This blog was published by Caroline Johnson but written by Dawn Prime SQP

Introduction

A zoonoses is a term commonly used to describe a disease which is transferable from companion animal to human and can be associated with dogs, cats, rabbits, guinea pigs, birds, reptiles, amphibians, and even tropical fish. 

Despite many owners not hearing of it, zoonotic diseases can be common. They diseases can be transmitted in several ways including scratches, bites, by direct contact and through contaminated faeces and urine.

Here is a guide to some of the more common zoonotic diseases we see and the all-important symptoms we should make pet owners aware of. 

Toxocariasis- Roundworm

Toxocariasis is a zoonotic disease transmitted from animals, such as dogs and cats, to people. 

It is caused by a parasitic roundworm found in the animal’s intestine. Animal owners, particularly young children, are commonly affected with roundworms (from handling animals) as the eggs are spread in the faeces. 

Many people do not show symptoms or are sick. However, two illnesses can occur. 

Firstly, Ocular Toxocariasis: This occurs when the Toxocara larvae migrate into the eye, causing retinal granuloma, macular edema or retinal detachment. 

The second is visual toxocariasis. This occurs when the Toxocara larvae migrates to other organs in the body such as the liver and the central nervous system. Symptoms of this include coughing, wheezing, abdominal pain, fever, headaches, and behavioural changes.

Salmonellosis- Salmonella

Salmonella is a bacteria that affect many distinct species of animals and humans. Dogs and cats that eat raw meat could potentially be at risk, depending how the raw meat is prepared*. 

Salmonella has been identified in companion animals, cattle, pigs, poultry, reptiles and even some tropical fish. 

The most common way that animals acquire salmonella is from eating contaminated food. Salmonella can be transmitted both from animal to humans and humans to animals. Contamination is often from an animal origin, from meat or eggs, or from vegetables, where manure has been used to fertilise the crop. 

Humans can be contaminated by direct contact with other infected humans or animals. Children, the elderly, and people with impaired immunity are particularly susceptible. The incubation period is between one and three days, but the illness can last up to ten days. 

Salmonella can cause severe abdominal pain, cramping, diarrhoea, fever, sickness and in severe cases, death can occur due to secondary problems. Once infected, whether the person shows symptoms or not, humans can continue to excrete the bacteria for between four and six weeks. 

Rabies

Rabies, a viral infection that affects the central nervous system, is very uncommon in the UK. It is not usually seen in our wildlife or domestic animals, thought there have been reports of rabies found in a Daubenton’s bat in recent years. Rabies is passed through bites or scratches, so it is unlikely to be passed human to human. 

Rabies in people can cause severe headaches, fever, anxiety, muscle spasms and can lead to hallucinations and respiratory failure. The incubation period is between two and eight weeks. Unfortunately, rabies is mostly fatal.

Psittacosis disease (Chlamydophila psittaci)

Humans can contract this zoonosis from birds, particularly species of domestic birds including parrots, budgerigars, cockatiels, doves, and pigeons. 

The disease is contracted from exposure to airborne particles of faeces or feather dust from infected birds. Psittacosis is an acute respiratory disease with an incubation period of between one and four weeks.

The symptoms in people can vary; they can be mild to severe. It can be more significant in the young, elderly and those with underlying health conditions. Symptoms include headache, fever, and respiratory tract problems. 

Bartonellosis (cat scratch disease)

Bartonellosis is caused by a bacteria carried in the blood of cats and can be transmitted to other animals and humans. Humans can contact Bartonellosis from a cat bite or a cat scratch. Cats get the bacteria from the bites of ticks, fleas or from rodents. 

The site of the scratch can result in the nearest lymph gland swelling. More serious infections can occur weeks later causing a non-painful, circular raised area, resulting in the lymph nodes around the infected area becoming swollen and painful.

Symptoms of cat scratch disease include flu like symptoms, headaches, and aching joints. The disease can be avoided by thoroughly cleaning and disinfecting any bites or scratches, with the main treatment for this being antibiotics. 

Tularaemia- Pasteurella

Tularaemia is an infection caused by Francisella tularensis. It affects a variety of animals such as small rodents, rabbits, and hares. Humans can be infected if they are bitten by an infected tick or by contact with infected animals. Bacteria break through the broken skin or can be inhaled.

The symptoms include enlarged lymph nodes, general aching, fever, skin ulcers, throat infections and occasional pneumonia. The disease cannot be passed human to human. Most symptoms will occur between three and five days after infection but can take up to two weeks to occur.

Hydatid disease

Hydatid disease is better known as the tapeworm whose lifecycle can involve several species; it needs a host to maintain the lifecycle (such as a dog or a human).

