First comprehensive assessment of dipteran diversity and vectorial potential in northeastern Algeria: Ecological, veterinary, and one health perspectives.

Dung-breeding flies of pastured cattle have substantial economic impacts on livestock production. To prevent losses, many producers use insecticidal fly treatments which have off-target impacts on beneficial pasture insects such as coprophagous and predatory dung-inhabiting beetles. These insects suppress pasture pest fly populations either through resource competition or direct predation of fly eggs and larvae in the dung. Feed-through insecticides such as insect growth regulators (IGRs) are thought to have fewer harmful off-target impacts because they target immature fly stages in the dung. However, impacts on the larval development of dung beetles are not well understood. The aim of this study was to analyze dung beetle and pest fly populations on grazing beef farms using feed-through insecticides for pest fly management. Between May and September in 2022 and 2024, populations of horn flies, face flies, and stable flies were counted on cattle, and dung-inhabiting Coleoptera populations were surveyed on pastures. The abundance and diversity of dung beetles (Scarabaeidae: Onthophagus and Aphodius spp.) and the abundance of predatory dung insects (Hydrophilidae and Staphylinidae) were significantly lower on farms using feed-through insecticides compared to farms not treating. Horn fly populations rarely exceeded economic thresholds without the use of feed-through insecticides, implying treatment was unnecessary. Face fly populations mostly exceeded economic thresholds even on farms using feed-through insecticides-indicating treatments were not adequately controlling their populations. The use of feed-through insecticides over the whole season is therefore not an integrated approach to controlling flies on pastures and puts other beneficial organisms in the pasture agroecosystem at risk.

The article presents data on the daily dynamics, activity and abundance of zoophilic flies at livestock facilities in Kostanay region for 2023-2024. As a result, the work has affected the productivity of cattle in Kostanay region. The species composition of flies and their distribution in livestock and pasture areas are described. The pastures were dominated by Stomoxys calcitrans, M. domestica, Muscina stabulans, Musca autumnalis, and Fannia canicularis. M. domestica, St. salcitrans, and Muscina stabulanswere the most abundant in all areas of livestock and grazing, while in pastures they were Talliphora uralensis and L. Illustris.The paper presents studies of the dynamics and activity depending on the time of day and season. On the pasture, the first peak of activity was noted between 11.00 and 12.00 (up to 198 individuals), the second rise was at 18.00-19.00 (up to 147 individuals). Indoors, the highest peak was at 12.00-14.00 (up to 103 individuals), and at 17.00-20.00 -a new rise (up to 55 individuals). The highest peak was observed in August.The data obtained make it possible to regulate fly control measures and minimize their negative impact on animal reproduction

Flies play an important role in the transmission of antimicrobial-resistant (AMR) and multidrug-resistant (MDR) foodborne pathogens in animal production systems, posing risks to food safety and public health. Synanthropic fly species, including house flies (Musca domestica), face flies (Musca autumnalis), blow flies (Calliphoridae), and flesh flies (Sarcophagidae), mechanically and/or biologically transmit bacterial pathogens such as Salmonella enterica, Escherichia coli, Listeria monocytogenes, Klebsiella, and Campylobacter spp. Their frequent contact with manure, animal waste, and processing environments enables the transfer of AMR pathogens across food production systems. This review synthesizes recent research on the interactions between flies and foodborne pathogens, highlighting the role of fly physiology, behavior, and microbial associations in pathogen transport. Additionally, it introduces the influence of environmental factors on pathogen dissemination and evaluates current Integrated Pest Management (IPM) strategies, including biological, chemical, and physical control methods, for mitigating fly-mediated pathogen transmission. Understanding these systems is essential for developing targeted interventions to reduce the burden of AMR pathogens in food production and enhance public health protection.

ABSTRACT Zoophilic flies play an important role in dairy farms by transmitting diseases to livestock. These flies can cause significant damage to animal husbandry through physical disturbance and the spread of pathogens. This study aims to identify insect species in both traditional and industrial animal husbandry settings, focusing on the dominant species of zoophilic flies. The research involved collecting livestock insects from March to October, between 2017 and 2021, using insect nets, sticky nets, and light traps. A total of 10,942 flies were collected from livestock farms in three counties Marvdasht, Shiraz, and Zarghan. The collected flies belong to 21 species from 6 families. Musca domestica, Fannia canicularis, Musca autumnalis, Stomoxys calcitrans, Muscina stabulans, Calliphora vomitoria, and Lucilia cuprina were identified as the dominant species. Musca domestica, F. canicularis and M. autumnalis accounted for 70.24% of the total number of flies on livestock farms. Among the collected samples, Eristalis tenax (Syrphidae) was found with a frequency of 0.96%. The importance of this species is related to the presence of its larvae that cause myiasis in livestock. Identification of the dominant species of flies put the scientific basis to reduce their populations in dairy farms and the costs caused by the damage made by these pests to livestock farms through safe ways, such as biological control.

