Harvest Mites in Dogs

The harvest mite feeds on your dog by digging their fangs into the sensitive part of your dog’s body and injecting a special fluid into the skin. This fluid will liquefy the cells surrounding the bite. The harvest mite then drinks the liquefied cells. Generally, a harvest mite will feed for 2 to 3 days on your dog.

Harvest mites are tiny mites that live in dense vegetation and eat plants and other insects. It can cause extreme discomfort and irritation to dogs when the mite attaches to the skin. The Latin name for harvest mite is Trombicula Autumnalis and from this phrase you can guess when they are most active and biting warm blooded animals. During late summer up to the first frost, the harvest mite will bite warm blooded mammals, especially dogs and cats. They will jump up onto your dog and find the area of the body where the skin is the thinnest. They only feed on warm blooded mammals during the larval stage.

Harvest mites may not sound like a serious health problem for your dog; however, if left untreated, your dog can develop a secondary bacterial infection. Some dogs are allergic to the fluid that the mites inject into their skin and this can cause severe irritation. If you notice your dog is itching constantly or you notice orange bumps or a red dusting on their skin, you should have your veterinarian check your dog over thoroughly. Your dog will most likely itch on his ears, between his toes, armpits, stomach, chest and chin.

• Reddening of the skin
• Crusting on the skin
• Orange dots on the skin
• Red “dust” on the skin
• Intense itching

The fluid that the harvest mite injects into your dog’s skin is actually a digestive enzyme that causes the skin to liquefy which then allows the mite to ingest the skin cells. They will feed for 2 to 3 days before they drop off your dog. During those 2 to 3 days of feeding, the mite will grow in size to about 3 to 4 times its original size.

The digestive enzyme most likely causes an allergic reaction in your dog. This then causes him to scratch at the offending mites. When your dog itches or scratches at his skin, he can cause abrasions that can then become infected.

If you notice your dog scratching or little orange dots on their skin, you should make an appointment with your veterinarian to make sure that it is harvest mites that are affecting your dog. Your veterinarian will do a complete physical examination, paying close attention to the areas that seem to be itching the most. 

Your veterinarian may be able to determine that harvest mites are the cause if there is a large grouping of the mites, forming a large orange or reddish spot on your dog’s skin. If the mites are not grouped closely together, your veterinarian may take a skin scraping. The skin sample will be viewed under a microscope, looking for harvest mites. 

If your veterinarian suspects your dog is suffering from a secondary infection they may opt to perform more diagnostic tests to pinpoint the infection. A skin swab, complete blood count, urinalysis and biochemistry panel may be ordered. Once your veterinarian has determined harvest mites have attached themselves to your dog they can then discuss treatments with you.

Dogs that are susceptible to harvest mite bites will require medications to soothe the irritation and reduce any inflammation. This can be done by first giving your dog a soothing bath using a shampoo that relieves itching. Then, once he is dry apply a topical ointment or spray to eradicate any remaining harvest mites and keep any others from biting. Your veterinarian may recommend Frontline Spray to be applied to the affected areas. The Frontline Spray is different from the topical drops that are generally used for flea prevention. Some topical drops are effective against harvest mites but not all.

A corticosteroid may be prescribed to relieve the itch and reduce any inflammation caused by the mites biting or your dog scratching. If your dog has developed a secondary bacterial infection from scratching, antibiotics will also be prescribed.

Dogs that suffer from harvest mites will generally recover without any lasting effects. If your dog is susceptible to harvest mites, you may want to take preventative measures to ensure that they are safe during the times when harvest mites are actively biting warm blooded mammals. Frontline Spray or other topical sprays can be applied as a preventative spray to keep harvest mites from biting. 

You can also spray your vegetation for mites to eradicate them from your yard. Harvest mites are most active on bright, sunny days and during late morning and afternoon. They are generally not active in early morning, late evening or night or on cloudy, chilly days.