Coccidiosis: Diagnosis, Treatment, and Prevention
What is Coccidiosis?
Coccidiosis is an intestinal disease that affects several different animal species including canines and humans. Coccidia is one of the most prevalent protozoal infections in North American animals, second only to giardia. Eimeria and Isospora are the two genera that are often referred to as “coccidia.” These two genera contain a large number of species that infect a variety of animals throughout the world.
The diseases caused by these microscopic protozoal parasites are referred to collectively as coccidiosis, and they vary tremendously in virulence.
Some species cause diseases that result in mild symptoms that might go unnoticed (i.e., mild diarrhea) and eventually disappear, while other species cause highly virulent infections that are rapidly fatal. The causative agent is a protozoan that has the ability to multiply rapidly. The major damage is due to the rapid multiplication of the parasite in the intestinal wall, and the subsequent rupture of the cells of the intestinal lining. Several stages of multiplication occur before the final stage, the oocyst, is passed in the feces. Oocysts are extremely resistant to environmental stress and are difficult to completely remove from the environm
ent. Oocysts are frequent contaminants of feed and water and when the sporulated oocysts are ingested by other animals they start the life cycle over in the new host.
Life Cycle of Coccidia
The life cycles of both genera of coccidia are similar. A host is infected when it ingests oocysts that have been passed in the feces of another host. The oocyst encysts in the host’s small intestine, and the sporozoites contained within the oocyst are liberated. The sporozoites penetrate the cells of the host’s small intestine and reproduce asexually. Each generation of asexual reproduction produces multiple me
rozoites; the merozoites are liberated from the cell and infect new cells. It is this stage of the infection that can result in destruction of massive numbers of cells in the host’s small intestine and, ultimately, lead to the host’s death. Some of the merozoites that enter the host’s cells transform into gametocytes. The gametocytes transform into gametes, the gametes fuse, and the resulting zygote begins to develop into an oocyst. The developing oocyst escapes from the host’s cell, and it is passed in the host’s feces. Typically, when the oocyst is passed in the feces, it is not infective because it does not contain sporozoites; this is an unsporulated oocyst. After several days (or weeks, depending on the species) outside of the host’s body, the oocyst completes development and sporozoites are found within; this is a sporulated oocyst, and it is infective to the next host (view diagram of the life cycle).
Clinical signs of coccidiosis usually are present or shortly following stress such as weather changes; weaning; overcrowding; long automobile or plane rides; relocation to a new home and new owners; and/or unsanitary conditions. Symptoms or signs of coccidiosis will depend on the state of the disease at the time of observation. In general, coccidiosis affects the intestinal tract and symptoms are associated with it. In mild cases, only a watery diarrhea may be present, and if blood is present in the feces, it is only in small amounts. Severely affected animals may have a thin, watery feces with considerable amounts of intestinal mucosa and blood. Straining usually is evident, rapid dehydra
tion, weight loss and anorexia (off feed) also may be clinically visible. One of the most prevalent canine coccidia is S. tenella and during autopsies of dead animals appears as microscopic muscle cysts in the host animal. Oocysts in the feces of dogs are also microscopic in size and can only be positively identified through lab tests or direct observation under a microscope.
“Nervous coccidiosis” is a nervous system condition associated with coccidial infection. Signs are consistent with central nervous system involvement, and include muscle tremors, convulsions and other central nervous system symptoms. A consistent sign in “nervous cocci” dogs is that stimulation of any type seems to trigger the symptoms.
Death may follow the acute disease either directly or from secondary diseases such as pneumonia. Animals that survive for 10 to 14 days may recover, however, permanent damage may occur. Research has indicated that canines may experience reduced food consumption for up to 13 weeks following clinical infection. Diagnosis usually is obvious but confusion does exist – apparently normal animals can also have oocysts present in their feces. Diarrhea may be present in the animal before the oocysts can be found, therefore, a confirmed laboratory diagnosis may not always be possible. Laboratory findings should be correlated with clinical signs for a diagnosis.
The susceptibility of animals to this disease varies. The ingestion of oocysts may not produce the disease; some animals constantly carry them without being affecte
d. Recovered animals develop immunity and seem to be partially resistant to reinfection.
Coccidiosis is frequently referred to as an opportunist – a disease that will develop when other stress factors are present. For example, the highest incidence of coccidiosis is in the first 21 days after a dog has changed owners and moved to a new residence. If a normal animal carries oocysts, it is relatively easy for rapid development when the conditions are right – adverse weather, shipping, dog food changes, new owners, new residence, and other stresses are important.
In case of a confirmed outbreak of coccidiosis in a kennel full of Beagles, the following steps should be started immediately: 1. Separate the sick animals from the healthy ones. 2. Treat sick animals with effective medications. 3. Medicate all the dogs in the kennel or home, as the other animals are likely infected.
