Zoonotic Diseases

As we all know, our dogs and cats comfort us, give us companionship, and become members of our families. With the popularity of dog and cat ownership increasing, the inherent risk of zoonotic infections affecting the health of both pets and human family members also increases.

A zoonotic infection refers to any disease that is transmittable between animals and humans. Even well-cared-for dogs and cats may harbor intestinal parasites that can be passed to people, specifically roundworms and hookworms. In fact, the incidence of human infection with these parasites is significant, estimated by the Centers for Disease Control and Prevention to be in excess of 10,000 cases per year in the US. Children are especially vulnerable to contracting parasitic infections. Almost 75% of pediatricians in the US have reported cases to the CDC.

Bacteria
HUMAN ANIMAL
Disease Route of Transmission Incubation Period Signs & Symptoms Species With Zoonotic Potential Incubation Period Clinical Signs
Brucellosis direct contact with infected animal tissue, inhalation, ingestion (unpasteurized milk) 1-21 days flu-like signs; cyclic fever; arthritis, orchitis; epididymitis; hepatomegaly; neurological, endocarditis dogs variable abortions; stillborn or weak newborns; retained placentas; placentitis; orchitis; epidiymitis; arthritis; lameness
Campylobacteriosis ingestion (contaminated food, fecal-oral) 1-10 days diarrhea with or without blood; fever; nausea; vomiting; abdominal pain; headache; muscle pain dogs, cats 3-25 days mucoid, watery, or blood-flecked diarrhea
Cat Scratch Disease direct contact (scratch or bite of cat) 3-20 days self-limiting; mild to severe skin rash at site of inoculation; lymphadenopathy; fever; malaise; fatigue cats 2-16 days no natural occurring disease reported
Chlamydiosis ingestion (fecal-oral); inhalation; direct contact unknown fever; headache; vomiting; abortion; pelvic inflammatory disease; septicemia; hepatitis; kidney dysfunction; disseminated intravascular coagulation cats 3-10 days fever; conjunctivitis; ocular discharge; corneal ulcers; rhinitis
Ehrlichiosis ticks 7-10 days headache; fever; chills; myalgia; vomiting; diarrhea; conjunctivitis; cough; confusion; children may develop a rash; severe symptoms in immunosuppressed patients dogs 1-20 days fever; lethargy; anorexia; petechiae; lameness; edema in hind legs; bleeding disorders
Leptospirosis ingestion (contaminated water); inhalation; direct contact (urine) 7-12 days biphasic illness; fever; headache; chills; severe leg myalgia; conjunctival injection; jaundice; aseptic meningitis; cough; dsypnea; acute renal failure; abortion dogs 4-12 days hemorrhagic syndromes; kidney disease
Listeriosis ingestion (contaminated food); direct contact 3-70 days in-utero death, premature births; newborns may develop meningitis, septicemia, respiratory disease; adults may develop rash, papules after handling infected newborns, placenta; fever; nausea; diarrhea dogs, cats 10 days to 3 weeks depression; anorexia; facial paralysis with profuse salivation, torticollis; strabismus; circling; incoordination; head pressing; abortions; death
Lyme Disease ticks 7-14 days “bulls-eye” rash with central clearing; malaise; fatigue; fever; headache; stiff neck; myalgia; arthralgia; lymphadenopathy; chronic recurring arthritis dogs 2-5 months lameness; arthritis
Plague direct contact; fleas; inhalation 1-6 days flu-like signs; enlarged tender lymph node; rapid pneumonia; respiratory failure; toxemia; shock; death dogs, cats 1-6 days high fever; extremely swollen lymph nodes; severe pneumonia; septicemia
Q Fever direct contact (infected body fluids); ingestion (unpasteurized milk); inhalation; ticks 10-40 days flu-like signs; profuse sweating; severe headache; pneumonitis but no cough or chest pain; hepatitis; osteomyelitis; arteritis; endocarditis; neurologic signs; thrombocytopenia; in-utero death; placentitis dogs, cats 1-3 weeks typically asymptomatic
Rocky Mountain Spotted Fever ticks 2-14 days fever; chills; malaise; headache; myalgia; vomiting; diarrhea; edema of the face or extremities; conjunctivitis; non-pruritic macular rash, may involve palms of hands or soles of feet; coma dogs 2-14 days fever; anorexia; depression; lymphadenopathy; dyspnea; diarrhea; vomiting; joint or muscle pain; edema of the face or extremities; petechiae of oral or ocular membranes; ataxia; paraparesis; seizures; renal failure; coma
Streptocococcosis ingestion (contaminated food); inhalation; direct contact hours to 3 days phryngitis; poderma; abscesses; cellulitis; endocarditis; polyarthritis; pneumonia; septicemia; streptococcal toxic shock syndrome dogs, cats varies mastitis; metritis; placentitis; abortion; septicemia; wound infection; polyarthritis; pleuritis; endocarditis; abscesses; pneumonia; meningitis; pyoderma; toxic shock; death
Tularemia ticks; deer flies; mosquitoes; direct contact; inhalation; ingestion 1-14 days flu-like signs; exhaustion; ulcerative lesion; enlarged painful lymph nodes; painful purulent conjunctivitis; abdominal pain; diarrhea; vomiting; chest pain; respiratory distress; pneumonia; sepsis; death dogs, cats 1-10 days sudden high fever with lethargy and anorexia; stiffness; reduced mobility; tachycardia; tachypnea; prostration and death; miliary white necrotic foci of liver, spleen or lymph node
