What are Antibiotics Allergies?
A variety of different antibiotics are prescribed to treat bacterial infection in dogs. These drugs either kill bacteria outright (bactericidal) or they make it more difficult for the bacteria to grow and reproduce (bacteriostatic). Some antibiotics are broad-spectrum, meaning they are effective for a variety of different diseases, while others are narrow-spectrum since they mainly target one type of bacteria or infection. Antibiotics fall into different classes, based on their chemical structure and the mechanism with which they target bacteria. The most common and well known are the beta-lactam antibiotics, like penicillin, which prevent bacteria from forming a cell wall. Other classes of antibiotics can affect DNA synthesis or the production of necessary proteins in certain bacteria.
Any drug has the potential for side-effects or allergic reaction. Side-effects refer to the negative effects the drug may have on the body, while allergic reaction describes an immune system response that targets the medication as a threat. While side-effects will be present to a greater or lesser degree in any dog taking the drug, allergic reactions are based on individual sensitivity to a specific medication. Unfortunately, antibiotics cause more allergic responses in dogs than any other group of drugs. Most symptoms are typical of other histamine producing allergies; dogs may develop an itchy rash, and watery eyes or nose. Swelling of the face or even the respiratory tract is possible. In rare cases, dogs can have a severe, life-threatening reaction called anaphylactic shock. This can cause collapse, difficulty breathing and even death.
Most owners won’t be aware of an allergic response until the antibiotic is prescribed to their dog. This is why it is important to watch dogs carefully anytime a new medication is started and get immediate treatment for symptoms that appear unusual or severe. All previous allergic reactions should be communicated to the veterinarian before an antibiotic is prescribed. If your dog has an allergic response to one antibiotic, it’s likely that he will experience a similar problem with other medications in the same class.
Antibiotics help to eliminate harmful bacteria and are some of the most important medications for dogs, however they are also one of the most common causes of allergic drug reaction. Symptoms range from mild rash and watery eyes, to rare, but life-threatening, anaphylaxis.
Symptoms of Antibiotics Allergies in Dogs
Look for these symptoms if your dog is taking an antibiotic for the first time.
- Rash (maculopapular lesions)
- Redness (erythroderma)
- Other types of skin lesion (blisters or scaling skin)
- Itchiness (pruritus)
- Incessant scratching
- Watery eyes
- Runny nose
- Swelling and hives (uticaria-angiodema)
- Purple rash caused by bleeding into the dermal tissue (purpura)
- Anaphylactic shock which is rare (vomiting, diarrhea, difficulty breathing, collapse, death)
Types
There are too many antibiotic classes to list them all. Following are some common types that could be prescribed to your dog. Penicillins and sulfonamides have the highest rates of allergic reaction.
- Beta-lactam antibiotics – group of bactericidal drugs that inhibit the formation of the cell wall including penicillin, cephalosporins, and cephamycins
- Sulfonamides (sulfa drugs) – a group of bacteriostatic drugs, one of the most common antibacterial agents prescribed to dogs because their low cost and relative effectiveness in treating typical bacterial infections; examples are sulfadiazine, sulfadimethoxine, and succinylsulfathiazole
- Tetracyclines – broad-spectrum bacteriostatic agents that get their name because of their chemical structure with four rings; Oxytetracycline, Minocycline, and Doxycycline are some examples used in dogs
- Quinolones and Fluoroquinolones – a group of bactericidal antibiotics that interfere with the bacteria’s ability to make DNA; some examples are ciprofloxacin, danofloxacin and difloxacin
- Aminoglycosides – this is a group bactericidal antibiotics that stops the production of necessary proteins in the bacteria, Gentamicin and Amikacin are two examples used in dogs
- Macrolides – bacteriostatic antibiotics that inhibit the production of bacterial protein; Azithromycin is the main example used in dogs
Causes of Antibiotics Allergies in Dogs
These are some causes and risk factors for antibiotics allergies.
- New antibiotic prescribed to your dog
- Dog develops a new allergy
- General tendency toward allergic reactions
Diagnosis of Antibiotics Allergies in Dogs
Antibiotic allergies are typically diagnosed because owners notice an unusual response when their dog begins a new medication. Rarely, dogs could also develop a new allergy to an antibiotic which previously didn’t cause a problem. There isn’t any way to test for an antibiotics allergy without actually giving the drug to your dog.
You should call the veterinarian if you see abnormal symptoms in your dog, especially when these correspond with the start of a new mediation. The veterinarian will be able to tell you if this is a typical side-effect, part of the original infection, or a more dangerous response. Life-threatening symptoms like collapse or difficulty breathing should be treated as an emergency.
Treatment of Antibiotics Allergies in Dogs
With any drug reaction, the first important treatment is to stop taking the medication. If the reaction was mild, your dog’s symptoms will likely clear up on their own and no further treatment will be necessary. However the veterinarian may still need to prescribe another antibiotic to treat the original infection.