General information on coccidiosis in canines:
1. Coccidiosis is an opportunistic disease – it generally affects stressed animals. 2. Kennel conditions provide ideal circumstances for an outbreak. 3. In most confinement
situations, prevention with sulfadimethoxine drug such as Albon® is recommended. 4. Mass treatment of all dogs in an entire kennel is usually the only effective method. 5. Sick animals should be treated as soon as possible and isolated from the healthy animals. 6. Have your veterinarian confirm positive diagnosis of the coccidia protozoa in your dog’s feces through the use of lab tests or positive identification through direct observation under a microscope. How can I be sure my dog has Coccidia?
Diagnosing coccidia is not easy. Diagnosis can be done in one of two ways: via fecal sample by a Vet or via educated evaluation of clinical findings by the breeder/owner or the Vet. Via fecal sample is not straightforward. Even when a flare is at it’s worst, the oocysts may not be shedding in every single stool. Therefore, a negative report does not rule out coccidia. The most thorough way to assess is to collect a sample from every single stool produced for 48 to 72 hours and have a Vet examine it.
How can infection be treated?
Treatment of infected animals is required. Individual treatment should be used when possible, however, medications are available for entire kennel applications. The actual coccidiosis problem is critical and in addition, dehydration and loss of appetite must be treated. Drug selection should be handled with regards to the number of animals infected and the type of application. Sulfas and antibiotics for secondary bacterial infections are available for use. Treatment and prevention are most effective when started early. Most kennels need to segregate and medicate new dogs at the time of arrival. Kennel owners can also reduce exposure by reducing stress, such as overcrowding and poor sanitation.
Infection may be treated using a sulfadimethoxine drug such as Albon®, Bactrovet®, or Tribrissen®. Data regarding acute and chronic toxicities of sulfadimethoxine indicate the drug is very safe. The LD50 in mice is greater than 2 g/kg of body weight when administered intraperitoneally and greater than 16 g/kg when administered orally. In dogs receiving massive single oral doses of 3.2 g/kg of body weight, diarrhea was the only adverse effect observed. Dogs given 160 mg/kg of body weight orally daily for 13 weeks showed no signs of toxicity. Treatment may be initiated by a Vet with an Albon Injection 40% (100-mL multiple-dose vials) to obtain effective blood levels almost immediately or to facilitate treatment of the fractious animal. With the Albon Injection 40%, each mL contains 400 mg sulfadimethoxine compounded with 20% propylene glycol, 1% benzyl alcohol, 0.1 mg disodium edetate, 1 mg sodium formaldehyde sulfoxylate, and pH adjusted with sodium hydroxide. Albon is also available in liquid form: Albon Oral Suspension 5%: 2- and 16-oz bottles; each tsp (5 mL) contains 250 mg sulfadimethoxine in a custard-flavored carrier. Length of treatment with any sulfadimethoxine drug depends on the clinical response. In most cases treatment for 5 days is adequate. Treatment should be continued until the animal is asymptomatic for at least 48 hours.
The cost to effectively keep coccidiosis infestations out of your Beagles may be entirely too much if you take your dog(s) to a Veterinarian. As already stated, a Vet will charge you for an office visit plus the cost of canine dosage sulfadimethoxine pills (Tablets-125 mg, 250 mg, and 500 mg), Albon Injection 40%, and/or Albon Oral Suspension 5%. The cost for the Veterinarian treatments along with the cost of the office visits will add up to a lot of money per year, especially if you have more than one Beagle. Once again, I want to remind everyone that I am not a Veterinarian, but rather a long time Beagle kennel owner. I’ll tell you what I use and do, you can use your own judgment whether you want to follow in my footsteps. This article is presented only as a documentation of how I treat coccidiosis infestations in the Beagles that I own at a fraction of the cost that a Veterinarian will charge you.
What I do is buy the Sulfadimethoxine 12 1/2% solution (generic Albon) from Lambert Vet Supply without a prescription and for a lot less money. Active ingredients: Each fluid ounce contains 3.75 grams Sulfadimethoxine solubilized with sodium hydroxide. I buy the one-gallon size jug of the generic brand of Albon which is the Sulfadimethoxine 12 1/2% solution for $40.75 (accurate price as of 04/20/2008) per gallon. Simply click on either picture to the left of this paragraph and order a gallon jug of either the Sulfadimethoxine (generic Albon) or the name brand Albon today. (NOTE: Lambert Vet Supply is not a sponsor of BEAGLES UNLIMITED and we do not make a cent by referring them to you. They do have the absolute lowest prices available to help all of us keep our Beagles in great health while we save hundreds of dollars each and every year. Here is more information about Lambert Vet Supply.)
