Disease Overview

Trichomonosis - known to breeders as canker or frounce - is caused by the flagellated protozoan Trichomonas gallinae, which colonises the oropharynx, crop and upper digestive tract of columbids. It is the most significant protozoal disease of domestic, racing and meat pigeons worldwide. Transmission is almost entirely horizontal within the loft: adults feed crop milk to squabs, birds bill during courtship, and the parasite passes readily through shared drinking water and feed. Because a single infected breeder can seed an entire generation of young birds, trichomonosis behaves less like an occasional clinical incident than like a permanent background pressure on the loft.

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Prevalence in European columbid populations is high. A multi-country survey of 281 wild columbids from Germany, Spain, Malta and Italy found 74% overall infection - 86% in stock doves, 70% in wood pigeons and 67% in turtle doves (Marx et al., 2017). Domestic and racing lofts are exposed to the same reservoir through shared water sources and contact with feral birds. Crucially, a large share of infection is subclinical: birds carry and shed the parasite with no visible oral lesions, while race performance, fertility and squab survival quietly decline. Subclinical carriage - not the dramatic caseous lesion - is what loft management actually has to control, and it is the form the Herba-Top clinical programme set out to measure.

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Clinically, established infection produces yellow-white caseous necrotic plaques in the oropharynx, pharynx and crop, leading to dysphagia, weight loss, poor feather condition and - in squabs - high mortality; systemic forms involving the liver and other organs also occur. Columbiformes are among the orders most severely affected by avian trichomonads (Amin et al., 2014).

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The therapeutic gap

Conventional control relies on nitroimidazoles - dimetridazole, ronidazole, metronidazole and carnidazole. Two constraints limit them.

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Resistance. In vitro nitroimidazole resistance in T. gallinae from racing pigeons was already documented in 1992, when successful therapy required an increased ronidazole dose (Franssen & Lumeij, 1992). Three decades of routine, often prophylactic, loft-wide dosing have consolidated the problem: in a recent survey of 79 isolates from meat pigeons, 25.3% were resistant to at least one of four nitroimidazoles and 70% of those resistant isolates were resistant to several (Cai et al., 2024). The standard reference review describes imidazole therapy as "sometimes hampered by resistant parasites" and names this a challenge for the future (Amin et al., 2014).

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Residues. Metronidazole, dimetridazole and ronidazole are listed in Table 2 (prohibited substances) of Commission Regulation (EU) No 37/2010, meaning they may not be administered to food-producing animals in the European Union. Wherever pigeons enter the food chain, the conventional toolbox is legally unavailable.

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This is the space a plant-based product is designed for: repeatable, residue-free pressure on subclinical carriage between races and before breeding, applied without adding to nitroimidazole selection pressure and without a withdrawal period - while the synthetic drugs remain in reserve for clinical outbreaks.

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Mechanism of Action

The tested product is a hydro-alcoholic plant extract administered through drinking water. The composition recorded in Scientific Report No. 3 is:

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Composition as stated in Scientific Report No. 3 (USAMV Cluj-Napoca, 29 January 2018).

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Four of the seven species carry constituents with documented activity against T. gallinae or against trichomonads generally. In a systematic screen of 36 essential oils and 19 pure terpenes against T. gallinae, the most active single compounds were α- and β-thujone (IC50 17.3 µg/ml) - the characteristic monoterpenes of Tanacetum vulgare - followed by camphene, β-pinene and thymol (IC50 38.4 µg/ml), the principal phenolic monoterpene of Thymus species; whole Thymus oils were active at 166–274 µg/ml, against metronidazole at 1.0 µg/ml as the reference standard (Bailén et al., 2022). Thymol combined this activity with low mammalian-cell toxicity.

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Garlic has been tested directly in the target host: an aqueous Allium sativum extract at 200 mg/kg body weight cleared T. gallinae from naturally infected domestic pigeons in 5 days versus 7 days for metronidazole at 50 mg/kg, with better weight gain, normalised haematology and lower mortality than untreated infected controls (Seddiek et al., 2014). The organosulfur compounds responsible (allicin and its derivatives) act on parasite thiol-dependent enzymes rather than on the nitroreductase pathway targeted by nitroimidazoles - a different mechanism, and therefore no cross-resistance with the drugs already failing in the loft.