Some dipteran flies play an important role in the transmission of pathogens such as viruses, bacteria, fungi, protozoan and metazoan parasites in humans and other animals. Despite this importance, knowledge of the prevalence and molecular characteristics of some pathogens in flies is limited, and no data are available for Türkiye. In this study, we investigated the possible vector role of muscid fly species for the transmission of Enterocytozoon bieneusi Desportes (Chytridiopsida: Enterocytozoonidae), Encephalitozoon spp., Coxiella burnetii Derrick (Legionellales: Coxiellaceae) and Thelazia spp. using polymerase chain reaction (PCR) and sequence analysis. The flies were trapped in different animal-related places and surroundings from two different geographical regions of Türkiye including Central Anatolia and Middle Black Sea. According to the morphological keys, 850 (85%), 141 (14.1%) and 6 (0.6%) of the total of 1000 fly specimens identified as Musca domestica Linnaeus (Diptera: Muscidae), Stomoxys calcitrans Linnaeus (Diptera: Muscidae) and Musca autumnalis De Geer (Diptera: Muscidae), respectively. The other species including Haematobia irritans Linnaeus (Diptera: Muscidae), Muscina stabulans Fallén (Diptera: Muscidae) and Hydrotaea ignava Harris (Diptera: Muscidae) were each represented by a single specimen. Screening of the pathogens identified E. bieneusi only in M. domestica with a prevalence of 2.4%. Sequence analyses identified three known genotypes, Type IV, BEB6 and BEB8, and one novel genotype named AEUEb of E. bieneusi in M. domestica. Coxiella burnetii was detected in M. domestica and S. calcitrans with prevalences of 2.9% and 2.8%, respectively. The one specimen of H. ignava was also positive for C. burnetii. Encephalitozoon spp. and Thelazia spp. were not found in the examined specimens. Our results contribute to the current knowledge on the vector potential of muscid flies and their possible role in the transmission dynamics of certain pathogens, especially in regions where diseases are prevalent and affect public and animal health.

The article presents data on the determination of the entomofauna of zoophilous flies in the conditions of the cattle breeding farm. Were subjected to parasitological research cattle of various ages: dairy cows, heifers of mating age, calves. The research was carried out on pastures, in production premises and walking areas. As a result of the conducted research, it was established that the main representatives of zoophilic flies parasitizing animals in pasture conditions were: Lyperosia irritans, Haematobia stimulans, Musca autumnalis Musca vitripennis. The following types of flies in the case of animals staying in the production premises, were identified on them: Musca domestic, Fannia canicularus, Calliphora uralensis, Calliphora visina, Lucilia sericata and Muscina stabulans. It was established that the extent of infestation by zoophilous flies was 100% among all age groups of cattle. Intensity of infestation in the group of dairy cows was 270.22±4.28 specimens/animal, among heifers and heifers of mating age – 244.67±3.49 specimens/animal, and among calves – 81.67±1.14 specimens/animal. We identified a clear trend regarding the specifics of parasitic insect damage in cattle of different breeds. When staying within the same production group, the highest intensity of infestation (354.50±5.08 insects per animal) was found in black Holstein cows, and the lowest II indicator was found in Simmental cows - 159.83±1.41 insects per animal. The intensity of the infestation of cows by zoophilic flies among representatives of the Holstein breed is 28% higher than that of the Simmental breed, and also 25% higher than that of the cows of the Ukrainian black-spotted dairy breed. It was noted that with high indicators of the intensity of invasion by zoophilous flies, the animals showed the maximum degree of restlessness, when analyzing behavioral reactions and the level of well-being of cows. It manifested itself in a constant effort to be in motion. Therefore, as a result of the conducted complex of studies, the extreme relevance of insecticidal treatments of cattle of different age groups has been proven, since a wide range of zoophilic flies has been identified in the places where animals stay.

