Pets can be great fun for the entire family. They can also provide health benefits, such as lowering your blood pressure and cholesterol. But watch out — your seemingly healthy puppy or kitten can also carry diseases that can make you and your family sick.

Keeping your pet's shots current and taking your pet to the veterinarian whenever anything seems wrong are good investments in your pet's health. But you still need to be on the lookout for signs of infectious diseases. These diseases can be transmitted not only by your cat or dog but by less common pets, too. Birds, fish, reptiles, amphibians and rodents all can pass infections on to humans.

Before bringing an animal into your home, make sure you understand the risk of disease associated with the new pet. Learn how to spot when something's wrong, and tell your children to stay away from wild animals or pets they don't know. Understanding how to protect your family can help ensure that your experience with animals will be a happy one.

Certain diseases are more commonly spread by dogs and cats than by other pets.

Rabies
Rabies is caused by a virus that enters your body through a wound — particularly a bite — and eventually affects your brain. Your cat, dog or ferret typically picks up rabies through a bite from or to another animal that has rabies. Other animals that can carry rabies include:

• Raccoons
• Bats
• Cattle
• Rabbits
• Skunks
• Foxes

Animals infected with rabies exhibit unusual behavior. Your cat, which might usually be shy, could suddenly become aggressive. And your dog, which might usually be friendly, could suddenly become shy. Stay away from animals that appear to be drooling or foaming at the mouth, both of which are symptoms of rabies. And avoid animals that appear injured or have trouble walking. Contact your veterinarian or, if the animal is loose outside, call your local animal control agency to tend to the animal.

Seek emergency medical care immediately if an animal you think could have rabies bites you or your child. That way you or your child can be given preventive vaccines to prevent the disease. Once symptoms develop, it may be too late to treat the disease. Early signs and symptoms of rabies in people include:

• Restlessness
• Fatigue
• Loss of appetite
• Headache
• Fever
• Itching at the site of the animal bite

As rabies progresses, infected people can become aggressive and alternate between periods of wild excitement and seemingly normal behavior. Eventually the person with rabies becomes unconscious and paralyzed. Rabies is nearly always fatal.

Protect your family and your pets by having your pets vaccinated for rabies. Don't leave your pets loose outside unsupervised — where they can encounter other animals that may carry rabies.

Cat-scratch disease
Cat-scratch disease can follow a cat scratch or bite, especially from kittens. Your cat doesn't need to be sick to carry the bacteria associated with cat-scratch disease, and you aren't likely to notice any signs of infection in your pet. You can also get cat-scratch disease from your cat's fleas.

You'll generally notice signs and symptoms of cat-scratch disease one to two weeks after a cat scratch or bite. These include:

• A pus-filled sore at the site of injury
• Swollen and tender lymph nodes
• Fever
• Headache
• Fatigue

The disease rarely results in long-term complications. Symptoms may disappear without treatment, although your doctor may prescribe antibiotics.

You and your family can avoid cat-scratch disease by avoiding situations in which your cat might want to scratch or bite you — 90 percent of cat bites are provoked. Don't tease or taunt your cat or any other cat, and keep away from cats you aren't familiar with.

Toxoplasmosis
Toxoplasmosis is sometimes called litter box disease and results from contact with a parasite present in cat feces, soil or undercooked meat. Your cat won't have any signs or symptoms of the infection. Initial symptoms in you or your family might resemble those of the flu, though sometimes you won't experience any symptoms at all. Signs and symptoms include:

• Swollen lymph glands
• Fatigue
• Fever
• Headache

Don't let your cat wander freely outside your home, where it can eat infected animals, and don't feed your cat undercooked meat. Wash your hands after cleaning your cat's litter box. If you're pregnant, have someone else clean the litter box because the disease can cause miscarriage, premature births and mental retardation in newborns. Toxoplasmosis can be treated, even during pregnancy.

In addition, keep your cat and the neighbors' cats out of your garden. Cat feces in the soil can leave behind parasites, even if you've cleaned up after them. Always wash your hands thoroughly after gardening. Also, cook meats thoroughly before you eat them. Toxoplasmosis is more often transmitted by undercooked meat than by cats.

Toxocariasis
Toxocariasis is a parasitic infection caused by roundworms. Although roundworms are most common in dogs, they're also found in cats. The infection usually doesn't cause symptoms in adults, although it can cause a variety of problems in children, including allergy-like signs and symptoms such as:

• Hives
• Muscle pain
• Fever
• Cough
• Wheeze
• Abdominal pain

In rare cases toxocariasis can lead to partial blindness and swelling of the organs and central nervous system.

To prevent toxocariasis, always clean up after your dog so feces aren't left on your lawn, where your children might play. Because the parasite can live in soil and sand, cover your sandboxes so dogs and cats aren't tempted to relieve themselves there. Have your dogs and cats treated regularly for worms, especially when they're young.

Q fever
The bacteria that causes Q fever is spread by cats as well as barnyard animals, such as cattle, sheep and goats. You can catch Q fever by eating or touching contaminated meat or by inhaling air that contains particles of animal feces, blood or birth products, such as the placenta. Q fever causes flu-like signs and symptoms, including:

• Fever
• Headache
• Muscle pain
• Joint pain
• Dry cough

You're at a higher risk if you work around animals — such as at a slaughterhouse, meat packing plant or a veterinary office — or if you live on a farm or ranch. Your doctor will likely prescribe antibiotics for you or your child for Q fever.

Have your pets and farm animals checked regularly by a veterinarian. If you notice any unusual signs or symptoms of illness, call your vet.

The soft, furry bunnies your children might take a liking to sure are cute, but they also can transmit infection.

