In OTC

Follow this topic

Bookmark

Record learning outcomes

Parasites such as fleas, ticks and worms pose more than just a simple irritation to pets and their owners – they can be vectors of serious, even fatal, diseases

 

 

 

The British Small Animal Veterinary Association (BSAVA) “strongly recommends” that companion animals are regularly treated against parasites, both internal (e.g. worms) and external (e.g. fleas, ticks), in the interests of animal health and welfare and, in the case of zoonotic infections, to minimise the risk to human health.

Infestations are highly seasonal, with the existence of two peaks in the UK – one in March to June and a second in August to November.

“Pets need treatment all year round. Some people think pets don’t need to be treated in the winter but fleas can survive in the carpet,” says Amanda Wilding, campaigns adviser for PDSA (the UK veterinary charity), “and cats that go outdoors need to be treated more regularly than household cats. 

“Last year three million pets weren’t protected against worms and another three million against fleas. People don’t realise that they can be passed on together. You need to treat both of these parasites, not just one or the other – the two go hand in hand.”

Fleas

Fleas are common among dogs, cats and other pets such as rabbits and ferrets, particularly in households that keep a number of pets. Flea bites cause pruritus – particularly in those animals that are sensitised – and have been known to cause anaemia in animals when the infestation is particularly heavy. And they are not just a problem for pets, as they can transmit zoonotic infections to humans.

Worms

Worms, or helminths, can be classified as intestinal worms (ascarids, hookworms, trichuris vulpis and tapeworms) and non-intestinal worms (heartworms, lungworms, subcutaneous worms and eye worms).

As most are transmitted via eggs or larvae in the faeces, key aspects of prevention are centred round hygiene measures – especially cleaning up pet faeces regularly – and ensuring pets have an appropriate diet and fresh water to prevent parasitic infections being transmitted via raw meat. Preventing access to rodents will also help.

The risk of infestation is life-long, so prophylaxis must be continued throughout the animal’s life

Despite this, many pets remain unprotected. Cases of lungworm appear to be on the rise. In September the PDSA issued a warning to dog owners saying that confirmed cases of lungworm had trebled in just five years. First reported in indigenous dogs in England in 1980, lungworm has since spread to Wales and south-east England.

More recently cases have been reported beyond these traditional ‘hotspots’ in the West Midlands, northern England and Scotland. Lungworm, or Angiostrongylus vasorum, can cause weight loss, breathing difficulties, chronic cough and difficulty exercising.

As well as causing these cardio-respiratory symptoms, it can also interfere with blood clotting leading to haemorrhage. Lungworm can be fatal. The larvae of lungworm are carried by slugs and snails, which can be eaten by dogs when rummaging through undergrowth.

It is believed that the increase in lungworm is due to more damp weather increasing the slug and snail population, says Amanda Wilding. “It is not just ingestion – any sort of contact can spread the larvae, such as drinking from a puddle that a slug has passed through.” A spokeswoman at the National Office of Animal Health (NOAH) agrees.

“Increasing slug and snail numbers combined with increased pet movement and urbanisation of foxes are all likely to have played a significant part. These factors make lungworm a year-round rather than a seasonal threat.”

Ticks

Ticks are temporary blood feeding parasites, which spend a variable amount of time on their hosts. Female ticks increase their weight up to 120 times as they engorge with blood prior to laying eggs. Measuring up to 1cm in length, they are easy to see.

Ticks can be found all over an animal’s body but they are most frequently found on the non-hairy and thin-skinned areas such as the face, ears and axillae. Tick bite wounds are prone to secondary infection or are sites for the development of micro-abscesses in cases where the tick is forcibly removed and the mouthparts remain embedded in the skin.

Blood loss in cases of heavy infestation can lead to anaemia. Ticks are vectors of bacteria, viruses, protozoa and nematodes, affecting both pets and humans.

 

 

Management regimens

According to guidelines published by the European Scientific Counsel Companion Animal Parasites (ESCCAP), the optimal choice of parasite management regimen should be influenced by a number of factors, including:

• Age of the animal: there is a greater risk among young and geriatric animals
• Reproductive status: Toxocara canis is commoner among pregnant and lactating dogs, and they can pass the larvae onto their puppies
• Health status (e.g. presence of, or history of, ectoparasite infection)
• Travel history, particularly where certain infections/infestations are more prevalent. Worryingly, diagnosis of non-endemic diseases can be difficult as vets may not be familiar with the symptoms and signs.

According to Dr Sally Everitt, BSAVA’s head of scientific policy, the environment and lifestyle of a pet will influence its specific risk – so it is “very important that owners consult their veterinary surgeon to discuss the appropriate prevention and treatment for individual animals”.

If prophylaxis is insufficient and a flea infestation occurs, the home should be treated as well as the pet. Regular vacuuming with safe, considered disposal of vacuum cleaner contents, washing of bedding, restriction of the pet’s access to recognised ‘hot spots’ and use of products on the pet itself will all help to keep an infestation under control. Limiting access to wildlife is also important.

Application of ectoparasiticides to the animal will target adult fleas, while treatment of the home will target fleas in their developmental stages. Elimination of pupal stages can be difficult, because they tend to be in hard-to-reach locations, such as the base of carpets.

Environmental measures should be focused on those areas inhabited most frequently by the animal. Combing for fleas can help to monitor levels of infestation. Pharmacists can educate pet owners on specific measures to prevent zoonotic disease.

According to the ESCCAP guidelines, a number of important measures should be adopted including:

• Good personal hygiene, such as washing hands after contact with animals and before eating food
• Repeated preventive treatments and/or regular diagnostic testing
• Cleaning up pet faeces to limit environmental contamination (including proper disposal; avoid disposal in recyclable waste or compost)
• Minimising exposure of children in particular to potentially contaminated environments, as well as teaching them good hygiene and keeping their nails short
• Regular grooming of dogs to limit contamination of their coat.

Special care should be taken by those individuals who are more susceptible to zoonotic disease, such as those who are immunocompromised (e.g. the elderly, people with diabetes or HIV, people undergoing immunosuppressive chemotherapy, organ transplantation), other susceptible groups (e.g. pregnant women, the very young) and people with a specific occupational risk such as farmers, kennel workers and hunters.

Prevention is better than cure, says Amanda Wilding. “Zoonotic diseases can get passed on from the pet to the owner, so hygiene is very important. Toxoplasmosis can be passed on through worms in the faeces of infected cats. Pregnant women need to be particularly vigilant.”

 

 

Animal health in pharmacy

A spokeswoman for NOAH says there is a strong case for maximising the animal health category in pharmacy, noting that pharmacists are in a unique position to dispense advice. “Thirteen million households have pets, so there are a lot of pet owners coming through the doors of pharmacies. There is a captive audience to pick up a leaflet or look at a TV screen broadcasting relevant content while they are waiting for a prescription to be dispensed.”

Writing in PJ Online a number of years ago, Michael H Jepson, co-editor of Veterinary Pharmacy, pointed out that pharmacists are in a key position to act as a link between pet owners and other health professionals as appropriate.

“Professional co-operation with veterinary surgeons and their practices is of paramount importance and is of special benefit to the animal “patient” and owner. Diagnosis and therapeutic treatments are understandably the main prerogative of veterinary surgeons, but disease prevention and prophylactic control is not so restricted.”

Potential areas in which pharmacists can contribute include animal contact and public health, routine prophylactic treatment of parasites, advice on hygiene and issues about zoonoses, guidance on dosage and administration, information on welfare and travel, and the need for prompt referral to a vet when necessary, he wrote.