Toxascaris leonina

Distribution:

Everywhere in Europe.

Infection:

Final hosts are dogs, cats and foxes and infection is via ingestion of embryonated eggs from soil or larvae from paratenic hosts.  In dogs, the pre-patent period is about 8 weeks and patent period 4–6 months.  In cats, the pre-patent period is about 13 weeks and the patent period is 4–6 months.

Clinical signs:

Mostly asymptomatic.

Diagnosis:

Egg detection by flotation from 3–5 g fresh or fixed faeces.  Coproantigen assays detect infections from immature and adult worms, and are not linked to egg production.  This enables identification of infections during pre-patent periods and alleviates challenges of intermittent egg shedding associated with microscopic examinations.

Zoonosis:

Yes, having been found in a few human instances.  Children at greatest risk.

Toxocara canis

Distribution:

Everywhere in Europe.

Infection:

Final hosts are dogs and foxes and the route of infection via ingestion of embryonated eggs from soil or on fur.  Larvae in milk or paratenic hosts.  In utero from dam.  Pre-patent period is variable, typically 21 days after prenatal infection; 27–35 days after lactogenic infection; 32–39 days after ingestion of eggs.  Patent period 4–6 months except where immunity intervenes for example in pups.

Clinical signs:

Low burden asymptomatic, higher burden may appear as cachexia and pot-bellied appearance in pups.  Heavy infection can cause intestinal blockage or intussusception.  A low burden in older animals is unlikely to cause clinical signs.

Diagnosis:

Egg detection by flotation from 3–5 g fresh or fixed faeces.  Coproantigen assays detect infections from immature and adult worms, and are not linked to egg production.  This enables identification of infections during pre-patent periods and alleviates challenges of intermittent egg shedding associated with microscopic examinations.

Zoonosis:

Yes, children at greatest risk through ingesting soil bearing contaminated eggs.

Toxocara cati

Distribution:

Everywhere in Europe.

Infection:

Final hosts are cats and infection is by ingestion of embryonated eggs from soil, larvae in milk or paratenic hosts.  Pre-patent period is variable usually around 6 weeks after ingestion of eggs and patent period is 4–6 months.

Clinical signs:

Low burden asymptomatic, higher burden may appear as cachexia and pot-bellied appearance in kittens.  Large number of worms may cause intestinal blockage or intussusceptions.  Occasional pneumonia in kittens.

Diagnosis:

Egg detection by flotation from 3–5 g fresh or fixed faeces.  Coproantigen assays detect infections from immature and adult worms, and are not linked to egg production.  This enables identification of infections during pre-patent periods and alleviates challenges of intermittent egg shedding associated with microscopic examinations.

Zoonosis:

Yes, not as frequently transmitted as T canis.  Small children are at greatest risk.

Ancylostoma caninum

Distribution:

Predominantly in southern Europe, sporadic in northern Europe.

Infection:

Final hosts are dogs and foxes.  Ingestion of L3 from environment, larvae in bitches' milk or paratenic hosts.  Percutaneous infection of larvae.  Pre-patent period is 2–3 weeks and patent period can be prolonged depending on immune status.

Clinical signs:

Diarrhoea, bloody diarrhoea, weight loss and anaemia.  May be acute or chronic signs.

Diagnosis:

Egg detection by flotation from 3–5 g fresh or fixed faeces.  Coproantigen assays detect infections from immature and adult worms, and are not linked to egg production.  This enables the identification of infections during pre-patent periods and alleviates challenges of intermittent egg shedding associated with microscopic examinations.

Ancylostoma tubaeforme

Distribution:

Throughout Europe.

Infection:

In cats.

Clinical signs:

Diarrhoea, bloody diarrhoea, weight loss and anaemia. May be acute or chronic signs.

Diagnosis:

Egg detection by flotation recovered from fresh faeces.  Coproantigen assays detect infections from immature and adult worms, and are not linked to  egg production.  This enables identification of infections during pre-patent periods and alleviates challenges of intermittent egg shedding associated with microscopic examinations.

Uncinaria stenocephala

Distribution:

Predominantly central and northern Europe.

Infection:

Dogs, foxes and cats.  Pre-patent period is about 3–4 weeks and patent period can be prolonged depending on immune status.  Infection is by ingestion of embryonated eggs from soil or larvae from paratenic hosts.

