Chemicals / Complex Chemical Agents/ Chemical:

Sulphonamides (with special reference to Hedgehogs, Elephants, Lagomorphs, Ferrets, Great Apes and Cranes)




Information in this page has been entered to support the current volumes of Wildpro and further information will be added as new volumes are completed. This page is not intended to substitute for the manufacturer's data sheet and the information is not yet complete for all species, or for all contra-indications etc.

CAUTION: Before any pharmaceutical product is used, the manufacturer's data sheet, containing information on uses, dosage and administration, contra-indications, warnings etc., should always be consulted. It is important to remember that licensing of pharmaceutical products for use in a particular species/condition, as well as mandatory meat and milk withdrawal times for food-producing animals, varies between countries and changes with time. Withdrawal times also may vary between different pharmaceutical formulations and depending on route of administration. In the EU, the prescription cascade must be followed (see LCofC1.2H and W564.Apr05.w1); note that specific restrictions apply for food-producing animals. In the USA, FARAD may be consulted regarding residues and meat and milk withdrawal times.

General Chemical Information

A group of antibacterial agents which are bacteriostatic when used alone but bactericidal when used in combination with trimethoprim.

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Names and Formulae
Type Sulphonamides. (B263)
Alternative Names
  • "Sulfadiazine (N1-(2-Pyrimidinyl)-sulfanilamide; Adiazine; Debenal; Delvoprim; Diazyl; Eskadiazine; Pyrimal; Sterazine; Sulfolex; Ultradiazin; Coco-Diazine; Cremodiazine; Deltazine; Diazolone; Diazovit; Honey Diazine; Lipo-Diazine; Lipo-Levazine; Liquadiazine; Microsulfon; Neazine; Piridisir; Sanodiazine; SDA; Sulfacombin; Spofadrizine; Sulfadiazina; Sulfapyrimidine; Theradiazine; Benzenesulfonamide, 4-amino-N-2-pyrimidinyl-; Solfadiazina." (W324))
  • "Sulfamethoxazole (Cotrimoxazole; bactrim; Cotrim; Septra; Sulfatrim; Trisulfam; Uroplus; Gantanol; 4-Amino-N-(5-methyl-3-isoxazolyl)benzenesulfonamide; Sulfisomezole; Sulfamethylisoxazole; Sulfamethoxizole; Sinomin; N1-(5-Methyl-3-isoxazolyl)sulfanilamide; 5-Methyl-3-sulfanilamidoisoxazole; 3-Sulfanilamido-5-methylisoxazole; 3(p-Aminophenylsulfonamido)-5-methylisoxazole; Eusaprim; Gantaprim; Gantrim; Baktar; Abacin; Bactromin; Drylin; Kepinol; Momentol; Nopil; Omsat; Septrim; Sigaprim; Sulfotrim; Sulfotrimin; Sulprim; Sumetrolim; Suprim; Tacumil; Teleprim; TMS 480; Trigonyl; Linaris; Eltrianyl; Microtrim; Trimesulf; Apo-sulfatrim; Fectrim; Trimforte; Uro-septra; Comox; Cotrim-Puren; Duratrimet; Helveprim; Imexim; Laratrim; Supracombin; Thiocuran; Bactramin; N-(5-methyl-3-isoxazolyl)sulfanilamide; azo-gantanol; Urobak; TMP/SMX; Resprim; Septrin; Triprim; Gamazole." (W324))
  • Sulfadoxine

Alternative names for sulphonamide/trimethoprim combinations:

  • Co-trimoxazole
  • Trimethoprim-sulfamethoxazole
  • Sulfamethoxazole-trimethoprim
  • Sulfadiazine-trimethoprim
  • Trimethoprim-sulfadiazine
  • Co-trimazine
Chemical Formula
  • Sulfadiazine: C10H10N4O2S (W324)
  • Sulfamethoxazole: C10H11N3O3S (W324)
Chemical Structure  
Molecular Weight
  • Sulfadiazine: 250.2746 (W324)
  • Sulfamethoxazole: 253.2752(W324)
Related Chemicals --

