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. 2025 Nov 26;88(2):236–243. doi: 10.1292/jvms.25-0388

Prevalence of ectoparasites in intensive laying poultry farms in Thailand using the feather-picking and AviVet™ trapping methods

Korapat ANURUGSA 1,#, Jinjutha ARAMMANUPUNYAKUL 1,#, Nuchcharin LERTSIRIKAJORN 1,#, Benchaporn PHOONCHAKO 1,#, Kritsada THONGMEESEE 1, Duriyang NARAPAKDEESAKUL 3, Jiroj SASIPREEYAJAN 4, Sonthaya TIAWSIRISUP 2,*
PMCID: PMC12887115  PMID: 41297927

Abstract

Poultry production in Thailand has expanded considerably and industrially; however, ectoparasite infestations in poultry farms could still occur. Information on ectoparasite prevalence in intensive poultry farms in Thailand is limited. This study investigated the current distribution and diversity of ectoparasites in commercial layer farms in central Thailand using two sampling methods: feather-picking and AviVet™ trapping. A total of 1,006 samples (507 feather and 499 trap samples) were collected from 28 poultry houses in 10 intensive farms across five provinces. Samples were examined microscopically, and the infestation status was recorded for each ectoparasite species. Seven taxa were identified, comprising three chewing lice species (Lipeurus caponis, Menacanthus stramineus, and Menopon gallinae) and four mite species (Dermanyssus gallinae, Megninia spp., Ornithonyssus bursa, and Pterolichus obtusus). Megninia spp. (44.0%) and P. obtusus (20.8%) were the most prevalent, whereas M. stramineus and O. bursa were rare (≤0.4%). No fleas or ticks were detected. Feather-picking yielded significantly higher detection rates than AviVet™ trapping for L. caponis, M. gallinae, Megninia spp., and P. obtusus (P<0.001 for all), while no significant method-related differences were found for M. stramineus, D. gallinae, or O. bursa. Spatial analysis was possible only for Megninia spp., which varied significantly among provinces and farms (P<0.001). This is the first report describing the diversity of ectoparasites collected using AviVet™ traps in intensive poultry farms in Thailand and provides baseline data to guide integrated control strategies in tropical poultry production systems.

Keywords: AviVet™ trapping method, feather-picking method, louse, mite, Thailand

INTRODUCTION

Poultry production in Thailand, especially for commercial meat, has rapidly increased over the past 15 years due to changing consumption patterns within the country as well as a growing export sector. Thai chicken exports have grown across a variety of meat products (i.e., cooked, uncooked, and salted poultry meat) while at the same time Thailand’s egg-producing business has expanded due to rising egg consumption [9]. During this growth, poultry production has been affected by important challenges, including emerging and reemerging bacterial, parasitic, and/or viral diseases. Arthropod ectoparasites are a serious problem for intensive poultry production [12], since they cause production, economic, and financial losses in the absence of proper pest control strategies [2, 3]. The impact of ectoparasites involves chickens experiencing intense stress, parasite feeding leading to anemia, and the fact that ectoparasites are vectors for various pathogens that cause vector-borne diseases [2]. In general, groups of arthropod ectoparasites that cause problems in chicken flocks include bedbugs, fleas, chewing lice, and mites. Moreover, the most common ectoparasites affecting poultry populations were listed by Axtell and Arends (1990) [2] as the northern fowl mite (Ornithonyssus sylviarum), chicken body louse (Menacanthus stramineus), chicken red mite (Dermanyssus gallinae), and bedbug (Cimex lectularius).

In Thailand, the study of ectoparasites afflicting domesticated chickens was first reported in 1976 by Arkom Sangvaranond [32]. Although several studies of chicken ectoparasites in Thailand were reported between 1976–1994, most of them are available only in the Thai language [20,21,22,23,24,25,26,27,28,29,30,31, 33, 34, 37]. Only two studies have been reported in English, appearing in 2009 [4] and 2022 [10]. Various ectoparasite species have been reported, and these fall into four groups (i.e., fleas, lice, mites, and ticks) [32]. To date, the majority of reports have focused on native chickens. Only one of the studies published between 1976–1994 related to intensive poultry farms; however, this study reported the identification of four species of chewing lice (i.e., Menopon gallinae, Menacanthus pallidulus, Lipeurus caponis, and an unidentified ischnoceran) as well as three species of mite (i.e., Megninia spp., Ornithonyssus bursa, and Pterolichus spp.) [33]. In the 21st century, only one study (reported in 2022) used a parasite evaluation protocol known as the “feather-picking method”; it also used a “skin suction method” and focused on ornamental chicken farms in the eastern part of Bangkok (e.g., the Minburi, Nong Chok, and Lat Krabang districts) [10]. This study revealed five species of chewing lice (i.e., Cuclotogaster heterographus, M. gallinae, L. caponis, Goniocotes gallinae, and M. stramineus) and three species of mite (i.e., Megninia cubitalis, M. ortari, and Pterolichus obtusus) [10]. This method is cheap and semi-quantitative but has several points of limitation, including intensive labor for counting, no fixed locations, no validation, and not all stages are detected [11]. At present, information on the ectoparasites present in intensive poultry farms in Thailand remains limited and requires further investigation in intensive farm-level settings to provide a valuable background and insight for farm veterinarians.

