2021 AAHA/AAFP Feline Life Stage Guidelines

Prevalence and clinical findings of feline otitis externa in Midwest Brazil

This study was conducted to evaluate the prevalence of otitis externa (OE) in cats using cytology, direct otoscopic examination, and parasitological examination through swabs and curettage, and to compare the accuracy between collection methods for parasitological examination. Direct otoscopic evaluation of the external auditory canal (right and left), swabs for cytological examination of the external auditory canal, and collection of cerumen for parasitological examination through swabs and curettage of 137 cats from a veterinary hospital care were conducted between March 2021 and March 2022. The influences of age, sex, habitat, street access, and the presence of fleas on OE were evaluated. Cytological evidence of OE was observed in 25.5 % of cats and was statistically associated with flea and mite parasitism. Otodectes cynotis was found in 13.9 % of the cats. Cocci and Bacilli were the secondary factors in 34.3 % and 22.9 % of cats with OE, respectively. The Malassezia genus was a secundary factor in 57.1 % of the cats with OE. The frequency of OE was high in cats receiving hospital care. O. cynotis was a frequent primary cause of OE in cats. The curette sampling method is a great option for diagnosing O. cynotis infestation due to its ease of use.

Nutrition and Aging in Dogs and Cats

Aging is often associated with chronic inflammation and declining health. Both veterinarians and owners of aging dogs and cats are interested in nutritional solutions and strategies to prevent signs of age-related disease, increase longevity, and improve quality of life. Physiological decreases in muscle mass, decreased immunity, and a decrease in sense acuity are some of the changes often seen in otherwise healthy senior pets; however, there may also be an increase in risk for pathologies such as renal, cardiovascular, musculoskeletal, and neoplastic diseases. Aging may also lead to cognitive decline and even cognitive dysfunction. Some nutritional strategies that may be helpful with the prevention and treatment of age-related diseases include supplementation with ω3 polyunsaturated fatty acids and antioxidant nutrients that can help modulate inflammation and benefit osteoarthritis, renal disease, cancer, and more. Supplementation with medium-chain triglycerides shows promise in the treatment of canine cognitive dysfunction as these may be metabolized to ketone bodies that are utilized as an alternative energy source for the central nervous system. Additionally, a high intake of dietary phosphorus in soluble and bioavailable forms can lead to renal disease, which is of greater concern in senior pets. There are no published guidelines for nutritional requirements specific to senior pets and as a result, products marketed for senior dogs and cats are highly variable.

Isolated discrete upper septal thickening in a non-referral cat population of senior and young cats

INTRODUCTION/OBJECTIVES

Discrete upper septal thickening (DUST) is a phenotype of elderly people. The cardiac phenotype in senior cats has been incompletely described. We aimed to characterize the echocardiographic phenotype of senior cats, specifically to determine prevalence of DUST and hypertrophic cardiomyopathy (HCM).

ANIMALS

One hundred and forty-nine healthy, normotensive cats.

MATERIALS AND METHODS

Prospective cross-sectional study. Senior (≥9 years) and young (<6 years) cats were recruited from non-referral population. We defined DUST as an isolated basilar septal bulge, and HCM as left ventricular wall thickness ≥6 mm. An interventricular septum ratio (basal-to-mid septal thickness ratio) was calculated. We assessed for associations between clinical and echocardiographic variables and DUST. Data are presented as mean (±SD), median (range), or frequency (percentage).

RESULTS

One-hundred and two senior and 47 young cats were enrolled. Aortoseptal angle (AoSA) was steeper in senior cats (137° (±14.5) vs. 145° (±12.3) in young cats, P=0.002). Eighteen cats had DUST (18/149, 12%), fourteen senior, and four young cats (P=0.4). Cats with DUST had steeper AoSA (125° (±8.3) vs. 142° (±13.7), P<0.0001) and higher interventricular septum ratio (1.4 (1.2-2.0) vs. 1.0 (0.7-1.8)). Univariable analysis showed decreased odds of DUST with greater AoSA (OR 0.9, P<0.0001), age was not associated with DUST. Twenty-nine senior cats had HCM (28.4%).

DISCUSSION/CONCLUSIONS

Prevalence of DUST was 12%. There was no association between age and DUST. Smaller/steeper AoSA was the main factor associated with DUST. There was a high prevalence of HCM in this senior population.