Conservation of the endangered notch-eared bat (M. emarginatus) requires a specific action plan based on precise ecological requirements of this species. The analysis of the diet of three colonies in southern Belgium revealed: (1) spatial and seasonal variations of the diet; (2) the consumption of web-building spiders (Araneus diadematus, Araneus triguttatus, Cyclosa conica, Enoplognatha sp., Larinioides patagiatus, Neriene emphana); (3) the predominance of blood-feeding dipterans in the diet (Stomoxys calcitrans and Musca autumnalis). Since the populations of these two ectoparasitic flies are sensitive to the use of antiparasitic drugs, these drugs should be used with caution by farmers and veterinarians in the vicinity of maternity colonies.

The fauna of zoophilic flies on cattle in livestock farms of the Tambov, Ryazan regions and Stavropol Krai was studied. The fauna of zoophilic flies of the Tambov region is represented by 5 families (Muscidae, Fanniidae, Calliphoridae, Sarcophagidae, Scatophagidae) and 15 species of which the dominant position in the fauna structure of the studied territories is occupied by: Musca domestica (family Muscidae) – 64,2 % and Muscina stabulans (family Muscidae) – 11,3 %. In the Ryazan region, the dominant species of zoophilic blood-sucking flies were identified – Haematobia irritans, Haematobosca stimulans, Haematobia spp., Stomoxys calcitrans and licking zoophilic flies – Musca domestica, Muscina stabulans, Musca autumnalis, Morrelia spp., Fannia canicularis. In the Stavropol region, it was found that cattle are attacked by the dominant species Haematobia irritans, Haematobia stimulans, Musca autumnalis and Stomoxys calcitrans.

Zoophilic Diptera plays a leading role in the epizootic foci formation of many infectious and parasitic diseases and directly affects the quality of livestock products. The current study aimed to analyze the number and species composition of parasitic Diptera in industrial, farm, and homestead agrobiocenoses of large and small cattle, pig, and poultry farms in Eastern Ukraine. The research involved entomological collection during the peak activity daylight hours in early May, July, and early September 2021-2022 per farm. A total of 360 entomological collections were made, and 4310 zoophilous flies were examined. In livestock farms of five districts of the Kharkiv region of Ukraine, 28 species of zoophilic flies were registered, among which Musca domestica, Muscina stabulans, Stomoxys calcitrans, Lucilia sericata, Protophormia terraenovae, and Drosophila species were dominant species. The analysis revealed that cattle biocenoses hosted 27 fly species, pigs had 8 species, and poultry and small cattle each had 7 species. The study indicated an increase in the population of Musca autumnalis, the main species in the pastures, near livestock premises during the summer. Stomoxys calcitrans was also recorded in livestock agrobiocenoses. The species Musca domestica, Musca autumnalis, and Stomoxys calcitrans account for 78.8% to 88.3% of the entire complex of zoophilous flies. The two species of Ortellia caesarion (shiny dung beetle) and Ortellia cornicina (green dung beetle), known for their role as manure mineralizers and deemed non-threatening to animals, were completely absent during the research period. The findings indicated the species of Eristalis tenax in agrobiocenoses in 2021. Therefore, it can be concluded that zoophilic flies are physical irritants to animals and potential carriers of many infectious diseases, especially diseases caused by unicellular organisms.

Simple SummaryFly control has always been a hot topic for dairy farmers, because there are not a lot of viable options to alleviate fly pressure. Dairy cows on pasture are commonly disturbed by many fly species, and dairy cow behavior may be affected by different fly species. In an experimental research trial, there was a strong relationship between the number of flies and the number of defensive behaviors of cows of different lactations. Milk yield was not affected by low fly numbers, indicating that greater than 40 horn flies per cow are needed to potentially lower the milk production of grazing dairy cows. To improve profitability, farmers need to properly identify key pasture flies, understand their biology and habitat, monitor their populations, and then reduce the fly population through mechanical or biological management techniques.Thirty-four crossbred dairy cows were observed on pasture six times per week from June to August 2014 at the University of Minnesota West Central Research and Outreach Center grazing dairy in Morris, MN, for defensive behaviors in response to three species of muscid flies. Counts of stable flies (Stomoxys calcitrans (L.)), horn flies (Haematobia irritans (L.)), and face flies (Musca autumnalis DeGeer) were recorded before and after pasture observation. Individual cows were monitored for 5 min intervals to observe the frequencies of five different defensive behaviors: front and back leg stomps, head tosses, skin twitches, and tail swishes. Fly numbers averaged 5 stable flies per leg, 37 horn flies per side, and 1 face fly per face during the study. The fly counts and behavior frequencies increased with ambient temperature. The results showed a very strong relationship between the numbers of flies and numbers of defensive behaviors, though correlations between specific flies and behaviors were low. Younger cows had fewer stable flies and horn flies than older cows. The thresholds of flies to lower production for pastured organic dairy cows may be greater than 5 for stable flies, 37 for horn flies, and 1 for face flies.

