Zinc Oxide Topical Poisoning in Dogs

Zinc is a mineral that is required within all animals in humans. Zinc oxide is found in many dog foods as well. Zinc oxide poisoning occurs when a dog ingests a high amount of this compound. This compound is found in many items around the home, such as diaper rash ointments, dental cements, bandages that are medicated, and it is also combined with other substances in various medications, such as vitamin A and E.

Zinc oxide is also used as an astringent, as it has bacteria-fighting properties. The specific mineral of zinc can be found in a variety of coins, such as pennies after 1982, and metal objects, including bolts, nuts, zippers, and other objects that have a high level of zinc. Of course, zinc is an ingredient in popular skin creams as well. Zinc oxide toxicity is dependent upon the amount of zinc ingested and the overall size of the dog. It also depends on the actual substance that was consumed; zinc oxide cream is combined with other ingredients and, fortunately, is not a form of pure zinc, unlike metal items.

Zinc oxide topical poisoning in dogs is a result of dogs ingesting zinc oxide ointments, commonly used in sunscreens, diaper rash ointments, and other ointments for topical medications.

If your dog has ingested zinc oxide cream or zinc in the pure form, he will begin to develop symptoms rapidly. The most common symptom is vomiting. Other symptoms that may occur are:

• Weakness
• Lethargy
• Anemia
• Rapid breathing
• Tachycardia
• Arrhythmia
• Discolored or highly concentrated urine
• Jaundiced in the gums
• Loss of appetite
• Seizures

Types

Many ointments that contain zinc oxide are combined with other ingredients. Although they are combined with other ingredients, it is important to know the percentage of the compound to the other components in the ointment. These other ingredients may cause a laxative effect. Types of ingredients that are commonly used with zinc oxide include:

• Vitamin A
• Vitamin D
• Vitamin E
• Cod liver oil
• Petrolatum
• Lanolin
• Mineral oil
• Dimethicone
• Butylated hydroxyanisole
• Methylparaben

The precise cause of zinc oxide poisoning due to the ingestion of this compound is still being researched. Possible causes of zinc oxide poisoning in dogs may include:

• Negatively affects the pancreas, liver, and kidneys
• Negatively affects the red blood cells
• Promotes oxidative damage
• Inhibits red blood cell enzymes

Zinc oxide toxicities can be quite difficult to diagnose, this is why it is highly helpful for the veterinarian if you suspect or have witnessed your dog ingesting a cream containing zinc oxide or a penny or other metal object that contains a high amount of zinc. If your dog has self-vomited, or if the veterinarian induced vomiting, there will be evidence of the ointment in the substance.

Your veterinarian will depend on the dog’s clinical signs and any information you can give him in terms of the ingestion of this compound or mineral. In addition to observing the clinical signs of toxicity, the veterinarian will do a complete physical examination, which includes blood testing to check for anemia and the zinc level in the blood. Any liver or kidney damage can also be tested with bloodwork and a biochemistry profile.

A urinalysis will communicate to the veterinarian any red blood cell pigmentation, which may be a sign for higher levels of zinc. The urinalysis will also allow the veterinarian to check for any kidney or liver damage. If you highly suspect or are sure that your dog ingested an object, the veterinarian may do an x-ray to determine if the dog has swallowed a metal object or pieces of the tube that contained the cream.

The veterinarian may advise you, the owner, to induce vomiting before the dog is brought in for treatment. The veterinarian will explain to you the process of doing so. After emesis, activated charcoal is not usually given with zinc, as it does not bind to metals and is not effective. Once your dog has been diagnosed, treatment may include:

IV fluids

Intravenous fluids will be given to the dog to support the kidney function and to keep the animal hydrated. This method will also restore the electrolytes, and help with the extraction of urine through the kidneys.

Blood transfusion

If your dog is suffering from anemia due to the toxic zinc, the veterinarian may choose to administer a blood transfusion. This procedure will strengthen the blood by restoring the iron, hemoglobin, and red blood cells.

Endoscopy

If the dog has ingested a zinc-containing item, or if parts of the tube from the cream are within the dog, the veterinarian will perform an endoscopy to remove the object

Medications

In order to protect the gastrointestinal tract, medications may be given to stabilize the area. Medications to stop vomiting may also be given if your dog is continuing to vomit. Medications may also be given to treat any occurring seizures and to stabilize the heart rate.

If the dog received immediate treatment, the ingestion of zinc oxide is typically not fatal. If your dog has responded to treatment and you are able to take him home, the veterinarian will give you specific instructions on how to care for him. The veterinarian may prescribe a diet, depending on the treatment plan.

The veterinarian will also want to have follow-up visits to ensure that he is recovering properly. In addition to these visits, the veterinarian will communicate with you as to what to watch for in terms of symptoms that may develop. Careful monitoring of your dog is very important after treatment, and if you have any questions or concerns do not hesitate to contact your physician.