Clinical signs:

Diarrhoea, weight loss and anaemia, may be acute or chronic signs.

Diagnosis:

Egg detection by flotation from 3–5 g fresh or fixed faeces.  Coproantigen assays detect infections from immature and adult worms, and are not linked to egg production.  This enables identification of infections during pre-patent periods and alleviates challenges of intermittent egg shedding associated with microscopic examinations.

Strongyloides stercoralis

Distribution:

Everywhere in Europe but more predominant in southern Europe.

Infection:

Final hosts are dogs, humans and cats with ingestion of embryonated eggs from soil or fur, larvae in milk or paratenic hosts.  In utero from dam.  Pre-patent period is variable from 9 days and patent period can be several months (3–15 months).

Clinical signs:

Bloody diarrhoea, dehydration and sometimes death.

Diagnosis:

Finding large numbers of the characteristic eggs in very young animals, usually in the first few weeks of life, are suggestive of strongyloidosis.

Zoonosis:

Yes, can cause several forms of disease: a) subcutaneous infection giving rise to an itching dermatitis, b) in the mucosa causing a chronic intestinal syndrome.  Symptoms include sporadic diarrhoea, epigastric abdominal pain, heartburn, bloating and weight loss, c) mild transient form can induce mild coughing, and d) can occasionally induce neurological effects such as Gram-negative polymicrobial meningitis.

Trichuris vulpis

Distribution:

Everywhere in Europe but most predominant in central and southern Europe.

Infection:

Dogs by ingestion of embryonated eggs from the environment.  Pre-patent period is 8 weeks and patent period is up to 18 months.

Clinical signs:

Asymptomatic but heavy infection associated with anaemia, diarrhoea and weight loss.

Diagnosis:

Egg detection by flotation from 3–5 g fresh or fixed faeces.  Coproantigen assays detect infections from immature and adult worms, and are not linked to egg production.  This enables identification of infections during pre-patent periods and alleviates challenges of intermittent egg shedding associated with microscopic examinations.

Angiostrongylus vasorum

Distribution:

Everywhere in endemic foci.

Infection:

Final hosts are foxes and dogs.  Infective larvae are ingested within molluscs or paratenic host.  Pre-patent period 40–49 days, patent period up to 5 years.

Clinical signs:

After an asymptomatic period, respiratory signs such as cough, tachypnoea and dyspnoea are most obvious.  Occasionally signs of coagulopathy (e.g. subcutaneous haematomas anaemia) and neurological signs are observed.  Sudden death can occur even in the absence of respiratory signs.

Diagnosis:

Detection of live larvae from at least 4 g fresh faeces using the Baermann method, or microscopic detection of larvae in bronchial lavage material.  A commercial serological test to detect circulating A. vasorum is now available.

Dirofilaria immitis

Distribution:

Portugal, Spain, South of France, Italy, Greece, Croatia, Bosnia, Czech Republic, Turkey, Hungary, Bulgaria and Romania.

Infection:

Final hosts are dogs, cats and other carnivores.  Rarely occurs in cats.  L3 stage larvae are transmitted by mosquito vectors (intermediate host).  Cutaneous infection.  In dogs, pre-patent period is 4–6 months, patent period is several years.  In cats, pre-patent period is approximately 8 months.

Clinical signs:

Low worm burden often asymptomatic.  Infections with D.immitis may cause a severe and potentially fatal disease in dogs and cats.  First clinical manifestation 5–7 months after infection: loss of condition, dyspnoea, cough.  Chronic disease: cough, tachycardia, "Caval syndrome", tachypnoea.  See GL5: Control of Vector-borne Diseases in Dogs and Cats.

Diagnosis:

Detection of microfilaria earliest 6 months after infection in dogs.  For cats, detection of microfilaria from 8 months p.i. may be negative as levels can be very low.  Detection improved by concentration of microfilaria with Difil Test or Knott’s Test.  Microfilariae can be speciated using morphological, biochemical or molecular species identification in specialised laboratories only.   Circulating antigens are detected from 5 months after infection with a sensitivity around 90% and approximately 100% if one female worm or more are present, respectively.

Zoonosis:

D. immitis is a zoonotic parasite, however human infection is rare.

Aelurostrongylus abstrusus

Distribution:

Everywhere in Europe.