Hydatid disease in humans is caused by the larvae stage of the dog tapeworm Echinococcus granulosus, when the eggs are excreted in the faeces of infected animals and ingested by a human. This can occur after managing an animal or its faeces, or when a dog is licking a person’s face after cleaning itself. 

The eggs are extremely resistant and can survive in the ground for at least a year. The eggs, once ingested, hatch in the intestine, penetrating the gut wall where they move about. The eggs hatch into larvae which form cysts. The cysts are most often found in the liver but can infect other organs such as brain and the heart.

Hydatid disease in humans can occur but it is rare. It is not spread person to person. Symptoms can take years to show, depending on the site of infestation, and can include abdominal pain, fever, skin problems and allergic reactions. 

Toxoplasmosis

 Toxoplasmosis is caused by the protozoan parasites Toxoplasma gondii and can be transmitted to humans by eating undercooked contaminated meat hence spreading from animal to human. 

Infection from cats is the most common cause; cats become infected after eating small birds or rodents. The parasite is then passed out of the cat in the faeces as an oocyst. The toxoplasmosis cat will then infect any area where it defecates, including its litter tray, the soil, and other outside environments. 

Toxoplasmosis can be transmitted to humans from contact with cat faeces, including contaminated soil in the garden. Toxoplasmosis has significant and profound consequences for pregnant women, as the infection can pass to the unborn child, which can cause diseases of the nervous system and eyes.

The disease is not transmitted from person to person, except in utero, which means when an infection of the foetus occurs. The mother will often have no symptoms and it is believed that a sizeable proportion of this disease goes unnoticed.

Dermatophytosis (Ringworm)

Ringworm is one of the most common zoonotic diseases affecting cats, dogs, cattle, and guinea pigs. It can also be acquired indirectly from a contaminated environment.

Dermatophytosis is a fungal infection of the skin, hair, and nails, and is spread by direct human to human contact and animal to animal contact. In humans you will see a red rash that is itchy. An itchy red rash and hair loss can occur on animals. It is highly contagious, and symptoms appear four to fourteen days after exposure. Treatment is with an antifungal cream.

Sarcoptic manage

Sarcoptic mange is easily passed from animals to humans by direct contact. It is a common skin disease in dogs and other companion animals. 

This skin condition is caused by mites that live under the skin, which cause severe itchy red bumps or blisters. The most common type of mange in humans is scabies and although treatable, it is highly contagious and can result in reinfection. 

The mites can live on the skin for ten to seventeen days. Infections in humans are usually self-limiting but it is strongly advisable for customers to visit their doctor. 

Cats and dogs can be treated under veterinary care after diagnosis in their owners.

Leptospirosis  

Leptospirosis is a bacterial disease, spread by urine from infected animals. Rats are the main carrier of the disease, transmitting this to other animals including dogs and cattle via infected urine or contamination of water sources. Dogs and cattle that have been infected with leptospirosis can be carriers for the disease over a prolonged period. 

It is spread in contaminated water supplies, urine, pastures, and soil. The disease can also be contracted by managing aborted foetuses or after birth membranes and without the handler using personal protective equipment. 

Leptospirosis can be treated by a penicillin medicine. Those affected can have flu like symptoms, severe headaches, chills, muscle aches, abdominal pains, diarrhoea, kidney disease and even inflammation of the brain and spinal cord. In rare cases, death can occur.

What practical advice can SQPs offer?

The main defence against zoonoses is educating pet owners about these diseases. As SQPs we not only have an obligation to consider animal health and welfare, but we also have an obligation for the health of the customer too. You can offer the following advice to customers:

• Ensure all pets in the household have regular flea and worm treatment. There are many distinct types of fleas and worm treatment available, so it is desirable we discuss the right course of action and a plan for clients. 
• Maintain hygiene standards, (especially for young children) like washing hands after contact with all animals.
• Wear gloves when overseeing faeces, this includes cats litter trays. Pregnant women should avoid managing any cat’s faeces or litter trays, due to the risk of Toxoplasmosis (see above). 
• Dispose of faeces in an appropriate manner and wash hands afterwards. 
• Use suitable disinfectant solutions for a prominent level of hygiene. 

If your customer is concerned about their pet or that they are showing signs of a zoonotic disease, then it is vital they seek veterinary advice to prevent any disease from spreading. 

If their pet has a confirmed zoonotic disease or the customer is showing signs of a zoonotic disease, then they must seek medical advice from their pharmacist or Doctor. 

*For more information on the safe feeding of raw food, we recommended Natures Menu CPD modules which can be found via the Accredited CPD Page on our website.

YOU MAY CLAIM 30 MINUTES OF ACCREDITED CPD AFTER READING THIS BLOG.