Coccidiosis: Catching It Before It Costs a Batch

There is no coccidiosis off-season here, and that is arithmetic

Every month of the Philippine year sits inside the temperature window an Eimeria oocyst needs to become infective. The MSD Veterinary Manual gives optimal sporulation conditions as “70°–90°F [21°–32°C] with adequate moisture and oxygen”, taking 1 to 2 days. PAGASA puts the coolest Philippine month at a national mean of 25.5 °C and the warmest at 28.3 °C.

So the whole Philippine year travels 2.8 °C, inside an 11 °C window, with room at both ends. Wala pong buwan dito na masyadong malamig para dito.

Now the row that should change what you do. Cobb’s 2021 broiler guide says “Ideally, litter moisture should be < 35 % throughout the broiler house”, and describes the same squeeze test the brooding page already prints: friable, loosely compact, crumbles when you open your hand.

Aviagen’s sporulation band is 25 to 35%. Cobb’s ceiling is the top edge of it. Litter that passes the industry’s own moisture standard is litter sitting inside the range an oocyst needs, and the band is 10 percentage points wide with the acceptable side of the line running straight through it. Ibig sabihin, hindi magkapareho ang “tuyo ang litter” at “hindi na kayang mag-sporulate ng oocyst”. Getting under 35% is a housekeeping job. Getting under 25% across a whole floor, in this climate, is not something a bakuran does on purpose.

That is not a reason to give up on dry litter. It is the reason UC Cooperative Extension treats the presence of coccidia as normal rather than as a failure: “coccidia in the poultry environment are common and hence their presence is not necessarily a sign of poor husbandry.” The target is a low and steady load that lets immunity build, not zero. Zero is not on the menu, and every page that implies it is has never kept manok on a dirt floor in August.

Ano ang nakikita mo, at kailan mo ito makikita

Nothing shows for the first four to five days. Aviagen tabulates the prepatent period, the time between exposure and the first oocyst shed, at 97 hours for E. acervulina, 115 hours for E. tenella and 121 hours for E. maxima. Kapag nagbago na ang dumi, luma na ang problema ng isang linggo.

The signs themselves come from the extension side, and the order matters because the cheap ones come first. UC Davis lists “mucoid or bloody diarrhea, dehydration, anemia, listlessness, ruffled feathers, suboptimal growth and death”, and in laying hens “a drop in egg production”. Ang unang dalawa ay makikita mo sa sahig bago mo pa mahawakan ang manok.

Three things make this harder in a bakuran than in a commercial house, and all three are structural rather than sloppy. Mixed-age flocks: UC Davis notes that older apparently healthy birds shed oocysts that infect the younger ones, which is the normal shape of a backyard flock rather than a mistake in it. Ang matandang inahin na mukhang malusog ay siyang nagpapakain nito sa mga sisiw sa tabi niya, at wala kang makikitang mali sa kanya. Immunity is species-specific, so surviving one Eimeria protects against nothing else. And full immunity is not reached “until approximately 7 weeks of age”, which is past the harvest date of every broiler batch on this site.

The one Philippine measurement, and the sentence in it nobody quotes

There is a single published Philippine trial that counted coccidia in native chickens, and the most useful line in it is an admission. Nagrampa, Manugo and Puso (2016), in the Philippine Journal of Veterinary and Animal Sciences, write it plainly: “The prevalence of coccidiosis in Philippine native chicken is unknown.” Ten years on, it still is.

What the trial did measure is worth more than a prevalence figure anyway, because it measured when. One hundred Paraoakan day-old chicks from the BAI National Swine and Poultry Research and Development Center in Tiaong, Quezon were brooded on autoclaved rice hull for three weeks, then ranged at 10 sq m per bird to week 12.

Counts from Nagrampa et al. (2016) Table 2. Zero, then a peak, then a decline. The zero is the part the imported guides get wrong when they tell you the brooder is where coccidiosis lives: a clean brooder with fresh litter produced no oocysts at all for three weeks, and the count only started once the birds met the ground. Ang lupa ang nagbigay nito, hindi ang kahon.

Nobody in that trial got sick. The paper cites North and Bell (1990) for a threshold of at least 10,000 oocysts of a specific Eimeria species before clinical signs appear, and the highest count recorded was 3,024, which is 30.24% of it. The authors call it subclinical, and note that the wider ranging area “also allows greater area for oocyst dispersal”.

Subclinical is not free. Between weeks 9 and 12 the unmedicated control group needed ₱187.6 of feed to put on one kilo of body weight, against ₱140.9 for the birds given maduramicin, organic selenium or prebiotics. That is ₱46.70 per kilo at 2016 feed prices, on birds nobody would have looked at twice, and it is the clearest Philippine answer there is to what an invisible infection costs. There is no /presyo series behind those two numbers and there will not be: they are a 2016 research result on a research diet, not a market price. The gastos on your own feed is in the archive only for the chick.