In addition to the feather-picking and skin suction methods, several other protocols (e.g., an automatic counter, examining dried droppings, cardboard traps, and a mite monitoring score) are also used to detect ectoparasites within poultry farms, and are especially useful for targeting mite populations [11]. One of these methods is the AviVet™ trap (AviVet B.V., Lunteren, Netherlands), a validated method that has been used to quantitatively detect D. gallinae population dynamics in poultry farms [11]. However, this method is not cheap, and traps need to be purchased, making it more expensive than feather-picking and skin suction methods. Elsewhere in Asia, similar traps have been used to study mite populations in Myanmar (i.e., iTraps-2) [39] and South Korea (i.e., corrugated cardboard trap) [15]. Nevertheless, information regarding the effectiveness of AviVet™ or other traps in intensive Thai poultry farms is unavailable. Given that most prior reports from Thailand are in Thai and focus on native or backyard chickens, there remains a lack of updated, English-language data on ectoparasites in modern commercial poultry production systems under tropical conditions. The present study addresses this gap by investigating the current distribution and diversity of ectoparasites in commercial layer poultry farms in central Thailand, with specific emphasis on differences in infestation patterns between farms and provinces. We hypothesized that infestation prevalence and species composition would vary geographically and between farms, reflecting differences in management practices, biosecurity measures, and housing designs. By presenting these findings in English, this study aims to facilitate broader regional and global comparisons and to provide a baseline for future epidemiological surveillance and integrated pest management planning. Moreover, we did so by using both the feather-picking and commercial AviVet™ trapping methods, thereby providing a comparison that can provide information on poultry ectoparasites and lead to the implementation of suitable integrated control strategies for intensive poultry farms in Thailand.

MATERIALS AND METHODS

Ethical statements

This project was conducted in compliance with the CUVET-Institutional Animal Care and Use Committee (IACUC protocol No. 1831055).

Study site

A total of ten sample groups were collected from poultry farms across five provinces in central Thailand between May 24 and September 12, 2018, spanning the transition from the end of the hot season into the peak of the rainy season (Table 1). The provinces surveyed were Chachoengsao (2 farms), Nakhon Nayok (4 farms), Nakhon Pathom (2 farms), Saraburi (1 farm), and Chonburi (1 farm) (Fig. 1). The number of poultry houses sampled per farm ranged from one to four, with a total of 28 poultry houses included in the study. Sampling was conducted on specific dates: two farms on May 24 (Groups 1 and 2), one farm on June 12 (Group 3), two farms on June 25 (Groups 4 and 5), three farms on July 3 (Groups 6 to 8), one farm on September 4 (Group 9), and one farm on September 12 (Group 10). Nakhon Nayok had the highest number of sampled farms (four). This sampling strategy was designed to encompass diverse geographic areas and to capture different parts of the rainy season, thereby providing representative data on ectoparasite infestations.

Table 1. Sample group (farm), province, number of housing units, sampling date, and average temperature and rainfall for ectoparasite surveillance in Thailand (May–September 2018).

Sample group (farm) Province Number of housing units Sampling date Average temperature and rainfall*
1 Chachoengsao 3 24 May 2018 Eastern region (May): 29.0°C, 128.8 mm
2 Chachoengsao 4 24 May 2018
3 Nakhon Nayok 3 12 June 2018 Central region (June): 29.2°C, 133.4 mm
4 Nakhon Pathom 3 25 June 2018
5 Nakhon Pathom 3 25 June 2018
6 Saraburi 3 3 July 2018 Central region (July): 28.6°C, 177.5 mm
7 Nakhon Nayok 1 3 July 2018
8 Nakhon Nayok 2 3 July 2018
9 Nakhon Nayok 3 4 September 2018 Central region (September): 28.6°C, 194.1 mm
10 Chonburi 3 12 September 2018 Eastern region (September): 28.0°C, 361.3 mm
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*Thai Meteorological Department.

Fig. 1.

Fig. 1.

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Map of Thailand showing the locations of poultry farms sampled in this study.

The poultry housing units are equipped with evaporative cooling systems and operated under a battery cage housing system. This conventional system is commonly used in commercial egg production and consists of rows and columns of wire cages arranged in multiple tiers. Each cage typically accommodates 3–8 laying hens, depending on housing design and animal welfare regulations. Each housing unit accommodated approximately 2,500–12,000 laying hens, depending on the design and farm size. Monthly average temperature and rainfall data during the sampling months were obtained from the Thai Meteorological Department (Table 1). Morphological identification of collected ectoparasites was performed at the Parasitology Unit, Department of Veterinary Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand.

