Table 1.

Important infections caused by bites, scratches and licks from dogs and cats

Disease	Aetiology	Transmission	Incidence	Severity	Presentation
Rabies	Lyssavirus spp. in saliva	Dog bites in developing world, bat bites in developed world. Rarely cats	Extremely rare in developed world	Near 100% mortality	1–3-month incubation period followed by flu-like illness, hyperactivity, hydrophobia and reduced consciousness
Capnocytophaga sepsis	C. canimorsus in saliva	Dogs >cats saliva	Rare	Severe; 30% mortality	Fulminant sepsis. Occasionally meningitis and endocarditis. Rarely wound infection
Gram-positive/anaerobic infection	Various, including staph species, strep species and anaerobes	Contamination of wound by skin flora	Uncommon	Variable	Frequently self-limiting localised cellulitis, occasionally systemic sepsis, ie, MRSA, anaerobic sepsis in the immunocompromised
Pasteurellosis	Pasteurella spp. in saliva	Dog or cat bites, scratches or licks, often occult	Common: most frequent isolate from bites	Mild to moderate	Rapid-onset cellulitis, septic arthritis proximal to wound, osteomyelitis, occasionally pneumonia and severe sepsis
Brucellosis	Brucella spp (B. canis from dog saliva)	Exposure to body fluids from domestic animals (especially farm settings), consumption of unpasteurised dairy products	Rare in developed world, most common zoonosis worldwide	Mild	1–4-week incubation; broad range of symptoms ranging from asymptomatic to fever, arthralgia and severe sepsis
Cat scratch disease	Bartonella henselae in saliva	Cat bites, scratches and licks. Occasionally flea bites	Common, especially in children and young adults	Mild	Inoculation site lesion followed by regional lymphadenopathy; occasionally disseminated disease

MRSA, methicillin-resistant staphylococcus aureus; Staph, staphylococcus; Strep, streptococcus.