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The remaining species contribute supporting rather than directly trichomonacidal actions: Chelidonium majus (isoquinoline alkaloids) and Inula helenium (sesquiterpene lactones) are used in the manufacturer's range for choleretic, antispasmodic and mucosal-tonic effects, while Calendula officinalis and Coriandrum sativum bring anti-inflammatory and carminative properties relevant to a mucosa already damaged by the parasite.

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Research Studies

All four supplied reports were produced by the Discipline of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine (USAMV) Cluj-Napoca, under contract CTR. No. 6142/10.04.2017 // 195/13.04.2017, with Lect. Dr. Adriana Györke as principal investigator and Promedivet (Sovata, Romania) as sponsor. They are internal scientific reports; none has been published in a peer-reviewed journal.

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Study 1 - Clinical study of the trichomonosis formula 2018 (pivotal)

Title:  Testing and evaluation of the efficacy of Herba-Top (trichomonosis formula 2018) in trichomonosis and other endoparasitoses in pigeons (clinical study)

Report reference:  Scientific Report, CTR. No. 6142/10.04.2017 // 195/13.04.2017, chapter 4

Principal investigator:  Lect. Dr. Adriana Györke, DVM, PhD

Institution:  USAMV Cluj-Napoca - Faculty of Veterinary Medicine, Discipline of Parasitology and Parasitic Diseases

Sponsor / product owner:  Promedivet (Sovata, Romania)

Report date:  Cluj-Napoca, 12 May 2018

Design:  Open, uncontrolled before/after clinical study (day 0 vs day 10) in one naturally infected loft of approximately 40 pigeons of mixed breed and age; 10 birds selected at random for parasitological examination

Dose:  10 ml/L drinking water, 10 consecutive days

Methods:  Direct microscopic examination of warm-saline swabs of the buccopharyngeal mucosa, Trichomonas spp. counted over 3 microscopic fields at ×40; coproparasitological examination by flotation and McMaster (OPG); MedCalc, independent-samples t-test, significance at p ≤ 0.05

Peer-review status:  Internal report - not published in a peer-reviewed journal.

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Study 2 - Clinical study of the first trichomonosis formula

Title:  Testing and evaluation of the efficacy of Herba-Top (trichomonosis formula) in trichomonosis and other endoparasitoses in pigeons (clinical study)

Report reference:  Scientific Report No. 3, CTR. No. 6142/10.04.2017 // 195/13.04.2017

Report date:  Cluj-Napoca, 29 January 2018

Design:  Open, uncontrolled before/after clinical study in two lofts, approximately 40 pigeons in total; 10 pigeons per loft examined per sampling day

Dose:  10 ml/L drinking water, 10 consecutive days

Methods:  As Study 1; trichomonad counts over 3 fields at ×40

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Study 3 - Formulation development baseline (2017)

Report reference:  Scientific Report No. 1, Cluj-Napoca, 6 July 2017

Design:  Two controlled experiments, each with an untreated control group and a treated group of 10 pigeons (approximately 40 birds in total)

Doses:  Herba-Top formula 1 at 4 ml/L and formula 2 at 10 ml/L, 9 days

Outcome:  No therapeutic effect in pigeon trichomonosis - see "Experiments" below. This negative result is the reason a dedicated trichomonosis formula was developed.

A fourth supplied report (Scientific Report No. 2, 16 August 2017) covers a separate branch of the same contract - the anticoccidial formula Herba-Top 3C in experimental broiler coccidiosis, where it achieved a good/marked anti-eimerian index (175.22 at 5 ml/L; 164.38 at 10 ml/L). It concerns a different product and a different indication and belongs on the coccidiosis page, not here.

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Experiments

In the pivotal study, trichomonads were found in all 10 pigeons examined before treatment, at 25 to 100 organisms per microscopic field; more than half the birds carried over 50 per field, and the arithmetic mean was 50 (±9.51). After 10 days of continuous administration at 10 ml/L of drinking water, counts ranged from 0 to 33 per field with a mean of 8 (±3.52) - a reduction of 83.3%, statistically significant at p = 0.002. Four of the ten birds were microscopically negative after treatment; two still carried 20 and 33 organisms per field. No change in health status, water consumption or feed consumption was recorded over the treatment period. The investigator classified the product as having a "very good trichomonacidal effect" and concluded that it can be recommended for the prophylactic treatment of trichomonosis in pigeons.