Sample collection

Ectoparasite samples were collected from chickens using the feather-picking and AviVet™ trapping methods (Fig. 2). For the feather-picking method, approximately 15 feathers for each chicken were collected from the left wing, right wing, and the area around the cloaca. For the trapping method, AviVet™ traps were placed at various locations within the poultry houses for seven days. For each housing unit, 10–20 individual chicken feather samples and 10–20 AviVet™ traps were collected. Upon collection, all samples were immediately transported to the Parasitology Unit and stored at 4°C until further analysis.

Fig. 2.

Fig. 2.

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AviVet™ traps (AviVet B.V., Lunteren, Netherlands) used for mite collection.

Ectoparasite identification

All samples from both methods were sorted and examined to identify the species of ectoparasites present. All identifications were performed under a compound light microscope or stereomicroscope [1, 4, 17]. For each sample, information regarding the date of sample collection, farm, and housing unit was collected, as was the parasite species and the number of parasites present.

Data analysis

Statistical analyses were conducted using IBM® SPSS® Statistics 29.0 (IBM, Armonk, NY, USA) provided by the University Office of Information Technology. Descriptive statistics were used to calculate the prevalence of each ectoparasite species across all samples, by farm, and by province. For inferential statistics, chi-square tests were used to compare infestation rates among provinces, among farms, and between sampling methods, where sample sizes were sufficient to meet test assumptions. Fisher’s exact test was applied for 2 × 2 comparisons when expected counts were <5. Statistical comparisons were performed for L. caponis, M. gallinae, Megninia spp., and P. obtusus when data were adequate, with Megninia spp. being the only taxon tested across provinces and farms. M. stramineus, D. gallinae, and O. bursa were not subjected to province- or farm-level statistical testing due to very low counts, and their distributions are presented descriptively. A P-value of <0.05 was considered statistically significant.

RESULTS

A total of 1,006 samples were collected from 28 poultry houses across 10 commercial layer farms in five provinces of central Thailand (Table 2). Seven ectoparasite taxa were identified, with Megninia spp. being the most prevalent (44.0%, 443/1,006), followed by P. obtusus (20.8%, 209/1,006), M. gallinae (8.9%, 90/1,006), L. caponis (1.6%, 16/1,006), D. gallinae (1.5%, 15/1,006), M. stramineus (0.2%, 2/1,006), and O. bursa (0.2%, 2/1,006). Detection rates differed markedly between sampling methods. Feather-picking yielded significantly higher prevalences than AviVet™ trapping for L. caponis (3.2% vs. 0.0%, P<0.001), M. gallinae (16.4% vs. 1.4%, P<0.001), Megninia spp. (71.6% vs. 16.0%, P<0.001), and P. obtusus (36.7% vs. 4.6%, P<0.001). No significant method-related differences were observed for M. stramineus (P=1.000), D. gallinae (P=0.116), or O. bursa (P=0.500).

Table 2. Prevalence of ectoparasites from ten layer poultry farms across five provinces in Thailand, collected by using the feather-picking and AviVet™ trapping methods.