Infection:

Final host is the cat, particularly strays, and intermediate stage larvae are found in molluscs.  Cats are infected when they ingest an intermediate host.  Pre-patent period is 7–9 weeks with patent period of several years.

Clinical signs:

Respiratory symptoms, coughing and possible exercise intolerance.  There may be no signs (in a proportion of cats).

Diagnosis:

Detection of live larvae from at least 4 g of fresh faeces using the Baermann method or microscopic detection of larvae in bronchial lavage material.

Capillaria spp.

Distribution:

Everywhere in Europe.

Infection:

Final hosts are foxes, dogs and cats and infective larvae are ingested from the environment or from earthworms.  Pre-patent period is 4 weeks and patent period Is 10–11 months.

Clinical signs:

Mild infections are usually asymptomatic.  Heavy infection of C. hepatica can result in hepatic lesions and hepatic capillariosis is usually fatal.  Capillaria philippinensis in the small intestine can cause fatal enteropathy.

Diagnosis:

Most infections are discovered at routine autopsy.

Zoonosis:

Yes, three species can infect man: C. philippinensis, C. hepatica and C. aerophila.  Capillaria philippinensis infects the small intestine and is largely found in the Philippines with sporadic outbreaks in southern Europe. Capillaria hepatica infection is acquired through the ingestion of soil or via contaminated food or water.  Human capillariosis from C. aerophila infection is very rare.

Crenosoma vulpis

Distribution:

Everywhere in Europe.

Infection:

Final hosts are dogs and foxes and infection is orally from larvae within mollusc or paratenic host.  Pre-patent period is 3 weeks, patent period is up to 10 months.

Clinical signs:

Respiratory symptoms, coughing and possibly exercise intolerance.

Diagnosis:

Detection of live larvae from at least 4 g fresh faeces or bronchial lavage fluid by Baermann method or microscopic detection in bronchial lavage material.

Filaroides hirthi

Distribution:

Everywhere sporadically in Europe.

Infection:

Final hosts are dogs and the route of infection is unknown. Pre-patent period is 10–18 weeks and patent period is unknown.

Clinical signs:

Respiratory symptoms, coughing and possible exercise intolerance.

Diagnosis:

Detection of live larvae in at least 4 g fresh faeces using the Baermann method or microscopic detection of larvae in bronchial lavage material.

Oslerus osleri

Distribution:

Everywhere sporadically in Europe.

Infection:

Infecting foxes and dogs — direct oral transmission from bitches to pups.  Pre-patent period is 10 weeks and the patent period is unknown.

Clinical signs:

Respiratory symptoms, coughing and possibly exercise intolerance.

Diagnosis:

Detection of live larvae in at least 4 g fresh faeces using the Baermann method or by microscopic detection of larvae in bronchial lavage material.  Adult worms inhabit nodules at the base of the trachea — these may be seen on radiography or endoscopy.

Dirofilaria repens

Distribution:

Spain, South of France, Italy, Greece, Croatia, Bosnia, Czech Republic, Turkey and Hungary.

Infection:

Final hosts are dogs, cats and other carnivores.  L3 larvae are transmitted by mosquito vector (intermediate host).  Cutaneous infection. Pre-patent period is 27–34 weeks, patent period – several years.

Clinical signs:

Mostly asymptomatic, very rarely modules or other cutaneous lesions.

Diagnosis:

Requires 2–4 ml EDTA blood.  Detection of microfilariae from 6.2 months post infection.  Detection improved by concentration of microfilariae with Difil Test or Knott’s Test.  Microfilariae can be speciated using morphological, biochemical or molecular species identification by the use of specialised laboratories.

Zoonosis:

Yes, usually manifests itself in humans as a single subcutaneous nodule or a single worm in the conjuctiva.

Spirocerca lupi

Distribution:

In tropical and sub-tropical areas.

Infection:

Dog, wild dog, fox, occasionally cats and wild cats.

Clinical signs:

Many infected dogs do not show clinical signs.  In some dogs, infection can induce persistent vomiting with worms in the vomit.  Sometimes difficultly in swallowing or interference with the action of the stomach.

Diagnosis:

Granulomatous lesions comprising the spirally coiled worms up to 8 cm in length.  Eggs may be found in faeces or vomit otherwise diagnosis may be by endoscopy or radiography.

