Zoonotic diseases are diseases that are transmitted from animals to humans. Some diseases result from direct contact with the animal. Other diseases result from contact with articles infected with pathogens from the animal. This can include contact with infected food, water, soil, bedding, toys, or grooming equipment. Some diseases result from infected droplets from an animal sneezing or coughing. Some diseases are transmitted by vectors, such as, fleas, ticks and mosquitoes. We are going to look at some of the more commonly recognized zoonotic diseases found in this area.

Diseases that you will not find discussed include feline leukemia, feline immunodeficiency disease, pinworms, colds and sore throats. These are diseases people mistakenly think they get from animals.

The very young, the elderly and people who are immunocompromised are especially susceptible to zoonotic diseases and may develop much more severe cases of disease.

Babesiosis
A parasitic infection of the red blood cells that causes the destruction of the red blood cells as the organism multiplies within the cells. Babesia is spread by a tick bite. The primary tick vectors are the black-legged deer tick and the brown dog tick. Animals involved in the transmission of Babesia include white-footed deer mice, field mice, voles, rats, chipmunks, cottontail rabbits and deer. Dogs can bring infected ticks into their environment where disease can also be transmitted to people.

Prevention
Tick and rodent control is the best prevention. Tick control products on pets will help protect them from Babesia infection and will decrease the number of ticks they bring into their environment. Check pets and people daily for ticks. Remove ticks promptly using tweezers or wearing gloves if possible, especially if you have any open skin lesions. Wash hands with warm water and soap immediately. Kill the tick by dropping in alcohol. Save the tick in alcohol as a possible diagnostic aid.

Cat Scratch Disease (Cat Scratch Fever)
CSD is caused by the bacteria Bartonella henselae. Cats are the primary reservoir for the bacteria. At this time, it is not definitively known how cats acquire the bacteria. It is thought that cats ingest infected flea feces during grooming and that bacteria from the cat’s mouth is then distributed to the cat’s feet during subsequent grooming. CSD is transmitted to people by a bite, lick or scratch. Kittens under 1 year of age are most likely to transmit the disease. CSD is not contagious from person to person or from person to cat.

Prevention
Keep cats indoors. Use flea prevention on cats that have flea exposure. Do not allow kittens to bite and scratch when playing. Scrub bites and scratches with warm water and soap immediately. Do not allow cats to lick open wounds.

Ehrlichiosis
This is a group of tick borne diseases caused by Ehrlichia spp. bacteria. The bacteria attack white blood cells which are the cells that help provide immunity from disease. Ticks are the vectors in the transmission of ehrlichiosis. The bacteria are spread from host to host by tick feedings. Ehrlichiosis has been found in many different animals, including, dogs, cats, deer, coyotes, red foxes, rodents, horses, cattle, sheep and goats.

Prevention
Tick and rodent control are the best approach. Tick control on pets will help protect them from possible infection and will decrease the number of infected ticks they introduce into their home environment. Avoid areas where ticks are found. Check people and pets daily for ticks. Remove ticks promptly using tweezers or wearing gloves, if possible, especially if you have any open skin lesions. Wash hands with warm water and soap immediately. Kill the tick by dropping it in alcohol. Save the tick in alcohol as a possible diagnostic aid.

Giardiasis
Giardia is a protozoan parasite. Giardiasis is the second most common cause of parasitic diarrhea in people. Giardia is the most common cause of water-borne disease. The cyst stage of the parasite is passed in the host’s feces. Infection occurs when a potential host consumes feces contaminated water, food or puts contaminated objects in the mouth. Giardiasis is found in most warm-blooded animals, including, people, dogs, cats, sheep, cattle, horses, pigs, guinea pigs, mice, deer, beavers, bears and muskrats.

Prevention
Use good sanitation procedures to prevent ingestion of feces contaminated food, water or objects.

Hookworms
Hookworms are intestinal parasitic worms. They are also known as nematode parasites. Dogs and cats are hosts for hookworms. In humans, hookworms cause a disease called cutaneous larva migrans when the hookworms migrate under the skin. Transmission is from infective larvae that develop from the eggs passed in the feces of infected dogs and cats. The larvae may be ingested or they may penetrate the skin. Puppies can be infected when nursing by larvae from the mammary glands.

