Diseases spread by fleas and ticks are transmitted when these insects feed on the blood of a host. Fleas and ticks are externally parasitic to dogs, cats, humans and many small mammals. Different species of fleas and ticks are vectors of specific viruses, bacteria or protozoal parasites. These infections are often host and/or carrier specific.
1. Parasitic Dermatitis
Parasitic dermatitis is an allergic reaction that is caused by a pet's hypersensitivity to substances in flea saliva. Itchy, inflamed skin and papules will appear on the skin where fleas are concentrated. Eventually the irritation may cause hair loss and infection. These symptoms can exist long after flea infestation has been eliminated and may require treatments of antihistamines and antibiotics. Parasitic dermatitis is usually caused by flea bites but can sometimes be triggered by tick bites.
2. Lyme Disease
Lyme disease is caused by a bacteria that is transmitted by the bite of a tick. Lyme disease is considered the most common tick-borne disease in the United States. Symptoms include a sudden onset of lameness that is occasionally accompanied by fever, anorexia and lethargy. Lyme vaccinations in conjunction with flea and tick preventatives are recommended for all dogs, specifically those in endemic areas or those that are often outdoors.
Bartonella strains are bacterial parasites that are transmitted through flea or tick bites. Bartonella can infect humans, dogs, cats and rodents. Bartonella invades red blood cells and uses the cell's membrane as protection while multiplying. Bartonella can cause multiple ailments depending upon the strain existent in the host. It is responsible for Cat-scratch disease in humans. Bartonella can be diagnosed with laboratory blood work and most strains can be effectively treated with antibiotics.
Erlichiosis is a bacterial infection transmitted through tick bites. Erlichiae infect and destroy the white blood cells in the body of the host. Infection results in lethargy, weight loss, anemia and enlarged lymph nodes and spleen. Erlichiosis can be diagnosed by laboratory blood work and is usually responsive to aggressive treatment with the antibiotic doxycycline.
Rickettsiae are bacteria that can be transmitted by flea or tick bites. Multiple strains of rickettsia exist that can cause different ailments. Rickettsiae ailments include typhus, Rocky Mountain spotted fever, flea-borne spotted fever and tick bite fever. Diagnosis and treatment are dependant upon the strain of rickettsia and the associated illness.
Meningoencephalitis is an inflammatory disease that can be caused by numerous tick-borne viruses. Meningoencephalitis infects the brain and spinal cord, and their surrounding membranes. The result of infection is a loss of nervous system function. Fever, pain, convulsions and paralysis are symptoms of infection. Meningoencephalitis has a rapid onset and can be fatal. Diagnosis can be made by cerebrospinal fluid analysis. Treatment with antibiotics and anticonvulsants can be effective providing that the meningoencephalitis is the result of a tick-borne virus.
Tapeworms are parasitic flatworms that can be transmitted by fleas that are ingested during grooming. Tapeworms exist in the digestive tract and shed reproductive segments of their body called proglottids. The proglottids are passed in the feces of the host and are visible to the naked eye. Proglottids are often the only noticeable indication of a tapeworm infestation.
Vaccines exist for few of these illnesses. The recommended preventative for all flea and tick associated illnesses is the prevention of the parasites themselves.