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Table 1. Trichomonad counts per microscopic field before and after treatment, across the three pigeon trichomonosis studies. Studies 1 and 2 were uncontrolled; Study 3 included untreated control groups, whose reduction matched or exceeded that of the treated groups.

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The same birds were screened for other endoparasites by flotation and McMaster. In the pivotal study, Capillaria spp. egg counts fell from 350 to 185 OPG - a statistically significant 47.14% reduction (p = 0.03), described in the report as a moderate therapeutic effect. Eimeria spp. oocyst counts fell by only 12.32% (p = 0.56, not significant), and Ascaridia/Heterakis egg counts rose 4.17-fold (p = 0.0001). The report states plainly that the product had no effect on Eimeria or on Ascaridia/Heterakis infestation.

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Table 2. Concurrent coproparasitological findings in the same treated birds (ns = not statistically significant).

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The earlier clinical study of the first trichomonosis formula covered two lofts. In the first, 35 (±11.4) trichomonads per field were counted on day 0; on day 7 the birds developed diarrhoea, the owner declined the day-10 re-examination, and no post-treatment value exists - the report states that the cause of the diarrhoeic episode could not be established. In the second loft, counts fell from 40 (±6.03) to 26 (±2.61) per field, a 35.0% reduction at the boundary of statistical significance (p = 0.047). On that basis the investigator concluded that the formula could be recommended for the prophylaxis of trichomonosis. Against the other parasites in the same birds the pattern anticipated the later study: a strong, highly significant effect on Capillaria spp. (−91.23%, p < 0.0001), a non-significant reduction in Eimeria spp. (−69.8%, p = 0.123), and no effect on Ascaridia/Heterakis.

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The 2017 baseline study is the reason the formula exists in its present form. Two original Herba-Top formulations were tested against untreated controls - formula 1 at 4 ml/L and formula 2 at 10 ml/L, both for 9 days. Parasite counts did fall in the treated groups, by 38.57% and 64.45% respectively, but they fell as much or more in the untreated control groups (94.25% and 65.08%), and no statistically significant difference was found between treated and control birds after treatment. The report concluded that neither original formula had a therapeutic effect in pigeon trichomonosis. That finding - obtained, notably, in the only one of the three trichomonosis studies to include a control group - prompted the development of the dedicated trichomonosis formula whose results are reported above.

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References

1. Amin, A., Bilic, I., Liebhart, D., Hess, M. (2014). Trichomonads in birds – a review. Parasitology, 141(6), 733–747. DOI: 10.1017/S0031182013002096. PubMed: PMID 24476968.
2. Marx, M., Reiner, G., Willems, H., et al. (2017). High prevalence of Trichomonas gallinae in wild columbids across western and southern Europe. Parasites & Vectors, 10, 242. DOI: 10.1186/s13071-017-2170-0.
3. Franssen, F.F.J., Lumeij, J.T. (1992). In vitro nitroimidazole resistance of Trichomonas gallinae and successful therapy with an increased dosage of ronidazole in racing pigeons (Columba livia domestica). Journal of Veterinary Pharmacology and Therapeutics, 15(4), 409–415. DOI: 10.1111/j.1365-2885.1992.tb01032.x. PubMed: PMID 1487839.
4. Cai, H., Liu, Y., Zhu, Y., et al. (2024). Drug resistance patterns and genotype associations of Trichomonas gallinae in meat pigeons (Columba livia): insights from Guangdong Province, China. Frontiers in Veterinary Science, 10, 1343321. DOI: 10.3389/fvets.2023.1343321.
5. Bailén, M., et al. (2022). Anti-Trichomonas gallinae activity of essential oils and main compounds from Lamiaceae and Asteraceae plants. Frontiers in Veterinary Science, 9, 981763. DOI: 10.3389/fvets.2022.981763.
6. Seddiek, S.A., El-Shorbagy, M.M., Khater, H.F., Ali, M.M. (2014). The antitrichomonal efficacy of garlic and metronidazole against Trichomonas gallinae infecting domestic pigeons. Parasitology Research, 113(4), 1319–1329. DOI: 10.1007/s00436-014-3771-6. PubMed: PMID 24488107.
7. Commission Regulation (EU) No 37/2010 of 22 December 2009 on pharmacologically active substances and their classification regarding maximum residue limits in foodstuffs of animal origin - Table 2 (prohibited substances). EUR-Lex 32010R0037.
8. Györke, A. (2018). Testing and evaluation of the efficacy of Herba-Top (trichomonosis formula 2018) in trichomonosis and other endoparasitoses in pigeons (clinical study). Scientific Report, CTR. No. 6142/10.04.2017 // 195/13.04.2017. USAMV Cluj-Napoca, 12 May 2018. (Internal report - not peer-reviewed.)
9. Györke, A. (2018). Testing and evaluation of the efficacy of Herba-Top (trichomonosis formula) in trichomonosis and other endoparasitoses in pigeons (clinical study). Scientific Report No. 3, USAMV Cluj-Napoca, 29 January 2018. (Internal report - not peer-reviewed.)
10. Györke, A. (2017). Testing and evaluation of the efficacy of Herba-Top in trichomonosis, eimeriosis and other endoparasitoses in pigeons and in experimental and subclinical coccidiosis in broiler chickens. Scientific Report No. 1, USAMV Cluj-Napoca, 6 July 2017. (Internal report - not peer-reviewed.)