One caution on the size of it. Twenty birds per treatment, five per replicate, one station, one breed. Maliit po ang pag-aaral na ito, kaya hugis lang ng problema ang makukuha mo rito at hindi bilang na puwede mong ipantapat sa sarili mong gastos.

What the Philippine residue standard carries, and what it leaves out

PNS/BAFS 48:2022, the DA-BAFS standard on veterinary drug residues in food, runs to 64 numbered drug sections and its scope explicitly includes eggs. Five of those sections are anticoccidials. Not one carries an egg limit.

Seven drugs in the whole standard have an Eggs row and all seven are antimicrobials, an insecticide or an anthelmintic: chlortetracycline, colistin, deltamethrin, flubendazole, neomycin, spectinomycin and tylosin. The remaining 57 do not, and every anticoccidial is among them.

Two absences are louder than any of the entries. Amprolium is not in PNS/BAFS 48:2022 at all, for any species or any tissue, which is the same shape the deworming page found for piperazine. And maduramicin is absent too, which is awkward, because maduramicin is the positive control the only published Philippine native-chicken trial used. The state has no residue ceiling for the compound its own funded research fed.

Nothing here is banned. Table 67 of the standard lists the drugs that are, and it holds beta-agonists, nitrofurans, carbadox and olaquindox, chloramphenicol, diethylstilbestrol, malachite green and chloroform. Walang anticoccidial doon. The distinction is the same one the deworming page draws: an MRL is a ceiling on what may be found in the food, and a withdrawal period is how long you wait to get under it. The Philippines publishes the first and not the second, and it is the second you need before an itlog leaves the bakuran.

Bakuna, gamot sa feeds, o gamutin kapag nakita

Three routes exist and only two of them are realistically open to a bakuran. The honest comparison is below rather than in prose, because the differences are in what each one costs and who can actually buy it.

The trap in the first two is the same trap and it points in opposite directions. Vaccination fails if the litter is too dry or too clean for the vaccine oocysts to cycle, because Aviagen needs that second cycle to happen on the farm. In-feed prevention fails slowly in the other direction: MSD states that “continuous use of anticoccidial drugs promotes the emergence of drug-resistant strains of coccidia” and that there is “widespread resistance to most drugs”. UC Davis goes further and says the treatment drugs “should only be used as a treatment of an affected flock and not used as a periodic preventative treatment”.

For a flock of 20 to 50 birds the arithmetic is mostly about stock rather than about medicine. A day-old chick was ₱33.50 per head in BAI monitoring on 13 July 2026, so ten dead sisiw out of 50 is ₱335 of chick plus every peso of feed already in them. Iyon ang perang inilibing mo sa bakuran, at iyon ang dapat mong itapat sa presyo ng kahit anong sako o bote na binibili mo bilang panlaban.

What usually goes wrong

1. The mistake: Treating bloody droppings with a dewormer because that is what the agrivet had.

   Do this instead: Coccidia are protozoa. No anthelmintic on any label reaches Eimeria, and the money is simply gone.

   Eimeria appeared in 43.2% of the Leyte faecal samples in Ybañez et al. (2018), sitting in the same results table as five genuine worms, which is exactly how the confusion starts.

2. The mistake: Treating the brooder as the source and the range as the safe place.

   Do this instead: Clean the brooder, then watch the ground from week 4 onward.

   The Nagrampa et al. (2016) trial recorded zero oocysts per gram across all five treatment groups for weeks 0 to 3 in the brooder, then 1,437 to 3,024 once the birds were ranged on soil.

3. The mistake: Feeding a medicated starter continuously and calling it prevention forever.

   Do this instead: Use it for what it is licensed for, and read the sack rather than assuming.

   MSD states that continuous anticoccidial use promotes resistant strains and that widespread resistance to most drugs already exists. UC Extension recommends rotation where anticoccidials are used at all.

4. The mistake: Selling or eating eggs on the assumption that an anticoccidial has no waiting time.

   Do this instead: Find the withdrawal period on the pack before the first dose, and if it is not printed, ask rather than assume it is zero.

   No anticoccidial in PNS/BAFS 48:2022 carries an egg limit, and the lasalocid entry says outright that the compound is not registered for laying hens. An absent MRL is not permission.

5. The mistake: Aiming for zero coccidia in the kulungan.

   Do this instead: Aim for a low, steady load and dry litter, and let immunity build.

   UC Extension states coccidia are common and their presence is not necessarily a sign of poor husbandry, and that moderate exposure is how birds develop immunity. Full immunity is not reached until roughly 7 weeks.

Ang tuyong sulok ang tanging hakbang na walang resibo

Everything on this page that a keeper can act on today is free, and none of it involves a bottle. Walang binibili sa alinman sa dalawang hakbang na nasa ibaba, at iyon mismo ang dahilan kung bakit madalas silang nalalampasan sa payo ng kapitbahay.

