Emerging coronavirus strains and veterinary patients
Diagnostic update • April 2020
A novel coronavirus causing an outbreak of respiratory disease in humans has led to questions about the importance of this newly discovered virus, if any, to our veterinary patients. This guide provides summary information intended to answer some of the more frequently asked questions about coronavirus. Understanding of coronaviruses and their transmission is rapidly evolving, and for the most up-to-date information, we suggest you check the reference sources provided at the end of this update.
Coronavirus disease 2019 (COVID-19) was first detected in China with an initial outbreak in the city of Wuhan. This disease is caused by a novel coronavirus named SARS-CoV-2 and is believed to have originated from bats. Since its emergence in late 2019, COVID-19 has spread to locations around the globe.1–3
The SARS-CoV-2 virus, which causes COVID-19, is a unique coronavirus that infects the human respiratory tract and is different from previously identified coronaviruses infecting humans or veterinary patients. Coronaviruses are a large family of viruses consisting of multiple subgroups of viruses that are commonly found in humans as well as other mammals, birds, and reptiles.
Alpha and beta coronaviruses (including coronaviruses such as those responsible for the common cold in humans) usually infect mammals, while gamma and delta coronaviruses usually infect birds and fish. Many of the common coronaviruses causing disease in pets, such as feline enteric coronavirus, are alpha coronaviruses. SARS-CoV-2, responsible for the recent COVID-19 respiratory outbreaks in humans, is a beta coronavirus.
Coronaviruses in companion animals
While COVID-19 (caused by the SARS-CoV-2 coronavirus) is primarily a human disease, there are other coronaviruses that play a significant role in causing disease in animals. IDEXX RealPCR tests are available for these common coronavirus infections in dogs, cats, ferrets, and horses. These tests are specific to various veterinary coronaviruses and do not detect SARS-CoV-2.6 The coronaviruses detected by these tests are species-specific and do not infect humans.
- Canine respiratory coronavirus contributes to canine infectious respiratory disease complex (also known as infectious tracheobronchitis or “kennel cough”). It causes clinical signs similar to that of the common cold. The IDEXX RealPCR test for canine respiratory coronavirus is included in our Comprehensive Canine Respiratory Disease (CRD) RealPCR Panel.
- Enteric coronaviruses can cause intestinal infection leading to diarrhea, particularly in younger animals. Many infections may be asymptomatic. IDEXX RealPCR tests for canine, equine, feline, or ferret enteric coronavirus are included in our Comprehensive Diarrhea RealPCR panels. As noted above, these viruses are species-specific. For example, the canine enteric coronavirus does not infect felines and vice versa.
- Feline infectious peritonitis (FIP) is a mutated form of feline enteric coronavirus that results in severe, generally fatal, systemic inflammatory disease. IDEXX offers an FIP Virus RealPCR Biotype, which detects the most common mutations causing FIP.
Coronaviruses in livestock and poultry
IDEXX also offers tests for a number of coronaviruses that impact livestock and production animals. A gamma coronavirus, infectious bronchitis virus (IBV), is of significant economic importance in poultry. Alpha coronaviruses can cause mild gastrointestinal or respiratory disease in livestock, similar to the signs seen with canine and feline coronaviruses. As with the test above, these tests are specific to various veterinary coronaviruses and do not detect SARS-CoV-2, and the coronaviruses detected by these tests are species-specific and do not infect humans.
- Infectious bronchitis virus (IBV) causes rapidly spreading respiratory disease in young chicks. Reduced production and poor egg quality can be seen in infected adult hens. An IDEXX ELISA is available for IBV antibody detection.
- Swine enteric coronaviruses are several coronaviruses that infect swine and cause respiratory or gastrointestinal signs, including transmissible gastroenteritis virus (TGEV). Mild or asymptomatic infections may also occur. An IDEXX RealPCR test is available for TGEV.
