The Truth About Giardia and Coccidia in Your Puppy

The Truth About Giardia and Coccidia in Your Puppy

Designed for survival

If your dog tests positive for a parasite – most commonly coccidia or giardia, you are probably wondering how an infection like this is possible, who or what is to blame, and what the best treatment is.  It’s quite the surprise to suddenly learn your sweet pup could be infected with an intestinal parasite.  The following information outlines how a parasite like coccidia or giardia behaves and the best treatments to eliminate them from your pup’s intestinal tract.

The first truth to remember is that the parasitic – canine relationship is slightly more normalized than our 1st world minds like to admit.  Intestinal parasites and canines have existed for thousands of years together.  Parasites – due to their unique lifecycle are designed to survive and thrive in mammals like dogs and rely on their host to continue their species life cycle.  This isn’t to say we want to ignore a positive parasite test, rather understand that parasite treatment is a normal part of every responsible breeder.     

The Intestinal Parasite Life Cycle

Giardia and Coccidia

Intestinal parasites like giardia and coccidia participate in a circle of life that relies on a mammal host like a dog.  The cycle begins often when an adult dog ingests parasitic cysts from a blade of grass, water, or really any host organism in the outdoors. Consumed feces, infected water dishes and blades of grass are common locations where dogs ingest parasitic cysts.  The cysts move to the intestinal tract where they transform into Trophozoites which is their feeding and reproductive stage. During this time period the adult Trophozoite duplicate and multiply.  After the reproductive stage most Trophozoite return to their cyst stage and leave the intestinal tract via feces with the goal of infecting another animal.  Further, some consumed cysts never leave the intestinal tract and only release during the nursing phase of a female dog with newborn puppies.  The puppies are then infected through milk supply.  

Other Parasites

Other parasitic worms like tapeworms and roundworms follow a very similar life cycle as coccidia and giardia but are often not as resistant to medication and are much easier to eliminate.

A Responsible Breeder’s Tension with Parasite Management

The simplest way to eliminate parasites from a puppy is treatment and isolation.  In fact, in an isolated and sterile environment the spread of parasites would theoretically be eliminated.  This looks like cold, drop deck wire cages where puppies sit alone from one another.  Naturally, this type of environment goes against many of our socialization and environmental values that we have as a responsible breeder.  As an ethical bulldog breeder, we want our puppies and adult bulldogs to engage, play and be mentally stimulated by one another.  This means that littermates will always interact and live amongst one another along with their mother.  We create these types of environments because we care about the social and mental development of our bulldogs.  A social bulldog is a happy bulldog!  Isolation should not ever be used as a tool to reduce parasites.  While this is the most effective strategy for parasite management, the mental development of bulldog puppies comes first.  Instead, timing and a correct preventative medication should be utilized to eliminate parasites like giardia and coccidia.

Bruiser Bulldog’s Step by Step Solution to Eliminate Intestinal Parasites.

By far the most important factor is risk reduction.  Infection hotspots like consumed feces and infected water dishes need to be eliminated.  We understand that a clean environment leads to a reduction of parasitic infection risk.  By maintaining a clean environment our bulldogs naturally run a lower risk of reinfection.  Cleanliness is important!

  1. Timely, Comprehensive Parasite Prevention Treatment

The main parasites that affect puppies and adult dogs are the following: roundworms, hookworms, lungworms, whipworms, tapeworms, and the two most commonly stubborn parasites – giardia and coccidia.  Because such a wide range of potential parasites exists, an effective prevention plan includes multiple “modes of action”.  

The following medications are useful in an effective parasite treatment plan

Pyrantel: Safe for puppies under 6 weeks old.  Treats roundworms and hookworms

Toltrazuril: Specializes in Coccidia treatment.  Albon is also used to treat coccidia but from our 15 years of experience is appears toltrazuril is superior. 

Fenbendazole: Treats a wide variety of parasites.  Is for more mature puppies.  Effective against roundworms, hookworms, lungworms, whipworms and tapeworms as well as semi effective against Giardia.

Metronidazole: Effective against giardia

Metro/Fenbendazole: Very effective against giardia

The key to an effective treatment plan is using the correct medication at the correct time.  Many parasites (coccidia and giardia) are cyst-like in nature during certain portions of their life cycle and are immune to treatments during this time.  Only consistent, multi-week treatment plans can effectively eliminate these types of parasites.   The following is our current puppy and adult treatment plan:


Week 2, 4, and 6 – Pyrantel (1 dose)

Week 7 and 9 – Metronidazole/Fenbendazole (5 days)

When the puppy goes home – Metronidazole/Fendbendazole (We send medication home with our adopters because often the stress of the ride home activates cysts in the intestinal tract and is a perfect time to medicate).

Week 6 and 10 – Toltrazuril (1-3 days)

Adult Bulldogs

Odd months of the year – Toltrazuril

Even months of the year – Metronidazole/Fenbendazole

As you can see there is quite a bit of effort and orderliness in effectively preventing parasites like coccidia and giardia.  Our goal is to never send a puppy home that is infected with a parasite.  By nature, these parasites are sometimes difficult to entirely eliminate if their cyst form stay attached to the intestinal tract for long periods of time.  The random nature of this behavior adds to the difficulty of treatment.  

The Correct Stool Sample is Vital!

When a puppy goes to their new adopter home a vet check with an accompanied stool sample is usually required.  During this process it is important to remember there are two very different types of stool samples.  

Fecal Float Test

A normal fecal float is standard during the initial puppy exam.  

During a fecal float, your puppy’s feces will be placed under a microscope and analyzed for cysts that indicate infection.  This type of test effectively detects ACTIVE infection of a parasite.  A fecal test is an important and vital test to ensure that the breeder( Bruiser Bulldogs!) has effectively eliminated all parasites from your puppy.  We support this type of parasite test as it is important to double check and ensure a parasite did not slip past our prevention plan.

Antigen Test: Commonly called an Eliza or PCR test

On rare occasions a vet will improperly use an Antigen test for parasite detection.  An antigen test tracks the parasite history of the animal by detecting trace elements of parasites in the pup’s intestinal tract from up to 6 months in the past.  It is important to note that the test records positive for parasites “antigens” that are detected regardless if this was a past or active infection.  An antigen test is an inaccurate and unreliable test to give to a young puppy that has already undergone a rigorous parasite prevention plan.  It is assumed that almost all puppies have been at some point infected by a parasite due to their lifecycle and will test positive for this test.  

Admittedly, the administering of antigen tests by vet clinics is a source of frustration.  Often vet clinics will unethically use the positive antigen test to undergo an additional round of parasite prevention medication and monthly fecal tests while painting the breeder as irresponsible.  This behavior is often a manipulative, money driven method of controlling clients through fear.  Just because a puppy has had a parasite in it’s past does not mean it is actively infected.  Of course the antigen test came back positive.  This makes perfect sense if we understand that parasite life cycle.  We have found this type of behavior as problematic, indicating the vet clinic in question should not be trusted.  


The natural life cycle of parasites makes them difficult to eliminate.  Only an effective and orderly prevention plan, along with a clean environment can reduce the risk of parasites.  We have had great success in controlling parasites like giardia and coccidia in our bulldogs by utilizing an orderly prevention plan and sticking to it.