Despite our best efforts to maintain the cleanliness and well-being of our pets, such as dogs, cats, birds, hamsters, or even fish, they can still harbour bacteria and viruses that can have detrimental effects on human health.

Given the close relationship between humans and animals, it is crucial to understand the common routes through which people can contract infectious germs capable of causing zoonotic diseases. Some of these routes include:

Direct contact: This involves encountering the bodily fluids of an infected animal, such as saliva, blood, urine, mucous, or faeces. Direct contact can occur when petting or touching animals, or when receiving bites or scratches from them.

Indirect contact: This refers to coming into contact with environments where animals reside or move around, as well as objects or surfaces contaminated with germs. 

Vector-borne: This occurs when an individual is bitten by a disease-carrying tick, mosquito, flea, or other similar insects.

Foodborne: Contaminated food can lead to illness in both humans and animals, including pets. This can happen by consuming unsafe substances, such as unpasteurized (raw) milk, undercooked meat or eggs, or raw fruits and vegetables contaminated with faeces from an infected animal. 

Waterborne transmission occurs when individuals drink or come into contact with water that has been tainted by faecal matter from an infected animal. This mode of transmission can facilitate the transfer of pathogens between animals and humans.

Some common zoonotic disease

E. coli 

Escherichia coli (E. coli), a type of bacteria, is naturally present in the human intestinal tract and serves important functions. However, certain strains of E. coli can be harmful and lead to diseases, with E. coli O157 being the most common.

When infected with E. coli, individuals may experience symptoms such as diarrhoea, fever, abdominal cramps, nausea, and vomiting.

Young children are particularly susceptible to severe complications caused by E. coli O157, including kidney failure and even death.

The bacteria can be transmitted directly to humans through contact with the skin, fur, and feathers of animals that have been contaminated, particularly cows (especially calves), goats, sheep, and deer.

Cat-scratch disease

Also known as CSD, it is a condition that occurs when humans are infected by bacteria transmitted through bites, scratches, or when an infected cat licks an open wound.

While approximately 40 percent of cats carry these bacteria at some point in their lives, kittens are more prone to biting or scratching, increasing the risk of transmitting the infection to humans.

The presence of these bacteria can lead to a mild yet uncomfortable infection characterised by swelling and the formation of lesions at the site of the wound.

In addition, individuals with CSD may experience symptoms such as fever, headache, decreased appetite, and fatigue.

Mycobacterium marinum

This bacterial infection is acquired from water sources and primarily affects the fingers and hands, resulting in skin lesions. Individuals who handle fish or maintain home aquariums are particularly susceptible to contracting this illness.

Although rare, people with weakened immune systems are at risk of severe complications and even death from the infection. If you encounter any symptoms, it is advisable to promptly seek medical attention from your doctor.

Ringworm

This is a  fungal infection that affects the skin and scalp and can be transmitted between animals and from animals to humans through direct contact. Additionally, it can be contracted by touching contaminated objects or surfaces.

Individuals who contract ringworm may experience symptoms such as a scaly, reddened, circular rash accompanied by itching

Toxoplasmosis

Although typically harmless, toxoplasmosis can pose significant risks to certain individuals, particularly pregnant women or those with compromised immune systems. This infection can be contracted by coming into contact with the faeces of infected cats or consuming contaminated meat. While many individuals remain asymptomatic or unaware of the infection, it can manifest flu-like symptoms such as fatigue, nausea, a sore throat, and swollen glands.

Pasteurellosis

It is a zoonotic disease that arises from the bacteria belonging to the Pasteurella genus. It is prevalent among various animals such as chickens, cats, dogs, rodents, and livestock. Humans can contract this infection through animal bites, scratches, or contact with saliva. If left untreated, the infection can lead to complications like meningitis, ocular infections, and respiratory issues. Therefore, it is crucial to seek medical attention for significant animal bites or scratches.

Tapeworms

Also known as ribbon-like worms, they have the ability to inhabit the digestive tracts of both humans and animals. One common type of tapeworm, dipylidium caninum, is often found in dogs and cats. However, humans can occasionally experience this issue if they come into contact with fleas that carry tapeworm eggs. Fortunately, doctors can effectively treat this parasite using medication.