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Physical Properties / Chemistry
  • Sulfadiazine: white to slightly yellow powder, odourless or nearly odourless. (B263)
  • Sulfamethoxazole: white to off-white crystalline powder, odourless or nearly odourless. (B263)
Melting point
  • Sulfamethoxazole: 167 C. (W324)
Boiling point --
Density --
Water solubility
  • Sulfadiazine: very slightly soluble in water. (B263)
  • Sulfamethoxazole: solubility 0.29mg/ml water. (B263); <0.1 g/100 mL at 20 C. (W324)
Other solubility
  • Sulfadiazine: sparingly soluble in alcohol. (B263)
  • Sulfamethoxazole: solubility 20mg/ml alcohol. (B263)
  • Sulphadizine sodium salts are alkaline. (B201.1.w1)

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Pharmacology & General Information
  • Bacteriostatic, but bactericidal in combination with trimethoprim. (B263)
  • Sulphonamides block the conversion of para-aminobenzoic acid (PABA) to dihydrofolic acid (DFA) (a step in the folic acid pathway). (B263) by competing with PABA for the enzyme dihydropteroate synthase, forming nonfunctional analogues of folic acid. (B135.47.w47)
Storage / Stability
  • Store sulfadiazine-trimethoprim and sulphamethoxazole-trimethoprim at room temperature (15-30C), in tight container. (B263)
Legal Category (In UK) --

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Associated Techniques




(Further Reading)
Click image for full contents list of ELECTRONIC LIBRARY

Authors Debra Bourne (V.w5); Gracia Vila-Garcia (V.w67)
Referees Suzanne I. Boardman (V.w6); Becki Lawson (V.w26); Susan Mikota (V.w72)

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Therapeutic Information

  • Potentiated sulphonamides (trimethoprim-sulphonamide combinations):
    • Active against a range of Gram-positive and Gram-negative bacteria, including aerobic Gram-positive cocci and some rods, and many Gram-negative rods including Enterobacteriaceae. (B201.1.w1)
    • Active against Chlamydia, coccidia, Toxoplasma. (B201.1.w1)
    • Active against Pneumocystis carinii, coccidia, Toxoplasma. (B263)
    • Active against Gram-positive bacteria including most streptococci, many staphylococcus strain, Nocardia spp. (B263)
    • Active against many of the Gram-negative family Enterobacteriaceae (not Pseudomonas aeruginosa). (B263)
Appropriate Use
  • Silver sulfadiazine, topical application to wounds. (B135.47.w47)
  • Insoluble sulphonamides may be given orally for effect on the aerobic flora of the intestine prior to surgery. (B135.47.w47)
  • Resistance may emerge from mutation causing PABA overproduction, a structural change in the enzyme involved such that it has a lower affinity for sulphonamides, or a loss of permeability. Resistance is most commonly transmitted by plasmid. (B135.47.w47)
  • In horses: about 30% of Streptococcus zooepidemicus strains are resistant to potentiated sulphonamides. (B135.47.w47)
  • Sulphonamides stimulate the growth of rickettsiae. (B135.47.w47)
  • Inactive against Pseudomonas aeruginosa. (B263)
  • Slower development of resistance if trimethoprim-sulphonamide combinations are used rather than trimethoprim alone or sulphonamides alone. (B263)

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Pharmacokinetics and Drug Interactions
Absorption /Bioavailability
  • Good absorption following oral administration. (B201.1.w1)
  • Peak levels about one to four hours after oral administration. (B263)
  • Slower absorption following subcutaneous administration. (B263)
  • Slow absorption following oral administration for sulfadiazine (peak levels in four to eight hours); slow absorption for sulfamethoxazole. (B135.47.w47)
  • Widely distributed to tissues and body fluids including CSF and the central nervous system. (B135.47.w47, B201)
  • Well distributed. (B263)
  • Cross the placenta. (B263)
  • Distributed into milk. (B263)
  • In CSF, in the presence of inflamed meninges, may reach about 50% of serum levels. (B263)

Volume of distribution:

  • Dogs: sulfadiazine 1.02 L/kg. (B263)
  • Horses: sulfadiazine 0.59-1.51 L/kg. (B263)
Plasma Protein binding / Storage
  • About 65-70% (human); varies 20-90%. (B135.47.w47)
Elimination Route
  • Excretion mainly in urine, via glomerular filtration. (B135.47.w47)
  • Also excretion in urine of the acetylated metabolite. (B135.47.w47)
  • Renal excretion unchanged, both glomerular filtration and tubular secretion. (B263)
  • Metabolised by acetylation and conjugation with glucuronic acid in the liver. (B201, B263)
Elimination half-life / Clearance Rate
  • About 30 to 50% of the drug/its metabolites excreted in urine within 24 hours. (B135.47.w47)
Serum elimination half life of sulfadiazine:
  • Dogs 9.84 hours. (B263)
  • Horses: 2.71 hours. (B263)
  • Cattle 2.5 hours. (B263)
Drug Interactions
  • Trimethoprim/sulphonamide: Clotting time may be increased if used in individuals receiving coumarin (warfarin) anticoagualants. (B263)
  • Sulphonamides: may displace other drugs which are highly protein-bound (e.g. methotrexate, phenylbutazone, thiazide diuretics, salicylates, probenicid, phenytoin. The clinical effects of this are not clear. (B263)

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Formulations available --
Doses / Administration Routes / Frequencies

Use of Drugs (Medication):

  • Before administration of any pharmaceutical product the manufacturer's datasheet must be consulted regarding operator safety, relevant withdrawal times etc.
  • Many drugs are not registered for use in particular species and additional care should be taken in their use, with proper regard for possible toxic effects. 
  • Consideration should be given to relevant legislation regarding the use of drugs.
  • In the UK, guidelines regarding the use of drugs are set out in the Royal College of Veterinary Surgeons' Guide to Professional Conduct 2000: (See: LCofC1 - RCVS Guide to Professional Conduct 2000 - Choice of Medicinal Products).
General comments: Erinaceus europaeus - West European Hedgehog:
  • Sulfadimidine: 100-200 mg/kg subcutaneously every 24 hours for three days. For coccidia. (B267)
  • Sulphadimidine (Intradine 33.3%, Norbrook) subcutaneously, 110 mg/kg initial dose then 55 mg/kg once daily for the next four days, no drug for five days, then 55 mg/kg once daily for a further five days. (D107)
  • Trimethoprim 5mg/kg + sulfamethoxazole 25mg/kg intramuscularly or orally twice daily. Pulmonary infections, gram-negative bacteria. (B22.27.w3)
  • Sulfadimethoxine: 2-20 mg/kg intramuscularly, subcutaneously or orally (orally for coccidiosis), daily. Treat for two to five days, off drug for five days then repeat for two to five days. For coccidiosis; broad-spectrum. May be slightly nephrotoxic therefore pause in therapy. (B22.27.w3)
  • Sulphadoxine/trimethoprim. 50 mg/kg subcutaneously or intramuscularly. For treatment of Coccidiosis. (B284.6.w6)
  • Sulphadimidine. 200 mg/kg subcutaneously for three days. For treatment of Coccidiosis. (B284.6.w6)
  • Sulphadiazine/trimethoprim30 mg/kg once daily for 5-8 days, intramuscularly or subcutaneously. (D107)
  • Sulphadoxine/trimethoprim/lidocaine (lignocaine)(Borgal 7.5%, Intervet UK Limited) 75 mg/kg once daily for five days, subcutaneously. (D107)

Atelerix albiventris - Four-toed hedgehog:

  • Sulfadimethoxine: 2-20 mg/kg orally, subcutaneously or intramuscularly every 24 hours. (B267)
  • Sulfadimethoxine: 2-20 mg/kg subcutaneously or orally daily for 2-5 days, stop treatment for five days then repeat. Gram-negative organisms. (J204.59.w1)
  • Trimethoprim/sulphonamide 30mg/kg orally, subcutaneous or intramuscular every 12 hours. For respiratory infections. (B267)
  • Trimethoprim/sulphonamide 30 mg/kg orally every 24 hours. Gram-negative organisms. (J204.59.w1)

"Hedgehog" (species not distinguished between Erinaceus europaeus - West European Hedgehogor Erinaceus europaeus - West European Hedgehog):

  • Sulfadimethoxine: 2-20 mg/kg oral, subcutaneously or intramuscularly, every 24 hours for two to five days, off drug for five days then repeat for two to five days. For coccidia. (B267)
  • Sulfadimethoxine: 2-20 mg/kg intramuscularly, subcutaneously or orally, daily. (B150.w1)
  • Trimethoprim/sulphonamide (SMZ/TMP) 30 mg/kg intramuscularly or orally every 12 hours. (B150.w1)

In Elephants:

Elephas maximus - Asian Elephant

  • Topical sulfonamide in powder form was used in the treatment of an elephant with priapism. (J3.153.w4, P5.40.w3)
  • Sulfamethoxazole- trimethoprim, 48 g orally twice daily, was administered for four week to an adult elephant following Regional Digital Intravenous Perfusion for treatment of a sole abscess. (J2.34.w2)
  • Sulfamethoxazole-trimethoprim was given, 57 g orally for 21 days, to a 40-year-old 3,300 kg female in the treatment of a nail infection complicated by phalangeal osteomyelitis. (J2.28.w2, P9.1.w7)

Loxodonta africana - African Elephant

  • Trimethoprim-sulphamethaxazole, 9,600 mg orally twice daily for 14 days was used in the treatment of a 1,136 kg eight-year-old male Loxodonta africana - African Elephant with a fractured and infected tusk, in addition to initial topical treatment with 0.9% sodium chloride followed by povidone iodine solution to flush the pulp cavity. (J4.185.w2)

The following information is taken with permission directly from the Elephant Care International website (W580.Aug2005.w30, W580.Aug2005.w31):



a) 22 mg/kg PO 4-6 times/day to maintain trough concentrations above the MIC in African elephants, however, the authors suggest favorable clinical response which is the basis for BID dosing in horses may also be effective in elephants (Page et al. 1991). 

Elephant References:

a) Page,C.D., Mautino,M., Derendorf,H.D., and Anhalt,J.P. 1991. Comparative pharmacokinetics of trimethoprim-sulfamethoxazole administered intravenously and orally to captive elephants. Journal of Zoo and Wildlife Medicine 22:(4):409-416 Abstract: Three healthy captive female African elephants (Loxodonta africana) were used to determine the pharmacokinetics of trimethoprim-sulfamethoxazole (TMP-SMZ) after a single i.v. and a single oral dose of 3.7mg/kg TMP and 18.3mg/kg SMZ. A 2-mo wash-out period was allowed between the i.v. and oral trials. An adult female Asian elephant (Elephas maximus) was also used in this investigation; however, pharmacokinetic parameters calculated from data from this animal were not used to calculate mean pharmacokinetic parameters for TMP-SMZ in African elephants. Serum concentrations of TMP-SMZ were measured by high-performance liquid chromatography on blood samples collected via venous catheterization predose, over 12 hr after i.v. drug administration, and over 24 hr after oral drug administration.  For African elephants, the mean terminal half-life (t1/2,z), clearance (CL), and volume distribution at steady state (Vdss) of TMP following i.v. administration were 1.4 + 0.7 hr, 856.0 + 114.0 ml/hr/kg, and 1.1 + 0.4 L/kg, respectively. For SMZ, these parameters were 1.83 + 0.06 hr, 93.6 + 10.8 ml/hr/kg, and 0.2 + 0.02 L/kg, respectively. Following oral administration, the mean t1/2,z was 3.0 + 1.1 hr, the maximum concentration (Cmax) was 0.43 + 0.07 micrograms/ml at time (tmax) 1.7 + 0.6 hr, and the bioavailability (F) was 61.2 + 21.3% for TMP. For SMZ, the mean t1/2,z was 2.0 + 0.3 hr, the Cmax was 30.7 + 2.5 micrograms/ml at tmax 3.0 + 1.0 hr, and F was 81.7 + 17.5%. Calculated pharmacokinetic parameters from this investigation were similar to values reported in horses. Based on these findings, metabolic scaling should not be employed to calculate the dose of TMP-SMZ in elephants.



a) Sulfadimethoxine/ormetoprim (Primor; 1200:100mg of sulfadimethoxine/200 mg ormetoprim): 16.2 18.5 mg/kg po BID on day 1 then 9.25 mg/kg thereafter. This regimen has been used for 30 days with positive therapeutic results and no adverse effects. For more severe infections: 23.2 26.4 mg/kg po BID on day 1 then 13.2 mg/kg thereafter.  Diarrhea may result at the higher dose but will resolve with the discontinuation of treatment (Schmidt,1986).

Elephant References:

a) Schmidt, M.J: Senior Research Veterinarian, Washington Park Zoo, Portland, Oregon, personal communication, 1986. In: Olsen,J.H., 1999. Antibiotic therapy in elephants. In: Fowler,M.E. and Miller R.E. (Editors), Zoo and Wild Animal Medicine: Current Therapy 4. W.B. Saunders, Philadelphia, PA,USA p. 537. [B23.77.w12]. 