Providing safe and qualitative drinking water is becoming increasingly important due to climate change and population growth. Water towers are often used to provide storage and ensure water pressure for drinking water distribution. However, microbial regrowth of water is still a challenge during storage and distribution. Moreover, water towers can be used as an aggregation site by insects, mainly flies (Diptera). In this study, ten water towers in Belgium were monitored for 8 months with sticky traps to evaluate fly species diversity, abundances and activity. The results showed the presence of three fly species: Thaumatomyia notata (yellow swarming fly), Musca autumnalis (face fly) and Pollenia spp. (cluster fly). The flies entered the towers in autumn and took shelter against wintering conditions in cracks and crevices, especially on the highest floors where the water tank is located. In this way, flies can come into contact with the drinking water. Based on the monitoring campaign, a risk assessment matrix was set up to determine risks of possible microbial water contaminations caused by flies in water towers. This was validated by a worst-case experiment in laboratory conditions. Face flies (living and dead) were added to tap water to evaluate their influence on microbial water quality and safety using several techniques such as 16S rRNA amplicon sequencing, flow cytometric cell counts and fingerprinting. Our research showed that flies in drinking water promote bacterial growth and change the phenotypic resident drinking water community. Furthermore, new genera such as Pseudomonas and Acinetobacter as well as the coliforms Serratia fonticola and S. liquefaciens were detected when flies were added to tap water. Hence, prevention and intervention measures are important in water quality management to avoid contact between flies and drinking water in water towers. In this study, several effective prevention methods are discussed, such as sealing ventilation, overflow and weep holes with insect screens with adequate mesh size and covering water tanks.

Houseflies and cockroaches are adapted to live in close association with human habitations. They carry lots of medically important parasites and pathogens to humans and animals. The study was carried out in Malegaon city of District Nashik (M.S., India). The objective of the present work was to investigate the presence of human intestinal parasites transmitted mechanically by these insects and to evaluate prevalence of diarrhea in the present study area. Houseflies and cockroaches were collected for a period of four months (July to October, 2020) from different areas like kitchen, restaurants, canteen, garbage piles, grocery stores, and fish and meat shops. Microscopic examination of intestinal parasites was conducted by using standard procedure. A total of 265 flies (166 Musca domestica, 49 Chrysomya megacephala, 31 Musca autumnalis, 19 Musca sorbens) and 230 cockroaches (137 Periplaneta americana, 54 Blatella germanica, 39 Blattella orientalis) were collected and examined for possible human intestinal parasites. Of the total examined flies and cockroaches, 181 (68.3%) flies and 163 (70.9%) cockroaches were found to be carriers of various parasites. A total of four protozoan and three helminth parasites were isolated from these insects. The most common protozoan and helminth parasites were Balantidium coli and Ascaris lumbricoides. There were also higher numbers of cockroaches positive for Balantidium coli and Entamoeba coli than houseflies. Similarly, females of both the insects were found to be more vectorial than males. Significant correlation (r=0.95197) was found between the incidence of diarrhea and number of positive flies. These data suggest that both the insects should be considered potential mechanical vectors of human intestinal parasites in the present study area.

