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What Happens if Giardia Goes Untreated in Dogs?

| Updated September 26, 2017

According to the Centers for Disease Control, Giardia is a protozoan parasite that causes diarrhea, cramping and dehydration. It can survive on surfaces, as well as in food, soil and water that have been contaminated with feces. It is a zoonotic disease, which means it can be passed easily from companion animals to humans. A veterinarian looking at a fecal sample will see Giardia clearly and, when combined with clinical findings, be able to make a definitive diagnosis. Symptoms of Giardia should be taken very seriously as Giardia can make a dog very sick.

Collie Dog on Dog Bed
i Collie Dog on Dog Bed image by Janet Wall from Fotolia.com

If Giardia is suspected, it should be treated aggressively. According to the online magazine, Dog Owner’s Guide, Giardia can be potentially serious. Although some dogs are carriers, showing no symptoms whatsoever, others can suffer from severe symptoms. Therefore, Giardia should never remain untreated. According to the Mayo Clinic, the Giardia organism encases itself in hard shells before it is passed out of the body, allowing it to survive outside the intestines “for months.” The hard shell dissolves once the parasite is inside the host.

Giardia Problems

The biggest problem with Giardia is that it interferes with the absorption of food. Dogs will have an appetite and eat normally, but will not be able to absorb the nutrients and minerals in the foods. Animals need certain nutrients to have energy, fight off diseases and remain well. The inability to absorb the nutrients dogs need to live means they are at risk for certain deficiencies.

The diarrhea caused by Giardia infestation can result in serious dehydration. The diarrhea usually is chronic, though it can be intermittent, causing the pet owner to wonder if the issue has resolved.

Untreated Giardia

If Giardia remains untreated in dogs, several things may occur. The dog will continue to suffer uncomfortable, even painful, gastrointestinal symptoms. The feces will be greasy and malodorous, even more so than the usual unpleasant smell of dog fecal matter. He may lose weight, fail to thrive and become very sick due to the dietary malabsorption. The dehydration caused by diarrhea often is a debilitating symptom that causes problems because the body cannot then carry out its normal functions, such as removing waste products. A risk to humans is inherent, as Giardia can be passed from the infected dog to the human who is caring for him.

Giardia Treatment

Treating a dog for Giardia is simple. There are several treatment protocols, some lasting only a few days while others need a week to 10 days to be effective. Metronidazole (Flagyl) is the treatment of choice for many veterinarians and is about 65 percent effective in treating Giardia. However, Flagyl has been known to cause undesirable side effects, such as vomiting, anorexia and liver toxicity, in some dogs. Therefore, Panacur, known best for its effective treatment of a variety of worms, also is effective in treating Giardia and carries less risk of side effects.

Those who may be tempted to let a case of Giardia or other internal parasites remain untreated should know that treatment usually is very inexpensive and easy to administer. Often, if paying for a veterinary visit is cost-prohibitive, local shelters and humane societies will have Panacur on hand for this purpose and will help out a worried pet-owner. On the other hand, in some states failure to render veterinary care to an animal who is sick and suffering from a disease is a misdemeanor, with a felony upgrade should the animal die. Therefore, one would be wise to seek veterinary care if Giardia is suspected.