External parasites

Despite their tiny size (no bigger than a sesame seed), fleas pack a mighty punch. Fleas thrive when the weather is warm and humid, and they may be either a seasonal or year-round problem, depending on where you live. Outdoors, a common source of fleas is cool, shady spots, especially places where other pets rest. Pets also can pick up fleas from flea-infested indoor areas such as pet bedding or carpets, or directly from a flea-infested animal. The “cat flea” is the most common flea species affecting both cats and dogs.

Adult fleas bite and eat blood, but that’s not all. After jumping aboard an animal or “host,” adult fleas soon start reproducing. A single female flea can produce up to 50 eggs a day! These eggs fall off the host, into the environment, then hatch into tiny, worm-like larvae that embed themselves in carpets, under furniture, on plants, or in soil. There, the larvae spin a cocoon and can remain cocooned for weeks before hatching as adults, ready to continue the life cycle anew.

Disease and diagnosis

Signs of flea problems in pets range from mild redness to severe scratching that can lead to open sores and skin infections (“hot spots”). One of the first things you may notice on your pet is “flea dirt”—the black flea droppings left on your pet’s coat. Even if you don’t actually see the fleas themselves, the parasites can be on your pet and in the environment.

Itchiness isn’t the only problem. Young or small pets with heavy infestations may become anemic from blood loss. Some pets can become allergic to flea saliva, making them severely itchy from just one or two flea bites. Also, pets—and children—can catch certain types of tapeworms if they swallow fleas carrying tapeworm eggs. In households with more severe flea infestations, fleas also may bite people, causing an allergic response. Although fleas can spread some bacterial diseases to pets and people (including bartonellosis or “cat scratch disease”), this happens only rarely.

Treatment and control

Even the best-cared-for pets can catch fleas. If your pet has fleas, your veterinarian will recommend an appropriate flea control plan based on the severity of the infestation and the needs of your pet, you, and your family.

To keep fleas away altogether, your veterinarian also can identify the best preventive product for your and your pet’s circumstances. Never use a dog flea product for cats because some products made for dogs—including those containing permethrin—are toxic to cats.

Because much of the flea’s life cycle is spent somewhere other than on a pet, treating just your pet will provide only temporary relief. If you kill the adult fleas but not the eggs, larvae, and pupae, your pet will become re-infested when these early-stage fleas become adults, and the cycle will start all over again.

• Carpets and bedding provide protection for developing fleas, so you also will need to regularly clean your pet’s living area to remove and kill early-stage fleas. This means thoroughly cleaning your pet’s sleeping quarters and vacuuming/cleaning floors where your pet hangs out.
• You may be advised to treat your house with flea-killing products. Ask your veterinarian which products are effective and safe for use around pets and children.
• With moderate and severe flea infestations, you may also be advised to treat your yard. Your veterinarian can recommend an appropriate course of action and suggest ways to prevent future flea infestations.

See also: Safe use of flea and tick preventive products

Ticks are commonly found in wooded or grassy areas, brush, shrubs, and wild undergrowth. Any animal (or person) that enters these environments is at risk of catching ticks. This risk may be seasonal or year-round, depending on where you live.

Like fleas, ticks bite and eat blood. Immature ticks often feed on small, wild animals like rodents and birds. Adult ticks seek larger hosts like dogs and cats. Many different species of ticks can affect dogs and cats. The geographic regions where each species can be found vary and are constantly changing.

Disease and diagnosis

In dogs, ticks are most often found around the neck, in the ears, in the folds between the legs and body, and between the toes. However, they can be found anywhere on the body. Cats may have ticks on their neck or face.

Tick bites can cause skin irritation in pets, and heavy infestations can cause anemia from blood loss. An adult female tick can eat up to 100 times her weight in blood! Ticks also can spread serious infectious diseases to pets and people, including Lyme disease, Rocky Mountain Spotted Fever, and others. Disease risk varies by geographic region and tick species. Plus, certain species produce a toxin that can cause pets to become paralyzed.

Treatment and control

To lessen the chance of your pet becoming sick from tick bites, it’s important to promptly and properly remove ticks:

• Carefully use tweezers to firmly grip the tick as close to the pet’s skin as possible.
• Then, gently and steadily pull the tick free without twisting or crushing it.
• Once the tick is free, crush it while avoiding contact with tick fluids that can carry disease.