Lagomorphs - Oryctolagus cuniculus domesticus - Domestic rabbit:

  • Trimethoprim/sulphadiazine 48 mg/kg subcutaneously every 24 hours. (B373.Guide.w41, B603.5.w5)
  • Sulfadimethoxine10 - 15 mg/kg orally every 12 hours. (B548.w8)
  • Sulfamethazine 1 mg per mL of drinking water (B548.w8)
  • Sulfaquinoxaline 1 mg/mL drinking water or 0.6 g per kg feed. (B548.w8)
  • Trimethoprim /sulphadiazine 30 mg/kg orally twice daily or 48 mg/kg subcutaneously. As an antibiotic. (B600.4.w4)
  • Trimethoprim/sulfamethoxazole 40 mg/kg orally twice daily for seven days. As an antibiotic or as a coccidiostat. Note ""Co-trimoxazole" human formulation is available as a human paediatric syrup. (B600.4.w4)
  • Trimethoprim/sulphamethoxazole 30 mg/kg orally every 12 hours. (B603.5.w5)
  • Silver sulphadiazine topically as required (e.g. on abscesses following marsupialization). (B603.5.w5)
  • Note: Broad-spectrum including against some anaerobes, and bactericidal in combination with trimeoprim. However, they are inactivated in the presence of exudate and debris, which limits their use in the treatment of established abscesses. (B603.5.w5)
  • Sulphadimidine 100 mg/kg orally every 24 hours or 100 - 233 mg per litre of drinking water. (B603.5.w5)
  • Trimethoprim sulphamethoxazole 30 mg/kg orally every 24 hours. (B603.5.w5)
  • Sulfadimethoxine 10 - 15 mg/kg orally every 12 hours. (B546)
  • Trimethoprim-sulfadiazine 30 mg/kg orally or subcutaneously every 24 hours. (B546)
  • Trimethoprim-sulfamethoxazole 40 mg/kg orally every 24 hours. (B546)
  • Sulphadimethoxine 75 - 100 mg/kg orally for seven days. Antibiotic. (B601.15.w15)
  • Sulfadimidine 100 - 233 mg per litre of drinking water. Antibiotic. (B601.15.w15)
  • Sulfamethazine 1,000 mg per litre of drinking water. Antibiotic. (B601.15.w15)
  • Sulfaquinoxaline 1,000 mg per litre of drinking water. Antibiotic. (B601.15.w15)
Coccidiosis treatment:
  • Sulfadimethoxine 50 mg/kg orally once followed by 25 mg/kg every 24 hours for 10 - 20 days. (B548.w8)
  • Sulphadimidine 100 - 233 mg/L of drinking water. For the treatment of coccidiosis infections. (B548.w8, B600.4.w4)
  • Sulfamerazine 100 mg/kg orally. (B548.w8)
  • Sulfamerazine 0.05 - 0.15% in drinking water. (B548.w8)
  • Sulfamethoxine 50 mg/kg orally then 25 mg/kg orally every 24 hours for 10 - 20 days. Note: diurnal variation in excretion and half-life, therefore administer in the evening, not in the morning. (B548.w8)
  • Sulfaquinoxaline 0.02 - 0.05% in drinking water. Can be given for prevention of coccidiosis. (B548.w8)
  • Sulfaquinoxaline 0.025 - 0.1% in drinking water. Alternating two week periods for four to eight weeks during weaning.(B548.w8)
  • Sulfaquinoxaline 0.04 - 0.15 in drinking water. (B548.w8)
  • Sulfaquinoxaline 0.1 - 0.15% in drinking water for the treatment of coccidiosis. (B548.w8)
  • Sulfaquinoxaline 1 mg/mL drinking water. (B548.w8)
  • Sulfaquinoxaline 0.025 - 0.03% in feed for four to six weeks. (B548.w8)
  • Sulfaquinoxaline 125 - 250 ppm in feed. (B548.w8)
  • Sulphaquinoxaline 1 - 3 mg/litre of drinking water. For the treatment of coccidiosis. (B603.5.w5)
  • Sulphadimethoxine 50 mg/kg orally once, followed by 25 mg/kg orally daily for 10 - 20 days. In the management of coccidiosis. 
  • Sulfamethazine 100 mg/kg orally every 24 hours. In the management of coccidiosis. (B601.15.w15)
  • Sulfamethazine 0.5 - 1.0% in feed. In the management of coccidiosis. (B601.15.w15)
  • Sulfamethazine 0.77g per litre of drinking water. In the management of coccidiosis. (B601.15.w15)
  • Sulfaquinoxaline 125 - 500 mg per kilogram feed for three to four weeks. (B601.15.w15)
  • Sulfaquinoxaline 0.04 - 0.1% in drinking water. In the management of coccidiosis. (B601.15.w15)
  • Sulphadimethoxine-ormethoprim 62.5 - 250 mg per kilogram of feed. In the management of coccidiosis. (B601.15.w15)
  • Sulfadimidine 100 - 233 mg per litre of drinking water. In the management of coccidiosis. (B600.4.w4, B601.15.w15)
  • Trimethoprim-sulfamethoxazole (Sulphonamides) 40 mg/kg orally every 12 hours. For the treatment of coccidiosis. (B601.15.w15)
  • Sulfadimethoxine 50 mg/kg orally once, then 25 mg/kg orally every 24 hours for 10 - 20 days. (B602.41.w41)
  • Sulfamerazine 100 mg/kg orally. (B602.41.w41)
  • Sulfaquinoxaline 1 mg/mL in drinking water. (B602.41.w41)

