Molecular detection and characterization of SARS-CoV-2 in cats and dogs of positive owners during the first COVID-19 wave in Brazil.

Despite previous reports of SARS-CoV-2 infection in dogs and cats worldwide, the type of swab sample used for its detection through RT-qPCR needs to be better compared and described. Accordingly, as part of a multicenter study in Brazil, the aim of the present study was to assess which rectal or oropharyngeal swabs would be more appropriate for detecting SARS-CoV-2 in cats and dogs, through viral load comparison. Pets of owners diagnosed with COVID-19 in the last 7 days were eligible. A total of 148 animals from four of the five Brazilian geographical regions were analyzed, among which 10/48 cats (20.83%) and 11/100 dogs (11.00%) were positive. The results suggested that oropharyngeal swabs should be considered for SARS-CoV-2 detection, particularly in cats, due to the higher cDNA viral load. Also, the genomic results showed similarities between SARS-CoV-2 animal variants and human variants that were circulating at the time of sampling, thus corroborating the existence of zooanthroponotic transmission. In conclusion, the present study highlighted the importance of SARS-CoV-2 monitoring among cats and dogs, as virus modification may indicate the possibility of mutations in animals and spillover back to owners. Thus, positive individuals should always self-isolate from their pets during COVID-19, to prevent trans-species transmission and mutation.

Infection of SARS-CoV-2 in domestic dogs associated with owner viral load.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive pet owners are reported to be a risk factor for infection of their pets; however, the influence of the viral load and associated risks has not been fully established. This study aimed to assess potential association of viral load in owners with the presence of SARS-CoV-2 infection in their dogs. Of 20 SARS-CoV-2-positive pet owners from 13 families in Curitiba, Brazil, 5 of 22 (22.7%) dogs were positive for SARS-CoV-2. Viral presence was detected in oropharyngeal samples for 2 of 5 (40.0%) dogs at 8 and 9 days after the first positive sample. Detection of SARS-CoV-2 in these dogs was associated with higher viral loads in the owners and close owner contact. All 5 RT-qPCR-positive dogs had antibodies to at least one viral protein tested in the serological assay. Molecular detection of SARS-CoV-2 in dogs was statistically associated with clinical signs in owners such as cold, cough, or diarrhea (P = 0.039), number of positive persons in the household (P = 0.002), and higher viral load (P = 0.039). Such findings serve as a warning for risks of human to dog infection, mainly due to sharing beds and other close interactions without protection. In conclusion, people with coronavirus disease 2019 (COVID-19), particularly in households with multiple residents and high viral load, should take the same preventive measures when interacting with their dogs during self-isolation as they do with people.

Persistent SARS-CoV-2 antigen presence in multiple organs of a naturally infected cat from Brazil.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent of the disease coronavirus 2019 (COVID-19) in humans. SARS-CoV-2 has been identified in cats with or without clinical signs. Case presentation: We describe the pathological and molecular findings in a six-month-old asymptomatic cat with SARS-CoV-2 infection from Brazil, belonging to a human family with COVID-19 cases. The pool of nasopharynx and oropharynx swabs at day zero tested positive by RT-qPCR for SARS-CoV-2. No amplification resulted from molecular testing performed on days 7 and 14. The cat was hit by a car and died 43 days after the molecular diagnosis. Immunohistochemistry at post-mortem examination demonstrated nucleocapsid protein in samples from the lungs, kidneys, nasal conchae, trachea, intestine, brain and spleen. Conclusion: The present study has highlighted the possibility that viral antigens can be detected by immunohistochemistry in multiple organs six weeks after infection, although the same tissues tested negative by RT-PCR.

First report of severe acute respiratory syndrome coronavirus 2 detection in two asymptomatic cats in the state of Pernambuco, Northeastern Brazil.

