A dog has died from the parasitic disease leishmaniasis in what is thought to be the first ever reported case in the UK.
The three-year-old Shih Tzu, who lived in Hertfordshire, became increasingly ill with vomiting, diarrhoea and weight loss over three weeks.
Having never left the British isles, vets suspect the pooch caught the Leishmania infantum parasite from another dog it lived with.
This dog had come over from Spain and was put down six months earlier after developing severe leishmaniasis.
Although dogs cannot transmit leishmaniasis directly to humans, sand flies can act as a reservoir for the infection by biting the popular pets and then passing the infection onto people.
Sand flies are not found in the UK, however, humans infected in tropical regions can endure oozing sores, fever, and even deadly swelling of the liver and spleen.
The three-year-old Shih Tzu, who lived in Hertfordshire, became increasingly ill with vomiting, diarrhoea and weight loss over three weeks. The pooch became infected in the UK (stock)
The dog was examined by a team at the Royal Veterinary College in Hatfield, UK, led by Myles McKenna, from the department of clinical science and services.
‘To the authors’ knowledge, this is the first reported case of leishmaniosis in the UK in a dog without a history of travel to an endemic area,’ they wrote in the BMJ journal Vet Record.
‘In an era of increased foreign travel of dogs and increased importation of dogs to the UK, it is likely that the number of dogs seropositive for L infantum will continue to increase.
‘Leishmania-infected dogs may present an infection risk to other dogs, even in the absence of natural vectors, as direct transmission between dogs is possible.’
Leishmaniasis is transmitted via sandflies, but infected dogs can spread the disease by biting other canines.
A veterinary examination of the Shih Tzu revealed he was deficient in all three blood cells – red blood cells, which carry oxygen around the body; white blood cells, which make up the immune system; and platelets, which cause blood to clot.
He also had an elevated level of calcium in his blood, as well as an abnormally high amount of the protein globulin, which is usually a sign of liver disease.
Bone marrow and skin biopsies revealed the Shih Tzu was infected with L. infantum.
WHAT IS LEISHMANIASIS?
Leishmaniasis is a parasitic infection found in tropical and subtropical regions, as well as southern Europe.
The disease is caused by being infected with one of more than 20 Leishmania parasites, which is spread by over 30 species of sand flies.
The most common forms of the condition are cutaneous leishmaniasis – which causes skin sores – and visceral leishmaniasis – which affects the spleen, liver and bone marrow.
Cutaneous symptoms usually start out as bumps that then ulcerate. These are typically painless.
Visceral symptoms include fever, weight loss, abnormally low blood cells, and an enlarged spleen and liver.
Some people have a ‘silent infection’ and never develop symptoms.
Leishmaniasis’ prevalence is difficult to estimate.
The cutaneous form of the disease is thought to affect between 700,000 and 1.2million people globally every year.
And the visceral form affects around 100,000-to-400,000 annually.
The infections are found in parts of Asia, Middle East, Africa, southern Europe, Mexico, Central America and South America.
Cases that arise in the US or UK are almost always from people who have become infected while travelling or living in other countries.
Cutaneous leishmaniasis usually heals on its own without treatment, but this can take years and leave scars.
There is also the risk the ulcers may spread from the skin to the nose, mouth or throat.
Visceral leishmaniasis is often deadly if untreated, however, medication is available.
There is no vaccine or preventative medication for humans, with people being advised to avoid sand flies via nets and insecticide sprays.
However, a vaccine does exist for dogs.
Collars impregnated with insecticides and spot-on treatments that prevent sand-fly bites are also effective.
This is one of 20 known parasites that cause Leishmaniasis.
The Shih Tzu case sparked a second leishmaniasis incident in the UK to come to light.
A three-year-old English Pointer – who never went beyond Essex borders – developed leishmaniasis earlier this year.
He was eventually diagnosed after his owners took him to the vet four times between February 2016 and September 2017 when he developed an eczema-like reaction and hair loss.
Although the pooch had never left the UK, its owners had lived in Spain.
The couple also traveled between Alicante and Valencia last summer.
Unlike the first case, this dog was not living with an infected pooch.
Vets therefore believe his owners may have brought back sand flies in their luggage.
His case was written up in Vet Record by a team at Mount Veterinary Practice in Fleetwood, Lancashire.
‘The increased importation of infected dogs into the UK also makes incidental socialising with infected dogs increasingly likely,’ they warned.
‘We should not be complacent about the risk of Leishmania infantum establishing in the UK, even in the current absence of the sand fly vector’.
There is some evidence Ibizian Hounds are resistant to certain Leishmania strains, according to The British Small Animal Veterinary Association.
And German Shepherds, Rottweilers, Cocker Spaniels and Boxers may be less at risk of the infection developing into the disease.
Daniella Dos Santos, junior vice president of the British Veterinary Association (BVA), said: ‘The increase in cases of non-endemic diseases such as leishmaniasis is extremely concerning.
‘More than a quarter of vets surveyed by BVA last year mentioning [reported] seeing cases of this rare disease in practice.
‘Leishmaniasis is mainly associated with pets who have recently travelled outside of the UK or “trojan” rescue dogs from abroad with unknown health histories’.
Ms Santos advises pet owners who are planning to travel with their dogs to seek advice from a vet, while those who have rescued an imported pooch should have them tested.
‘Anyone looking to get a dog should consider adopting from a UK rehoming charity or welfare organisation instead of rescuing from abroad as the unintended consequences from trojan can be severe for the health and welfare of UK’s pets’, she said.
Sand flies capable of transmitting leishmania have been found in Greece, Italy, Spain and southern France.
Paolo Silvestrini, a lecturer in small animal internal medicine at the University of Liverpool, told Vet Times: ‘Canine leishmaniasis is still not well known here in the UK.
‘Vets would not have seen these cases 15 years ago, but they are becoming more frequent now as it becomes easier for pets to travel across Europe and the UK.’