Introduction: Habronemiasis, equine summer sore, is caused by habronema larvae, commonly in tropical and subtropical climates. House flies, face flies, and stable flies transmit the pathogenic nematode larvae. Cutaneous habronemiais is the most common form of habronemiasis in horses. Cutaneous habronemiais is associated with the deposition of larvae in areas where they cannot complete their life cycle. Deposition of larvae is related to local hypersensitivity. Habronema larvae could cause preocular infectious resulting in conjunctivitis, blepharitis, or dermatitis. Case report: An eight-year-old male Arabian horse was referred to the Large Animal Medicine Unit, Veterinary Clinical hospital, Shiraz University, Shiraz, Iran, with a history of wounds on the preocular region and hind limbs. The right eye's ocular examination revealed abundant mucopurulent discharge, blepharospasm, and chemosis. The granulomatous tumor had a diameter of 1.8 cm and was evident on the palpebral conjunctiva of the medial canthus. The skin lesion was identified as habronemiasis based on the history, clinical symptoms. Treatment includes prednisolone tab with reducing dosage for 30 days, an oral dose of Ivermectin, topical oxytetracycline ointment for seven days, chloramphenicol and triamcinolone eye drop for seven days. The diagnosis was confirmed due to the positive reaction of the lesions to treatment protocol. Conclusion: Ocular habronemiasis is the common form of habronemiasis. Deposing of dead larva causes a hypersensitivity reaction. Treatments include corticosteroid to reduce inflammation-association tissue proliferation, antibiotic ointment for prevention of second bacterial infection, an antihistamine for the prevention of histamine-mediated pruritic and allergic conditions, and oral antihelminth for the killing of adult form in the stomach. The current study authors suggest fly control is essential in preventing habronemiasis.

BackgroundEquine thelaziosis is a neglected vector-borne parasitic disease in modern veterinary medicine, lacking recent reports. It is transmitted by Musca autumnalis, and potentially other Muscidae species, by ingesting the lachrymal secretions of its equine host. The distribution of both Thelazia lacrymalis and its intermediate hosts remains largely unknown throughout Europe, with most studies dating back 20 years. The aim of this study was to assess the presence, prevalence and distribution of T. lacrymalis in horses from Romania.MethodsThe eyes of 273 horses, slaughtered at two abattoirs from the Northwestern and Western regions of Romania, were examined for the presence of T. lacrymalis between March and November 2021. Upon detection, the nematodes were collected and morphologically identified using the keys from literature. Following identification, one specimen from each animal was selected for molecular analysis while the rest underwent detailed morphometric measurements. Mapping and distribution, according to ecoregions, was done using the QGis 3.20 software, while sequences obtained were compared to those available in GenBank through BLAST analysis using the MEGA X software.ResultsOf the 273 animals sampled, 12 (4.39%) were positive for Thelazia spp. infection. Eighty-seven nematodes were recovered, all morphologically identified as T. lacrymalis. The intensity of infestation varied between one and 33 nematodes/animal while five animals presented a bilateral infestation and seven a unilateral one. The highest prevalence was encountered in Pannonian ecoregion (12.12%) while the lowest was in the Alpine ecoregion (0%). Seventy-five intact specimens underwent detailed morphometric analysis, of the 18–20 parameters, resulting in notable differences in striation lengths compared to the data available in other reports. BLAST analysis identified a 96.46–98.60% similarity to the only other COI gene sequence available for T. lacrymalis.ConclusionsThe current study represents the first report of T. lacrymalis in horses in Romania. The low prevalence rates are probably linked to the wide use of macrocyclic lactones.Graphic

The beef industry endures major economic losses from a complex of flies that feed on bovine blood and mucus. For cattle on pasture, the most important of these pests are horn flies (Haematobia irritans [L.] [Diptera: Muscidae]) and face flies (Musca autumnalis [Diptera: Muscidae] De Geer). Pasture dragging to spread manure pats has been promoted as a management tactic for these species because their larvae inhabit bovine manure pats, but the efficacy of this practice has not been empirically validated. Spreading pats might promote fly mortality through desiccation or overheating, but these processes are weather-dependent and warrant testing in disparate climates. We evaluated pasture dragging effects while monitoring for weather interactions throughout nine experiment rounds in summers of 2018 and 2020 in Pennsylvania, USA. The manure spreading treatments increased pat surface area up to 300% but failed to significantly reduce emergence of horn flies and face flies as compared to controls. In contrast, precipitation and temperature were significant predictors in fly emergence models. Surprisingly, face fly emergence was significantly elevated in dragged pats twice in 2020. These data call for a reevaluation of pasture dragging as a management technique for horn flies and face flies across a range of climates.