BACKGROUND AND AIM: Despite worldwide case reports, including Brazilian cases, no frequency study on infection of pets by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been conducted to date in Brazil. Accordingly, the present study was aimed to assess dogs and cats belonging to positive owners in Recife, Northeastern Brazil. MATERIALS AND METHODS: This was a longitudinal prospective study on dogs and cats in the city of Recife whose owners were in isolation at home due to a confirmed laboratory diagnosis of SARS-CoV-2 through reverse-transcriptase polymerase chain reaction (RT-qPCR). Oral and rectal swabs from the pets were tested for the presence of SARS-CoV-2-specific RNA by means of RT-qPCR. RESULTS: Among the pets tested, 0/16 dogs and 2/15 cats were positive for SARS-CoV-2. Interestingly, the two positive cats were owned by two unrelated asymptomatic veterinary students, which, therefore, post a warning to veterinarians worldwide. CONCLUSION: The findings herein indicate that cats may act as sentinels for human cases, particularly sharing households with asymptomatic human cases. Although with small sampling and convenient recruiting, the presence of infected cats by SARS-CoV-2 was most likely due to close cat-human contact with positive owners, posting a human-animal health threat when pets share the same bed and interact with owners without protection, particularly during owner self-isolation. Thus, infected owners should follow the same human preventive guidelines with their pets to avoid spreading infection.

Natural Infection by SARS-CoV-2 in Companion Animals: A Review of Case Reports and Current Evidence of Their Role in the Epidemiology of COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the coronavirus disease 2019 (COVID-19), is the causative infectious agent of the current pandemic. As researchers and health professionals are still learning the capabilities of this virus, public health concerns arise regarding the zoonotic potential of SARS-CoV-2. With millions of people detected with SARS-CoV-2 worldwide, reports of companion animals possibly infected with the virus started to emerge. Therefore, our aim is to review reported cases of animals naturally infected with SARS-CoV-2, particularly companion pets, shedding light on the role of these animals in the epidemiology of COVID-19.

A Quick Reference on Chloride.

Chloride is an essential element, playing important roles in digestion, muscular activity, regulation of body fluids, and acid-base balance. As the most abundant anion in extracellular fluid, chloride plays a major role in maintaining electroneutrality. Chloride is intrinsically linked to sodium in maintaining osmolality and fluid balance and has an inverse relationship with bicarbonate in maintaining acid-base balance. It is likely because of these close ties that chloride does not get the individual attention it deserves; we can use these facts to simplify and interpret changes in serum chloride concentrations.

A Quick Reference on High Anion Gap Metabolic Acidosis.

High anion gap (AG) metabolic acidoses can be identified by a decrease in pH, decrease in HCO3- or base excess, and an increased AG. The AG represents the difference between unmeasured cations and unmeasured anions; it increases secondary to the accumulation of anions other than bicarbonate and chloride. The most common causes of high AG acidosis are renal failure, diabetic ketoacidosis, and lactic acidosis. Severe increases in concentration of phosphorus can cause hyperphosphatemic acidosis.

A Quick Reference on Hyperchloremic Metabolic Acidosis.

Metabolic acidosis results from an increase in the concentration of a strong anion. Metabolic acidosis is divided into hyperchloremic metabolic acidosis and high anion gap acidosis based on the changes in the anion gap. Hyperchloremic metabolic acidosis is the result of chloride retention, excessive loss of sodium relative to chloride, or excessive gain of chloride relative to sodium. Clinical signs are related to the underlying disease that accompanies the metabolic acidosis. Treatment of hyperchloremic acidosis is based on addressing the underlying disease process.

A Quick Reference on Hyperkalemia.

The clinical signs of hyperkalemia usually are less evident than hypokalemia. Arrhythmia and bradycardia could be the first changes noticed. Most cases of persistent hyperkalemia are associated with renal retention of potassium. Common causes for hyperkalemia include hypoadrenocorticism, ruptured bladder, and urethral or bilateral ureteral obstruction. Drug such as angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, potassium-sparing diuretics, and nonsteroidal antiinflammatory drugs can also lead to hyperkalemia.

A Quick Reference on Hypokalemia.

Hypokalemia is more common than hyperkalemia and usually is caused by excessive losses of potassium from the kidneys or gastrointestinal tract. Serum potassium should be investigated in patients developing chronic or frequent vomiting or diarrhea, marked polyuria, muscle weakness, or unexpected cardiac arrhythmias, as well as in those undergoing therapy with insulin, diuretics, or total parenteral nutrition. Clinical signs develop when serum potassium deficit is moderate or severe.

