External parasites (living on the outside of the body) are not just a nuisance for your pet and your family: These pests carry disease that can harm both humans and pets, they stimulate allergies and contribute to skin and ear infections.

Pets with external parasites tend to be itchy. Some external parasites can be seen with the naked eye (e.g.: fleas, ticks), however, others require a microscope to find.

Common external parasites that infect dogs and cats include:

  • TicksTicks represent an important cause of disease transmission.
  • FleasWhen a single flea is found, this represents a mere 1% of the entire problem: the other 99% includes their eggs and larvae that are developing in your carpets and bedding.
  • Cheyletiellia: A mite infection also known as walking dandruff.
  • Lice: Appearance similar to dandruff. Lice on your pets are not contagious to people and vice versa.
  • Ear mitesThese microscopic mites inhabit the surface of the ear canal and surrounding facial skin.
  • Scabies (or sarcoptic mange)Highly contagious infection caused by a microscopic mite. Scabies causes intense itching and can be transmitted to people.

Fortunately, living in Colorado we don’t have a lot of external parasites. Mostly ticks in the spring and fall and a few fleas in late summer.  However, with the large amount of May rain and now the very hot weather it is prime time for fleas to get out of control.

Fleas love hot humid places and, while we are not as humid as many states, right now conditions are perfect for fleas to multiply rapidly. We generally see flea infestations in areas where there are a lot of rabbits and prairie dogs. The fleas, and flea eggs, drop off of the rabbits and hatch in the warm humid grass. If your pet enjoys sitting outside in the yard and you have a multitude of rabbits in your area your pet is at higher risk of getting fleas.

So, what can you do?

At Harmony we recognize the need to be safe with flea and tick products. We advise not using anything that is permethrin, organophosphate, or DEET based. These types of chemicals are highly effective at killing fleas and ticks but are also highly carcinogenic.  Be careful there is a new Heartworm prevention being heavily advertise on TV that says it will also kill fleas and ticks. The main killing agent is permethrin, we do not recommend using this product.

Lemongrass, citronella and neem essential oils in dilute concentrations are good natural preventatives for both dogs and cats. A word of caution, not all essential oils are safe for cats and dogs, check the label carefully and when in doubt ask one of the veterinarians at Harmony.

Dr. Jean Hofve, holistic veterinarian and personal friend of Harmony Vet, has helped develop Herbal Defense Flea and Tick Spray for dogs and cats. We also recommend Vetri-Repel Spray or Wipes for cats and dogs. These two-essential oil-based repellents do a pretty good job at keeping fleas and ticks off of your dog or cat. We also recommend the very basic tick check, every time after every walk and using a flea comb regularly.

When you have an infestation, however, repellents just don’t have the kill factor you need to make your pet, and yourself comfortable or safe. Our veterinarians recognize the limited use of products like Frontline Gold or Nexgard are necessary to kill external parasites. These products have been on the market for many years and provide a fast and safe way to get rid of an infestation. Frontline can be used on dogs or cats. It is applied topically and stays at the lipid layer of the skin killing the flea or tick when it bites your pet.

Nexgard can only be used for dogs. It is a new generation biomimicry product and is not an insecticide. It is an oral chew that when ingested by a dog mimics the defenses of a sea snail. When a flea or tick bites your dog Nexgard short circuits the pest’s neurology and the flea or tick dies. With a thorough home cleaning program and limited use of either of these products your pet can be free of a flea infestation within one to two months.  

It is important to seek veterinary advice when dealing with any parasite prevention because dogs and cats CANNOT use the same prevention. Many of the over the counter remedies (natural or otherwise) can be toxic or ineffective. We can help you find the right preventative protocol to fit your pet and your family’s needs. Feel free to call us with any questions.

Watch for your next blog post on how to thoroughly and safely clean your home if you have a flea infestation.

Your friends at,

Harmony Veterinary Center