Sulfa/Trimethoprim
“This page provides important general information for pet owners whose animals have been prescribed Sulfa/Trimethoprim in Perth during a consultation by Dr Noor.”
Key Information
Note: This handout is meant to address common questions. It does not include every detail that exists about this medicine. It also does not replace guidance from your veterinary care team.
- Sulfa/trimethoprim is an antibiotic medicine used to treat infections caused by bacteria.
- You may give this medicine either with food or on an empty stomach. If your pet’s stomach seems upset, giving it with food may help.
- If you are using a liquid form, shake the bottle well each time before you measure a dose.
- While your pet is taking this medicine, be sure they can drink plenty of clean, fresh water.
- Often-seen side effects include throwing up, loose stools, and eating less.
- This medicine may lead to “dry eye” (not enough tears). Call your veterinarian if you notice eye redness, discharge from the eyes, more blinking than usual, or squinting.
- Give all doses for the full time prescribed, even if your pet seems improved before the medicine is finished.
Description
- This is a combination antibiotic. It contains trimethoprim plus either sulfamethoxazole or sulfadiazine.
- It comes as tablets and as a liquid taken by mouth.
Other common names
- Bactrim
- SMZ-TMP
- Sulfatrim
Uses of Sulfa/Trimethoprim
FDA-approved uses in animals:
- Treatment of bacterial infections in dogs involving:
- the urinary tract
- lungs
- digestive tract
- surgery sites
- wounds
- abscesses
At your veterinarian’s judgment, this medicine may also be used in other animal types or for other purposes (this is called extra-label use), including:
- Treatment of urinary tract infections in cats.
- Treatment of protozoal infections in dogs and cats (protozoa are tiny organisms that can cause illness).
Before this medication is given
No medicine is completely safe for every patient. Talk with your veterinarian about:
- Any other medicines or supplements your pet is taking.
- Any health problems your pet has now, or has had before.
- Any unwanted reactions your pet has had to medicines in the past.
- The possible risks of using this medicine if your pet is pregnant or nursing.
Warnings for animals
Do not use in animals that:
- Are allergic to either of the two medicines in this product, or to other “sulfa” medicines.
- Have serious liver or kidney disease.
- Have blood-related disorders.
- Are dehydrated.
Use with caution in:
Doberman pinschers, Samoyeds, and miniature schnauzers.
Pets that have liver or kidney disease.
Pets that currently have, or previously had, kidney stones or bladder stones.
Pets with low vitamin B9 (folate) levels.
Pets that are pregnant or nursing.
Some animal sports or competitions do not allow certain medicines. If your animal competes, check the rules while your animal is taking any medication.
Warnings for humans
- Wash your hands after you handle any medication.
- If you are allergic to sulfonamide antibiotics or other sulfa medicines, wear gloves or do not handle this medication.
How do I give this medication?
- Give this medicine exactly the way your veterinarian prescribed it.
- Follow the directions on the prescription label every time.
- Give with or without food. If your pet gets an upset stomach, giving it with food may help.
- Shake liquid forms well before each dose.
- Use an oral syringe, a medicine cup, or a dosing spoon to measure liquids. Do not use kitchen spoons or other household measuring tools.
- Make sure your animal can drink plenty of fresh water while taking this medicine.
Side effects of Sulfa/Trimethoprim
Common – contact your veterinarian if any of these signs are severe, keep happening, or get worse over time:
- Throwing up, loose stools, or eating less.
- Drooling or extra saliva after giving the dose.
- Eye redness, eye discharge, more blinking, or squinting. These can be signs of dry eye syndrome (also called keratoconjunctivitis sicca, meaning the eyes do not make enough tears).
Severe – stop the medication and contact your veterinarian immediately if you notice any of these signs:
- Straining to urinate or blood in the urine.
- Skin problems such as sores, skin that looks burned, intense itching, or fur loss.
- Drinking more and urinating more.
- Swelling of the face.
- Yellow color of the gums or the whites of the eyes (jaundice).
How will I know it’s working?
- Your pet should begin to seem better within 1 to 2 days.
- Call your veterinary clinic if your pet’s signs get worse or do not get better.
How long will the medication effects last?
- This medicine will no longer work within 24 hours after the final dose.
- The effects may continue longer if your pet’s kidneys or liver do not work as well.
How long do I give it for?
- This medicine may be prescribed for different time periods.
- Keep giving it for the full length of time your veterinarian instructs.
- You may need another fill of the prescription.
- It is important to complete the entire treatment course, even if your pet seems improved.
Overdose
- Possible overdose signs include throwing up, loose stools, acting depressed, and swelling of the face.
- Too much of this medicine can harm the nervous system, the liver, and the blood.
If you see or think an overdose may have happened, contact your veterinarian right away or call an animal poison control service (a consultation fee applies):
- Have the product container or label available if you can.
Missed dose
In most situations, if you forget a dose:
- Give the dose as soon as you remember, and then go back to the usual schedule.
If it is almost time for the next dose:
Do not give the missed dose.
Give the next dose at the regular time.
Continue with the normal schedule.
If you are not sure what to do, call your veterinary clinic. Do not give two doses at once and do not give extra doses.
Storage
- Keep this medicine in its original container at room temperature.
- Keep it away from light.
- Store it where children and animals cannot reach it.
Disposal
- Do not flush this medicine in the toilet and do not pour it down a sink.
Ways to get rid of unused or expired medicine include:
Drug take-back locations: This is the best option when available. To find a nearby site, contact local law enforcement or your waste management office.
Home disposal: Combine the medicine with coffee grounds or kitty litter, put the mixture into a sealed plastic bag, and place it in the trash.
Do not keep leftover medicine and do not give it to anyone else to use.
Questions?
Speak with your veterinarian.
“Disclaimer: The information on this page is provided as general educational material only. Every animal’s health situation is unique, and treatment decisions must be based on a full veterinary assessment. Always follow the specific instructions given during your consultation, and contact the prescribing veterinarian if you have any concerns.”