Fungi
HUMAN ANIMAL
Disease Route of Transmission Incubation Period Signs & Symptoms Species With Zoonotic Potential Incubation Period Clinical Signs
Cryptococcosis inhalation (infected pigeion droppings) unknown typically asymptomatic dogs, cats unknown chronic rhinitis; sinusitis; lymphadenopathy; non-pruritic nodules on face; CNS disease; ocular lesions; osteomyelitis
Dermatophytosis direct contact 7-14 days “ringworm” raidsed, inflamed, pruritic, circular lesion with central clearing; alopecia; thick, discolored nails; may disseminate in immunosuppressed patients dogs, cats 2-4 weeks young animals most susceptible; small circular areas of alopecia; flakey skin; most species non-pruritic
Sporotrichosis direct contact; inhalation 3-12 weeks cutaneous form most common; nodule or pustule at site of inoculation; progresses to slow-healing ulcerations; infection follows lymphatic vessles dogs, cats 1 month cutaneous form most common; nodules develop into slow-healing ulcers; supperative lymphadenitis
Parasites
HUMAN ANIMAL
Disease Route of Transmission Incubation Period Signs & Symptoms Species With Zoonotic Potential Incubation Period Clinical Signs
Acariasis (Mange) direct contact 1-4 days severe pruritis on arms, chest, abdomen, thighs; macules, papules, pustules; possible severe painful dermatitis with allergic reactions and chronic lesions dogs, cats 10-60 days pruritic; secondary pyoderma; depressions; anorexia; chronic infection may lead to yperkeratotic lesions
Baylisascariasis injestion (fecal-oral) 7-30 days symptoms vary with number and location of larvae; fever; nausea; lethargy; hepatomegaly; pneumonitis; neurological signs; brain damage; blindness; death dogs 10-20 hours usually asymptomatic
Cysticercosis ingestion (fecal-oral) 10 days to years symptoms vary with number and location of larvae; chronic headaches, seizures most common; stroke; focal neurological signs; blurred vision; death dogs, cats 10 days to 6 months severity of clinical signs depend upon number and location of larvae; neurological signs
Echinococcosis ingestion (fecal-oral) months to years signs associated with mass lesion; liver and lungs most common; abdominal pain; vomiting; jaundice; liver failure; cough; chest pain; blindness; seizures dogs, cats unknown asymptomatic
Giardiasis ingestion (contaminated water, fecal-oral) 1-25 days sudden onset of diarrhea with foul-smelling stools; abdominal cramps; bloating; flatulence; nausea; fatigue; dehydration; chronic infections may occur dogs, cats 5-14 days adults may be asymptomatic; young animals: diarrhea or soft stools; poor hair coat; flatulence; weight loss or failure to gain weight
Larva Migrans (cutaneous) (Hookworms) direct contact 7-14 days pruritus; winding threadlike cutaneous lesion with erythema and swelling dogs, cats 7-20 days disease will vary with parasite burden and age of the animal; sever in puppies; diarrhea; anorexia; emaciation; weakness; poor hair coat; anemia; interdigital dermatitis; death
Larva Migrans (visceral, ocular) (Roundworms) ingestion (fecal-oral) weeks to months severe in young children; fever; cough; hepatomegaly; pneumonia; ocular invasion; vomiting; weakness; anorexia; arthralgia; myalgia; lymphadenopathy dogs, cats 30 days severe in puppies and kittens; lack of growth; loss of condition; “potbellied” appearance; parasites in vomit and feces; pneumonia; diarrhea
Leishmaniasis sand flies 7 days to years cutaneous: papule; ulcer; may be chronic; visceral: prolonged undulant fever; splenomegaly; hepatomegaly; fatal if untreated dogs, cats 3 months to years cutaneous form; non-pruritic exfoliative dermatitis around eyes, ears; cutaneous lesions; fever; anemia; lymphadenopathy; weight loss; ocular lesions; splenomegaly
Toxoplasmosis ingestions (fecal-oral, undercooked meat) 5-23 days flu-like signs; fetal death; congenital abnormalities, hydrocephaly, microcephaly); severe in immunocompromised patients; encephalitis cats unknown usually asymptomatic; lethargy; persistent fever; anorexia; incoordination; paralysis; retinal detachment; death
Trichuriasis ingestions (fecal-oral) variable often asymptomatic; may develop chronic diarrhea; abdominal pain; nausea; vomiting; flatulence; headache; weight loss; anemia; children may develop rectal prolapse dogs 10-12 days usually asymptomatic; mucoid or hemorrhagic diarrhea; weight loss; unthriftiness; anemia
Viruses
HUMAN ANIMAL
Disease Route of Transmission Incubation Period Signs & Symptoms Species With Zoonotic Potential Incubation Period Clinical Signs
Lymphocytic Choriomeningitis direct contact (abraded skin, bites); inhalation 5-21 days usually asymptomatic or mild self-limiting flu-like signs; aseptic meningitis; meningoencephalitis; orchtis; arthritis; ocular lesions; neurological dogs 5-6 days usually asymptomatic, glomerulonephritis; weight loss; ruffled fur; hunched posture; ascites; blepharitis; death
Rabies direct contact (infective saliva into break in skin, on mucous membranes); organ transplant 1-3 months headache; fever; malaise; abnormal behavior; paresis or paralsis; difficulty swallowing; delirium; convulsions; death dogs, cats 1- days to 6 months restlessness; anorexia or increased appetite; vomiting; fever; ataxia; incoordination; ascending paralysis; increased aggression; death