Arthropod group: Ectoparasite species Sampling method % Infested samples (number of infested/tested samples)
Farm 1* Farm 2* Farm 3** Farm 4*** Farm 5*** Farm 6**** Farm 7** Farm 8** Farm 9** Farm 10***** Total
(unit n=3) (unit n=4) (unit n=3) (unit n=3) (unit n=3) (unit n=3) (unit n=1) (unit n=2) (unit n=3) (unit n=3) (unit n=28)
Louse: Lipeurus caponis Feather-picking 9.1 (5/55) 0 (0/71) 0 (0/60) 0 (0/60) 0 (0/60) 0 (0/60) 0 (0/20) 0 (0/40) 0 (0/50) 35.5 (11/31) 3.2 (16/507)
AviVet™ 0 (0/55) 0 (0/71) 0 (0/55) 0 (0/60) 0 (0/60) 0 (0/59) 0 (0/20) 0 (0/40) 0 (0/50) 0 (0/29) 0 (0/499)
Total 4.5 (5/110) 0 (0/142) 0 (0/115) 0 (0/120) 0 (0/120) 0 (0/119) 0 (0/40) 0 (0/80) 0 (0/100) 18.3 (11/60) 1.6 (16/1,006)
Louse: Menacanthus stramineus Feather-picking 1.8 (1/55) 0 (0/71) 0 (0/60) 0 (0/60) 0 (0/60) 0 (0/60) 0 (0/20) 0 (0/40) 0 (0/50) 0 (0/31) 0.2 (1/507)
AviVet™ 0 (0/55) 1.4 (1/71) 0 (0/55) 0 (0/60) 0 (0/60) 0 (0/59) 0 (0/20) 0 (0/40) 0 (0/50) 0 (0/29) 0.2 (1/499)
Total 0.9 (1/110) 0.7 (1/142) 0 (0/115) 0 (0/120) 0 (0/120) 0 (0/119) 0 (0/40) 0 (0/80) 0 (0/100) 0 (0/60) 0.2 (2/1,006)
Louse: Menopon gallinae Feather-picking 89.1 (49/55) 1.4 (1/71) 0 (0/60) 30 (18/60) 3.3 (2/60) 0 (0/60) 5 (1/20) 0 (0/40) 0 (0/50) 38.7 (12/31) 16.3 (83/507)
AviVet™ 9.1 (5/55) 0 (0/71) 0 (0/55) 1.7 (1/60) 1.7 (1/60) 0 (0/59) 0 (0/20) 0 (0/40) 0 (0/50) 0 (0/29) 1.4 (7/499)
Total 49.1 (54/110) 0.7 (1/142) 0 (0/115) 15.8 (19/120) 2.5 (3/120) 0 (0/119) 2.5 (1/40) 0 (0/80) 0 (0/100) 20.0 (12/60) 8.9 (90/1,006)
Mite: Dermanyssus gallinae Feather-picking 16.4 (9/55) 2.8 (2/71) 0 (0/60) 0 (0/60) 0 (0/60) 0 (0/60) 0 (0/20) 0 (0/40) 0 (0/50) 0 (0/31) 2.2 (11/507)
AviVet™ 1.8 (1/55) 4.2 (3/71) 0 (0/55) 0 (0/60) 0 (0/60) 0 (0/59) 0 (0/20) 0 (0/40) 0 (0/50) 0 (0/29) 0.8 (4/499)
Total 9.1 (10/110) 3.5 (5/142) 0 (0/115) 0 (0/120) 0 (0/120) 0 (0/119) 0 (0/40) 0 (0/80) 0 (0/100) 0 (0/60) 1.5 (15/1,006)
Mite: Megninia spp. Feather-picking 92.7 (51/55) 33.8 (24/71) 100 (60/60) 76.7 (46/60) 70 (42/60) 95 (57/60) 100 (20/20) 52.5 (21/40) 44 (22/50) 64.5 (20/31) 71.6 (363/507)
AviVet™ 25.5 (14/55) 4.2 (3/71) 56.4 (31/55) 11.7 (7/60) 5 (3/60) 3.4 (2/59) 10 (2/20) 32.5 (13/40) 10 (5/50) 0 (0/29) 16.0 (80/499)
Total 59.1 (65/110) 19.0 (27/142) 79.1 (91/115) 44.2 (53/120) 37.5 (45/120) 49.6 (59/119) 55 (22/40) 42.5 (34/80) 27.0 (27/100) 33.3 (20/60) 44.0 (443/1,006)
Mite: Ornithonyssus bursa Feather-picking 3.6 (2/55) 0 (0/71) 0 (0/60) 0 (0/60) 0 (0/60) 0 (0/60) 0 (0/20) 0 (0/40) 0 (0/50) 0 (0/31) 0.4 (2/507)
AviVet™ 0 (0/55) 0 (0/71) 0 (0/55) 0 (0/60) 0 (0/60) 0 (0/59) 0 (0/20) 0 (0/40) 0 (0/50) 0 (0/29) 0 (0/499)
Total 1.8 (2/110) 0 (0/142) 0 (0/115) 0 (0/120) 0 (0/120) 0 (0/119) 0 (0/40) 0 (0/80) 0 (0/100) 0 (0/60) 0.2 (2/1,006)
Mite: Pterolichus obtusus Feather-picking 9.1 (5/55) 35.2 (25/71) 46.7 (28/60) 88.3 (53/60) 86.7 (52/60) 0 (0/60) 100 (20/20) 7.5 (3/40) 0 (0/50) 0 (0/31) 36.7 (186/507)
AviVet™ 20 (11/55) 2.8 (2/71) 1.8 (1/55) 8.3 (5/60) 5 (3/60) 0 (0/59) 0 (0/20) 2.5 (1/40) 0 (0/50) 0 (0/29) 4.6 (23/499)
Total 14.5 (16/110) 19.0 (27/142) 25.2 (29/115) 48.3 (58/120) 45.8 (55/120) 0 (0/119) 50.0 (20/40) 5.0 (4/80) 0 (0/100) 0 (0/60) 20.8 (209/1,006)
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*Chachoengsao province, **Nakhon Nayok province, ***Nakhon Pathom province, ****Saraburi province, *****Chonburi province.

Spatial analysis was feasible only for Megninia spp., which exhibited significant variation among provinces (P<0.001) and among farms (P<0.001). Prevalence was highest in Nakhon Nayok (51.9%, 174/335) and Saraburi (49.6%, 59/119), intermediate in Nakhon Pathom (40.8%, 98/240) and Chachoengsao (36.5%, 92/252), and lowest in Chonburi (33.3%, 20/60). Farm-level prevalence ranged from 19.0% (Farm 2, Chachoengsao) to 79.1% (Farm 3, Nakhon Nayok). For other taxa, counts were insufficient for statistical testing; however, descriptive data indicated that P. obtusus was most common in Nakhon Pathom (47.1%, 113/240) and absent in Saraburi and Chonburi, D. gallinae was detected only in Chachoengsao (6.0%, 15/252), L. caponis was concentrated in Chonburi (18.3%) and Chachoengsao (4.5%), and M. stramineus and O. bursa were rare (≤0.4%).