Dyne High Calorie Supplement
This gallon jug of liquid Sulfadimethoxine is enough antibiotic to medicate a huge kennel full of Beagles for several months or even years. If you have more than one Beagle to treat with the Sulfadimethoxine drug for a coccidiosis outbreak, I highly recommend you follow in my footsteps and buy and use the gallon size jug of this medication as well as another product described below and then you can make your own 5% Albon solution just like you get from the Vet.
I also purchase a gallon jug of Dyne High Calorie Supplement, which is a liquid nutritional supplement, from Lambert Vet Supply. I buy the one-gallon size jug for $33.50 each (accurate price as of 04/20/2008). Simply click on the picture of Dyne High Calorie Supplement to the right of this paragraph and order a gallon jug today. This product is formulated to provide a nutrient dense liquid diet with essential vitamins and has a high caloric value. This product expedites the rate of recovery of weak or sick animals. It also may be fed as is or diluted with milk for animals unable to eat solid foods.
Then what I do next is I mix 5 ounces of Dyne High Calorie Supplement with 4 ounces of the Sulfadimethoxine 12 1/2% solution discussed above. This gives me a fairly palatable mixture of the 5% Albon (Rx) at a 85% or higher savings without the required prescription or the expense of a Vet office visit. I know many breeders that are paying $75 or more per pint for the 5% Albon (Rx) solution that they get from their Vet. This will give you approximately 2-gallons of the 5% Albon (RX) for only $75 rather than only 1-pint that a Vet will sell you for $75 — you figure up the savings! Once you have this 5% Albon solution mix, each teaspoonful (5 mL) will contain 250 mg of Sulfadimethoxine. Beagles should receive 1 teaspoonful of this 5% Albon Oral Suspension mixture per 10 lb of body weight (25 mg/lb or 55 mg/kg) as an initial dose, followed by ½ teaspoonful per 10 lb of body weight (12.5 mg/lb or 27.5 mg/kg) every 24 hours thereafter. I recommend you give this treatment for a total of 10 days. The medication may be administered in food or water, given as a drench orally. I give each dog its own food and medicine in its own feed dish to make sure each dog is getting the proper amount of food and medicine or at least use it as a drench to be given orally to each dog/puppy. This Sulfadimethoxine 12 1/2% solution mixed with the Dyne High Calorie Supplement will save you hundreds of dollars a year. I urge all kennels to keep a gallon of each handy. This Sulfadimethoxine 5% solution mix has a wide margin for safety, is very easy to administer, and absolutely works miracles on getting rid of coccidiosis in your hounds. Since coccidiosis is so easily spread from one Beagle to the next, I highly recommend all hounds get a full treatment even if only one hound shows symptoms — better to be safe than sorry.
This is the treatment that I use in my kennel and you can also check out the article Giardiasis: Diagnosis, Treatment, and Prevention to learn more about the other common protozoal infection called giardiasis. It is very unlikely to eliminate 100% of the coccidiosis infection in all dogs. Adaptations that may be made to try to improve the success rate of a treatment regime include extending the duration and dose of the treatment. Care must obviously be taken with this approach to make sure that an adequate safety margin is always maintained. Another approach is to retreat after an interval of one week of completion of the initial treatment. Alternatively, repeat fecal samples may be collected one week after the treatment and dogs which are still passing oocysts can be identified and treated. It should be recognized that, when treating a large number of dogs, there may still be one or two dogs that remain as carriers of infection that will act as a potential source for reintroducing the infection into your entire kennel.
No matter which treatment you choose to utilize (Vet Rx or over-the-counter cattle drugs), the simple fact is that it may not kill all of the coccidia oocysts. A certain number of them can burrow into the lining of the intestines and go dormant. They can stay dormant for years. Due to the hard shell protecting the oocysts, it is almost impossible to kill them when they are encysted in the lining of the intestines. Therefore, during times of stress, the oocysts may re-activate and start to reproduce, causing another outbreak of coccidiosis in your Beagle or Beagle kennel. The amount of stress needed to cause a flare seems to be highly variable with different dogs and dog breeds. Beagles are one of the hardiest breeds since they were developed as hunting hounds.
Important Note: A healthy dog may have been infected years before and never have shown any symptoms (asymptomatic carrier). They may occasionally shed very low numbers of oocysts in stools–evaluating every stool (the WHOLE stool) for something like six months is supposed to be the conclusive way to rule out an asymptomatic carrier (someone did this with a couple dogs for a study). This would cost literally thousands of dollars! Not exactly a practical way to test. Coccidiosis and giardiasis are both very common protozoal infestations that have the exact same clinical symptoms; therefore, I recommend that both diseases get treated one right after the other: coccidiosis for 10 days and giardiasis for 5 days if using Metronidazole or 3 days if using Fenbendazole. Once again, I treat coccidiosis with Sulfadimethoxine (Albon), and giardiasis with Metronidazole (Flagyl) or Fenbendazole (Safe-Guard).