- Bovine coronaviruses may cause diarrhea in calves. They can also cause winter dysentery, with bloody diarrhea, mild respiratory signs, and decreased production in adult cattle. An IDEXX ELISA is available for detection of coronavirus antigen in calf diarrhea.
Transmission of COVID-19 and pets
Leading public health authorities agree that COVID-19 is primarily a human disease that is transmitted by direct human-to-human transmission in respiratory droplets.1-4 Secondary transmission by touching a surface with the virus on it may also be possible, particularly from smooth surfaces such as plastic or metal.5,6 Porous surfaces such as clothing and fur are thought to be less than ideal surfaces for fomite transmission.
Recent studies have demonstrated that cats and ferrets may be infected in experimental settings and transmit to other animals, while dogs are generally resistant to infection, likely due to species differences in their ACE-2 receptors.7-9 In isolated cases, reverse zoonotic (infected human to pet) transmission has been reported in cats and tigers.10,11 Serologic evidence suggests asymptomatic infections in cats may be more common than initially suspected.12 Infection in cats and ferrets is often subclinical but may present with mild respiratory signs, fever and, in some cases, gastrointestinal signs. In these non-primary host species, infection seems to be shorter in duration than in humans. Although transient reverse zoonotic infections have been sporadically reported in dogs living with COVID-19 infected humans, no clinical signs have been reported in these dogs.10,13 Pets are not believed to play a role in transmitting COVID-19 to humans.1-4
Understanding of SARS-CoV-2 transmission and COVID-19 disease is rapidly evolving. For the most up-to-date information on the risk of SARS-CoV-2 transmission to animals, please visit the CDC COVID-19 website.
Development of an IDEXX SARS-CoV-2 (COVID-19) RealPCR Test
IDEXX Reference Laboratories has developed a real-time PCR test to detect SARS-CoV-2 based on the published genetic sequences of the virus from the human outbreak. The IDEXX SARS-CoV2 (COVID-19) RealPCR Test targets the same nucleocapsid gene as the CDC assay but has been adapted with a unique alignment for use in animals. It has been carefully designed to avoid cross-reactivity with other veterinary-specific coronaviruses. Specificity studies confirm that there is no cross-reactivity with the new PCR test against common veterinary coronaviruses affecting companion animals. Likewise, currently available RealPCR tests for these veterinary coronaviruses were demonstrated to not detect the SARS-CoV-2 viral nucleic acid.
During the initial a four-week validation of the new SARS-CoV-2 (COVID-19) RealPCR Test, IDEXX tested more than 3,500 canine, feline, and equine specimens submitted to IDEXX Reference Laboratories for respiratory RealPCR panels. Specimens were tested in parallel with three assays from the Centers for Disease Control and Prevention (CDC). A subset of fecal specimens submitted for diagnostic diarrhea RealPCR panels were also evaluated as part of the cross-reactivity studies. The specimens originated from the United States and South Korea. Screening was expanded starting in mid-March to Canada and European countries, including areas with high rates of COVID-19 in the human population.
When to use the IDEXX SARS-CoV-2 (COVID-19) RealPCR Test
At this time, experts do not recommend screening of nonclinical pets for the SARS-CoV-2 virus unless recommended by a public health authority. Testing of symptomatic pets in COVID-19 infected households may not always be indicated as clinical signs, when present, may be mild and transient. The IDEXX SARS-CoV-2 (COVID-19) RealPCR Test may be considered when investigating respiratory disease in ferrets or cats after more common respiratory infections have been ruled out. Consultation with a local health authority prior to considering testing for COVID-19 in a pet is recommended. Testing should be limited to those animals with known or strongly suspected COVID-19 exposure. For cats presenting with respiratory signs, a Feline Upper Respiratory Disease (URD) RealPCR Panel should be considered prior to evaluating for SARS-CoV-2 infection, even in cats from a COVID-19 positive household. Ferrets presenting with respiratory signs should be evaluated with an Influenza Virus RealPCR Panel in addition to testing with the IDEXX SARS-CoV-2 (COVID-19) RealPCR Test.
