5 Most Dangerous Side Effects of Pet Medicines

Pet medicines usually tend to have side effects that may be potentially harmful to your dog. Therefore, it is important to be aware of the possible side effects of such medicines. Following are some of the most dangerous side effects of pet medicines.

Gastrointestinal Side Effects

The long-term use of NSAIDs (such as acetaminophen, ibuprofen and aspirin) in dogs can cause ulcers in the gastrointestinal tract. NSAIDs are dog medicines that mainly help in relief from pain. If the dog shows symptoms such as vomiting, nausea, diarrhea and darkened stools or urine after the administration of NSAIDs, then the use of such medicines should be immediately discontinued. Overdose of NSAIDs also causes stomach punctures in dogs.

The prolonged use of antibiotics can also cause fatal gastrointestinal side effects in dogs. Pencillin is also known to cause gastrointestinal problems. Apart from vomiting and diarrhea, antibiotics such as Erythromycin, Clindamycin, Enrofloxacin and Rifampin damage the gastrointestinal tract.

Certain pet flea medicines, if ingested by the dog, may cause irritation to the gastrointestinal tract in addition to other side effects such as skin irritation and excessive drooling.

Side Effects on Kidneys

NSAIDs should not be administered in dogs with kidney diseases. NSAIDs such as aspirin also affect the dog's kidneys. Over dosage of aspirin can lead to seizures, coma and even death due to salicylate poisoning. One of the harmful side effects of aminoglycosides and sulpha medicines is kidney damage. Injecting Neomycin and Gentamycin can also damage the pet's kidneys.

Side Effects on Liver

There are reports on dogs being affected by acute fulminant hepatic necrosis due to the overdose of Mebendazole. The clinical signs are depression, anorexia and hemorrhagic diarrhea. Prolonged use of Sulpha medications can also damage the liver.

Side Effects on Heart

NSAIDs relieve arthritic pain in the joints of dogs by inhibiting the production of prostaglandins. However, the over usage can lead to poisoning of the dog, leading to heart failure.


Overdose of Dexamethasone and Prednisolone causes hyperadrenocorticism (Cushing's disease) in dogs. These drugs suppress the immune system and are used to treat autoimmune diseases. The clinical signs to look for are increased appetite, increase in water consumption, excessive hair loss, thinning of skin and a "pot-bellied" appearance.

Some NSAIDs such as Deracoxib and Etodolac adversely affect the stomach, liver and kidneys together. The simultaneous administration of different types of medication, especially NSAIDs, should be done under expert advice only. This is because the prolonged usage of such drugs can lead to long-term complications in the animal and even death. Therefore, it is very important to take the advice of a veterinarian before administering any kind of medication to your dog. At present, a lot of herbal formulations have been introduced in the market, and most of these medicines claim to have no side effects.