How to eliminate coccidia from your kennel or home?
Once infection is present in a kennel, control may be approached in two ways:- 1. identification, isolation and treatment of infected dogs. 2. mass treatment of all dogs.
Option 1 is only practical where a few dogs in a discrete area have been identified as being infected and where complete isolation is feasible, either within their own block or in a specific isolation block. Such isolation includes segregation of exercise areas and these animals should be fed and cleaned after all others on the premises, preferably using separate cleaning and feeding equipment and separate staff if possible. Treatment of all dogs should commence on the same day when option 2 is adopted.
Thorough cleaning of all kennel areas where infected dogs have access is essential. Once organic debris has been removed, thorough disinfection will help to further reduce the level of environmental contamination and reduce the risk of dogs becoming re-infected after the completion of treatment. Disinfectants containing quaternary ammonium compounds have been found to kill Coccidia oocysts at the manufacturers’ recommended dilutions (dilutions of one disinfectant up to 1:704 were found to be effective at both low and high environmental temperatures). I disinfect all my kennels twice per month by washing everything down with a mixture consisting of 8 ounces of Clorox bleach per gallon of water. Make sure you let it set at least 20 minutes, rinse thoroughly, and then let it get completely dry before letting your Beagles use the kennels again. Important Note: The efficacy of killing is increased by prolonged contact time, therefore disinfectant solution should be left for 20 minutes to half an hour before being rinsed off kennel or run surfaces. Since disinfection of grass runs is impossible, such area should be regarded as contaminated for at least a month after infected dogs last had access.
Introduction of new dogs into the infected area should be avoided until the period of treatment and fecal sample checking has been completed. It should not be overlooked that some of the infected dogs may continue to excrete low numbers of oocysts even after all treatments and examinations have been completed. It is therefore important that rigorous disinfection is maintained and a careful check is kept on the condition of all treated and introduced animals.
The following are recommendations for eliminating coccidia from kennels and homes:
- treat all dogs with sulfadimethoxine for 10 days
- disinfect kennel areas, etc, with quaternary ammonium disinfectants which are effective in inactivating coccidia oocysts
- bathe dogs with shampoo to remove all fecal matter, rinse with water
- rinse dogs with quaternary ammonium disinfectants, then waterallow kennels to dry thoroughly for several day
- retreat with sulfadimethoxine for 7 days
- treat any new dogs with sulfadimethoxine (e.g. Albon) for 10 days even if they test negative for coccidia because it is so hard to detect in fecal tests
How can infection be prevented?
It is very difficult to prevent the entry of an infection that is known to be carried by a percentage of normal dogs into a kennel. However, an initial period of isolation for all new entrants into kennels, for perhaps ten days, would reduce the risk of an infected dog spreading a large number of oocysts around the main kennel area. All dogs could be observed and any infection present, which in the case case of coccidia might be exacerbated by the stress of entry in kennels, could be identified and treated before entry into the main kennels.
Dogs should be prevented from access to foul water that may contain large numbers of oocysts (e.g.: river-flooded paddocks). Small numbers of oocysts may occasionally be present in the potable water supply but the risk of this being a major source of infection is small. It is best to use chlorinated water for your dogs drinking water as much as possible. If you are using non-chlorinated water from a well, lake, or stream, you need to chlorinate the water yourself. To chlorinate drinking water: Use only liquid bleach that contains 5.25% sodium hypochlorite as its only active ingredient – no soap. Use a scant 4 drops of Clorox bleach per quart of water or 2 teaspoons per 10 gallons. As an alternate method of purification, you can also boil all of your dog’s drinking water. To make sure the water is completely bacteria free, you need to bring the water to a rapid boil for a minimum of five (5) minutes. Remember, Cool moist conditions favor the survival of the organism; therefore, simply by keeping everything clean, disinfected, and dry you will be getting a lot further toward exterminating this nasty little one-celled parasite.
Remember, coccidiosis and giardiasis are both very common protozoal infestations that have the exact same clinical symptoms; therefore, I recommend that both protozoans get treated one right after the other: coccidia for 10 days and then giardia for 5 days if using Metronidazole or 3 days if using Fenbendazole. Once again, I treat coccidiosis with Sulfadimethoxine (Albon) and giardiasis with Metronidazole (Flagyl), which is my 1st choice, or Fenbendazole (Safe-Guard), which is my second choice.