When may it be appropriate to test a pet for COVID-19?
Does patient have respiratory or other clinical signs of COVID-19?
Do not test for COVID-19
Test for more common causes:
Upper Respiratory Disease (URD) RealPCR Panel—Feline
Comprehensive Respiratory Disease (CRD) RealPCR Panel—Canine
Influenza Virus RealPCR Panel—Canine/Ferret
Has the patient been tested for common respiratory pathogens?
Cause found on respiratory RealPCR panel?
Is there a history of the patient being exposed to COVID-19 (e.g., infected human in household)?
Do not test for COVID-19
Do not test for COVID-19
Consultation with state public health veterinarian recommended prior to testing
IDEXX SARS-CoV-2 (COVID-19) RealPCR Test
SARS-CoV-2 specimen collection guidelines
It is encouraged to consult with your state public health veterinarian or the AVMA for latest guidelines on safely collecting specimens prior to testing for SARS-CoV-2 in a pet. The use of personal protective equipment (PPE) including gloves, mask, gown and eye protection is recommended when collecting specimens from a pet in which SARS-CoV-2 infection is suspected.
The ideal specimen should be based on clinical presentation and purpose for testing.
- For respiratory manifestations: deep pharyngeal swab (with visible organic material on swab; please rub firmly) and a conjunctival swab (wipe eye clean, swab inside of eyelid), in the same tube. If the patient is cooperative, a swab from the caudal nasal cavity may also be included. Please submit dry, plastic-stemmed swabs, without transport media, in an RTT or an empty, sterile tube; keep refrigerated.
- For gastrointestinal manifestations: 3-5 g (1 g minimum) fresh feces in a sterile container and deep pharyngeal swab (with visible organic material on swab; please rub firmly) and a conjunctival swab (wipe eye clean, swab inside of eyelid), in the same tube. Please submit dry, plastic-stemmed swabs, without transport media, in an RTT or an empty, sterile tube; keep refrigerated.
- No distinct clinical signs (e.g. public health investigations): 3-5 g (1 g minimum) fresh feces in a sterile container and deep pharyngeal swab (with visible organic material on swab; please rub firmly), conjunctival swab (wipe eye clean, swab inside of eyelid), and caudal nasal swab, in the same tube.
Managing SARS-CoV-2 positive pets
COVID-19 is an internationally reportable disease. If a positive SARS-CoV-2 result is detected, the IDEXX RealPCR team will provide essential information (consistent with applicable privacy and other laws) to the public health and/or veterinary authorities (for example, to the applicable state public health veterinarian in the United States). The submitting veterinarian is then responsible for providing additional clinical details to the local public health authorities as required by applicable law. Positive IDEXX SARS-CoV-2 (COVID-19) RealPCR tests will be further confirmed at a third-party government laboratory, according to regulatory guidance.
Positive PCR results in a pet from a COVID-19 positive household may result from either reverse zoonotic transmission of infection from the infected owner (or other infected human) to the pet or may reflect environmental contamination. It is important to interpret results based on history, clinical signs, and result of diagnostic tests for common veterinary pathogens.
Infected pets should be treated symptomatically based on their clinical signs and monitored for evidence of secondary complication (e.g. bacterial infection). If respiratory signs are mild enough that hospitalization is not required, it is recommended that the pet be isolated at home with its owner. If there is no history of human COVID-19 infection in the household, consultation with a public health authority is recommended to determine the best course for testing of humans in the household and management of infected pet. Repeat RealPCR testing in one to two weeks should be considered to confirm the pet is no longer PCR positive before considering the household clear of infection or allowing the pet to mingle with other unexposed animals (especially cats or ferrets).
IDEXX SARS-CoV-2 (COVID-19) RealPCR Test positive result
Reportable disease: veterinarian must notify local public health authorities
Does pet require hospitalization?
