• Liza Marie Moon

Using Toltrazuril in the treatment and prevention of coccidiosis in dogs and puppies

Updated: Sep 14

This article contains affiliate links, which means I will earn a small commission if you purchase something after clicking on some of these links.


I have chosen to place the FAQs at the start of this article for those that are looking for specific information.


Please consider reading this article in its entirety, as it is important to understand all aspects of this illness if you are seeking to treat or prevent it.


Frequently Asked Questions:


Where can I purchase Toltrazuril?

Click here to view details in this article about purchasing options.


I purchase my toltrazuril from Total Toltrazuril. Use coupon code TOLT10 to receive 10% off of your order. You can use the code as many times as you want, it will not expire.



Should I mix the Toltrazuril with something to flavor it?

Click here


Can I use Toltrazuril to treat coccidiosis in any age dog?

Yes! It is known to be safe and effective for all ages of dogs.


Can I give Toltrazuril to a pregnant or nursing female?

Yes! Though I prefer to give after whelping if being used as a preventative. This statement is based on anecdotal evidence, only. Safety in pregnant and lactating dogs has not been officially evaluated.


Can I call you and ask you some questions?

No. I will not speak to you over the phone regarding the treatment or diagnosis of an illness. I am not a veterinarian, do not claim to be one, and do not claim to know as much as or more than one. This article was written based on personal experience, as well as online research from credible sources. The information in this article is not intended to diagnose or treat a serious illness or disease. Always verify online medical advice with your board certified veterinarian. Thank you!


Are you experiencing unexplainable puppy diarrhea?



I've been there. So many breeders have been there, but not many want to talk about it. I spent an entire year researching and developing solid prevention protocol to avoid dealing with puppy diarrhea in general, as well as this horrible infection (coccidiosis) that young puppies are so susceptible to.


I would have saved so much time if other breeders has simply come forward and talked about their experiences and treatment plans that worked. But I found that so many other breeders were too embarrassed to admit that they had once had sick puppies. I made Facebook post after Facebook post about what I was experiencing, what worked for me, what hadn't, and wanting other breeders' advice and opinions. All I got was "change kibble!" Or, "give probiotics!" These were not the answers I needed.


Finally, after many posts and pleas for help were made (OF COURSE I had already consulted with my primary care veterinarian, but he was at a loss!), private messages started coming in. Messages from breeders who had experienced this same problem--unexplainable puppy diarrhea. Some of them desperate for help, just like me, but many of them offering treatment and prevention protocol because they had been through the same thing, but were afraid to share publicly about it.


Many breeders have experienced this illness, not just you.


If you are experiencing puppy diarrhea, puppy vomiting, or other digestive related problems, please consider treating your litter for coccidiosis


Left untreated, the symptoms of coccidiosis can cause death in young puppies due to dehydration and malnutrition. Coccidiocides (medications used to treat coccidiosis), as discussed further in this article, do not typically interact with other anthelmintics (dewormers), medications, and supplements. They target only the protozoa (coccidia) that are making your puppies sick.


Please read this article from top to bottom. There is a big difference in protocol when it comes to treating coccidiosis vs preventing coccidiosis. It is important to be informed of all your options before you purchase expensive medications and supplements and begin your regimen.


If you are still experiencing problems with puppy diarrhea, please see one of our other blog posts (click the button below):


What is Coccidiosis?


“Coccidiosis is a parasitic disease of the intestinal tract of animals caused by coccidian protozoa. The disease spreads from one animal to another by contact with infected feces or ingestion of infected tissue. Diarrhea, which may become bloody in severe cases, is the primary symptom. Diarrhea is typically accompanied by dehydration and fatigue. Vomiting is not uncommon for infected individuals, but a more rare side effect of the infection. Most animals infected with coccidia are asymptomatic, but young or immunocompromised animals may suffer severe symptoms and death.” (https://en.wikipedia.org/wiki/Coccidiosis)


Important: Coccidia is a protozoan parasite, not an intestinal "worm." Traditional dewormers will not kill coccidia. These can include pyrantel pamoate (Nemex), fenbendazole (Safeguard, Panacur), Advantage Multi (moxidectin), etc. These products do not kill coccidia.


Severe coccidiosis symptoms can mimic the symptoms of canine parvovirus (parvo). Many breeders seek out expensive treatment for coccidiosis in fear that they are dealing with parvo, when in fact if caught early enough, coccidiosis can be very treatable at home.


Coccidia oocysts under microscope dog puppy parasite diarrhea
Coccidia oocysts under a microscope

How are my puppies becoming infected with coccidia?


“Puppies are frequently infected with coccidia from the feces of their mother, and are more likely to develop coccidiosis due to their undeveloped immune systems. Stress can trigger symptoms in susceptible animals.“ (https://en.wikipedia.org/wiki/Coccidiosis)


Please do not feel guilty or discouraged if you are dealing with a problem with coccidia in your kennel--but please don't ignore the problem


This protozoa is everywhere. It can live and reproduce in the environment for a very long time and is almost impossible to completely destroy with the use of disinfectants and chemicals. Once an animal has been exposed, it can live and reproduce inside their intestinal tract indefinitely.


And let me reiterate that all of your dogs have been exposed at some point or another. There is nothing you can do to prevent this exposure! Lack of exposure to coccidia is not a matter of "superior cleanliness" or "being a better dog owner." It's luck of the draw.


Infection (showing symptoms of illness) only occurs when an animal is weak or when their immune system has been compromised. This is why it is so common for young puppies to develop coccidiosis and become ill--their immune systems are still developing and are very susceptible to parasites, viruses, and bacteria.


