With the Delta COVID-19 variant now becoming more prevalent in New Zealand we are fielding questions regarding the significance of this for our pet cats and dogs. We will try to answer some of the common questions around this.
- Can Covid-19 infect animals?
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the cause of COVID-19 is a zoonotic (from animal source) virus now almost exclusively spread amongst humans, however, some animal species are also susceptible to infection.
- Can COVID-19 infect our pet cats and dogs?
Cats appear to be among the most susceptible domestic animals, dogs being much less susceptible. The information to date indicates they are more likely to pick it up from humans than the other way around. Internationally there have been reports of both clinical and sub-clinical infections. The good news is generally infected cats will show either no or very little in the way of clinical signs of the disease. There have been studies to understand how this virus behaves in species such as cats to assess potential animal and human health consequences of SARS-CoV-2 exposure and infection.
- What have studies in cats shown with regard to the virus?
One study from Canada involved experimental infection of cats with SARS-CoV-2 using serial sampling to detect presence of the virus in different tissues. The virus was detected in the nasal chambers and airways of all cats on day 3 and in most cats on day 6. The virus was not detectable by day 10; this expected short duration of shedding is consistent with infection in humans. Although disease symptoms have been reported in naturally infected cats, no cats in this study developed signs of disease, and the virus was not detected in tissues outside the respiratory tract. Although clinical signs were not apparent, there was microscopic evidence of inflammation in the upper and lower respiratory tracts, including one cat with severe pneumonia.
- What signs do cats show when infected with the virus?
In the majority of cases cats do not show symptoms when infected with the virus, although there have been a few cases where mild respiratory signs have occurred.
- Can cats become reinfected?
In the study 6 cats were re-exposed to the virus 28 days after their initial exposure. None developed symptoms and no virus was isolated after re-exposure. This indicates that they had developed short term immunity against the virus however it is unknown as to how long that immunity would last.
- What does this mean for us as pet cat owners?
If one of our households develops a known positive COVID-19 infection, there is a possibility that the pet cat could become infected as well. On a rare occasion, the cat may show symptoms, however in most cases although infected may not show any symptoms at all. So although unlikely, it is possible that the pet cat may be a source of infection for other household members. Household members will need to be aware of this in terms of how they treat the cat. This will be a relatively rare situation and human to human transmission is a much more likely scenario.