The aim of this thesis is the determinations of insects species of forensic importance in Kayserı province. The experimental part of our study was carried out between September 2018 – May 2019; during the periods of winter, spring, autumn seasons in four different regions. In this study, fresh cow liver and chicken muscle were used as the experimental materials. The traps which allow the insects to enter easily but which prevent exit were used to collect insect species. As a result, 21 species were identified in four different study areas. Calliphora vicina (Robineau-Desvoidy, 1830) (Diptera: Calliphoridae), Lucilia sericata (Meigen, 1826) (Diptera: Calliphoridae), Chrysomya albiceps (Wiedemann, 1819) (Diptera: Calliphoridae), Muscina stabulans (Fallen, 1817) (Diptera: Muscidae), Musca autumnalis (De Geer,1776) (Diptera: Muscidae), were identified in fall season at all study areas. C. vicina was identified in winter season. C. vicina, Thricops sp. (Rondani, 1856) (Diptera: Muscidae), Fannia canicularis (Linnaeus, 1761) (Diptera: Fanniade), L. sericata, Dermestes frischii (Kugelann, 1792) (Coleoptera: Dermestidae), were identified in spring season at all study areas. C. vicina was seen from September to the end of May at all study areas. L. sericata was seen from September to the end of November and April to end of May at all study areas. Therefore, C. vicina and L. sericata can be used as an indicator species for determining the Postmortem Interval in Kayseri.

Bovine parafilariosis - New autochthonous cases from Germany and summary of recent reports from Europe.

An evaluation of fly pests of cattle was conducted in Federal College of Animal Health and Production Technology (FCAH&PT) Farm, Chaha Village, Jos South Local Government Area, Plateau State, Nigeria between August and October, 2020. Samples were collected from the farm weekly for three months. A total of nine hundred and nineteen (919) adult dipterous flies comprising fifteen species in eight genera across the three sub-orders were caught and identified using aerial sweeping hand net, light trapping and aerial insecticide spray. Phlebotomus papaltasi (44.18%) was the most prevalent while Simulium damnosum (0.22%) was the least. Others were Musca domestica (17.73%), Stomoxys calcitrans (11.43%), Culicoides species (10.99%), Musca autumnalis (10.23%), mosquitoes – Anopheles gambiae/Culex quequinfasciatus (4.89%) and Tabanus species (0.33%). The haematophagous flies (72.04%) out-numbered the non-haematophagous flies (27.96%) and the number of females collected/caught 780 (84.87%) were higher than the males 139 (15.13%). The highest collections were made in October (353 representing 38.41%) while September had the lowest (263 /28.62%). The study established the presence of fly pests in the farm and recommends that appropriate control measures should be put in place to forestall any disease outbreak.

Infectious bovine keratoconjunctivitis (IBK) is a painful ocular disease in cattle that is characterized by the presence of a corneal ulcer and production losses. A common industry practice is to cover an affected eye with a piece of cloth to reduce exposure to face flies and ultraviolet light with the goal of alleviating pain, accelerating healing, and reducing spread. To study the efficacy of eye patches in the treatment of IBK, a group of 216 clinically normal Angus crossbred steers were followed between April and August 2019 and evaluated weekly for the development of IBK. Eyes of cattle that developed IBK were enrolled with a blocked randomization scheme based on ulcer severity score to receive either an eye patch (treatment group) or no eye patch (control group). All treatment and control group animals received parenteral antimicrobial and nonsteroidal anti-inflammatory treatments and were housed in a pasture separated from the rest of the cohort for a maximum of 28 d or until clinical cure. Corneal ulcer areas were measured, and body weights were recorded twice weekly for steers in the treatment and control groups. Weights of all steers in the cohort were recorded three times during the trial period. The primary outcome, rate of corneal ulcer healing, was higher (P = 0.001) for lesions in eyes receiving an eye patch as determined by a linear mixed model that controlled for ulcer severity score at enrollment and previous IBK in the opposite eye. Median corneal ulcer healing time was 10 (IQR [Interquartile range] 7–17) d for patched eyes vs. 14 (IQR 7–21) d for unpatched eyes. In a Cox proportional hazards model adjusted for severity score at diagnosis, the hazard ratio for ulcer healing was 1.62 (95% CI: 1.02–2.56, P = 0.042) for eyes that received a patch compared to eyes that did not. Among all 216 steers in the cohort, those that were diagnosed with IBK had a numerically higher average daily gain (ADG) (0.45 [±SE 0.01] kg) vs. those that were not (0.42 [±SE 0.12] kg; P = 0.06). In enrolled steers that received a patch, the secondary outcome ADG was 0.47 (±SE 0.02) kg compared to 0.43 (±SE 0.02) kg in controls (P = 0.22). Weight gain may have been confounded by pasture during the treatment period. Results of this trial support the use of this low-cost intervention; further investigation into possible reasons for observed differences in weight gain may be warranted.