Most puppies contract coccidia from their mothers.

Your dogs have coccidia from being exposed to the infected feces of other dogs. This exposure can happen anywhere--the vet's office, the dog park, the pet store, or literally any public place where dogs (or wild dogs) poop on the ground. You cannot fully prevent your dog from being exposed to coccidia in the environment.


Dogs contract coccidia from other dogs.

Your puppies probably got coccidia from their mom, who passed it on to them through exposure to her infected feces. Remember, "infected feces" does not imply that the dog who passed the feces is ill. It implies that the feces contains the protozoa. Your bitch is not sick because she has a strong immune system that does not allow the coccidia always present in her body to cause illness, but now that your puppies are infected, they might become sick because their immune systems will not be fully developed for many months.



Why didn't my vet know my dog was infected with coccidia?


This is the most perplexing piece of the coccidiosis puzzle. Coccidiosis is very under-diagnosed in dogs, but especially young puppies.


Coccidia is spread from dog to dog when coccidia oocysts (baby coccidia) are shed in a dog's feces. These oocysts can be shed from a dog who carries coccidia, but has never been ill. These oocysts are shed intermittently, meaning they are not shed every day.


Coccidia oocysts (baby coccidia) are very tiny compared to other parasite eggs. Most vet clinics perform a "fecal float test" when looking for parasites. The oocysts that are detected in a fecal float test are shed intermittently, as the organisms reproduce. This "floating" method of diagnosing an active coccidiosis infection is not ideal, because the oocysts are either missed or they are not present in the fecal sample at all.


Because oocysts are shed intermittently, your vet may not detect coccidia in your dog or puppy's fecal sample because the oocysts were not being shed that day. Make sense?


Please do not blame your vet for being unable to accurately diagnose an infection. They're simply working with what they see under the microscope, which is more often than not nothing at all.


Continue reading to learn more about how to diagnose coccidiosis.


Diagnosing coccidiosis / coccidia


Diagnosing coccidiosis is difficult. Many fecal float tests will come back negative for coccidiosis because the oocysts are very small, and therefore in small numbers, can be almost impossible to detect. Even a small number of oocysts can cause infection, so fecal float tests are not always the best diagnostic tool. And, oocysts are shed intermittently, so there may not be any oocysts in your dog's fecal sample that day.



Be sure to rule out canine parvovirus (parvo) with a SNAP test while you are at the vet. Request a SNAP test specifically, do not allow your vet to use an antigen test. Antigen tests can give false positives very easily if your puppy has already been vaccinated against parvo.


You may request for your vet to send a stool sample to the lab for further analysis, but receiving results can take days. It is in your best interest to begin treatment for coccidiosis immediately, even if a fecal float test comes back negative (as well as a negative parvo SNAP test).



The most common symptoms include:

  • Diarrhea, from loose stool to watery liquid

  • Mucus and blood present in the diarrhea in severe cases

  • Poor appetite, lethargy

  • Vomiting in severe cases

  • Dehydration resulting from diarrhea (dehydration will kill young puppies very quickly)

Many breeders will report that the tell-tale sign of coccidiosis is bright yellow diarrhea. This is especially true in newborn puppies, and young puppies that have not started eating solid food yet. However, I have never experienced this "bright yellow" diarrhea. An older puppy that is eating solid food may not have this "bright yellow" diarrhea. Please do not rely on this anecdotal evidence as a sole diagnosis when considering treating litter for coccidia.



Dehydration from diarrhea and vomiting kills puppies fast. If you suspect your puppies are dehydrated, take them to the vet immediately.


Treating coccidiosis / coccidia


Routine veterinary treatment involves using a sulfa-type antibiotic called sulfadimethoxine (Albon). This drug works by stopping the reproduction cycle of the protozoa. Many experienced breeders will tell you that this method of treatment is not very effective, as it is costly and the medication must be given twice daily for 2-3 weeks in order to be effective. Many breeders are also seeing a strong resistance to this medication since it has been used for such a long time.


It is typically faster and more effective to administer an anti-protozoal/coccidiocide that kills the oocysts immediately, accompanied by fluids, electrolytes, and probiotics. An antibiotic such as tylosin (Tylan) can also be very effective in clearing out gram positive bacteria that have built up in the gut from the stress of infection.


Environment cleanliness is very important, though as discussed several times in this article, eradicating coccidia from your environment is near impossible. We simply recommend that you continue your normal cleaning and disinfecting protocol during a coccidia outbreak. Of course, when dealing with diarrhea you will be cleaning and disinfecting twice as much as what is normal! It is important to clean up infected feces immediately when dealing with a coccidia outbreak.


If your puppies have become lethargic and dehydrated (do a "skin pinch" test), and/or if their stool contains blood, bring them to a vet immediately


If your puppies have persistent diarrhea (liquid/watery stool) and/or vomiting for more than 24 hours, please bring your puppies to the vet.


The protozoa themselves (coccidia) do not kill puppies. Dehydration (caused by the symptoms of coccidiosis illness) causes death in puppies. Dehydration is very serious.



It has been suggested and somewhat proven through multiple controlled studies that Oregano Essential Oil has wonderful antibacterial properties. Combining the use of this all natural product with your coccidiosis treatment protocol could result in faster recovery and prevent infection relapse. Click here to purchase.


I do not have personal experience in using Oregano oil in my prevention or treatment protocol, however, it has been used as an antibacterial agent for centuries.