By method, feather-picking identified the highest number of louse-infested samples for M. gallinae (83/507), followed by L. caponis (16/507) and M. stramineus (1/507). Mite infestations detected by this method were dominated by Megninia spp. (363/507), followed by P. obtusus (186/507), D. gallinae (11/507), and O. bursa (2/507). M. gallinae was found in six farms, while L. caponis and M. stramineus were each detected in only two farms. Megninia spp. was present in all farms, whereas D. gallinae and O. bursa were recorded in only two and one farm, respectively. Using the AviVet™ trap, M. gallinae (7/499) was the most frequently detected louse, followed by M. stramineus (1/499). Among mites, Megninia spp. (80/499) was most prevalent, followed by P. obtusus (23/499) and D. gallinae (4/499). Farm-level infestation patterns were similar to those detected by feather-picking but with generally lower prevalence for all taxa.

Overall, the results indicate a predominance of Megninia spp. and P. obtusus in intensive layer farms, significant differences in detection efficiency between sampling methods, and limited but notable geographic variation, particularly for Megninia spp.

DISCUSSION

To the best of our knowledge, this is the first report of ectoparasite surveillance in Thailand using the AviVet™ trapping method. Our results demonstrated that the AviVet™ trap could detect infestations of chewing lice and mites in poultry housing units; however, the number of positive samples was consistently lower than those obtained by feather-picking from the same farms. The AviVet™ trap was originally developed as a non-invasive tool for monitoring D. gallinae in poultry systems, designed to provide shelter for nocturnally active mites during daylight hours. It has proven effective for passive monitoring of red mite populations under controlled and semi-natural conditions, offering advantages such as reduced animal handling stress, decreased sampling bias, and the ability to collect samples cumulatively over time.

Despite these advantages, the trap’s design for crevice-dwelling, nocturnal mites limits its effectiveness for ectoparasites with different host-seeking behaviors (e.g., lice, fleas, ticks, or diurnal mites). Its performance can also be influenced by placement, temperature, and humidity. Ectoparasites spending most of their life cycle on the host (e.g., lice) are unlikely to be captured in meaningful numbers, and the trap is not suitable for ticks or biting flies, which require alternative collection methods. Therefore, the AviVet™ trap should be considered part of an integrated surveillance strategy rather than a stand-alone tool, and complementary sampling methods remain necessary for comprehensive ectoparasite monitoring.

In the present study, Megninia spp. and P. obtusus were more frequently detected in AviVet™ trap samples than D. gallinae. This may result from high flock infestation levels, causing passive shedding of mites and feathers into the environment. Movement and preening activities of birds can dislodge mites that subsequently enter traps through airborne feather dust or debris. Additionally, the dark and humid microenvironment of the trap may provide a favorable refuge for these mites once detached from the host. Similar off-host occurrences of feather mites have been occasionally reported under heavy infestations or in confined housing systems. Moreover, the red mite may currently play a minor role in ectoparasitic infestations in the surveyed farms. Direct sampling from birds still provides a more complete assessment of ectoparasite diversity and abundance. Megninia spp., also known as feather mites, were the most common species overall (44.0%; 443/1,006) and have been a persistent problem in Thai poultry for decades, consistent with historical reports [33]. It was stated that Megninia spp. may affect the egg-production business in Thailand more than any other mite species [33]. These mites have also been associated with reduced egg production, skin irritation, and feather damage in multiple countries, with population peaks linked to high temperature and humidity [7, 8, 16, 18, 19, 40, 41]. However, feather mites are generally not considered to be economically important, and the real impact of Megninia spp. on chickens still needs to be defined [38]. Given their prevalence, potential impact, and integrated pest control strategies targeting Megninia spp., species identification should be conducted and prioritized in intensive poultry operations to gain more valuable insight into their infestations. P. obtusus was the second most common mite (20.8%; 209/1,006). Although some reports associate this species with reduced production and feather condition changes [9], other studies indicate minimal economic significance [32]. In Thailand, it has been found in both native and commercial chickens [10, 21,22,23,24,25,26, 30, 32, 33].

D. gallinae and O. bursa (tropical fowl mite) were detected at low prevalence (≤1.5%), but their hematophagous nature and zoonotic potential make them important from both animal health and public health perspectives [3, 4, 6, 10, 16, 20, 32, 37]. O. sylviarum (northern fowl mite) has been well-described and is known to decrease egg production [13, 15]. Apart from dermatitis caused by bites, D. gallinae may also potentially transmit various pathogens (e.g., avian influenza virus, fowl poxvirus, Pasteurella multocida, and SalmonellaGallinarum) [35], and proper control measures should be implemented in infested farms, alongside education for poultry workers about associated health risks.

Among the chewing lice, M. gallinae (8.9%; 90/1,006) was most common, followed by L. caponis (1.6%) and M. stramineus (0.2%). Although chewing lice were less common than mites, their economic impact remains poorly understood. Some studies suggest chewing lice may be more harmful than previously assumed; for example, M. stramineus infestation in cage-free housing has been shown to affect welfare even at low levels [14]. Data on economic losses from chewing lice infestations should therefore be scientifically documented.

