| Pathogen | Key pet sources | Disease in high-risk patients (age < 5 or ≥ 65 yr, immunocompromised or pregnant) | |
|---|---|---|---|
| Incidence | Severity | ||
| Bacterial diseases | |||
| Bartonella species | Cats (B. clarridgeiae, B. henselae); rodents, rabbits, and dogs (B. alsatica, B. vinsonii species) | Low (likely underdiagnosed) | Low to high |
| Brucella canis | Dogs | Rare | Moderate |
| Campylobacter jejuni | Dogs, cats (likely other species) | High | Low |
| Capnocytophaga canimorsus | Dogs, cats | Rare | High |
| Chlamydophila psittaci | Birds | Rare | Moderate |
| Leptospira interrogans | Dogs, cats, rodents | Low | Moderate |
| Multidrug-resistant bacteria (e.g., MRSA, Clostridium difficile, ESBL-producing organisms) | Likely all species (although data limited) | Variable | Variable |
| Mycobacterium marinum | Fish | Rare | Low |
| Pasteurella multocida | Dogs, cats | Moderate | Moderate |
| Salmonella species | All species; high prevalence in amphibians, reptiles, exotic animals, rodents and young poultry, in addition to certain raw pet foods (e.g., meat, eggs and animal product treats, such as pig’s ears) | Moderate | Moderate (particularly in newborns and patients with sickle cell anemia) |
| Parasitic diseases | |||
| Cutaneous larva migrans (hookworms; canine and feline) | Dogs, cats (particularly juvenile animals) | Low to high (depending on geography) | Low |
| Cryptosporidium species | Dogs, cats, possibly birds | Moderate | Moderate |
| Echinococcus species | Dog, cats | Rare | High |
| Giardia duodenalis | Dogs, cats | Moderate (species-specific assemblages; some shared by people and animals) | Low |
| Ocular or visceral larva migrans (roundworms; Toxocara canis [dogs] and T. cati [cats]) | Dogs, cats (particularly juvenile animals) | Low to moderate (depending on geography) | Low to high (particularly among children) |
| Toxoplasma gondii | Cats (although food and environment are main sources) | Moderate | High (particularly among pregnant women and very immunocompromised patients) |
| Fungal diseases | |||
| Dermatophytes (Microsporum canis, Trichophyton mentagrophytes) | Cats (other species possible, but less common) | High | Low |
| Viral diseases | |||
| Lymphocytic choriomeningitis | Rodents (particularly mice and hamsters) | Rare | Moderate to high (particularly among pregnant women and immunocompromised patients) |
| Rabies | Any mammal (particularly unvaccinated cats and dogs) | Rare | High |
Note: ESBL = extended-spectrum β-lactamase, MRSA = methicillin-resistant Staphylococcus aureus.