often cause non-specific systemic or behavioral changes. Early signs may be subtle but tend to progress over time.

Repeated vomiting or noticeably reduced appetite lasting more than a few days
Recurrent diarrhea or changes in stool consistency, including loose or bloody stools
Gradual weight loss or visible thinning, with significant loss over a short period
Increased urination frequency or nighttime urination, with abnormal volume or patterns
Noticeably increased water intake (polydipsia) accompanied by lethargy or sleepiness
Persistent pain, reluctance to be touched, or decreased activity levels
If any of the above are present, arrange a veterinary consultation as soon as possible

02How can you assess the situation at home? Key observations and when to go to the emergency clinic

Keeping a home log of key observations helps your vet quickly understand the progression of illness and plan a diagnostic workup.

Record the number of vomiting episodes each day, including time and appearance of vomit
Photograph or note any diarrhea, including whether blood or unusual material is present
Weigh your pet at the same time each week and track the trend
Log the frequency and approximate volume of urination each day
Measure and record daily water intake or observe how quickly the water bowl empties
Note changes in alertness, energy, sleep, and appetite with dates
Bring all records, photos, and videos to the veterinary clinic or specialist hospital

03How will the vet diagnose this? Common diagnostic tests

The vet will use a systematic physical examination combined with imaging to identify the likely cause and rule out other conditions.

Physical examination

includes palpation, temperature measurement, and overall condition assessment

Blood tests and biochemistry panel

to evaluate liver, kidney, and metabolic function

X-rays

to assess thoracic and abdominal organs, masses, or calcifications

Abdominal ultrasound

to evaluate organ structure, mass location, and blood flow

Advanced imaging (CT or MRI)

used for complex or deep-seated lesion assessment

May also require blood smears, urinalysis, cytology, or tissue biopsy

A specialist hospital capable of advanced imaging and pathology testing is recommended

04What happens after diagnosis? Medications, diet, and home care

Treatment and follow-up vary depending on the type and stage of disease. Regular check-ups and attentive home care are critical for a good outcome.

Treatment depends on the underlying cause — may include medication, surgery, or specialist referral, with follow-up monitoring
Regular blood tests and imaging to assess treatment response and watch for side effects
Prescription diet or nutritional adjustments as directed by your vet to support body condition
Monitor symptoms at home and keep records to bring to each follow-up appointment
If there is no improvement, consider referral to a specialist or a second opinion
Discuss a long-term care plan and quality-of-life management with your veterinarian

05What to prepare before the vet visit? Key information that helps the vet identify the problem

Prepare a log of symptoms such as vomiting and diarrhea, including timing and frequency

Note when symptoms started, any recent diet changes, and possible environmental exposures

Bring one week of records for weight, urination and defecation habits, and water intake

List all current medications, supplements, and the pet food brand and type being fed

Bring relevant photos, videos, or past diagnostic reports for comparison

Call ahead to book an appointment and choose a clinic that can perform advanced imaging

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.