If your cat has diarrhea for more than two days or shows additional signs of illness, it’s time to call your veterinarian and bag up a fresh poop sample from the litterbox to bring to the appointment.
Yes, your veterinarian really does want to see your cat’s poop. If the cat is having frequent or recurrent diarrhea, the stool appearance gives clues as to the cause of the diarrhea.
A photo with good lighting can help, but bringing in the real deal also means your veterinarian can check the stool for signs of parasites and other abnormal disease processes.
Your cat’s veterinarian will ask if you know how often your cat is having diarrhea and how he acts when it happens. This information helps narrow down the list of potential causes of diarrhea by helping to determine if the root of the issue is occurring in the small intestine, large bowel, or both. This information will then guide diagnostic testing and treatment decisions.
A focus on the frequency, volume, and appearance of diarrhea can help distinguish between small intestinal and large bowel diarrhea.
Small Intestinal Diarrhea
The small intestine is where most nutrient absorption occurs. Clues that your cat’s diarrhea may be caused by a small intestinal issue include:
Frequency: Your cat is defecating a little more often than usual and hops into the litterbox with a normal level of urgency or slightly more, with no straining observed during defecation.
Volume: Large volumes of stool are produced.
Appearance: The stool’s consistency is watery to semi-formed, and color can vary widely. If there is any blood present, it will be black or tar-like.
Other symptoms that cats with small bowel diarrhea may show include:
- Weight loss
- Vomiting
- Loud rumbly belly and flatulence
- Increased or decreased appetite
- Edema and swelling
- Dull brittle coat (chronic untreated diarrhea)
- Bloodwork may show low cobalamin and/or folate (B vitamins)
Large Intestinal Diarrhea
The large intestine is where most fecal water is absorbed and your cat’s stool is formed. Clues that your cat’s diarrhea may be caused by a large intestinal issue include:
Frequency: Your cat is defecating much more often than usual and dives into the litterbox urgently, with straining observed during defecation.
Volume: Small volumes of stool are produced with each bowel movement.
Appearance: The stool is usually semi-formed or gelatinous, with a normal color. There is often mucus in the stool. If there is any blood present, it will be bright red (fresh).
Cats with large intestinal diarrhea usually do not lose weight or have other symptoms of illness. They usually have a normal appetite.
Causes of Small Intestinal Diarrhea
Small intestinal diarrhea is the most common type of diarrhea seen in cats. Potential causes of small intestinal diarrhea include:
- Intestinal worms
- Giardia
- Coronavirus
- Panleukopenia
- Inflammatory bowel disease
- Intestinal lymphoma
- Food intolerance or allergy
- Pancreatitis
- Liver disease
- Hyperthyroidism
- Exocrine pancreatic insufficiency
- Hemorrhagic gastroenteritis
- Bacterial infections such as Salmonella, Clostridium, or Campylobacter
Causes of Large Intestinal Diarrhea
Potential causes of large intestinal diarrhea include:
- Intestinal worms
- Irritable bowel syndrome
- Food intolerance or allergy
- Bacterial infections such as Clostridium
Treatment
Treatment will vary depending on why your cat is having diarrhea. The cornerstone of diarrhea treatment in cats is feeding a bland diet and giving probiotics. Probiotics help to get the normal good bacteria reestablished in your cat’s gut and to promote normal digestive processes.
If your cat has intestinal worms, an appropriate dewormer will be administered.
Metronidazole is a common medication given to treat diarrhea, especially if Giardia or certain other infections are present or suspected. This medication also has anti-inflammatory properties.
Food allergies are best diagnosed with an elimination diet trial and can be treated long term with a limited ingredient or hydrolyzed diet.
Mixed Symptoms
Mixed bowel diarrhea originates from both sections of the intestines and can show characteristics of each. This is common in cats with chronic diarrhea and can make diagnosing the cause(s) and finding a treatment plan a little more challenging.