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Raw Material and Supplier Transparency

• Manufacturer: Promedivet, Sovata, Romania.
• Botanical sourcing: wild-harvested and cultivated plants from the native Romanian flora, processed in-house - the brand-level sourcing statement; species-level sourcing detail for this formula was not supplied.
• Extraction method: hydro-alcoholic extract administered via drinking water. The exact solvent ratio, extraction protocol and standardisation parameters are not detailed in the supplied reports.
• Formulation formats: within the Herba99 pigeon range, Tricho-Plus is offered as an oral extract (drinking water) and as tablets; equivalent Tricho-Plus extracts exist for exotic birds and rodents.
• Composition tested: seven plants as listed under Mechanism of Action. The composition of the revised "2018" formula used in the pivotal study is not stated in the reports.

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Additional Relevant Parameters

Dosing as tested

Both clinical studies used 10 ml per litre of drinking water for 10 consecutive days. The 2017 baseline study also tested 4 ml/L for 9 days, without effect. Any dose or duration printed on the page should match the tested regimen, or the difference should be stated.

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Tolerance

In the pivotal study, no change in health status, water consumption or feed consumption was recorded during the 10-day course. In the earlier study, one of two lofts developed diarrhoea on day 7; the report records that the cause could not be established, because the owner declined further examination.

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Withdrawal period and food-safety context

The supplied research reports do not address withdrawal periods - this is a product-file question, not a study finding. For the anthelmintic line the manufacturer declares no withdrawal period; the equivalent declaration for Tricho-Plus must be confirmed against current product literature before it is published. The regulatory contrast is nonetheless the strongest commercial argument available: the conventional alternatives - metronidazole, dimetridazole and ronidazole - are prohibited substances under Table 2 of Regulation (EU) No 37/2010 and may not be used in food-producing animals in the EU at all.

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Comparative advantage

• Non-nitroimidazole mode of action. The plant constituents with documented anti-trichomonal activity (thujones, thymol, organosulfur compounds) do not act through the nitroreductase pathway, so the product does not add to the resistance pressure already documented in racing and meat pigeon populations.
• Fit for routine loft use. Administration through drinking water over 10 days suits whole-loft prophylaxis between races and before the breeding season, where repeated nitroimidazole courses are precisely what drives resistance.
• Documented side benefit on Capillaria. Both clinical studies recorded a statistically significant reduction in Capillaria spp. egg counts (−91.2% and −47.1%) in the same birds - a consistent, directionally stable finding across two independent lofts.
• Honest limits. No effect on Eimeria spp. or Ascaridia/Heterakis; those indications are served by other products in the range (Cocci-Plus, Deworming) and should be cross-linked rather than claimed here.