Ferrets - Mustela putorius furo - Ferret:

  • Sulfadimethoxine 30 - 50 mg/kg orally once or twice daily. May cause renal disease in geriatric ferrets. (B626.App.w22)
  • Sulfamethazine 1 mg/mL water. May cause renal disease in geriatric ferrets. (B626.App.w22)
  • Sulphadimethoxine 25 mg/kg orally, subcutaneously or intramuscularly once daily. (J213.3.w1)
  • For the treatment of coccidiosis: 
    • Sulfadimethoxine 50 mg/kg orally once, followed by 25 mg/kg every 24 hours (once a day) for nine days. (B602.41.w41, B626.App.w22, B631.21.w21, J213.3.w1)

Great Apes

  • Adult Pan troglodytes - Chimpanzee: Sulfamethoxazole/Trimethoprim 800 mg of the sulfamethoxazole orally twice daily or 15-20 mg/kg per day intravenously divided into two to four doses. (W768.Jun2012.w1)
  • Primates: Trimethoprim/sulphonamide 20 mg/kg orally four times daily for 14 days. In the treatment of Pneumocystic carinii infection.


  • Ormetoprim-sulfadimethoxine, 0.015% ormetoprim and 0.026% sulfadimethoxine in food continuously for three weeks. Treatment of coccidiosis. (B336.20.w20)
  • Trimethoprim-sulfamethoxazole 16-24 mg/kg (based on trimethoprim) orally every 12-24 hours. In the treatment of coccidiosis. (B336.20.w20)
Monitoring parameters --

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Withdrawal period / Withholding time
Notes Before the use of any pharmaceutical product in food-producing animals the label instructions for the product should be consulted regarding withdrawal requirements.

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Toxic Information

Toxic effects of Pharmaceutical Products
Contraindications / Precautions
  • Use with caution in individuals with pre-existing hepatic disease. (B263)
  • Contraindicated in individuals with known hypersensitivity to sulphonamides. (B201)
  • "The manufacturer states that trimethoprim/sulfadiazine should not be used in dogs or horses [the species it is licensed in] showing marked liver parenchymal damage, blood dyscrasias, or in those with a history of sulfonamide sensitivity." (B263)
  • Avoid using sulfadiazine in dogs known to have uroliths, at increased risk of developing uroliths, or known to have highly concentrated or acidic urine, due to the potential for this drug to crystallise in the urine. (B263)
  • In horses: concurrent use of sulphonamides and sedatives/anaesthetics contraindicated due to risk of sever cardiac arrhythmias and collapse. (B201.1.w1)
  • Cattle, horses: intravenous administration may cause sudden collapse. (B201.1.w1)