Creams and topical ointments may be necessary for severe rashes and skin infections. This can help them heal and reduce the chances of further infection. Affected areas may need to be clipped of hair and covered with a bandage. Antihistamines or corticosteroids could be given to reduce symptoms and make your dog more comfortable.
Anaphylactic shock will need more aggressive treatment. Immediate epinephrine injection can reduce life-threatening symptoms. Additional oxygen, intravenous fluids, blood transfusions and other emergency measure could also be necessary.
If symptoms continue after the antibiotic is discontinued, this suggests the allergic reaction was likely related to another trigger. You should discuss this with the veterinarian and research other possible causes.
Recovery of Antibiotics Allergies in Dogs
Most dogs recover from an allergic reactions to antibiotics. Life-threatening symptoms are rare, and even anaphylactic shock can be treated as long as your dog gets emergency care in time. Your dog will likely have the allergy for life, however, so this will need to be managed. Any new veterinarian should be informed of all your dog’s known allergies. Discuss side-effects and the possibility of an allergic reaction anytime a new medication is prescribed, so you know what symptoms to watch for in your dog. If your dog has had an anaphylactic reaction to medications or other triggers, ask the veterinarian about getting a dog Epipen so that you have something on hand to use in case of another crisis.
Antibiotics Allergies Questions and Advice from Veterinary Professionals
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I took my one year old dog to the vet due to diarrhea, her not wanting to move, and just acting completely out of character. She had a fever of 105 and a high white cell count. They ran tests & they said she had an infection, but wasn’t sure of a definitive one. They prescribed doxycycline, rimadyl, and carafate.. She weighs 87 pounds & they said to give her the carafate to help coat her stomach, then to wait 30 minutes and give her two doxy with food twice a day; 1&1/2 rimadyl once a day. Which to me seemed like a lot! But I have listened. However; today is day 3 and she is developing a wheeze and cough and over all trouble breathing that didn’t start until after we started the medicine & seems to get worse after doses... She is beyond lethargic. I am very concerned & im not sure if this is part of an allergic reaction to something or not.. I am not sure what to do next or think. Any advice?
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My dog has breathing problems when she took Doxy, but because nothing else was stopping the infection (high white count) my vet said she had to take the doxy for a month or else. I stopped the Doxy after 27 days because she was lethargic, confused, and breathing was hard and rapid. How long will the drug stay in her system?
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My dog wa prescribed cephalexin for a UTI. After about day 6 of her 10 day dosing her tongue swelled up.. took her to the vet got a steroid shot and Benadryl.. could it be an allergic reaction to the antibiotics? I looked around the house and yard nothing looked like she got into anything.. no other symptoms.. nothing on her mouth to show a sign of anything getting her. Vet wasn’t sure what caused it.., could it have been the antibiotics??
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my 18 yr old doxy has sores, look like skin peeled away, raw, a few circular with scab. both ears. started after 3 pills of cephalexin. Been off drug 2 weeks. My vet gave steroid cream yesterday. Also bun is 90, albumin and t. protein slightly low. Looks painful.
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I think my dog has had a severe allergic reaction to amoxicillin. After two doses, I immediately stopped treatment and began giving him Benadryl. He seems to have almost all symptoms except the anaphylactic shock. He's face, nose, and stomach swole. Difficultly breathing, walking, lethargy, no interest in water, etc. I have given him Benadryl regularly for 2 days and can tell when it wears off because the swelling, stumbling, and difficulty breathing returns. However, I'm beginning to wonder if it's something else because of the time. How long does an allergic reaction to medication last in a dog?
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Antibiotics stay in the body for a while (some antibiotic residues can be found weeks after administration which is important in farm animals destined for human consumption); the half life is around 0.39 hours which means the levels of the dose will taper off over time and for however long it is still in Willy’s system the reaction may occur. In any situation where there has been a reaction to a prescribed medicine you must visit your Veterinarian. Regards Dr Callum Turner DVM
I HAVE A LONG-HAIR CHIHUAHUA/JAPANESE CHIN MIX, HE IS ALMOST 13 YRS OLD AND WEIGHS ABOUT 5.5 LBS. THE VET PRESCRIBED CLINDROPS FOR HIM TO TAKE DAILY. HE HAS DEVELOPED SEVERE DECAY IN HIS MOUTH & WILL NEED ALMOST ALL OF HIS TEETH PULLED. HE TOLD ME TO GIVE MY DOG THESE DROPS DAILY UNTIL THE PROCEDURE. MY DOG SMELLED IT AND STARTED SHAKING HIS HEAD FIERCE & BACKING UP. I HAD TO HOLD HIM WHILE MY DAUGHTER TRIED TO PUT THE DROPS IN...WE ONLY GOT 1/2 THE DROPPER IN, HE NEEDED 1 FULL DROPPER. AFTERWARDS, HE WAS OK BUT ACTED OUT, KIND OF LIKE HE WAS UPSET. IS THIS NORMAL?