Compensation for Acid-Base Disorders.

Hydrogen concentration is a critical determinant of many physiologic functions and is tightly regulated. Any alteration in acid-base equilibrium sets into motion a compensatory response by either the lungs or the kidneys. The compensatory response attempts to return the ratio between Pco2 and [HCO3-] to normal and thereby minimize the pH change. A primary increase or decrease in one component is associated with a predictable compensatory change in the same direction in the other component, and the expected compensation can be estimated clinically in dogs and cats.

A Quick Reference on Metabolic Alkalosis.

Metabolic alkalemia is characterized by an increase in bicarbonate concentration and base excess, an increase in pH, and a compensatory increase in carbon dioxide pressure. This article outlines indications for analysis, reference ranges, causes, and clinical signs of metabolic alkalosis. Algorithms for evaluation of patients with acid-base disorders and metabolic alkalosis are included.

Ehrlichiosis in Brazil.

Ehrlichiosis is a disease caused by rickettsial organisms belonging to the genus Ehrlichia. In Brazil, molecular and serological studies have evaluated the occurrence of Ehrlichia species in dogs, cats, wild animals and humans. Ehrlichia canis is the main species found in dogs in Brazil, although E. ewingii infection has been recently suspected in five dogs. Ehrlichia chaffeensis DNA has been detected and characterized in mash deer, whereas E. muris and E. ruminantium have not yet been identified in Brazil. Canine monocytic ehrlichiosis caused by E. canis appears to be highly endemic in several regions of Brazil, however prevalence data are not available for several regions. Ehrlichia canis DNA also has been detected and molecularly characterized in three domestic cats, and antibodies against E. canis were detected in free-ranging Neotropical felids. There is serological evidence suggesting the occurrence of human ehrlichiosis in Brazil but its etiologic agent has not yet been established. Improved molecular diagnostic resources for laboratory testing will allow better identification and characterization of ehrlichial organisms associated with human ehrlichiosis in Brazil.

A review of the occurrence of hemoplasmas (hemotrophic mycoplasmas) in Brazil.

Recent studies have been conducted in Brazil using molecular techniques for the detection of hemotrophic mycoplasmas in several mammals. In domestic cats, Mycoplasma haemofelis, "Candidatus M. haemominutum", and "Candidatus M. turicensis" infections have been identified. These species have also been found in free-ranging and captive neotropical felid species. Two canine hemoplasmas, Mycoplasma haemocanis and "Candidatus Mycoplasma haematoparvum", have been identified in dogs. In commercial swine populations, Mycoplasma suis was found to be highly prevalent, especially in sows. Moreover, novel mycoplasma species have been identified in Brazilian commercial pigs and domestic dogs. A hemoplasma infection in a human patient infected with the human immunodeficiency virus (HIV) was also recently documented. In conclusion, hemoplasma species are common and important infectious agents in Brazil. Further studies should be conducted to better understand their impact on pets, production animals, and wildlife fauna, as well as their role as zoonotic agents, particularly in immunocompromised patients.

Hemoplasma infection in HIV-positive patient, Brazil.

Hemotrophic mycoplasmas infect a variety of mammals. Although infection in humans is rarely reported, an association with an immunocompromised state has been suggested. We report a case of a Mycoplasma haemofelis-like infection in an HIV-positive patient co-infected with Bartonella henselae.

Metabolic alkalosis: a quick reference.

This article serves as a quick reference for metabolic alkalosis. Guidelines for analysis and causes, signs, and a stepwise approach are presented.

Metabolic acidosis: a quick reference.

This article serves as a quick reference for metabolic acidosis. Guidelines for analysis and causes, signs, and a stepwise approach are presented.

Anion gap and strong ion gap: a quick reference.

This article serves as a quick reference for the anion gap and strong ion gap. Guidelines for analysis and interpretation of changes are presented.

Chloride: a quick reference.

This article serves as a quick reference for the analysis of chloride abnormalities. Guidelines for causes, signs, and stepwise approaches for corrected hypochloremia and hyperchloremia are presented.