  • Horses: contraindicated in individuals with drug-induced cardiac arrhythmias. (B201.1.w1)
  • Dogs: contraindicated in dogs with keratoconjunctivitis sicca. (B201.1.w1)
  • Contraindicated in individuals with severe hepatic impairment. (B201.1.w1)
  • Contraindicated in individuals with blood dyscrasias. (B201.1.w1)
  • Oral administration contraindicated in calves with a functional rumen. (B201.1.w1)
Adverse Effects / Side Effects / Warnings
  • Intramuscular injection of sulphonamide sodium salts are irritant (due to their alkalinity). (B201.1.w1)
  • Acetylated derivatives of sulphonamides are relatively insoluble in acidic urine (i.e. urine of carnivores); they may precipitate in the renal tubules resulting in crystalluria and renal failure. This problem may be decreased by increasing urine volume or by increasing the pH of the urine. (B201.1.w1)
  • In dogs: 
    • Keratoconjunctivitis sicca (sometimes irreversible). (B263); from prolonged administration of some sulphonamides. (B201.1.w1)
    • Acute neutrophilic hepatitis (jaundice, vomiting, anorexia, diarrhoea, fever, haemolytic anaemia, urticaria, polyarthritis, facial swelling, polydipsia, polyuria, cholestasis). (B263)
    • Hypothyroidism (particularly with prolonged treatment. (B263) due to inhibition of thyroid hormone synthesis (subclinical, subnormal T4 concentrations, high plasma TSH); reversible when medication ceases. (B201.1.w1)
    • Acute hypersensitivity reactions (Type I i.e. anaphylaxis or Type III i.e. serum sickness. commoner in larger breeds and perhaps especially in Doberman Pinschers. (B263)
    • Rarely other haematological disorders (anaemias, agranulocytosis). (B263)
    • Rarely idiosyncratic moderate to massive hepatic necrosis. (B263)
    • Possible risk factor for the development of acute pancreatitis (cause-and-effect have not been shown). (B263)
    • Sulfadiazine: immune-mediated sterile polyarthritis (reversible). (B201.1.w1)
  • In cats:
    • Anorexia. (B263)
    • Leucopaenia. (B263)
    • Anaemias. (B263)
    • Drowsiness (sulfadiazine/trimethoprim). (B201.1.w1)
    • Salivation of coating of tablets is broken. (B201.1.w1)
  • In horses:
    • Intravenous administration may be followed by transient pruritis. (B263)
    • Oral administration may cause diarrhoea. (B263)
    • 48% injectable product: intramuscular or subcutaneous inoculation, or extravasation following intravenous inoculation, may result in swelling, pain and minor tissue damage. (B263)
    • Hypersensitivity reactions. (B263)
    • Haematological effects (anaemias, thrombocytopaenia, leucopaenias). (B263)
    • Periodic haematological monitoring is recommended during prolonged treatment. (B263)
  • In poultry: 
    • Petechial haemorrhages due to antagonism of vitamin K. (B201.1.w1)
    • Agranulocytosis and haemolytic anaemia due to vitamin K deficiency in prolonged therapy. (B201.1.w1)
  • Sulphonamides/sulphonamide metabolites, particularly if administered at high doses for long periods may precipitate in urine. (B263)
    • Risk of crystalluria, haematuria and renal tubule obstruction may be increased if the urine is acidic or highly concentrated. (B263)
  • Safety of use of trimethoprim/sulphonamides in pregnant animals has not been clearly established. (B263)


  • Occasionally skin erythema and petechiation, internal haemorrhage, haematuria, keratoconjunctivitis sicca. (B201.1.w1)
Operator Warnings Before the use of any pharmaceutical product the label instructions for the product should be consulted regarding operator safety/warnings.
Overdose / Acute Toxicity --

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Detailed Toxicological Information
Classification --
Acute Toxicity --
Chronic Toxicity --
Reproductive effects --
Teratogenic effects
  • In some studies on rats, reports of teratogenic effects: cleft palate. (B263)
  • In studies on dogs, no evidence of teratogenic effects. (B263)
Mutagenic effects --
Carcinogenic effects


Organ toxicity --
Bird Toxicity --
Aquatic organism activity --
Other organism toxicity --

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Nutrient Information

Nutritional Data
Biological Use  
Recommended Daily Allowance / Recommended level in food  
Stability in food (Storage time)  

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External / Environmental Information

External / Environmental Uses
Use --
Formulation --
Application method --
Application Concentration --
Persistence of Effect / Frequency of Application --

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Effects on the Environment
Effects in the aquatic environment


Effects on land --

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Persistence in the Environment
Breakdown in soil and groundwater


Breakdown in water --
Breakdown in vegetation --

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