Care for in isolation ward to avoid infecting other unexposed patients
History of COVID-19 infected human(s) in the household?
Care for at home with owner, keep indoors and isolated from naïve animals, and wash hands before and after handling pets
Provide symptomatic care; monitor for secondary complications
Consider follow-up PCR test at 14 days; submit both respiratory swabs and fresh feces
Reintroduce to normal activities after at least 14 days following resolution of clinical signs and/or negative follow-up PCR test
Exposure source likely from outside home? (e.g., recently adopted, indoor/outdoor cat, history of boarding)
Consult with local public health authorities; risk assessment to determine whether to isolate pet at home or at veterinary clinic may depend on several factors, such as the following:
- Length of time animal has been in household since exposure occurred
- Whether other humans or pets were also exposed to suspected source
- Presence of immunocompromised or high-risk pets or humans in household
Human(s) in household may have subclinical infection; consult with local public health authorities to determine next steps, if any, to assess human(s) for infection
Prevention of COVID-19 infection
Recommendations for prevention of spread of COVID-19 are centered around preventing exposure. These include limiting person-to-person contact with sick individuals, limiting travel and attendance at gatherings of large numbers of people, regular hand washing, and covering mouth and nose when coughing or sneezing.1,2
At this time, there are no antiviral medications proven to be effective in treating COVID-19. Likewise, there are currently no commercially available vaccines indicated for prevention of SARS-CoV-2 infection in humans or animals.
Although reverse zoonotic infection (humans to their pets) resulting in clinical disease is considered uncommon, if a pet owner has been diagnosed with COVID-19 infection, the AVMA and CDC and other authorities globally recommend limiting contact with any pets as a precautionary animal health measure. If possible, another family or household member should provide daily care of the pet.
Visit these websites for the most updated information on the COVID-19 outbreak, as well as useful resources about prevention and control of COVID-19.
Centers for Disease Control and Prevention (CDC) | cdc.gov/covid19
American Veterinary Medical Association (AVMA) | avma.org/coronavirus
World Health Organization (WHO) | who.int/emergencies/diseases/novel-coronavirus-2019
Test names and codes
Test code: 8826
IDEXX SARS-CoV-2 (COVID-19) RealPCR Test
Test code: 88261
IDEXX SARS-CoV-2 (COVID-19) RealPCR Test Add-on
Add on to a prior RealPCR test or panel
Upper Respiratory Disease (URD) RealPCR Panel
Bordetella bronchiseptica, Chlamydophila felis, feline calicivirus, feline herpesvirus type 1 (FHV-1) Quant, H7N2 avian influenza virus, influenza A virus (includes H3N2, H1N1, H3N8) and Mycoplasma felis RealPCR tests. Includes quantification of feline herpesvirus type 1 (FHV-1) viral particles if PCR positive. Includes strain identification of influenza A if PCR positive.
Respiratory Disease (CRD) RealPCR Panel (Comprehensive)
Bordetella bronchiseptica, canine adenovirus type 2, canine distemper virus (CDV) Quant, canine herpesvirus type 1 (CHV-1), canine parainfluenza virus, canine pneumovirus, canine respiratory coronavirus (CRCoV), H3N2 canine influenza virus, influenza A virus (includes H1N1, H3N2, H3N8, H7N2), Mycoplasma cynos and Streptococcus equi subsp. zooepidemicus RealPCR tests. Includes quantification of distemper viral particles if PCR positive. Includes strain identification of influenza A if PCR positive.
Influenza Virus RealPCR Panel
H1N1 pandemic influenza virus, H3N2 canine influenza virus, H3N8 canine influenza virus, influenza A virus RealPCR tests. Includes strain identification of influenza A if PCR positive.
Deep pharyngeal swab (with visible organic material on swab; please rub firmly) and a conjunctival swab (wipe eye clean, swab inside of eyelid), in the same tube. Please submit dry, plastic-stemmed swabs, without transport media, in an RTT or an empty, sterile tube; keep refrigerated.
