External parasites, or "ectoparasites," cause mild to extreme dog skin problems. Four main external parasites-fleas, ticks, lice and mites-infect dogs and puppies. Living on or under the skin, external parasites feed on their hosts. Your dog may contract external parasites though contact with infected pets and their possessions, or exposure to infested outdoor terrain. Since most dogs will experience one or more external parasitic infections, taking aggressive eradication and prevention measures from the beginning of your dog's life will go far in sparing your dog the discomfort and the complications they may cause.
Skin Problems Associated with Fleas
Fleas prefer warmer weather and can be a year-round problem in some climates. Your dog contracts fleas through exposure to infested living areas or outdoor terrain. Dark brown and the size of a tiny seed, fleas suck the blood of hosts, causing redness, pruritis (itching), allergic reaction to flea saliva, open sores and skin infections. If you see "flea dirt"-the black flea droppings on your dog's coat-your dog has fleas.
Skin Problems Associated with Ticks
Ticks, in the adult stage, prefers larger hosts, like dogs. Indoors and out, ticks, which are hard-bodied arachnids, attach to your dog's neck, ears, legs, toes and body, irritating the skin and causing itching and localized as well as systemic infection. Correct removal of ticks is essential. Do not twist the tick as you pull it out with tweezers; if the head remains stuck an infection could follow. Also, do not smother the tick with alcohol or petroleum jelly, nor press a hot match to it, all of which could prompt the tick to expel saliva into the wound, increasing the risk of infection and disease.
Skin Problems Associated with Lice
Lice, flat, wingless parasites, contracted through contact with infested pets, live their entire lives on their hosts, some sucking blood (Anoplura) and others chewing skin (Mallophaga), causing a scruffy, dry hair coat, hair loss and severe itching.
Skin Problems Associated with Mites
Mites are tiny parasites that can cause big problems for your dog. These three types of mites may infect your dog:
Ear mites, contracted through close contact with an infected animal or bedding, causing intense irritation of the ear canal and itching. Scratching may cause bleeding sores; infestation may cause brown or black ear discharge.
Sarcoptic mange mites, contracted through close contact with infested animals, bedding or grooming implements, causing sarcoptic mange, or scabies. Sarcoptic mange mites burrow into your dog's skin, causing intense itching, hair loss, rash, crusting and secondary skin infections.
Demodectic mange mites, passed from mother to offspring and sometimes contracted through dog-to-dog contact, causing demodectic mange. Demodectic mange causes scaly skin; redness around the eyes, mouth, legs and trunk; hair loss; scaly, thickened skin.
Control and Prevention
Daily grooming is the best way to spot external parasites that can cause skin problems in your dog. Consultation with a professional groomer also helps in controlling external parasitic infections. Be alert to clinical symptoms--like your dog scratching, chewing or licking the coat, as well as skin inflammation or infection. Under the care of your vet, treat all pets in the household for the same external parasitic infections at the same time to completely eradicate them and prevent re-infection. Do not attempt to treat external parasitic infections in your dog on your own.