Move the drinker or fix it. UC Extension puts watering systems first on its prevention list and notes that nipple drinkers spill less onto litter than bell and trough drinkers. A leaking drinker builds a small permanent patch of exactly the moisture band the parasite needs, in a climate that supplies the temperature for free. Isang tumutulo na drinker sa dry season ay parehong problema ng ulan, mas maliit lang ang sukat.

Then the ground itself. UC Extension’s second line is to move the birds periodically, because “leaving land fallow for weeks is one of the most effective ways of reducing the pathogen load in the environment”, and its third is biosecurity, because oocysts arrive on contaminated equipment. Both of those sit inside what the biosecurity page already ranks for a bakuran, and neither costs anything but a decision. Ang oocyst ay tumatagal ng buwan-buwan sa lupa, kaya ang panahon mismo ang gamot dito.

The gap worth stating plainly is the one the 2016 paper stated first. There is still no Philippine prevalence figure for coccidiosis in native chickens, no Philippine anticoccidial resistance survey, and no Philippine withdrawal period published for any of the five compounds the residue standard covers. The global meta-analysis by Badri et al. (2024) pools 41 studies across 34,492 chickens and puts the WHO Western Pacific Region, which is the region this country sits in, at 80.5% pooled Eimeria prevalence. Not one of the studies behind that figure was Philippine. The rest of what is missing, and why so much of it is missing, is in the data gaps piece.

Questions people actually ask

What does coccidiosis look like in a backyard flock?

Nothing at all for the first four to five days after the birds swallow the oocysts. Aviagen puts the prepatent period, meaning exposure to the first oocyst shed, at 97 hours for Eimeria acervulina, 115 hours for Eimeria tenella and 121 hours for Eimeria maxima. After that the UC Davis extension list runs mucoid or bloody diarrhea, dehydration, anemia, listlessness, ruffled feathers, suboptimal growth and death, with a drop in egg production in laying hens. Bloody droppings point at the ceca and at Eimeria tenella, which the MSD Veterinary Manual describes as recognisable by accumulation of blood in the ceca. But signs alone do not settle it. The MSD manual diagnoses on lesion location plus oocysts in feces or intestinal scrapings, and a scavenging flock can carry oocysts without being clinically sick.

Is coccidiosis worse during the Philippine rainy season? Show the answer

The mechanism says yes and no Philippine study has measured it. Sporulation, the step that turns a harmless shed oocyst into an infective one, needs oxygen, litter moisture of 25 to 35% and litter temperatures of 26 to 30 °C according to the Aviagen Ross note. Temperature here is never the limiting factor: PAGASA puts the coolest Philippine month at a 25.5 °C national mean and the warmest at 28.3 °C, so the only variable a keeper is actually moving is the moisture. That is what makes the rainy months different, and it is also why a leaking drinker in the dry season produces the same result on a smaller patch of floor.

What can I give a chicken with coccidiosis in the Philippines? Show the answer

This page will not name a product or a dose for you, because the two published authorities I could open disagree by a factor of two and neither is a Philippine authorisation. UC Cooperative Extension gives amprolium at 0.024% of the active ingredient in drinking water for 3 to 5 days; the US FDA label for AmproMed-P gives 0.012% for three to five days followed by 0.006% for another one to two weeks. Read the pack in your hand, check what the FDA Philippines registration covers, and ask the agrivet or a veterinarian. Note also that no dewormer touches this: Eimeria is a coccidian, not a worm.

Does the Philippines set a residue limit for anticoccidials in eggs? Show the answer

No. PNS/BAFS 48:2022 carries five anticoccidial compounds — diclazuril, lasalocid sodium, monensin, narasin and nicarbazin — and not one of them has an Eggs row. Seven drugs in the whole 64-drug standard carry an egg limit and all seven are antimicrobials, an insecticide or an anthelmintic. The lasalocid entry says why in its own remarks column, noting that as the compound is not registered for use in laying hens it is not appropriate to recommend an MRL for egg. Amprolium, the drug most likely to be handed to a Philippine backyard keeper, does not appear in the standard at all, for any species or tissue.

How much does coccidiosis actually cost a backyard batch? Show the answer

The only Philippine figure is a feed-efficiency figure rather than a mortality one. In the 2016 PJVAS trial on Paraoakan native chickens, the unmedicated control group needed ₱187.60 of feed to put on one kilo of body weight between weeks 9 and 12, against ₱140.90 for the groups given maduramicin, organic selenium or prebiotics — a gap of ₱46.70 per kilo at 2016 feed prices. No bird in that trial showed a clinical sign. On the mortality side the arithmetic is simpler: a day-old chick was ₱33.50 per head in BAI monitoring on 13 July 2026, so a batch of 50 losing ten chicks is ₱335 of stock plus everything already fed to them.