Sunday, January 6, 2013

What Are Hot Spots on Pets?

What Are Hot Spots on Pets?

Hot spots (flea allergy dermatitis) is a skin disease (dermatitis) caused by your pet's allergic reaction to fleas. Derm means skin, and "itis" means inflammation, so your pet will have itchy, inflamed skin.
Inflamed skin is hot, red, and itchy.

Often the skin becomes smelly because yeast and bacteria grow well on unhealthy, inflamed skin. When your pet scratches the bacteria are rubbed deep into the skin and hot spots develop. 

Hot spots are just infected sores. Pets with flea allergy dermatitis are so sensitive they can develop hot spots if bitten just twice a month by fleas. Your pet is having an allergic reaction to flea saliva, feces and exoskeleton.

Hot Spots Symptoms

  • Compulsive biting
  • Licking
  • Chewing that looks like corncob nibbling
  • Scratching around the head & neck
  • Bald areas

Hot Spots on Dogs

Dogs with fleas often bite compulsively. They chew up and down their limbs as if they're nibbling on a corncob because they are so itchy. Dogs also roll on their backs to scratch the itching skin that can't be reached with their paws.

The skin may have red bites, rather like mosquito bites, or large raw, wet areas called hot spots. As the allergy worsens, the hot spots coalesce and become large open sores. Bacteria and yeast enter the skin and infect it creating oozing, pus-filled areas called pyodermatitis (Pyo means pus).

How Are Hot Spots Diagnosed?

Find the fleas on your pet or use the presence of flea dirt to confirm your suspicion of fleas. Some prefer to confirm flea bite allergies by doing skin tests that show your pet's immune response to flea proteins.

If you part your pet's coat, you may find tiny copper-colored or blackish pepper flakes, about 1/8 inch long. Unless the flea infestation is severe, you may see nothing unusual because fleas are programmed to live in dark areas.

They dash out of sight to hide as you part your pet's hair. Instead of finding fleas, you may find flea dirt, which looks like dark dust. When flea dirt is damp, it becomes red because it is made of blood. It's very difficult to see flea eggs because they are only 1/64th of an inch in size and because they fall off the pet and to the floor.

If you have a microscope and want to look for flea eggs, search along moldings, in cracks between boards, or in leaf litter. Eggs aren't normally seen on the pet.

What Is Flea Dirt?

You might suspect fleas are causing your pet's skin problems, but can't find them. This frequently happens with cats because cats can groom so fastidiously after they are bitten that they destroy the flea. Instead of looking for fleas, look for flea dirt. 

To find flea dirt, brush your pet over a white surface, such as a white rubber bath mat or dish drainer. Lightly dampen the dirt that falls on the mat and look for tiny streaks of reddish brown. That reddish brown material is your pet's blood.

Preventing Hot Spots

Hot spots are prevented by preventing fleas. The most common methods of flea prevention include topical flea medication and oral flea medication. 

Some of the most effective topical medications include Advantage II, K9 Advantix II, Frontline Plus, and Frontline Top Spot. These products begin killing fleas within minutes. 

Topical  Revolution also kills fleas, but requires at least 24 hours to become effective.

The most effective oral flea prevention medications are Sentinel and Capstar. Capstar kills all adult fleas and begins acting within minutes. 

Capstar is given daily. The main difference between these two oral flea medications is that Sentinel doesn't kill adult fleas. Sentinel prevents eggs from developing into adult fleas.



  1. Very informative, thank-you! I always thought hot spots were formed by the hair matting & preventing the skin from getting fresh air. Can they be caused from that as well?

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