Thelazia callipaeda

Distribution:

Italy, France (Dordogne) and southern Switzerland.

Infection:

Dogs and cats probably via a dipteran arthropod vector.  Pre-patent period about 3 weeks and patent period of months to years.

Clinical signs:

Blepharospasm and epiphora.

Diagnosis:

By detection of adult or larval stages from samples of the tear film from the surface of the conjunctiva.

Dipylidium caninum

Distribution:

Everywhere in Europe.

Infection:

Final hosts are dogs, cats and foxes by the ingestion of larval stages in fleas or lice.  Pre-patent period is 3 weeks, patent period is several months.

Clinical signs:

Mostly asymptomatic, anal pruritus.  Look for proglottids in faeces.

Diagnosis:

Proglottids similar in size to Taenia spp. proglottids but morphologically distinct as they have two genital pores.  Eggs within proglottids are grouped in egg packets.  These can be seen microscopically in faecal samples.

Echinococcus granulosus

Distribution:

Widespread in Europe.

Infection:

Final hosts are dogs and rarely red foxes.  Intermediate hosts are domestic ruminants, primates and humans.

Clinical signs:

Asymptomatic in dogs.  Infections in cattle, sheep and pigs do not show clinical signs.

Diagnosis:

Difficult as the adult tapeworm segments are sparsely shed and small. Identification is based on size (2.0–3.0 mm), ovoid in shape with a single genital pore.

Zoonosis:

Yes, one or both lungs can be affected in the human intermediate host. If in the liver, several hydatids may give rise to gross abdominal distention. If a cyst ruptures, there is risk of death from anaphylaxis.

Echinococcus multilocularis

Distribution:

Endemic in central and eastern Europe.

Infection:

Final hosts are foxes, dogs, raccoon dogs and cats, after ingestion of larval stages in intermediate hosts (mainly rodents).  Dogs should be prevented from having access to raw offal and carcases.  Pre-patent period is 28 days and patent period can be for several months.

Clinical signs:

Asymptomatic.

Diagnosis:

Morphology and size of proglottids on faecal samples.  Egg detection with flotation, sedimentation or combined techniques (not very sensitive and Taenia-type eggs cannot be differentiated morphologically).  Coproantigen detection enables detection of pre-patent infections 10 days p.i. with a sensitivity of more than 90% if more than 50 worms are present, lower if less than 50 worms are present.  PCR/sequencing allows species identification (from isolated eggs or proglottids).

Zoonosis:

Red foxes, raccoon dogs and rarely dogs and cats may excrete eggs of Echinococcus multilocularis in faeces.  The accidental oral consumption of E. multilocularis eggs causes alveolar echinococcosis in humans, which if untreated has potentially fatal consequences and this is therefore of major public health concern.  Infection with eggs results in the formation of cysts also in animals such as pigs, horses and dogs.

Mesocestoides spp.

Distribution:

Everywhere in Europe.

Infection:

Final hosts are dogs, cats and foxes with ingestion of larval stages in meat or tissues of prey.  Pre-patent period is 4–10 weeks with patent period of several years.

Clinical signs:

None reported.

Diagnosis:

Infective larvae are found in the abdominal cavity and liver.

Taenia spp.

Distribution:

Everywhere in Europe.

Infection:

Dogs, cats and foxes after ingestion of larval stages in the intermediate host (cysticercus or coenurus).  After a pre-patent period of 4–10 weeks and for a patent period from months to several years.

Clinical signs:

Asymptomatic except sometimes segments or proglottids are seen.

Diagnosis:

Egg detection by flotation of eggs from 3–5 g fresh or fixed faeces.  Proglottids in faeces grossly visible.  Taenia-type eggs in faeces (see Echinococcus for method of distinguishing Taenia-type eggs).

Alaria alata

Distribution:

Eastern Europe.

Infection:

Dogs, cats, foxes, mink, wild carnivores and rarely humans.

Clinical signs:

Usually not evident.

Diagnosis:

Presence of eggs in faeces by the flotation method.

Zoonosis:

Yes, but rarely. One fatal incident was the result of consumption of inadequately cooked frogs’ legs. Intermediate hosts are frogs and freshwater snails.

x