Be careful to avoid crushing, twisting, or jerking the tick out of the skin while its head is still buried. This could cause the tick’s mouth parts to remain in your pet’s skin, leading to a skin reaction or infection. Also avoid smothering a still-attached tick with alcohol or petroleum jelly, or applying a hot match to it. This may cause the tick to inject saliva into the wound, increasing the risk of disease transmission.

You can help protect your pet from ticks by using an appropriate preventive product. Your veterinarian can recommend a product best suited to your pet’s needs. For further protection:

• Examine your pet for ticks immediately after returning home from any tick-prone areas (such as after camping, hiking, or hunting), and carefully remove any tick you find.
• Make your yard unfriendly to ticks by mowing grasses, trimming bushes, and removing brush.
• Perform daily “tick checks” on all pets and people in your home during high-risk seasons.
• If you do find ticks on your pet, remember to check yourself and your family for ticks, too!

See also: Safe use of flea and tick preventive products

Ear mites are common in young or stray cats, and also can affect dogs. These highly contagious parasites are tiny and invisible to the naked eye. They generally can be found in and around the ear canal. Your pet can pick up ear mites by close contact with an infested animal or its bedding.

Disease and diagnosis

Ear mites can be extremely irritating. Signs of ear mite infestation include excessive head shaking and ear scratching. Your pet may scratch to the point that they develop bleeding sores around the ears. Excessive scratching can also break blood vessels in the earflap, causing a large blood blister that may require surgery. Brown or black ear discharge is common with ear mite infections, and infections with bacteria or yeast can occur. To confirm whether mites are present, your veterinarian will collect an ear swab and examine the contents under a microscope.

Treatment and control

If your pet has ear mites, your veterinarian will recommend a thorough ear cleaning, followed by medication to kill the mites. Different types of medications are available to treat and/or prevent ear mite infestations, and some of these also are effective against other parasites. Your veterinarian can recommend an effective treatment and/or prevention plan tailored to your and your pet’s needs.

Sarcoptic mange mites cause sarcoptic mange, also known as scabies. These microscopic mites mostly affect dogs rather than cats. In cats, scabies is rare and usually caused by different (notoedric) mange mites. All ages and sizes of dogs can catch sarcoptic mange, at any time of year. The mites are highly contagious to other dogs and may be spread by close contact with infested animals, bedding, or grooming tools.

Disease and diagnosis

Sarcoptic mange mites burrow through the top layer of a dog’s skin, causing intense itching. Signs include constant scratching and chewing at the skin, hair loss, and thickened skin. Scratching and chewing may lead to bloody sores and skin infections. People who come in close contact with an affected dog also may develop a skin rash, which may need a doctor’s attention.

To confirm the presence of sarcoptic mange mites in your dog, your veterinarian will perform a skin scraping of affected areas and examine it under a microscope. If no mites are found but their presence is still strongly suspected, your veterinarian instead may diagnose sarcoptic mange based on the signs your dog is showing.

Treatment and control

Dogs with sarcoptic mange require medication to kill the mites, and additional treatment to soothe the skin and resolve related infections. Cleaning and treating the dog’s environment is also necessary.

Demodectic mange caused by demodectic mange mites is mainly a problem in dogs. It’s normal to find a few of these microscopic mites on a dog’s or cat’s skin. The mites are not highly contagious. However, a mother dog or cat may pass the mites to her puppies or kittens.

Disease and diagnosis

Demodectic mange may be limited to particular areas of the body (known as localized demodicosis) or may be more widely spread (known as generalized demodicosis). Localized demodicosis tends to appear in dogs less than 6 months old. It usually shows up as non-itchy patches of scaly skin and redness around the eyes and mouth and, perhaps, the legs and trunk. These patches generally will go away on their own, without treatment. On the other hand, generalized demodicosis is a more severe disease caused when an underlying medical condition affects the body’s ability to keep the mites in check. In this less common form, young and old dogs alike can have widespread patches of redness, hair loss, and scaly, thickened skin. They also can develop bacterial infections that require additional treatment.

To confirm demodectic mange, your veterinarian will perform a skin scraping from affected areas and examine it under a microscope. A fecal test also may be recommended to increase the chance of finding the mites, because pets may swallow them when self-grooming.

Treatment and control

Your veterinarian will discuss treatment options with you. For dogs with localized demodicosis that fails to go away on its own, treatment generally results in good outcomes. Generalized demodicosis is more difficult to treat, and aggressive, extended treatment may be necessary.