Pets can experience side effects from medication like human. Depending on several factors, these reactions can vary from mild to severe.
It's important to talk with your veterinarian about the risks and benefits of any medication. If you notice any side effects in your pet, contact your veterinarian promptly to discuss the appropriate action.
Typical Side Effects Of Pet Medications
Like people, pets can have side effects from medications. These side effects can depend from mild to severe, depending the type of medication and the pet's health and age.
Gastrointestinal Upset
Mild stomach upset is a common side effect of pet medications, particularly those taken orally and absorbed in the gastrointestinal tract. Symptoms can include vomiting, diarrhea, and a lack of appetite. These may resolve as the pet adjusts to the medication. Always consult your veterinarian about whether the medication should be given with food.
Medications that often cause stomach upset include:
- Antibiotics: Consider probiotics to prevent diarrhea, vomiting, and appetite issues.
- Levothyroxine: Used for hypothyroidism in dogs.
- Methimazole: Used for hyperthyroidism in cats.
- Steroids: Such as prednisone and prednisolone.
- Blood pressure medications.
- Gabapentin: Particularly in cats.
- Oral and topical flea and tick medications.
Excessive Salivation
Some medications cause hypersalivation due to their bitter taste. For example, tramadol, a pain medication, should not be crushed as it can worsen the taste. Antibiotics, steroids, and antihistamines can cause dry mouth, triggering excessive saliva production.
Stomach Ulcers
Nonsteroidal anti-inflammatory drugs (NSAIDs) like carprofen, deracoxib, meloxicam, and robenacoxib, as well as steroids like prednisone and prednisolone, can increase the risk of gastrointestinal ulcers. Symptoms include vomiting, diarrhea, and dark, tarry stools. These medications should never be given together due to the increased risk of ulcers. Treatment typically involves medications to protect the gastrointestinal lining and reduce stomach acid.
Lumps And Bumps
Injectable medications can cause lumps at the injection site. These usually disappear as the drug is absorbed into the body.
Skin Irritation
Medications can cause skin irritation, leading to hair loss, itchiness, redness, and blisters. Skin reactions can vary from mild to severe and may cause intense licking or chewing, worsening the condition.
Liver Or Kidney Damage
Medications processed by the liver and kidneys can potentially cause damage. Symptoms include increased thirst and urination, vomiting, yellowing of the skin or eyes, and lethargy. NSAIDs and steroids are commonly associated with liver and kidney issues, particularly with long-term use or if pre-existing conditions are present.
Lethargy Or Behavioral Changes
Medications affecting the brain can cause changes in behavior. This can be an intended effect, such as with anti-anxiety medications, or an unintended side effect, like restlessness or hyperactivity. Medications such as metronidazole, antihistamines, levothyroxine, steroids, blood pressure medications, insulin, and flea and tick medications can cause these changes.
Always consult your veterinarian if you notice any side effects in your pet. They can guide you in managing these reactions and ensuring your pet's well-being.
Uncommon Side Effects Of Pet Medications
If your dog shows any of the rare side effects listed below, seek veterinary care immediately, as these conditions can be life-threatening. Often, the risks of these side effects outweigh the benefits of the medication.
Severe Allergic Reaction
Anaphylaxis, a severe allergic reaction, is one of the most alarming side effects pets can have from medications. It can occur with any drug if the pet's immune system reacts. Anaphylaxis can be deadly and may happen the first time a medication is given (acute) or after multiple doses (delayed).
In most pets, anaphylaxis affects the lungs and airways, leading to difficulty breathing. In dogs, it often causes the gastrointestinal system to release histamine into the liver, resulting in symptoms such as vomiting, diarrhea, and elevated liver enzymes.
Blood Disorders
In rare cases, medications can cause blood disorders like low platelets (thrombocytopenia) or low red blood cells (anemia), leading to spontaneous bleeding. Antibiotics can sometimes trigger low platelet disorders, causing hemorrhaging or bruising, which can be fatal if not treated promptly. Methimazole in cats is also occasionally linked to blood disorders.
Neurologic Issues
Certain medications can lead to seizures, tremors, and loss of coordination. These include:
- Antibiotics
- Anti-anxiety medications
- Flea and tick medications (e.g., Bravecto, NexGard, Simparica, Revolution Plus, Credelio)
- Insulin
- Chemotherapy drugs
These side effects can be dose-related or unpredictable. Unlike toxin-induced seizures, those related to antibiotics often respond well to anti-seizure treatments.
Difficulty Standing/Walking And Collapse
Some medications can affect the cardiovascular system, altering blood pressure and heart rhythms and leading to severe consequences like collapse. Blood pressure medications and certain flea and tick treatments are known to cause these issues.
Breed-Related Reactions to Parasite Medication
Herding breeds like Collies, Australian Shepherds, Shetland Sheepdogs, and English Sheepdogs may have a gene mutation that makes them particularly sensitive to certain parasite medications, like ivermectin or moxidectin. Genetic testing can identify at-risk dogs.
While the doses of ivermectin or moxidectin in heartworm preventatives are generally safe for all breeds, high doses can cause severe and potentially fatal side effects, including dilated pupils, tremors, mental dullness, drooling, vomiting, unsteadiness, blindness, seizures, coma, and death.
Critical Side Effects Of Pet Medications: What To Watch For
If your pet shows any side effects, whether mild or severe, consult your veterinarian before making any changes to the medication. It's necessary to discuss potential side effects with your vet when starting any new medication.
Ask your veterinarian about specific adverse reactions to watch for. If you notice any of these signs, contact your vet immediately. Do not discontinue the medication unless instructed by your veterinarian.
If you have severe symptoms, take your pet to an emergency clinic or vet immediately to prevent life-threatening consequences. In cases of significant side effects, your vet will likely recommend stopping the medication right away to see if symptoms improve. Serious symptoms include:
- Seizures
- Difficulty breathing
- Collapse
- Lethargy or weakness
- Unexplained bleeding or bruising
- Anaphylaxis
- Yellowing of the skin, mouth or eyes
- Blood in the stool, tarry stool or dark
- Blood in the vomit
- Loss of appetite
For mild side effects, like stomach upset, your vet may help you create a new treatment plan over the phone. If mild symptoms persist for more than 24 hours, have your pet examined by a vet.
Some medications should not be stopped abruptly in less severe cases. Your veterinarian will determine the safest plan, often involving gradually tapering off the medication to prevent additional side effects.
Side Effects Or Accidental Overdose Of Pet Medications?
Your pet may be experiencing side effects from a prescribed medication or have accidentally received more than the recommended dose. This can happen if multiple family members unknowingly administer the medication or if you forget and give an extra dose. Additionally, your pet might access the medication container on their own.
Monitoring your pet's reactions to medication is crucial. Contact your veterinarian immediately if you have any concerns or notice severe symptoms. In mild cases, treatment is possible, but depending on the medication and the amount ingested, an overdose can lead to severe illness or even death.
