(by Andres Rojas)


Whether they are lurking in the park or sneaking around your house, pet parasites represent a serious health risk for both dogs and cats.


While the effects of a parasite infestation on your pet health can range from having an itchy skin to a life-threatening condition, the good news is that you can nurse your dog or cat back to normal with some over-the-counter parasite treatments.

See what Dr. Jeff Werber recommends, at the end of this article. First, let's understand what we're dealing with, and what we can expect.

Internal Parasite Types

Internal or intestinal parasites are organisms that are found mostly in an animal’s gastrointestinal tract. Left to their own devices, parasites can compromise a pet’s immune system or cause a serious case of anemia.

Some common internal parasites that you need to watch out for include:


The good news is that all of these common pet parasites are treatable. However, as Dr. Jeff  points out, medication isn’t always a straightforward solution:

“There are some issues with hookworms that are now becoming resistant to most of the typical medications that we've used in the past.”

Please note: although hookworms medication is already approved to treat pet parasites for cats, it hasn’t been tested to treat parasites for dogs yet. So make sure you check with your veterinarian for the best solution.

External Parasite Types

Although less dangerous than intestinal ones, external parasites can still make your dog’s or cat’s life a living hell. Some of the most common external parasites include:

As a pet owner and animal care professional, Dr. Jeff has first-hand experience with many common dog parasites and has found some of the available treatment options lacking:

“A lot of the older over-the-counter products – especially with the active ingredients of Fipronil and Imidacloprid – are no longer as effective. The Ivermectin/Selamectin products are still pretty effective – especially for air mites and mange mites.”

Treatment Options: ‘Newer Treatments Offer Better Results”

Since some common dog parasites are developing resistance to older products, Dr. Werbs recommends using Isoxazoline flea and tick products such as:


Isoxazolines are highly effective against external parasites. Still, there are some potential side effects you should be aware of:

“There are some concerns about safety issues about the seizures that were implicated in animals that already had some underlying seizure disorder. So I still think they are very safe and effective.”

Safety First and Foremost

Although common cat parasites mostly inhabit our furry companions and not us, there are always exceptions to the rule – children in particular. As Dr. Jeff explains:

“Since many of these parasites are contagious to other dogs and some even potentially to people (zoonotic) one needs to get some answers as far as diagnostics and be very careful on how you handle animals with these parasites – especially when it comes to some of the intestinal parasites.”

Take Steps to Protect Yourself While Treating Your Pet

Although the chances of getting Giardia or another pet parasite from your dog or cat are small, the CDC advises pet parents to keep minimum contact with their dogs and cats and to take these steps:

  1. Wear rubber gloves when touching their pets or anything they come in contact with – toys, beds, blankets, etc.
  2. Clean and disinfect their living spaces regularly – change cat litter boxes every day.
  3. Contact their veterinarian as soon as possible.

Dealing with pet parasites can be a stressful and expensive process. 

Get free advice from the doctor himself, through Weekly Instagram AMAs (@werbs_dvm) or call 424-835-0576, and leave a message. For emergencies, download Dr. Jeff Werber’s app Airvet, a video-chat option for veterinary needs at any time of day or night!