Fleas are wingless insects, 1/16 to 1/8-inch (1.5 to 3.3 mm) long, that are agile, usually dark colored (for example, the reddish-brown of the cat flea), with tube-like mouth parts adapted to feeding on the blood of their hosts. Their legs are long, the hind pair well adapted for jumping; a flea can jump vertically up to 7 in (18 cm) and horizontally up to 13 in (33 cm), making the flea one of the best jumpers of all known animals (relative to body size).
Once the flea reaches adulthood, its primary goal is to find blood and then to reproduce Its total life span can be as long as one and one-half years in ideal conditions. Female fleas can lay 5000 or more eggs over their life, allowing for phenomenal growth rates. Average 30–90 days.
The bites often appear in clusters or lines of two bites, and can remain itchy and inflamed for up to several weeks afterwards. Fleas can also lead to hair loss as a result of frequent scratching and biting by the animal, and can cause anemia in extreme cases.
Ticks are invertebrate animals in the phylum Arthropoda, and are related to spiders. Ticks are in the subclass Acari which consists of many orders of mites and one tick order, the Ixodida. Some mites are parasitic, but all ticks are parasitic feeders on blood.
Ehrlichiosis also known as canine rickettsiosis, canine hemorrhagic fever, canine typhus, tracker dog disease, and tropical canine pancytopenia is a tick-borne disease of dogs usually caused by the organism Ehrlichia canis. Ehrlichia canis is the pathogen of animals. Humans can become infected by E. canis and other species after tick exposure. German Shepherd Dogs are thought to be susceptible to a particularly severe form of the disease, other breeds generally have milder clinical signs.
Be aware of risk factors for specific types of worms. Because worms can look very similar, one of the best ways to identify the type of parasite that is plaguing your dog is to understand the environmental or situational factors that most lead to each type of worms.
Roundworms are often passed to puppies from a roundworm-infested mother because the eggs and larvae cross the placenta to infect the puppy in the womb, and eggs are also excreted in the mother's milk. Puppies should be wormed as a matter of routine.
Tapeworms are caused by a dog’s eating vermin already infected with tapeworm, or from fleas that contain tapeworm eggs. Thus, hunting dogs or dogs with a flea infestation are likely to pick up tapeworms.
Hookworms and Whipworms thrive in damp soil and the dogs most at risk are those kept on grass runs, especially in warm, humid conditions. These infections are more common in kenneled dogs that have access to communal grassy runs.
Heartworm is spread by insects such as mosquitoes and is therefore endemic in certain areas where insects are more common. High risk areas include the Southeastern and Midwestern United States and along the Atlantic coast.
Lungworm is becoming more prevalent and is spread via fox feces, slugs, and snails. Contact with any of these is considered a risk factor.
Hookworms* Signs include diarrhea, vomiting, and weight loss.
Tapeworms* are also common and in the dog, which is spread by ingesting fleas and lice. There are usually no symptoms.
Roundworms*. Signs are usually mild, but may include diarrhea, pot-bellied appearance, poor growth, and vomiting.
Fleas* in dogs cause itching and hair loss. The most common flea in dogs is the cat flea, followed by the dog flea.
Ticks* are an external parasite of the dog and can spread diseases such as Lyme disease, Rocky Mountain spotted fever. They can also cause a neurological disorder known as tick paralysis.
Heartworm disease in dogs is spread by mosquitoes and is spread by the parasite Dirofilaria immitis. Signs include cough, difficulty breathing, and death.
Mites* Ear mites in dogs are microscopic. Symptoms include itching, inflammation, and black debris in the ear.
Cheyletiellosis is a mild pruritic skin disease in dogs. Humans can be transiently infected.
Chiggers*, also known as harvest mites, can cause itching, redness and crusting in dogs.
Mange in dogs include demodectic mange and sarcoptic mange. Signs include hair loss, redness, and scaling, and is not contagious to humans! Sarcoptic mange. Signs include intense itching and scaling, and is contagious to humans.
Demodex These mites can cause inflammation and hair loss, they can also lead to secondary bacterial infections such as fever, lethargy, and enlarged lymph nodes.
Sarcoptes scabiei is a mite that burrows into humans and dogs alike and causes scabies. There is only one symptom, itchy and red skin.
Echinococcus granulosus is an infectious disease infecting dogs and sheep.
Gnathostoma is a disease from mammal feces and undercooked seafood.