What Are the Causes of Diarrhea in Kittens?

Parasites

• One of the most common causes of diarrhea in cats is a heavy parasite load. Hookworms and roundworms are two of the most frequent culprits. Other symptoms of worms may include a distended belly and a voracious appetite with stunted growth. Most kittens are routinely dewormed at vet appointments, but if the mother of the litter has parasites, her kittens may acquire them prior to the age at which they'd first see a vet for vaccinations and deworming.

  If you suspect that your kitten has worms, see a veterinarian. A simple paste dewormer will clear up most cases.

Giardia

• Giardia is also a type of parasite, but different from worms in that it is a one-celled organism. It causes violent gastrointestinal disturbances, including persistent diarrhea and vomiting. Kittens most often contract giardia from the feces of an infected cat. Cats permitted to go outdoors may acquire the parasite from water sources where infected animals have defecated.

  Giardia is diagnosed with a fecal exam and most often treated with metronidazone (Flagyl). Some kittens require multiple courses of treatment.

Diet Changes

• Some kittens experience temporary or persistent diarrhea after a change in their diet. A change between dry and wet food will often trigger diarrhea. Changing brands or formulas of cat food can also have the same effect.

  To avoid this symptom, make any diet changes gradually, mixing the old food and new foods over the course of at least a week. If your kitten gets diarrhea after every food change no matter how gradual, he should see a veterinarian. Kittens raised on a high-quality food with quality animal protein and no corn, wheat or soy tend to have more resilient digestive systems and cope more easily with food changes.

Human Food

• Kittens often experience diarrhea after drinking milk or eating table scraps. After the age of weaning, most cats become mildly lactose intolerant and should not drink milk. If milk must be given, goat's milk, kitten milk replacer or a commercial "cat milk" product should be used. Cow's milk is not healthful for cats.

  Table scraps often cause diarrhea because they are high in fat and contain ingredients the cat isn't used to eating. While lean meats can be a healthful addition to a cat's diet, most table scraps should not be fed. If you would like to give your kitten a treat at mealtime, shred some cooked skinless chicken breast with no seasonings or sauces and place about a teaspoon of it in the kitten's dish. Compost your table scraps instead of sharing them with pets and use the compost to grow catnip in your garden.

Viruses

• Viral infections in kittens may cause diarrhea. A feline retrovirus infection may cause diarrhea lasting weeks and unresponsive to any treatment. Viruses don't generally respond to medication, though some new antiviral drugs have shown promising results for seriously ill cats and kittens. In general, it is necessary to let the virus run its course while treating the cat for symptoms that may extend the illness, like dehydration due to diarrhea. A vet may recommend antibiotics to prevent secondary bacterial infection while the kitten's immune system is weakened by a virus.

Serious Illness

• If a veterinarian has ruled out parasites, diet and viral infection as causes of a kitten's diarrhea, a serious health condition may be to blame. This could include cancer or organ failure, which sometimes present with persistent diarrhea. Diagnosis may require invasive procedures, up to or including organ biopsy.

  Don't worry about these more unusual and life-threatening conditions unless the most common causes of diarrhea have been ruled out. Organ failure and cancer are very rare in young kittens. Most cases of diarrhea resolve with time, dietary changes, and antibiotics or deworming.