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Educational Articles

Infectious Diseases

  • Giardiasis is an intestinal infection caused by a microscopic protozoan. The parasites attach themselves to the intestinal wall and the damage causes an acute, sudden onset of foul-smelling diarrhea. Diagnosis may be by routine fecal flotation or presumptively based on clinical signs. Fenbendazole and metronidazole are the drugs most commonly used to kill Giardia. Giardiasis is the most common intestinal parasitic infection of man and can potentially be passed from cats to humans.

  • Giardiasis is an intestinal infection caused by a microscopic protozoan. These parasites attach themselves to the intestinal wall and the damage causes an acute, sudden onset of foul-smelling diarrhea. Diagnosis may be by routine fecal flotation or presumptively based on clinical signs. Fenbendazole and metronidazole are the drugs most commonly used to treat giardiasis.

  • Heartworms (Dirofilaria immitis) are blood-borne parasites that reside in the heart or nearby large blood vessels of infected animals. Recent studies of cats with heart and respiratory diseases have found an incidence of heartworms that is far greater than previously thought. Veterinarians now strongly recommend that all cats receive year-round monthly heartworm preventives. There are excellent heartworm preventives now available for cats, making prevention of heartworm disease safe and easy.

  • Heartworms are blood-borne parasites that reside in the heart or adjacent large blood vessels of infected animals. There is no drug approved for treating heartworms in cats and surgical removal is generally the best option. Veterinarians now strongly recommend that all cats receive year-round monthly heartworm preventative in areas where mosquitoes are active all year round. Cats that live in colder areas, where mosquitoes are seasonal, should be given monthly preventives for at least six months of the year.

  • Heartworm disease is a serious and potentially fatal disease. It is caused by a blood-borne parasite known as Dirofilaria immitis. Adult heartworms may live for five to seven years and, during this time, the female produces millions of offspring called microfilaria. You can prevent your dog from getting heartworms by using a heartworm preventive.

  • Heartworm disease is serious and potentially life-threatening to dogs. Treatment involves several components to combat potential bacterial infection, kill the heartworm larvae (microfilaria), kill the adult heartworms, and then test to confirm successful treatment. Complete rest for a dog undergoing treatment is essential. The prognosis for dogs after heartworm treatment is generally good if the pet owner follows all veterinary recommendations closely.

  • Hepatozoonosis in dogs is caused by ingestion of one of two organisms: H. americanum and H. canis. Both parasites are more common in the southern United States. The clinical sign and treatments for dogs with hepatozoonosis differ depending on the parasite species causing the infection. In either case, with appropriate treatment, the prognosis is generally good.

  • Canine herpesvirus, or canine herpes, is a systemic, often fatal disease of puppies caused by the canine herpes virus. It may remain latent in tissues after a dog is infected and may be passed on to other dogs, particularly to fetuses developing in the mother's uterus. Clinical signs in puppies include difficulty breathing, nasal discharge, anorexia, soft stools, crying, seizures, and sudden death. Symptoms in adult dogs include coughing and sneezing, miscarriage, lesions on the external genitalia, conjunctivitis, and corneal ulcers. The disease may be prevented by avoiding contact with infected dogs. Pregnant dogs should be isolated to prevent infection.

  • Feline viral rhinotracheitis (FVR) is an infectious disease caused by feline herpesvirus type-1. It is a major cause of upper respiratory disease in cats and is the most common cause of conjunctivitis. The typical symptoms of FVR involve the nose, throat, and eyes, and include sneezing, nasal congestion, conjunctivitis, excessive blinking, squinting, and discharges from the eyes and nose that range from clear and watery to thick and purulent (containing yellow/green pus). Treatment consists of supportive care, hydration of the environment, and control of secondary bacterial infections with antibiotics and antibiotic eye medications. An effective vaccine exists and is recommended for all cats.

  • Histoplasmosis is an infection caused by histoplasma, a fungus found in moist soils and especially prevalent around the Ohio, Mississippi, Missouri, and St. Lawrence rivers, as well as the southern Great Lakes and Alberta. Fungal spores are inhaled or ingested and cause infection in many sites including the lungs, gastrointestinal tract, eyes, joints, and spleen. This handout outlines signs, diagnosis, treatment, and prognosis. Histoplasmosis is transmissible to humans, especially if they are immunocompromised.