Most Thai ectoparasite studies have reported lice in native chickens [14, 22,23,24,25,26,27,28,29,30, 34, 37], bantams [31], and ornamental chickens [10]. Three lice species were reported in domestic chickens along the Thai–Myanmar border in Tak province [4]. Only one study has reported lice in laying chickens in private farms [33], identifying four chewing lice species (M. gallinae, L. caponis, M. pallidulus, and an unidentified ischnoceran), findings consistent with our results. Integrated pest control or management protocols should be implemented to reduce both mite and louse populations. Due to their high host specificity, the chewing lice species identified here are not of public health concern.

We observed no fleas or ticks, consistent with previous private farm surveys [33]. Fleas and ticks have been reported in native chickens [32] and along the Thai–Myanmar border, though only one flea species (Echidnophaga gallinacea) was found [4]. As in Thailand, a variety of ectoparasites, including fleas, lice, mites, and ticks, have been observed in native chicken populations across different provinces [4, 32]. Intensive poultry farming likely reduces flea and tick incidence but may increase exposure to other ectoparasites such as mites. Poor farm hygiene and absence of parasite control are major risk factors for all ectoparasites [6, 12]. In Thailand, the relatively low prevalence of D. gallinae in commercial farms is likely due to the combined effects of acaricide use, improved biosecurity, and the predominance of open or well-ventilated housing systems, which create less favorable conditions for this nocturnal mite [5, 36]. All surveyed farms reported regular use of pyrethroid-based acaricides (permethrin or cypermethrin formulations) applied every 4–8 weeks by spraying cage surfaces and walkways. Such routine chemical control likely contributed to the low detection rate of D. gallinae in this study, consistent with the observed absence of heavy infestations.

Although no novel ectoparasite species were detected, the present findings offer an updated baseline for infestation prevalence and diversity in Thai commercial poultry farms. Such baseline data are crucial for monitoring temporal trends, evaluating the impact of evolving production systems, and informing targeted integrated pest management strategies. In particular, the comparative analysis between farms and provinces highlights potential risk factors that warrant further investigation, and the English-language presentation of these results addresses an important gap by making locally derived evidence accessible for regional and global comparisons.

Overall, this study provides the first comprehensive overview of ectoparasite diversity in intensive layer farms in central Thailand using both direct (feather-picking) and indirect (AviVet™ trapping) approaches. A limitation of this study is that quantitative counts of ectoparasites per sample were not recorded, which may have provided additional information on infestation intensity and monitoring accuracy. The predominance of Megninia spp. and P. obtusus highlights the need for targeted control measures against feather mites, while the low prevalence of D. gallinae reflects effective current management and biosecurity in these farms. Our findings emphasize that integrated surveillance strategies combining multiple sampling methods are essential for accurate assessment of ectoparasite burdens. Continued monitoring, coupled with farmer education and strategic control programs, will be critical to minimizing economic losses, safeguarding animal welfare, and preventing the potential spread of zoonotic pathogens.

CONFLICT OF INTEREST

The authors declare that they have no conflict of interest.

Acknowledgments

The study was submitted for partial fulfillment of the veterinary degree (DVM) for the first four authors. Part of this study was presented at the 19th Chulalongkorn University Veterinary Conference (CUVC 2020) in a paper entitled “Diversity of Poultry Ectoparasites in Poultry Farms.” This study was financially supported by the Chulalongkorn University Faculty of Veterinary Science for the senior project of veterinary students, the Chulalongkorn University Center of Excellence (Grant No. CE68_053_3100_001), and by Intervet (Thailand) Ltd. The authors would also like to thank the staff from Intervet for their kind assistance in sample collection from poultry farms. Finally, we would like to thank all the staff from the Parasitology Unit for their technical and laboratory support.