Tularemia is also known as rabbit fever. Rabbits and rodents are the most common carriers of the bacteria that cause tularemia. However, your cats and dogs can also contract tularemia from eating the internal organs of infected rabbits or coming into contact with infected fleas or ticks from rabbits. If your pet shows signs of illness, such as a loss of appetite or listlessness, take it to your veterinarian.

You and members of your family can be infected with tularemia if infected fleas or ticks move from your pets to you. Also, handling sick or infected pets can cause tularemia.

If you have tularemia, you'll likely notice:

• A red spot on your skin that gets bigger
• Enlarged lymph nodes in your groin and your armpits
• Headache
• Muscle pain
• Shortness of breath
• Fever

Don't let your pets loose outside unsupervised. Put a flea and tick collar on your cat or dog to reduce the chance that they'll bring fleas and ticks into your house. You and your pets should avoid direct contact with wild animals — both dead and alive — as well as with their droppings.

Your pet snake or iguana may be confined to a cage most of the time, but that doesn't mean it can't get sick and infect you or your family.

Salmonella is the most common disease spread by reptiles. In people, this bacterial infection commonly leads to gastroenteritis, an inflammation of the stomach and intestine. Common symptoms include diarrhea and vomiting.

All reptiles can carry salmonella. Turtles and iguanas are the most common reptilian sources of the infection. Amphibians, such as frogs and toads, can also carry salmonella.

Salmonella can be serious in children younger than 5 and people with weakened immune systems. The organism can also leave the intestinal tract and invade other organs, which can lead to a more serious form of the disease.

The Centers for Disease Control and Prevention recommends keeping reptiles and amphibians outside your house if you have children under the age of 5 or if you're pregnant. Always wash your hands after handling reptiles, amphibians or their cages. Don't let your pet reptiles and amphibians roam your home, and keep them out of your kitchen.

Birds can pass diseases on to you and your family, as well.

Parrot fever
Parrot fever (psittacosis) is a bacterial disease that affects more than 100 species of wild and domestic birds, including parrots, macaws, cockatiels and parakeets. Though some birds with psittacosis don't display any signs or symptoms, others lose feathers or change their eating habits.

In humans, psittacosis signs and symptoms include:

• Cough
• Chest pains
• Fever
• Chills
• Headache
• Muscle pain

You or your child can contract the infection through even brief contact with bird feces or with the dust that accumulates in birdcages. This dust, which can remain infected for several months, may become airborne and be inhaled. Psittacosis is also transmitted by bird bites, holding your bird or touching your mouth to your bird's beak. Treatment for both your family and your bird includes antibiotics.

To prevent parrot fever, regularly rinse and refill your bird's water and food dishes and clean the cage daily. If you have two or more birds, keep their cages away from each other. That way the birds can't pass psittacosis to each other by dropping feces or feathers into each other's cages.

Cryptococcosis
Cryptococcosis is a fungal disease transmitted to humans when they inhale organisms found in bird droppings, especially from pigeons. Playing, working or being near places where birds gather can put you and your family at risk. The dried droppings from birds can become stirred up, creating an airborne dust that you can inhale.

It's likely you won't notice any signs or symptoms after contracting cryptococcosis. But some people might notice:

• Confusion
• Dizziness
• Headaches
• Sleepiness

Your dog and cat can get sick from inhaling cryptococcosis, too. But cats and dogs can't pass it on to you.

Just because you can't cuddle them doesn't mean your fish can't make you sick.

Mycobacteria
Mycobacteria, such as Mycobacterium marinum, can be found in aquariums. Infection usually occurs when cuts on your hands or arms are exposed to contaminated water. Though infection is deadly in fish, it's rare in humans and usually produces only mild symptoms. People with AIDS and other diseases of the immune system are especially susceptible to infection, though. Mycobacteria can cause tender, raised bumps on your hands and wrists. Sometimes these bumps contain pus or turn into lesions. Mycobacteria in people can be treated with drugs, though it usually clears up on its own.

In fish, mycobacteria infection isn't curable. Most likely your veterinarian or local aquarium store will recommend isolating your infected fish or disposing of them. Wear gloves if you have to put your hands into water you believe is contaminated with mycobacteria, and don't handle infected fish without wearing gloves. A fish tank that's been contaminated with mycobacteria should be cleaned thoroughly before you refill it and place new fish inside. You can purchase special mycobacteria-removing-cleaner at your local aquarium store.

While catching a disease from your pet is rare, certain groups of people are more likely than others are to become seriously ill from a pet. Talk to your doctor before you get a pet if you have:

• Children ages 5 and younger. Young children are prone to picking up germs because they spend time crawling on the ground and don't wash their hands as frequently as adults. Teach your children the importance of frequent and thorough handwashing. The Centers for Disease Control and Prevention recommends that you refrain from keeping reptiles and amphibians as pets if you have children 5 and younger, and keep children that young away from farm animals and petting zoos.
• Had an organ transplant. If you've had organ transplant surgery, wash your hands thoroughly after handling your pet. If possible, have someone else clean up after your dog or clean your cat's litter box. Wear gloves when cleaning bird cages or fish tanks, and avoid contact with reptiles and exotic pets, such as monkeys.
• HIV/AIDS. Wash your hands after playing with your pet. Have someone else clean up after your pets, or wear gloves to protect your hands. If you're getting a new pet, avoid animals younger than 6 months old — younger animals are at a higher risk of infections just as younger children are. If your pet has diarrhea, have someone who is not infected with HIV take your pet to the veterinarian. Diarrhea could be a sign that your pet has an infectious disease.

Talk to your doctor and veterinarian about specific ways you can protect your family and your pets from infections. Keep your family and your pets up-to-date with their vaccinations. Knowing how to prevent infections from spreading from your pets to your family can lead to a greater sense of security, helping you enjoy your companion animals even more.