Amebiasis in Dogs

Although "tropical" is often used synonymously with "paradise," the warm regions of the world host disease-causing organisms not found in colder climes. People and dogs living in tropical climates are vulnerable to the parasitic infection known as amebiasis. Usually caused by the amoeba Entamoeba histolytica, infection can result in chronic diarrhea in humans and canines. Another type of ameba, Acanthamoeba, causes neurological issues.

Dogs usually pick up Entamoeba histolytica from consuming contaminated feces, while infection with Acanthamoeba results from drinking polluted water. Many dogs exposed to these amoebas remain asymptomatic, or experience a brief bout of loose bowels. Puppies and older dogs, as well as those with compromised immune systems, are most vulnerable to infection.

The chronic inflammation of the large intestine caused by the amoeba Entamoeba histolytica results in constant diarrhea, often tinged with blood. Although colitis, or persistent diarrhea, is the most obvious symptom of amebiasis, dogs suffering from the condition might experience lack of appetite, weight loss and problems defecating. However, affected dogs might seem to improve, only to relapse over time. Untreated, this infection can prove fatal.

Dogs infected with Acanthamoeba might experience nasal and eye discharge, along with respiratory problems and fever. Some dog exhibit neurological issues, such as seizures or odd gaits. The nasal infection can head to the brain, causing a form of encephalitis, or brain inflammation. This form of amebiasis eventually kills the animal, but a veterinarian can treat the symptoms to give the dog a better quality of life.

Your veterinarian diagnoses amebiasis by conducting blood, urine and fecal tests, or a colonoscopy. Some drugs used to combat amebiasis in tropical countries aren't legal in the United States. To treat Entamoeba histolytica infection, your vet might prescribe paromomycin in an oral solution or capsule form. Another commonly prescribed drug for amebiasis treatment is metronidazole, marketed under the trade name Flagyl. In standard doses, this medication causes few side effects, although it should not be given to pregnant dogs. Even after treatment, dogs might continue to shed amoeba cysts in their feces.