REFERENCES

  • 1.Atyeo WT, Gaud J. 1992. The identity of Pterolichus obtusus Robin, 1877 with descriptions of new genera and species of feather mites (Acarina, Pterolichidae) from the Galliformes (Aves). Acarologia 33: 193–206. [Google Scholar]
  • 2.Axtell RC, Arends JJ. 1990. Ecology and management of arthropod pests of poultry. Annu Rev Entomol 35: 101–126. doi: 10.1146/annurev.en.35.010190.000533 [DOI] [PubMed] [Google Scholar]
  • 3.Chambless KN, Cornell KA, Crespo R, Snyder WE, Owen JP. 2022. Diversity and prevalence of ectoparasites on poultry from open environment farms in the Western-United States of Washington, Idaho, Oregon, and California. J Med Entomol 59: 1837–1841. doi: 10.1093/jme/tjac093 [DOI] [PubMed] [Google Scholar]
  • 4.Changbunjong T, Buddhirongawatr R, Suwanpakdee S, Siengsanan J, Yongyuttawichai P, Cheewajorn K, Jangjaras J, Sangloung C, Ratanakorn P. 2009. A survey of ectoparasitic arthropods on domestic animals in Tak Province, Thailand. Southeast Asian J Trop Med Public Health 40: 435–442. [PubMed] [Google Scholar]
  • 5.Decru E, Mul M, Nisbet AJ, Vargas Navarro AH, Chiron G, Walton J, Norton T, Roy L, Sleeckx N. 2020. Possibilities for IPM strategies in European laying hen farms for improved control of the poultry red mite (Dermanyssus gallinae): Details and state of affairs. Front Vet Sci 7: 565866. doi: 10.3389/fvets.2020.565866 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 6.Endale H, Aliye S, Mathewos M, Adimasu W. 2023. Identification and estimation of the prevalence of ectoparasites of backyard chicken in Boloso Sore District, Wolaita zone, southern Ethiopia. Vet Parasitol Reg Stud Reports 42: 100884. [DOI] [PubMed] [Google Scholar]
  • 7.Horn TB, Granich J, da Silva VL, Ferla NJ. 2019. Population fluctuation of predatory and sanitary importance mites (Acari) in commercial laying hens: Ecological interactions. Vet Parasitol 272: 64–74. doi: 10.1016/j.vetpar.2019.06.002 [DOI] [PubMed] [Google Scholar]
  • 8.Horn TB, Rocha MS, Granich J, Körbes JH, Alves LFA, Ferla NJ. 2017. Ectoparasitism of commercial laying hen by Megninia ginglymura (Mégnin) (Acari): population dynamic and distribution on the body regions. Poult Sci 96: 4253–4260. doi: 10.3382/ps/pex243 [DOI] [PubMed] [Google Scholar]
  • 9.Kitiwong K, Saeliw K. 2019. Production and marketing of egg in Thailand. Khon Kaen Agr J 47: 889–894. [Google Scholar]
  • 10.Lakyat A, Pumnuan J, Thipmanee K. 2022. Ectoparasite species attacking chicken in eastern area of Bangkok, Thailand. Agric Technol Thail 18: 1619–1632. [Google Scholar]
  • 11.Lammers GA, Bronneberg RGG, Vernooij JCM, Stegeman JA. 2017. Experimental validation of the AVIVET trap, a tool to quantitatively monitor the dynamics of Dermanyssus gallinae populations in laying hens. Poult Sci 96: 1563–1572. doi: 10.3382/ps/pew428 [DOI] [PubMed] [Google Scholar]
  • 12.Mungube EO, Bauni SM, Tenhagen BA, Wamae LW, Nzioka SM, Muhammed L, Nginyi JM. 2008. Prevalence of parasites of the local scavenging chickens in a selected semi-arid zone of Eastern Kenya. Trop Anim Health Prod 40: 101–109. doi: 10.1007/s11250-007-9068-3 [DOI] [PubMed] [Google Scholar]
  • 13.Murillo AC, Chappell MA, Owen JP, Mullens BA. 2016. Northern fowl mite (Ornithonyssus sylviarum) effects on metabolism, body temperatures, skin condition, and egg production as a function of hen MHC haplotype. Poult Sci 95: 2536–2546. doi: 10.3382/ps/pew175 [DOI] [PubMed] [Google Scholar]
  • 14.Murillo AC, Abdoli A, Blatchford RA, Keogh EJ, Gerry AC. 2024. Low levels of chicken body louse (Menacanthus stramineus) infestations affect chicken welfare in a cage-free housing system. Parasit Vectors 17: 221. doi: 10.1186/s13071-024-06313-6 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 15.Oh SI, Park KT, Jung Y, Do YJ, Choe C, Cho A, Kim S, Yoo JG. 2020. A sampling and estimation method for monitoring poultry red mite (Dermanyssus gallinae) infestation on caged-layer poultry farms. J Vet Sci 21: e41. doi: 10.4142/jvs.2020.21.e41 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 16.Pavan AM, Schussler M, Silva FR, Ferla NJ, Johann L, Silva GLD. 2022. Influence of laying hen-systems and ecologic variables on mites of medical and veterinary importance. Vet Parasitol 304: 109682. doi: 10.1016/j.vetpar.2022.109682 [DOI] [PubMed] [Google Scholar]
  • 17.Pedroso LGA, Hernandes FA. 2016. New records of feather mites (Acariformes: Astigmata) from non-passerine birds (Aves) in Brazil. Check List 12: 2000. doi: 10.15560/12.6.2000 [DOI] [Google Scholar]
