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External Parasites in Dogs and Cats

We have dipped our share of dogs and cats over the years to get rid of external parasites and have never figured out a way to enjoy it. We always end up with as much dip on ourselves as the dogs or cats! The good thing is people like to take you fishing afterwards as the mosquitoes don’t bother you. The bad thing is insecticidal dips affect your nervous system, especially with repeated use.

Before going further, there is a place for dipping. Lime Sulfur Dip is a great treatment for kittens and puppies with skin issues we can’t resolve. Lime sulfur is an old natural treatment that is safe for your nervous system and won't create issues later in life. Skin infections, fungal problems, and mange are all improved by lime sulfur dipping. Be aware, it smells like rotten eggs, but the odor dissipates quickly.


Demodectic mange, also known as follicular mange or red mange, occurs when mites suddenly multiply beyond what the dog can tolerate. This skin disease is caused by the mite, Demodex canis. Demodex is common in many species of animals. Some have suggested that it is a normal inhabitant of the skin. No matter what, if your dog is showing signs, you need to treat and eliminate if possible.

The primary symptom is patchy hair loss, usually occurring around the eyes and the face, often with a greasy or moist appearance. Demodex is not contagious and dogs only pick up Demodex as babies while they are nursing during the first two weeks of life. They cannot acquire Demodex after that age. Demodex in cats is uncommon, but if a cat gets this, it affects their head and neck area.

The confusion with Demodex is the genetics associated with it. If your dog or cat has a lot of genetic resistance, they may not get Demodex at all. Breeders have done a good job of breeding resistance into their dogs as they want a healthy and happy dog with lots of hair. Their success in breeding away from Demodex problems is remarkable.


Sarcoptic mange, commonly known as scabies, is intensely itchy and contagious. Sarcoptic mange attacks the skin of the ears, elbows, and hocks first, but over time will occupy all of your dog or cat's body. The onset is abrupt with scratching, hair loss, and inflamed skin. Crusty ear tips are often seen. Treatment includes clipping the hair and removing the crusty lesions.

Sarcoptic is contagious from dog to dog in adults; therefore, all dogs in the family should be treated to eliminate the problem. Though some dogs scratch more than others, there is no real genetic component to sarcoptic mange.


Cheyletiella mange, also known as “walking dandruff,” produces scaly skin, but is not as itchy as the other mange mites. Owners often report it looks like cradle cap in kids, dry scalp, and a bit flaky. This is the only mange that crosses species and will spread to cats, birds, and humans. In humans, this mange produces pimple lesions which appear on the inside of the arms. Humans are a temporary host as they do not like living on us.


Ear mites are just a mange mite that lives in the ear and face areas. They tend to hide in the scale and debris where they are protected from topical treatments that cannot reach them.


Lice first appear as tiny white egg casings, called nits, which attach to the hair shafts of your dog or cat's fur. When the eggs hatch, they produce six-legged insects. Dogs and cats are usually infested with lice by contact with another infested dog or cat. Lice do not travel in the environment, but can be transmitted through grooming tools, bedding, kennels, and pet carriers that have not been properly washed after an outbreak. Lice do not cross species and do not affect humans.

Our attitude toward internal parasites is to manage them to a tolerable level. Our attitude toward the external parasites is to eliminate them from our catteries or kennels. We can eliminate these parasites if we pay attention to their life cycle and prevent environmental contamination. Once out of the kennel or cattery, don’t allow them back in!


Eliminate mites and lice. Treat every dog and cat at the same time. You can kill all the adults, but remember, mites weld their eggs on the base of the hair shaft and you cannot kill them! These eggs hatch out in 7 days, so you need to re-treat in 2 weeks before they hatch and lay more eggs. Many people treat once and have the problem back in 6 weeks; you have to treat twice.

My favorite treatment is Ivomec® topical. (Never use Ivomec on Collies, Shelties, or Collie/Sheltie mixed breeds.) Topical Ivomec 0.5% also called Ivomec®/Ivermectin Pour-On is advantageous as we know we are getting an accurate dose in the animal. It’s used between the shoulder blades so they can't lick it. Although licking it won’t hurt a dog or cat, the alcohol carrier makes them salivate and look terrible. If you have Collies or Shelties, use Revolution® on these sensitive breeds to get the same effect.

Injectable Ivomec® is used orally and usually mixed with Propylene Glycol to sweeten the taste for dogs, making it easier to get down. Cats cannot have propylene glycol so use Doc Roy's® Forti Cal or Meg-A-Cal to sweeten the dose. Most take it well, but if they vomit or spit out the dose, you will have to redo as we need everyone’s parasites killed at the same time to avoid sharing back into the group.

You will need to repeat your treatment again in two weeks. Don’t forget to treat the outside cats and the house dog, or the ear mites will return. If there is any doubt as to whether or not you have eliminated them, repeat the treatment in one month to be sure you are free of lice and mange mites.


Bio Security means we do not bring an infection or disease back in after we have eliminated it. Put any new arrivals on the end of the building and keep one empty kennel between them and any other dog or cat. Any dog or cat brought in should not be allowed contact for three weeks. Treat them twice with Ivomec® or Revolution® before entering the group. Also vaccinate and deworm with Safeguard® before allowing access to the group.

Follow these procedures and you will eliminate lice, mange, and ear mites from your kennel or cattery for good!

If you need help, call us at 1-800-786-4751.

-Dr. B
Don Bramlage, DVM, Director of Veterinary Services at Revival Animal Health

The materials, information and answers provided through this website are not intended to replace the medical advice or services of your personal veterinarian or other pet health care professional. Consult your own veterinarian for answers to specific medical questions, including diagnosis, treatment, therapy or medical attention.

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