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My little dog was put on clavubactin and carprofen last wed.i started to notice itching i gave a flea treatment but then i noticed a red raw rash appear on tummy vhest and an a sore under his tail i feel it is an allergic reavtion to medication i stopped it todayand am tteeating it with diluted quit itch lotion
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I think they prescribed to high a dose and slowly have been killing off his red cells from what i read.how can we try to help him produce more cells? I dont have money for transfussions and ultrasounds.they told me he would die within 24 hours but he is improving from water with honey and boiled chicken broth and some raw egg.he was totatly out of it at the vet but now seems stable and has some color in his gums.
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My 4 week old puppy had an allergic reaction due to a mix of sulfa drugs and now he his a swollen lymph node in 1his neck thats getting bigger. Pill Septra, injection Sulfadiazine, Trimethoprim and Tylosin. How can i treat this node, please?
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My dogs a cocker spaniel and a Yorkshire terrier that both are itching constantly can’t afford to go to vet right now what can I do to relieve there itching? I have been giving baths with oatmeal in the shampoo helps a little but I need something else. Please help me.
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I just adopted a 13 week old hound mix. I originally took her to the vet today due to an infection at an incision site on her stomach. They vet prescribed Clavamox. After two doses, I noticed a large area on her stomach of white bumps that were surrounded by red irritated skin. Also, she has a runny nose. The strange thing is she continues to act like her normal self: happy, playful, eating, drinking water, peeing and pooping. I'm lost at what options I have?
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my dog a has an ear infection- this has been on and off since July. I took him to our vet and got prescription We are on our third bottle of prescription and doesn't seem to be working. It's been 7 days since the last set of prescription and doesn't seem to be helping. last night I put the drops in his ear and he screamed jump off my lap seemed weak and ran outside where he vomit. After throwing up he came back in inside and lay down. I watched him all night and he seemed comfortable. I don't know what to do but the meds doesn't seem to be helping him. Should I take him to see another vet?
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Hello. My chihuahua was rushed to the emergency vet sunday night with an abcess tooth. The emergency vet said they are not equipped for dental procedures and only gave her tramadol and clindrops and said to talk to my primary vet when they open Wednesday because of the holiday. Well tonight her skin is turning pink and she's been vomiting. I think the medication may be giving her an allergic reaction. She is my baby of 14 years and I'm so worried about her. Any suggestions at all would be so greatly appreciated.
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Skin rashes are a possible adverse reaction from administration with clindamycin; in these instances it is best to stop treatment and to return to your prescribing Veterinarian or Emergency Veterinarian. If there is just a skin rash and vomiting, keep a close eye on her and take her to your Veterinarian in the morning; if the reaction gets more severe or you have concerns, visit an Emergency Veterinarian. Regards Dr Callum Turner DVM
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How long will it take for dog to have reaction after taking a new med . She can't breath fabulous anyways so i can't tell if it meds or her. All of the symptoms for allergic reactions she usually has anyways
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There is no real set reaction time, animals (like people) may have a reaction to a medicine (or any allergen) within minutes or after a few hours. If you have some concerns regarding some medications, you can either keep a close eye on her for the first few hours after administration counting her respiratory rate (get a count before the first dose) or ask your Veterinarian to monitor her for the first day. Normally, if there is no history of drug reactions, there shouldn’t be anything to be concerned about but it wouldn’t hurt to keep a close eye on her. Regards Dr Callum Turner DVM
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Possible allergic reaction to antibiotics, red inflamed lump to the right of his nose , breed is a male pug, not sure if it is irritating him but will not let me clean it , I have managed to clean it but worried as to what it might be . He has had 3 doses over 3 days taken with food.
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Has Billy taken any antibiotics? Antibiotic allergies usually present as generalised irritation, swelling, itching, watery eyes, hives or severe reactions (vomiting, diarrhoea, respiratory failure). Meloxicam is a non-steroidal anti-inflammatory drug. An inflamed lump may be caused by an insect bite, trauma, allergies or chemical irritation. It would be best to have your Veterinarian take a look at it as different causes require different treatment. Regards Dr Callum Turner DVM
My sweet Iill dog had a severe allergic reaction only 10 mins after taking an antibiotic shot to help cure a fungle infection on his skin. This happened last night. His reaction started with rubbing on his eyes while screaming, dizziness and loss of control on his bladder, he also defecated, and vomited his stomach empty. Once out of the car he started having episodes of violont head shakes while spraying huge amounts of Silvia. These episodes happened more than 8 times during the short period it took us to take him to the ER. His skin become bloody red all over his body, his temperature very high.
He was hooked on an IV and given a shot to rule out suffocating and took lots of tests. We still do not know how he's doing but we are hoping for the best. 😢
An allergic reaction could be very scary and extremely painful for dogs. It could mean their life if you do not act quickly. It is no joke.
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