Prevention
Puppies and kittens should be routinely de-wormed at regular intervals. Adult pets should have regular fecal checks. Use a heartworm prevention product that also controls intestinal parasites year round. Dog parks, walking trails and around apartment buildings are examples of areas that are often contaminated with hookworm larvae. Avoid going barefoot in areas contaminated with feces. Keep sandboxes covered. Clean up feces on a regular basis.

Leptospirosis
Leptospira spp. are bacteria that are passed in the urine of infected animals. There are many species of Leptospira that can cause disease in animals and humans. Over 160 species of mammals, including humans, are susceptible to leptospirosis. Transmission occurs through exposure to water, soil or food that has been contaminated with infected urine. Other common modes of transmission include eating infected rodents and contaminated grass. Transmission occurs through mucus membranes and skin lesions. Leptospira travel through the blood stream and cause blood vessel damage throughout the body. Leptospirosis can cause spontaneous abortion in animals and people.

Prevention
Avoid areas where animals frequently urinate. Leptospira can be found in fresh-water rivers, lakes and streams; damp soil found around river banks; and mud. There is a vaccine available for dogs who are at high risk, but the vaccine does not protect against all strains or serovars that can infect dogs.

Lyme Disease
Borrelia burgdorferi is the bacteria responsible for Lyme disease. Lyme disease affects many different body systems. The bacteria is transmitted by tick bites. The primary reservoir hosts are white-footed mice and whitetail deer. People, dogs, cats, horses and cattle are some of the animals that can become infected. After the tick egg hatches, all stages of the infected tick can transmit the disease. Infected animals cannot pass Lyme disease directly to people, but they can bring infected ticks into their home environment.

Prevention
Tick control products should be used on all pets with possible tick exposure. Avoid areas where ticks can be found. Check pets and people daily for ticks. The larvae and nymphs are extremely small – the size pinheads and poppy seeds. Remove ticks promptly. When removing ticks, use tweezers or wear gloves, if possible, especially if you have open skin lesions. Wash hands with warm water and soap. Kill the tick with alcohol. Save the tick in alcohol as a possible diagnostic aid.

Rabies
Rabies is a viral infection that causes acute encephalitis in most mammals. If not treated before symptoms are present, it is nearly always fatal. The virus spreads rapidly through the nervous system. In the United States, rabies has been found in several animals, including dogs, cats, raccoons, foxes, coyotes, bats and cattle. Transmission occurs through various routes, including, bites, rabies virus contact with the mucus membranes and aerosol transmission. Bites contaminated with virus-containing saliva are the most common route of transmission.

Prevention
Keeping up to date with rabies vaccinations for dogs and cats not only protects pets from contracting rabies, but also helps protect owners and anyone else who has contact with pets who have been bitten by a rabid animal. Keep pets and people away from unfamiliar animals. Avoid contact with wild animals, especially if they are exhibiting unusual behaviors. Do not handle dead animals; under the right conditions, the virus can live for several months in dead animals. Seek medical attention promptly for people and animals that are bitten by unfamiliar animals or wild animals.

Rocky Mountain Spotted Fever (RMSF)
Rickettsia rickettsii is the bacteria responsible for RMSF. The bacteria invade the cells that line blood vessels. As the bacteria multiply within the cells, the cells die allowing blood to leak out of the blood vessels into surrounding tissue. There can be blood seepage into almost any tissue so RMSF is potentially a multi-organ disease. Tick bites spread the disease. Rarely, infection can occur through crushing a tick with the fingers and the organism entering through breaks in the skin. All life stages of the tick after hatching from the egg can be infective to animals and people. Dogs and people are the only animals that will show signs of RMSF.

Prevention
Tick control on pets helps prevent their infection and reduces the number of ticks the pet brings into the home environment. Avoid areas where ticks are found. Check people and pets daily for ticks. Remove ticks promptly using tweezers or wearing gloves if possible. Wash hands thoroughly with warm water and soap immediately. Kill the tick by dropping it in alcohol. Save the tick in alcohol as a possible diagnostic aid.

