Good news on the coccidiosis front - Baycox is back!
Sunday, April 3, 2011
Removed from the market some years ago, this long-acting and effective coccidiocidal compound is now available by prescription from veterinarians once again
by ERNEST SANFORD
I have written about coccidiosis (cocci) more than once over the last several years. The first occasion (Better Pork, October 2004) was to announce that the menace of piglet cocci was alive and well in many farrowing rooms across the country. Some years later, (Better Pork, August 2007) it was when, Baycox (scientific name, toltrazuril), the only product that worked well in combating porcine cocci, was removed from the market by the Canadian Food Inspection Agency.
I'm very pleased to say that Baycox is now a fully licensed product in Canada and is available to producers by prescription through their veterinarian. Now that Baycox is back on the market here is a quick refresher on cocci.
Clinical signs. Cocci is a protozoal (parasitic) infection that causes scours in suckling piglets, usually at one to two weeks of age. The scour is pasty to watery and ranges from white to yellow or more commonly a pasty gray. It is notoriously unresponsive to antibiotics. Piglets continue to nurse, but develop a rough hair coat, are dehydrated, depressed and become poor doers.
Severity of clinical signs may vary between litters in the same farrowing room and even between pigs in the same litter. Subclinical infection is common, although it can be suspected when pigs, one to two weeks age of age, show rough hair coats and poor growth. Morbidity is high, but mortality is usually low unless secondary bacterial or viral infections occur.
The infecting protozoan, Isospora suis, has a very short life cycle and produces oocysts (eggs) which are shed in the feces into the environment within four to five days after initial infection, by which time the cells lining the intestinal surface have already been damaged and the intestine is vulnerable to secondary bacterial and viral infections, which can then lead to increased mortality. The damage to the intestinal mucosa also means that much-needed nutrients cannot be absorbed by these young growing pigs.
Diagnosis. Diagnosis of cocci is best made by histological identification of various asexual and sexual stages of the coccidia in intestinal sections from pigs necropsied by your veterinarian or from pre-selected, live acutely scouring pigs, or poor doing suspect pigs, one to two weeks of age, and submitted to the diagnostic laboratory. Examination of feces for cocci oocysts (eggs) is often unrewarding, unless specialized techniques are used and the fecal samples are taken later rather than earlier in the course of the disease.
Disinfection, hygiene and management. Cocci persists in the environment, specifically on the farrowing room floors, on the edges of slats or wherever fecal material is present. The sow plays a minor or nonexistent role in transmission of cocci. Furthermore, cocci eggs are resistant to most disinfectants.
Some disinfectants (cresolic acid or cresol-based compounds like Neopredisan, chlorine or ammonia in a 50 per cent solution) can kill cocci eggs. However, high-pressure washing of farrowing room floors with hot water (>70 C) and good old "elbow grease" are necessary for removal of egg-infested fecal material from pen floors, so that these disinfectants can get to do their job.
It is worth noting that high-pressure washers are actually capable of aerosolizing cocci eggs, which then fall back onto the pen floor when "the dust settles," ready and waiting for the next litter of pigs to inhabit the pen. With this in mind, washing and cleaning should be followed by applying an effective disinfectant with a sprinkler can to avoid aerosolization.
What can Baycox do? Toltrazuril (Baycox) is an intracellular, long-acting coccidiocidal compound manufactured by Bayer Animal Health, recommended for use for one-shot prevention of baby pig coccidiosis. Does it work? You bet it does!
Practising veterinarians have been scratching around since Baycox was removed from the market to find a suitable replacement that was as effective a preventative or treatment for cocci. Baycox had been available to veterinarians by special permit for nearly 20 years prior to its sudden and untimely removal by the Canadian regulatory authorities, leaving veterinarians and producers virtually defenseless against baby pig cocci.
Baycox, dispensed as a five per cent suspension, is administered orally, 20 milligrams per kilogram of body weight, at three to five days of age. Given at this age, it effectively destroys the various developmental stages of cocci before they have had time to do their damage to the cells lining the surface of the small intestines. Furthermore, by thus protecting the intestinal surface, there is reduced ability for secondary bacteria to create the destruction of the intestinal mucosa frequently seen after cocci such as Clostridium perfringens, E. coli, etc.
Supportive treatments. Baycox controls the reproduction of cocci, but additional work has to be done to control eggs that are already in the environment that allow cocci to infect subsequent litters of piglets in the farrowing room. Coccidial oocysts are notoriously resistant to most disinfectants. Good old "elbow grease" along with thorough washing and scrubbing, then applying six per cent Javex (bleach) is recommended.
Concrete floors in the creep area should be painted with a concrete sealer. Concrete is a very porous material and can harbour cocci eggs indefinitely, waiting for the young piglets to consume them during their routine foraging. The sealer effectively buries the eggs lodged in the porous concrete, blocking them from being picked up by successive litters that occupy the crate. BP
S. Ernest Sanford, DVM, Dip. Path., Diplomate ACVP, is a swine specialist with Boehringer Ingelheim Vetmedica (Canada) in Burlington. Email: ernest.sanford@boehringer-ingelheim.com