Additional specimens for IDEXX SARS-CoV-2 (COVID-19) RealPCR Test: if the patient is cooperative, a swab from the caudal nasal cavity may also be included. If gastrointestinal signs are present, also include 3-5 g (1 g minimum) fresh feces in a sterile tube.
NOTE: Please call for more information or see protocol in the Online Test Directory at vetconnectplus.com for special specimen submission instructions.
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Preliminary results in 1-4 days; allow additional time for confirmation of SARS-CoV-2 PCR positive results.
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- Centers for Disease Control and Prevention. Coronavirus Disease 2019 (COVID-19). www.cdc.gov/COVID19. Accessed April 16, 2020.
- World Health Organization. Coronavirus disease (COVID-19) outbreak. www.who.int/emergencies/diseases/novel-coronavirus-2019. Accessed April 16, 2020.
- American Veterinary Medical Association. COVID-19: What veterinarians need to know. www.avma.org/coronavirus. Accessed April 16, 2020.
- World Small Animal Veterinary Association (WSAVA). The new coronavirus and companion animals—advice for WSAVA members. www.wsava.org/news/highlighted-news/the-new-coronavirus-and-companion-animals-advice-for-wsava-members. Accessed April 16, 2020.
- Ong SWX, Tan YK, Chia PY, et al. Air, surface environmental, and personal protective equipment contamination by serve acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from a symptomatic patient [published online ahead of print March 4, 2020]. JAMA. 2020;e203227. doi:10.1001/jama.2020.3227
- van Doremalen N, Bushmaker Y, Morris DH, et al. Aerosol and surface stability of SARS-COV-2 as compared with SARS-CoV-1. N Engl J Med. 2020;382(16):1564–1567. doi:10.1056/NEJMc2004973
- Wan Y, Shang J, Graham R, Baric RS, Li F. Receptor recognition by the novel coronavirus from Wuhan: An analysis based on decade-long structural studies of SARS coronavirus. J Virol. 2020;94(7):e00127-20. doi:10.1128/JVI.00127-20
- Shi J, Wen Z, Zhong G, et al. Susceptibility of ferrets, cats, dogs and other domesticated animals to SARS-coronavirus 2. Science. 2020;eabb7015. doi:10.1126/science.abb7015
- Kim Y, Kim SG, Kim SM, et al. Infection and rapid transmission of SARS-CoV-2 in ferrets [published online ahead of print April 5, 2020]. Cell Host Microbe. 2020;S1931-3128(20)30187-6. doi:10.1016/j.chom.2020.03.023
- Questions and answers on the 2019 coronavirus disease (COVID-19): Surveillance and events in animals. World Organisation for Animal Health (OIE) website. www.oie.int/en/scientific-expertise/specific-information-and-recommendations/questions-and-answers-on-2019novel-coronavirus. Updated April 9, 2020. Accessed April 16, 2020.
- USDA statement on the confirmation of COVID-19 in a tiger in New York. USDA Animal and Plant Health Inspection Service website. www.aphis.usda.gov/aphis/newsroom/news/sa_by_date/sa-2020/ny-zoo-covid-19. Updated April 6, 2020. Accessed April 16, 2020.
- Zhang Q, Zhang H, Huang K, et al. SARS-CoV-2 neutralizing serum antibodies in cats: a serological investigation [preprint]. doi:10.1101/2020.04.01.021196
- Low-level of infection with COVID-19 in pet dog [news release]. Hong Kong: Government of the Hong Kong Special Administrative Region; March 4, 2020. www.info.gov.hk/gia/general/202003/04/P2020030400658.htm. Accessed April 16, 2020.
- COVID-19 RealPCR Validation Studies: sequence blast analyses and cross-reactivity studies. March 2020. Data on file at IDEXX Laboratories, Inc. Westbrook, Maine USA.
PCR testing is a service performed pursuant to an agreement with Roche Molecular Systems, Inc.