Page 1570 - Small Animal Internal Medicine, 6th Edition

1542 PART XIV Infectious Diseases

spp. was inoculated into cats, resulting in conjunctivitis and
persistent infection, suggesting that the isolate was a feline
VetBooks.ir strain. Occasionally the organism is associated with systemic
disease; atypical pneumonia was diagnosed in an apparently
immunocompetent 48-year-old man, malaise and cough
were diagnosed in an immunosuppressed woman, and endo-
carditis and glomerulonephritis were diagnosed in a 40-year-
old woman. Diagnosis is based on organism demonstration
by culture, cytologic documentation of characteristic inclu-
sion bodies, or fluorescent antibody staining of conjunctival
scrapings. Tetracycline- or chloramphenicol-containing eye
ointments are generally effective in the treatment of infec-
tion. Oral administration of doxycycline is still considered
the optimal way to clear the carrier state. Care should be
taken to avoid direct conjunctival contact with discharges
from the respiratory or ocular secretions of cats, especially
FIG 99.3 by immunosuppressed persons (see Box 99.2). Employees
Sporothrix schenckii-associated skin lesions in a cat in should be directed to wear gloves or wash hands carefully
Colorado. when attending cats with conjunctivitis.
Humans are the principal natural hosts for Streptococcus
evidence suggesting that the three retroviruses of cats— group A bacteria; Streptococcus pyogenes is the most common
feline leukemia virus (FeLV), feline immunodeficiency virus cause of “strep throat” in humans. Dogs and cats in close
(FIV), and feline foamy virus (FeFV)—infect humans. In one contact with infected humans can develop transient, sub-
study, 204 veterinarians and others potentially exposed to clinical colonization of pharyngeal tissues and can transmit
feline retroviruses were assessed for antibodies against FIV the infection to other humans. However, this is poorly docu-
and FeFV, FeLV p27 antigen, and FeLV provirus; test results mented and believed to be unusual (Wilson et al., 1995). The
on all were negative (Butera et al., 2000). Because both FeLV organism can be cultured from the tonsillar crypts. Culture-
and FIV can induce immune deficiency, infected cats should positive animals should be treated with penicillin deriva-
be considered more likely than retrovirus-naïve cats to be tives. If animals are to be treated in a household with chronic,
carrying other potential zoonotic agents, particularly if recurrent “strep throat,” all humans should also be treated
gastrointestinal tract signs are present. because they could be chronic subclinical carriers.
Yersinia pestis and F. tularensis can be transmitted from
cats to humans in respiratory secretions. In endemic areas,
RESPIRATORY TRACT AND cats with clinical signs or radiographic abnormalities consis-
OCULAR ZOONOSES tent with pneumonia should be handled as plague or tulare-
mia suspects. Gloves, mask, gown, and eye protection should
BACTERIA be worn while performing transoral airway washings in
Bordetella bronchiseptica is a bacterium that induces respira- suspect cats.
tory tract infections in dogs and cats (see Chapter 21). The
classic clinical manifestation is tracheobronchitis, but the VIRUSES
organism can also cause pneumonia, sneezing, and nasal Influenza A viral infections have been detected in some cats
discharge. Humans rarely develop clinical disease caused after close exposure to infected birds (Leschnik et al., 2007).
by B. bronchiseptica unless they are immunologically com- In studies of naturally exposed and experimentally infected
promised (see Table 99.1). Most cases of B. bronchiseptica cats, some cats developed respiratory disease and others have
infection in humans have been in patients that were immu- become asymptomatic carriers. Results of studies assessing
nodeficient (Dworkin et al., 1999; Wernli et al., 2011). Borde- transmission between infected cats have been variable. Very
tella bronchiseptica infection in humans has been associated rarely, cats infected with an influenza virus are associated
with cats and dogs. Amoxicillin-clavulanate, chlorampheni- with clinical disease in humans (Lee et al., 2017).
col, enrofloxacin, and tetracycline derivatives are all effec-
tive treatments. Animals with upper or lower respiratory
tract inflammatory disease should be kept away from immu- GENITAL AND URINARY
nodeficient people until the animals are clinically normal. TRACT ZOONOSES
However, treated animals can still shed the organism.
Chlamydia felis (formerly Chlamydia psittaci) causes Coxiella burnetii is a rickettsial agent found through-
mild conjunctival disease and rhinitis in cats. Conjuncti- out the world, including North America (see Table 99.1).
vitis in humans after direct contact with ocular discharges Many ticks, including Rhipicephalus sanguineus, are natu-
from cats has been described. A human isolate of Chlamydia rally infected with C. burnetii. Cattle, sheep, and goats are