Spanish authorities have issued a statement through ProMED-mail about their decision to euthanize the dog owned by a nursing assistant with Ebola virus disease.
Regarding the news [that] appeared in the magazine "Veterinary Record", dated 18 Oct 2014, where it was questioning the scientific reasons on which euthanasia of the dog Excalibur were based, we are
sending a report based on the opinion of the leading Spanish and European renowned specialists on this subject, epidemiologists, virologists and experts in preventive medicine on animal health.
Case background: [On] 6 Oct 2014 afternoon, the 1st indigenous clinical case of Ebola virus (EBOV) disease was confirmed in a health worker in Spain. The health worker had been involved in the care of a severely diseased missionary who had contracted the virus in Sierra Leone and had died on 25 Sep 2014. The patient developed fever on 29 Sep 2014, and at the time of the confirmation of the diagnosis, she presented with high fever and other typical clinical signs like vomiting and diarrhea. The cohabitation between the patient and the animal was close and constant during some of the period of virus excretion, and therefore the potential for disease transmission could not be ruled out.
In the epidemiological investigation, it was noticed that the health worker was cohabiting with her dog Excalibur in their apartment during the acute phase of her infection and before admission to the hospital. She kept close contact with the dog during the 5 days previous to the confirmation. Thus, the exposure of Excalibur to the virus was very likely, as well as the risk of its contagion.
There are numerous knowledge gaps related to the infection of dogs with EBOV. Allela et al. (2005) studied the potential role of dogs in the epidemiology of EBOV disease. They observed specific antibodies against the virus in pet dogs living in Gabon during the 2001-2002 epidemics. In fact, the apparent seroprevalence reached up to 25 percent in villages with confirmed viral activity. Although the study failed to detect the virus, the authors hypothesized that dogs may carry the virus without showing any clinical sign. Also not determined is possible viral excretion from dogs, the viral loads in these excretions and the lapse of time between the infection of animals and the potential viral shedding. Thus, the risk of EBOV transmission from dogs to humans cannot be ruled out.
The desire of the Spanish authorities would have been to move the dog to quarantine and confirm its infection. Unfortunately, there are no veterinary medical means in Spain to do so respecting the biosafety level 4 (BSL4) requirements pertaining to this virus (CDC, 2009). These missing minimal needs include proper means to carry the dog alive, contrasted protocols for this situation, BSL4 facilities for its quarantine, and training of personnel handling the animal. In addition, the procedure followed the ‘precautionary principle’, due to the lack of sufficient evidence to eliminate the potential role of EBOV transmission from dogs or other pets to humans, as stressed by Dr. Bernard Vallat, Director General of the World Organization for Animal Health (OIE) to AFP [Agence France-Presse].
Due to these uncertainties and the highly possible risk of infection, the Madrid regional government authorized the euthanasia of Excalibur on 8 Oct 2014 through a court order due to the rejection of the
husband of the patient to allow the health operatives to enter the apartment. The procedure was performed by highly qualified staff of the Health Surveillance Centre of Madrid (VISAVET) and following the strictest animal welfare measures.
The Spanish episode has been repeatedly compared with another EBOV case in Dallas (Texas, United States), although epidemiological and logistic differences exist. The American case occurred in a nurse who had contact with Thomas Eric Duncan and was confirmed on 12 Oct 2014. This nurse also has a dog, which was living with her before the diagnosis confirmation. In contrast to the Spanish case, the period of contact between the patient and the dog comprised the 1st 2 days of clinical infection, in which the viral load in the excretions is lower, so the contagion was less likely than in the Spanish dog. In addition, the US government has sufficient means to maintain the animal in quarantine.
In conclusion, the euthanasia of Excalibur was not an automatic procedure, but a health measure carried out in the best available way and always aimed to protect public health.
Direccion General de Ordenacion e Inspeccion Consejeria de Sanidad
Comunidad de Madrid
c/ Aduana 29 – 4a