  • 18.Rezende LC, Cunha LM, Martins NR, Teixeira CM, de Oliveira PR. 2015. Epidemiology of Megninia spp. in laying flocks from the State of Minas Gerais, Brazil. Rev Bras Parasitol Vet 24: 198–203. doi: 10.1590/S1984-29612015027 [DOI] [PubMed] [Google Scholar]
  • 19.Rosen S, Hadani A, Perlstein Z. 1988. The occurrence of Megninia hologastra (Analgidae Gaud, 1974) on poultry in Israel. Avian Pathol 17: 921–923. doi: 10.1080/03079458808436513 [DOI] [PubMed] [Google Scholar]
  • 20.Sangvaranond A. 1978. An outbreak of Megninia mite infestation in poultry. J Thai Vet Med Assoc 29: 33–40. [Google Scholar]
  • 21.Sangvaranond A. 1988. Study on ectoparasites of domestic chickens in Thailand. J Thai Vet Med Assoc 39: 115–132. [Google Scholar]
  • 22.Sangvaranond A. 1989. Study on ectoparasites of native chickens in Ubon Ratchathani province, Thailand. J Thai Vet Med Assoc 40: 43–48. [Google Scholar]
  • 23.Sangvaranond A. 1990. Study on ectoparasites of adult native chickens in Phranakhon Sri Ayutthaya province, Thailand. J Kasetsart Vet 9: 135–145. [Google Scholar]
  • 24.Sangvaranond A. 1990. Study on ectoparasites of native chickens in Phitsanulok province, Thailand. J Thai Vet Med Assoc 41: 159–164. [Google Scholar]
  • 25.Sangvaranond A. 1990. Study on ectoparasites of native chickens in Saraburi province, Thailand. J Thai Vet Med Assoc 41: 55–60. [Google Scholar]
  • 26.Sangvaranond A. 1990. Study on external parasites of native chickens in Chonburi province, Thailand. J Thai Vet Med Assoc 41: 182–186. [Google Scholar]
  • 27.Sangvaranond A. 1991. Study on incidence and outbreak of ectoparasites of native chickens in Nonthaburi province Thailand. J KKU Vet Sci 1: 68–74. [Google Scholar]
  • 28.Sangvaranond A. 1991. Study on incidence and outbreak of ectoparasites of native chickens in Roiet province. J KKU Vet Sci 1: 60–67. [Google Scholar]
  • 29.Sangvaranond A. 1992. Incidence and outbreak of external parasites of native chickens in Surin province. J KKU Vet Sci 2: 13–20. [Google Scholar]
  • 30.Sangvaranond A. 1993. Studies on prevalence and outbreak of ectoparasites in native chickens in central part of Thailand. Agric Nat Resour (Bangk) 27: 194–203. [Google Scholar]
  • 31.Sangvaranond A. 1994. Ectoparasites of bantams in the central region of Thailand. Agric Nat Resour (Bangk) 28: 58–65. [Google Scholar]
  • 32.Sangvaranond A. 2003. Ectoparasites of domesticated chickens in Thailand. J Kasetsart Vet 13: 42–54. [Google Scholar]
  • 33.Sangvaranond A, Ukosakul C. 1990. Studies on ectoparasites of chickens in private farms in Chachoengsao province, Thailand. J Kasetsart Vet 9: 125–133. [Google Scholar]
  • 34.Sangvaranond A, Thesathip S. 1992. Ectoparasites (lice, ticks and mites) occurring on native chickens in Petchaburi province, Thailand. Songklanakarin J Sci Technol 14: 97–103. [Google Scholar]
  • 35.Schiavone A, Pugliese N, Otranto D, Samarelli R, Circella E, De Virgilio C, Camarda A. 2022. Dermanyssus gallinae: the long journey of the poultry red mite to become a vector. Parasit Vectors 15: 29. doi: 10.1186/s13071-021-05142-1 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 36.Sioutas G, Gelasakis AI, Papadopoulos E. 2024. Spatial distribution of Dermanyssus gallinae infestations in Greece and their association with ambient temperature, humidity, and altitude. Pathogens 13: 347. doi: 10.3390/pathogens13040347 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 37.Sukpanyatham N, Bhodigen SE, Nantamingcharern T, Muangyai M. 1982. A survey of parasites in native chickens. Wetchasan Sattawaphaet 12: 227–237. [Google Scholar]
  • 38.Sulzbach A, Ferla NJ, da Silva GL, Johann L. 2022. World occurrence and related problems caused by Megninia ginglymura (Mégnin) (Acari: Analgidae) in commercial poultry farms −a review. Worlds Poult Sci J 78: 215–229. doi: 10.1080/00439339.2022.1988805 [DOI] [Google Scholar]
  • 39.Takehara M, Murata S, Katakura K, Fujisawa S, Hmoon MM, Win SY, Bawm S, Htun LL, Aung YH, Win MM, Isezaki M, Maekawa N, Okagawa T, Konnai S, Ohashi K. 2019. Haematophagous mites on poultry farms in the Republic of the Union of Myanmar. Heliyon 5: e01544. doi: 10.1016/j.heliyon.2019.e01544 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 40.Tucci EC, Guastali EAL, Rebouças MM, Mendes MC, Gama NMSQ. 2005. Infestation by Megninia spp. on chicken egg laying farms. Arq Inst Biol (Sao Paulo) 72: 121–124. doi: 10.1590/1808-1657v72p1212005 [DOI] [Google Scholar]
  • 41.Van Poucke S, Creighton R, Baker AS. 2016. Megninia ginglymura feather mite infestation in a Hamburg poultry flock in the United Kingdom. Vet Dermatol 27: 127–9e35. doi: 10.1111/vde.12296 [DOI] [PubMed] [Google Scholar]

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