Page 1564 - Small Animal Internal Medicine, 6th Edition

1536 PART XIV Infectious Diseases

BOX 99.2
VetBooks.ir General Guidelines for Pet Owners to Avoid Zoonotic Transfer of Disease

• If a new pet is to be adopted, the dog or cat least
• Clinically ill animals should not be handled by
likely to be a zoonotic risk is a clinically normal, immunocompromised people, if possible.
arthropod-free, adult animal from a private family. • Pets should be maintained within the home environment
• Once the animal to be adopted is identified, it should to lessen exposure to other animals that may carry
be quarantined from any immunocompromised person zoonotic agents, exposure to excrement of other
until a thorough physical examination and zoonoses animals, and exposure to fleas and ticks.
risk assessment is performed by a veterinarian. • Pets should only be fed commercially processed food.
• Veterinary care should be sought for all clinically • People should not share food utensils with pets.
ill pets. • Avoid being licked by animals.
• Physical examination and fecal examination should be • Claws of cats should be clipped frequently to lessen the
performed at least once or twice yearly. risk of skin penetration.
• Fecal material produced in the home environment • To lessen the risk of bites and scratches, do not tease
should be removed daily, preferably by someone other or physically restrain dogs and cats.
than an immunocompromised individual. • If bitten or scratched by a dog or cat, seek medical
• Use litterbox liners and periodically clean the litterbox attention.
with scalding water and detergent. • Control potential transport hosts, such as flies and
• Do not allow dogs or cats to drink from the toilet. cockroaches, that may bring zoonotic agents into the
• Wear gloves when gardening and wash hands home.
thoroughly when finished. • Cook meat for human consumption to 80° C for 15
• Filter or boil water from sources in the environment. minutes minimum (medium-well).
• Wash your hands after handling animals. • Wear gloves when handling meat and wash hands
• Do not handle animals that you are unfamiliar with. thoroughly with soap and water when finished.

the defecation habits of cats. Human infection after direct study in Florida (Liotta et al., 2012). After the passage of
contact with dogs or cats is extremely unlikely because the hookworm eggs into the environment in feces, infectious
eggs are not immediately infectious. larvae are released after incubating for 1 to 3 days; humans
Dogs and cats can be subclinically affected or may develop are infected by skin penetration. In addition, eosinophilic
poor haircoats, poor weight gain, and gastrointestinal signs. enteritis in humans was reported after ingestion of larvated
In people, eosinophilic granulomatous reactions involving A. caninum eggs (Landmann and Prociv, 2003).
the skin, lungs, central nervous system (CNS), or eyes then Animals are either subclinically ill or have nonspecific
occur, potentially leading to clinical signs of disease. Clini- signs such as poor haircoats, failure to gain weight, vomit-
cal signs and physical examination abnormalities in affected ing, or diarrhea. Heavily infected puppies and kittens may
individuals include skin rash, fever, failure to thrive, CNS have pale mucous membranes from blood loss anemia. In
signs, cough, pulmonary infiltrates, and hepatosplenomeg- humans, the larvae cannot penetrate the dermoepidermal
aly. Peripheral eosinophilia is common. Ocular larva migrans junction and usually die in the epidermis. Clinical signs are
most commonly involves the retina and can cause reduced related to migration of the larvae, which results in an erythe-
vision; uveitis and endophthalmitis can also occur. Visceral matous, pruritic cutaneous tunnel. Cutaneous signs usually
larva migrans is most common in children between 1 and 4 resolve within several weeks. Abdominal pain is the most
years of age, whereas ocular larva migrans is most common common clinical sign in humans with A. caninum intestinal
in older children. Diagnosis in human beings is confirmed infection.
by biopsy or can be presumed in cases with classic clinical Trichuris vulpis, the dog whipworm, is most commonly
manifestations, eosinophilia, and positive serology. associated with large-bowel diarrhea in dogs. The organism
Ancylostoma caninum, Ancylostoma braziliense, Ancylos- is common in dogs of the United States (overall prevalence
toma tubaeformis, Uncinaria stenocephala, and Strongyloides = 1.2%; Little et al., 2009) and has been detected in feces in
stercoralis have been associated with cutaneous larva migrans some people (George et al., 2017).
in the United States. Prevalence rates of hookworm infection Prevention of hookworms and roundworms is achieved
vary by the study and have changed over the years. In one by control of animal excrement in human environments. All
large study of more than 1 million dogs examined at 547 puppies and kittens should have a fecal flotation performed
private veterinary hospitals in 44 U.S. states, 4.5% of samples and should be routinely treated with an anthelmintic that has
contained eggs of Ancyclostoma spp. (Little et al., 2009). In efficacy against roundworms and hookworms. The Compan-
high-risk areas and animals, infection rates can be much ion Animal Parasite Council (http://www.capcvet.org) main-
higher. For example, A. tubaeforme and A. braziliense were tains current guidelines on how to optimally control zoonotic
found in feces of 26 of 40 (65%) of the feral cats tested in one parasitic infections of dogs and cats.