Target species
Horses
Indications for use
For the treatment of infections in horses caused by micro-organisms susceptible to the combination of trimethoprim and sulfadiazine, such as infections of the upper respiratory tract, the urogenital system and wound infections.
Contraindications
Do not use in horses with severe liver or kidney disease.
Do not use in known cases of hypersensitivity to the active substances or to any of the excipients.
Do not use in known cases of resistance to trimethoprim and sulphonamides.
Special precautions for use in animals
Throughout the treatment, animals should have free access to drinking water to avoid possible crystalluria.
In the treatment of new-born animals and animals with liver damage, caution should be exercised.
Renal impairment may cause accumulation, increasing the risk of side effects in long term treatment.
Use the product cautiously in horses with blood dyscrasias.
Use of the product should be based on identification and susceptibility testing of the target pathogen(s). If this is not possible, therapy should be based on epidemiological information and knowledge of susceptibility of the target bacteria at farm level, or at local/regional level.
Use of the product should be in accordance with official, national and regional antimicrobial policies.
Use of the product deviating from the instructions given in this datasheet may increase the prevalence of bacteria resistant to the product, and may decrease the effectiveness of treatment with other antimicrobials or classes of antimicrobials due to the potential for cross-resistance.
In case of infections involving purulent conditions, trimethoprim-sulphonamides combinations are not recommended due to a diminished efficacy under such conditions.
Special precautions to be taken by the person administering the veterinary medicinal product to animals
This product contains sulfadiazine, a sulphonamide which can cause hypersensitivity reactions following skin contact, inhalation or accidental ingestion. Hypersensitivity to sulphonamides may lead to cross reactions with other antibiotics. Allergic reactions to sulphonamides may occasionally be serious.
Contact with the veterinary medicinal product should be avoided. This is especially important for people with known hypersensitivity to sulphonamides.
Avoid inhalation of dust. Wear either a disposable half-mask respirator conforming to European Standard EN149 or a non-disposable respirator conforming to European Standard EN140 with filter EN143 when handling this product.
Avoid contact with skin. Rubber gloves should be worn when handling this product. In the case of contact with skin, wash with soap and water.
If symptoms develop following exposure such as a skin rash or difficulty with breathing and irritation persists, seek medical advice.
Wash hands thoroughly after use.
Adverse reactions
The following adverse reactions can occur:
- Hypersensitivity reactions such as urticaria
- Inappetence
- Gastrointestinal disturbances such as loose faeces, diarrhoea and colitis
- Hepatic or renal disorders.
- Hematologic effects, such as anaemia, thrombocytopenia, or leukopenia
- Haematuria, crystalluria, tubular obstruction
Use during pregnancy and lactation
Laboratory studies in rats and mice have shown evidence of teratogenic effects at dosages that are above therapeutic dosages.
The safety of the veterinary medicinal product during pregnancy and lactation has not been assessed in the target species; use in pregnant or lactating mares should therefore be avoided.
Interactions
Potentiated sulphonamides used in conjunction with alpha2-adrenoceptor agonists like detomidine are known to be able to cause fatal arrhythmias in the horse.
Amounts to be administered and administration route
In feed use.
The recommended dose is 30 mg of the active substances together (i.e. 25 mg sulfadiazine and 5 mg trimethoprim) per kg body weight, equivalent to 10 g powder per 100 kg, once or twice daily for 5 days. Frequency of dosing is decided on basis of the susceptibility of the pathogens involved and location of the infection.
To ensure a correct dosage body weight should be determined as accurately as possible to avoid under dosing. The use of suitably calibrated weighing equipment for the administration of the calculated amount of the product is recommended when using the jars or parts of the sachets.
The powder can be mixed in a handful of feed immediately prior to dosing. The active ingredients in the powder have a bitter taste. Adding molasses or other sweetener to the feed can facilitate administration of the product. The remaining feed should be withheld until half an hour after the horse has eaten the feed with the medicine. Should a horse continue to reject the medicated feed, treatment should be continued with another pharmaceutical form with the same actives.
Overdose
In case of an overdose loose faeces or diarrhoea may be observed. This is generally self-limiting, but if needed can be treated symptomatically, e.g. fluid therapy in case of dehydration.
Withdrawal periods
Meat and offal: 20 days
Milk: Not permitted for use in mares producing milk for human consumption.