Canine Giardia Treatment with Panacur (Fenbendazole) for Dogs

Panacur is a medication effective for the treatment of many intestinal infections in dogs. Fenbendazole, the active ingredient in Panacur, is useful against the most common intestinal worms including whipworms, hookworms, roundworms and tapeworms. This drug is also effective at fighting giardia, an intestinal protozoan which is contagious and easily spread through contaminated water and infected feces.


Giardia can cause infection in dogs, and can be contagious to other species as well, including humans. In healthy dogs, with uncompromised immune systems, this infection often doesn't cause symptoms or complications. If a dog is weakened by other factors, giardia may multiply and cause diarrhea which appears greasy, is oddly colored and has a very offensive odor. The digestive system will malfunction due to the infection, preventing proper absorption of important nutrients. This may cause weight loss, despite a normal appetite or eating habits.


Panacur contains the ingredient fenbendazole, which works by binding to the proteins in parasites and damaging the transport function of the cells. This drug is available over-the-counter and usually comes in power form. Dosage is based on weight and is given once a day for 3 consecutive days. Results have shown to be ineffective if complete treatment is avoided. This medication can be mixed with a small amount of food. Moisten if used with dry food. Full dosage must be consumed for best results.

Side Effects

Panacur is considered an extremely safe remedy for treatment of giardia and other intestinal infections. Side effects and overdose are rare and unlikely. This drug has been reported to be safe for use with pregnant and lactating dogs as well. Occasional loose stools have been reported. If your dog shows any signs of allergic reaction, use of Panacur should be discontinued. It's also possible that dogs will react to dying parasites. If facial swelling, hives, scratching, vomiting, shock, seizures, pale gums, cold limbs or lethargy ensue, your dog may be experiencing an allergic reaction. 

Prevent Reinfection

To prevent reinfection of giardia, there are a few things you can take into consideration. Hygiene is very important, as this parasite is spread by contamination. Never feed your dog raw or uncooked meat. Also keep swimming pools clean and select use of public waterways carefully. Always avoid parks or yards with large amounts of feces, and keep kennel and living areas clear of waste and debris that may collect bacteria. Cleaning with bleach or ammonium disinfectants is very effective at ridding common areas of the possibility of infection. It has been said that no medication can cure giardia 100%. Some of the giardia cysts may stay dormant for years by burrowing into the lining of the intestines, where they become almost impossible to kill. During times of stress in your dog's life, or situations that cause weakening of the immune system, this infection may reoccur.


There is currently a vaccination available for giardia. It's not intended for the prevention of giardia, but rather as an additional treatment option once dogs are already infected. The use of this vaccine may be recommended for people who are involved with a kennel situation, but the average dog owner may not benefit by using this product.