Roundworms
Roundworms are intestinal parasitic worms. They are also known as nematode parasites. Dogs, cats and raccoons are hosts for roundworms that can cause disease in people. People are abnormal or atypical deadend hosts. Transmission occurs through ingestion of infective eggs passed into the soil with feces. In the normal host, when eggs are ingested, the eggs hatch, the larvae burrow through the intestinal wall and into a blood vessel. The larvae travel through the body in the blood and end up back in the intestine where they become adults. In atypical hosts, such as, people, the larvae travel in the blood, but instead of ending up in the intestines, the larvae are deposited in various tissues causing damage during their continued migration. The tissues most often affected and permanently damaged are the liver, lungs, eye and brain.

Prevention
Puppies can acquire roundworms in the uterus, through nursing or by ingesting infective eggs. Kittens can acquire roundworms through nursing or by ingesting infective eggs. At 2 weeks, puppies can be shedding roundworm eggs in feces and, at 3 weeks, kittens can be shedding roundworm eggs. Deworming should begin at those ages. Unfortunately, most puppies and kittens are not dewormed until they see a vet at 6 weeks or older. Puppies and kittens should be given a series of dewormings along with their vaccinations. They should also have fecal examinations performed. Adult dogs and outdoor cats should have fecal exams done at least once a year. Heartworm prevention for dogs does not just prevent heartworms, but also controls intestinal parasites. Using heartworm prevention year round helps protect your pet and you from roundworms and hookworms. Good personal hygiene is important. Washing hands after handling pets and their feces helps prevent transmission of parasites. Children are particularly at risk for roundworm transmission.

Salmonellosis
Salmonella spp. are bacteria that cause infection of the gastrointestinal tract. Salmonella resides in the gastrointestinal tract of both warm-blooded and cold- blooded animals. It is usually transmitted by eating feces contaminated food. Unpasteurized milk or milk products, contaminated water, foods grown in contaminated soil, eggs, raw or undercooked meats and poultry and improper food preparation are all sources of salmonellosis. Reptiles, such as, snakes, iguanas and turtles commonly shed Salmonella.

Prevention
Washing hands after handling feces, raw meats, reptiles, etc. helps prevent transmission of Salmonella. Do not prepare foods on surfaces that may be contaminated.

Toxoplasmosis
Toxoplasma gondii is a protozoan parasite whose only definitive hosts for the infective stage are wild and domestic cats. However, cats are not the most common source of toxoplasmosis infection in people. There are two phases to the life cycle: the sexual and the asexual. During the sexual phase, which occurs only in the intestine of cats, the cat sheds millions of oocysts daily in feces for 2 to 3 weeks and then is done shedding oocysts for life. The asexual phase occurs when the oocysts become infective to other animals and people 1 to 5 days after being passed in the feces. The oocysts can remain infective for over a year. In animals other than cats and in people who ingest the infected oocysts, toxoplasma go through different stages of development within the new host’s cells and eventually form cysts within tissue cells throughout the body. The cysts are most commonly found in skeletal muscle, the heart and the brain. Nearly all warm-blooded animals and birds can be infected. Infective oocysts can be found anywhere a cat defecates. Infected rodents, birds and other small animals can infect the cats that prey on them. Animals can become infected with toxoplasma while grazing in contaminated pastures. Consuming raw or undercooked cyst infected meat from these animals transmits the disease. In rare cases, people can become infected by inhaling or ingesting cysts from an infected cat. Oocysts can be carried to distant places by water or wind. If infected near the time she becomes pregnant or shortly after that, toxoplasmosis can transferred across the placenta and result in congenital toxoplasmosis which is the least common but most severe form of the infection.

Prevention
Kittens and young adult cats are the most likely to be shedding infective oocysts, so pregnant women and persons who are immunosuppressed should use caution when adopting a kitten or young cat. Keep cats indoors. Do not eat raw or undercooked meat. Do not feed cats raw or undercooked meat. Wash hands, utensils and cutting boards in warm, soapy water after handling raw meat. Cysts can be passed in unpasteurized milk and dairy products, especially products from goats. Wear gloves when working in gardens and flower beds that potentially have been contaminated. Keep sandboxes covered. Clean litter boxes daily – it takes 1 to 5 days for cysts to become infective after being passed in feces. Cysts can be inhaled from litter dust, so use low dust litter. Do not drink untreated water from lakes, streams or rivers. Do not eat unwashed vegetables or fruit. Wash hands with warm, soapy water anytime there has been contact with potentially infected items – even if gloves have been worn.