A wound with maggots ("uod sa sugat") is a same-day problem. Chrysomya bezziana, the Old World screwworm, is established in the Philippines and lays 150-200 eggs at a single wound margin. Larvae burrow within 24 hours and the population doubles overnight. Pull them out, dust with Negasunt, inject ivermectin, cover with antibiotic. Most adult-pig wounds clear in a week.
DIY Or Vet?
| Situation | Action |
|---|---|
| Adult pig, single surface wound, fewer than ~50 maggots, eating | DIY with the protocol below |
| Castration wound day 2-5 with maggots | DIY — same protocol, prevention has failed |
| Newborn piglet with maggots in the navel | Vet today. Prognosis poor without intervention |
| Deep cavity, foul black exudate, fever, off feed | Vet. Antibiotics, possibly IV fluids |
| Multiple wounds on one pig | Vet. Systemic ivermectin is mandatory |
| Vulva of a post-farrow sow with maggots | Vet. Risk of tracking up the reproductive tract |
Time matters more than skill on this one. Larvae burrow head-down and dig deep. The longer you wait, the more tissue gets eaten.
The Four-Step Protocol
1. Pull them out
Restrain the pig (a snare or strong help, not a wrestling match). Glove up. Use blunt forceps or tweezers. Work systematically from the wound margin inward. Crush each maggot you remove, or burn them on a metal lid; do not toss them on the floor or compost — they pupate.
Flush after each pass with warm water plus dilute povidone-iodine (1 part Betadine to 10 parts water). Repeat removal until the wound is visibly clear. Expect 2-3 passes for a heavy infestation.
2. Dust with Negasunt
Negasunt (Bayer / Elanco), coumaphos 3% plus propoxur 2% plus sulfanilamide 5%. Dust the entire wound surface. Apply twice daily until the wound is granulating clean tissue, usually 5-7 days. ₱350-500 per 20 g sachet at Pacifica or Univet shops, or via Lazada and Shopee PH. The same powder also repels flies from re-laying.
3. Inject ivermectin
Ivermectin 1% subcutaneous, 1 mL per 33 kg body weight. PH brands: Agmectin (~₱180-280 / 50 mL), GenVet Ivermec, Iverbest. Single dose for surface infestation; repeat at 14 days for heavy or deep cases. Withdrawal before slaughter is 18 days. See how to inject pigs for SC technique.
4. Cover with antibiotic
Secondary bacterial infection is the killer once maggots are gone. Robipenstrep (procaine penicillin + dihydrostreptomycin), 1 mL per 10 kg IM daily for 5 days. Or long-acting oxytetracycline (Terramycin LA) at 20 mg/kg IM, repeated every 48-72 hours. ₱300-450 per 100 mL.
Finish with a petroleum jelly or camphor ring around the wound edge as a fly barrier. Keep the pig in a shaded, screened recovery pen for 7 days.
The PH Flystrike Kit
| Item | Use | Approx. PHP |
|---|---|---|
| Negasunt 20 g | Topical maggoticide + fly repellent | 350-500 |
| Agmectin 50 mL | Ivermectin SC | 180-280 |
| Robipenstrep 100 mL | Antibiotic cover | 300-450 |
| Povidone-iodine 120 mL | Wound flush | 280 |
| Cypermethrin spray (Cyporlene, Sumicidin) | Pen-wall fly control | 180-350 |
| Petroleum jelly | Wound-margin barrier | 60 |
| Tweezers + gauze + gloves | Manual removal | 100-200 |
Total under ₱2,000 for the full kit.
Where Flies Hit, And Why
The four PH backyard hotspots, in order of how often they go wrong:
- Castration wounds (day 2-5). The most preventable failure. Castrate in cool morning (5-8am), use a clean blade, keep the pig in a dry, shaded pen, dust the cut with Negasunt for 7 days. See when to castrate piglets.
- Newborn piglet navel. Highest mortality site. Dip the navel in 7% iodine within an hour of birth, repeat on day 2, check for cream-coloured rice-grain eggs at the wound edge for 5 days. See iron injection piglets and why piglets die in the first week.
- Vulva of post-farrow sows. Lochia (post-farrowing discharge) draws flies for 5-7 days. Spot-check, wipe clean. Compare with the swollen vulva guide.
- Foot abscesses, ear notches, fight wounds. Anywhere there is exposed tissue. The pig limping guide covers abscess care.
Prevention That Actually Works
- Spray pen walls weekly with cypermethrin or deltamethrin during May to November when fly burden peaks.
- Compost manure properly. Turn weekly, cover with rice hulls. Untreated manure piles are the number-one fly nursery in PH backyard pens.
- Fix pen drainage. Standing water and wet slurry are breeding sites.
- Window-screen the recovery pen. A small mesh-covered area for piglets recovering from castration cuts the post-cut flystrike rate to almost zero.
What Not To Do
These show up in old PH backyard advice and on Facebook posts. They cause more harm than the maggots:
- Kerosene or gasoline poured on the wound. Burns living tissue, does not kill embedded larvae, leaves the pig with a chemical burn on top of the original wound.
- Hot water "pasteurisation." Will burn the pig. Larvae buried in deep tissue do not feel surface heat.
- Tobacco juice or nicotine paste. No evidence it works, and nicotine absorbs through wounds. Real harm in piglets.
- Wait-and-see. Larvae double in 24 hours. The single most expensive thing you can do is leave it overnight.
Bisaya / Cebuano
Para sa mga mag-uuma
Kung naa nay uod sa sugat sa baboy (nilangawan na), karon dayon, dili ugma. Ang screwworm fly nga Chrysomya bezziana anaa dinhi sa Pilipinas, ug dobleha ang uod sulod sa 24 ka oras. Ipa-restrain ang baboy, sul-obi og guwantes, kuhaa pinaagi sa tweezer ang tanang uod nga makita. Hugasi og Betadine nga gisagol sa tubig (1:10), unya butangi og Negasunt nga pulbos kaduha kada adlaw.
Ipa-tuslok og Ivermectin (1 mL kada 33 ka kilo, SC sa liog), ug Robipenstrep IM kada adlaw sulod sa lima ka adlaw. Para sa bag-ong gianak nga biik nga gilangawan ang pusod, tawga dayon ang vet, peligro kaayo. Ayaw og bubu og kerosene, gasolina, init nga tubig, o tobacco juice. Mas grabe pa kaayo ang mahimo.
