Disease Guide

Gastrointestinal Disease in Dogs & Cats: Symptoms, Diagnosis & Home Care [2025]

Coccidiosis is an intestinal parasitic infection commonly seen in young pets. It causes diarrhoea and responds well to antiprotozoal medication.

Last updated: 2026/01/05
Pethealthmap Editorial Team
Sources: AVMA, WSAVA, National Taiwan University Veterinary Hospital

When to See a Vet

Seek immediate veterinary care (emergency)

  • Persistent vomiting for more than 24 hours and unable to drink water
  • Vomiting or stool contains obvious blood or appears black
  • Lethargy, confusion, or difficulty breathing occurs

Schedule a clinic visit as soon as possible (within 24-72 hours)

  • Vomiting for more than 12 hours but still able to drink water
  • Appetite is clearly reduced for more than two meals
  • Stool is watery and bowel movements continue to increase noticeably

01What symptoms indicate something is wrong?

Gastrointestinal issues in dogs and cats most commonly present as vomiting and diarrhoea, often accompanied by changes in appetite and energy levels.

  • Repeated vomiting or changes in vomit appearance (colour, contents)
  • Diarrhoea or loose stools, abnormal colour, or presence of mucus
  • Significant decrease in appetite or complete refusal to eat
  • Reduced energy and activity, lethargy, or unwillingness to play
  • Signs of dehydration, such as dry mouth or reduced skin elasticity

Seek emergency care immediately if you notice the following symptoms:

  • ⚠️ Vomiting lasting more than 24 hours or inability to keep water down
  • ⚠️ Fresh blood in vomit or stool, or black/tarry stools
  • ⚠️ Extreme lethargy, disorientation, or difficulty breathing

02How can I assess the situation at home? Key observations and emergency indicators

Before visiting the vet, observe and record key information at home — these details help the vet assess and manage the situation quickly.

  • Record the number of vomiting episodes, timing, contents, and colour
  • Record stool frequency, consistency, colour, and whether blood is present
  • Monitor changes in energy levels, appetite, water intake, and activity
  • Use your phone to film vomiting or diarrhoea episodes to show your vet
  • Organise all observations into a summary to share with your vet at the appointment

03How will the vet make a diagnosis? Common examination steps

At the clinic, the vet will assess your pet from the outside in and arrange blood tests, imaging, and other diagnostics to identify the cause and guide treatment.

Physical examination

including abdominal palpation, hydration assessment, and temperature

Blood count

checking white blood cells, electrolytes, and infection markers

Biochemistry panel

evaluating liver, kidney, and metabolic function

Urinalysis

to rule out urinary or metabolic conditions

Imaging

X-rays to assess the GI tract or detect foreign bodies; ultrasound or advanced imaging (CT/MRI) if needed

04How is treatment managed after diagnosis? Medications, diet adjustments, and home care

Treatment includes supportive care, medication, and dietary adjustments, along with follow-up visits and monitoring to confirm improvement.

  • Administer medications or IV/subcutaneous fluids as directed by your vet
  • Dietary management: withhold food briefly, then reintroduce with a bland, easily digestible, or prescription diet
  • If antibiotics or other medications are prescribed, attend follow-up appointments to monitor effectiveness
  • Schedule blood or imaging follow-ups to confirm the condition is improving
  • Home care focuses on hydration and monitoring elimination habits and energy levels
  • For persistent or recurring symptoms, a specialist referral or further diagnostics are recommended

05What should I prepare before the vet visit? Key information to help the vet diagnose quickly

1
Note the onset time, how symptoms started, and how they have progressed
2
List recent food types, amounts fed, and any potential exposure to foreign objects
3
Record vomiting and bowel movement frequency and appearance, and save photos or videos
4
Bring any current medications, supplements, and vaccination records
5
If prior test results or images are available, bring them for the vet's reference
6
Organising your observations into a checklist helps the vet assess the situation faster

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.

Frequently Asked Questions (FAQ)