Feline calicivirus and natural killer cells: A study of its relationship in chronic gingivostomatitis

Background and Aims

Feline chronic gingivostomatitis (FCGS) is a frequent chronic inflammatory condition in the oral cavity with an etiopathogenesis not completely identified. This study aimed to contribute to the knowledge of FCGS by identifying the presence of feline calicivirus (FCV) antigens and natural killer (NK) cells and comparing them.

Materials and Methods

Forty biopsies from the oral mucosa of cats diagnosed with chronic gingivostomatitis were subjected to immunohistochemical techniques to evaluate cells with FCV antigens and NK cells positive for CD56.

Results

NK cells were identified in all samples, with an average of 725.3 ± 409.1 cells. Regarding FCV, it was identified in 18 out of 30 samples (60%), with a different number of cells with virus in between the analyzed cases. In all cases, the number of cells infected with FCV was lower than the number of NK cells present in the same samples, but there was no statistical association between them.

Conclusion

This preliminary study shows that NK cells are present in gingivostomatitis lesions not exclusively caused by FCV-stimulus, as only 60% of all cases were positive for this virus, but other antigens should be considered in the etiology of FCGS.

Do Blood Phenotypes of Feline AB Blood Group System Affect the SARS-CoV-2 Antibody Serostatus in Cats?

Cats are susceptible to coronavirus infections, including infection by human severe acute respiratory syndrome coronavirus (SARS-CoV). In human ABO system blood groups, alloantibodies can play a direct role in resistance to infectious diseases. Individuals with the AB blood type were over-represented in the SARS-CoV-2 infection group. Blood type AB individuals lack both anti-A and anti-B antibodies, and therefore lack the protective effect against SARS-CoV-2 infection given by these antibodies. Starting from this knowledge, this pilot preliminary study evaluated a possible association between feline blood phenotypes A, B, and AB and serostatus for SARS-CoV-2 antibodies in cats. We also investigated selected risk or protective factors associated with seropositivity for this coronavirus. A feline population of 215 cats was analysed for AB group system blood phenotypes and antibodies against the nucleocapsid (N-protein) SARS-CoV-2 antigen using a double antigen ELISA. SARS-CoV-2 seropositive samples were confirmed using a surrogate virus neutralization test (sVNT). Origin (stray colony/shelter/owned cat), breed (DSH/non DSH), gender (male/female), reproductive status (neutered/intact), age class (kitten/young adult/mature adult/senior), retroviruses status (seropositive/seronegative), and blood phenotype (A, B, and AB) were evaluated as protective or risk factors for SARS-CoV-2 seropositivity. Seropositivity for antibodies against the SARS-CoV-2 N-protein was recorded in eight cats, but only four of these tested positive with sVNT. Of these four SARS-CoV-2 seropositive cats, three were blood phenotype A and one was phenotype AB. Young adult age (1-6 years), FeLV seropositivity and blood type AB were significantly associated with SARS-CoV-2 seropositivity according to a univariate analysis, but only blood type AB (p = 0.0344, OR = 15.4, 95%CI: 1.22-194.39) and FeLV seropositivity (p = 0.0444, OR = 13.2, 95%CI: 1.06-163.63) were significant associated risk factors according to a logistic regression. Blood phenotype AB might be associated with seropositivity for SARS-CoV-2 antibodies. This could be due, as in people, to the protective effect of naturally occurring alloantibodies to blood type antigens which are lacking in type AB cats. The results of this pilot study should be considered very preliminary, and we suggest the need for further research to assess this potential relationship.

Tissue motion annular displacement to assess the left ventricular systolic function in healthy cats

The tissue motion annular displacement (TMAD) measures the longitudinal displacement of the mitral annulus during systole, using speckle-tracking echocardiography (STE). The main objective was to determine the TMAD means in healthy cats, exploring the correlations with systolic surrogates. The influence of age, body surface area (BSA), heart rate, and systemic blood pressure on the indices was also analyzed. One hundred ninety-three healthy, client-owned cats participated in this prospective, cross-sectional observational study undergoing conventional and STE. Apical four-chamber (AP4) and two-chamber (AP2) images were recorded for offline calculations. Mean TMAD values were similar to mitral annulus plane systolic excursion (MAPSE), varying between 4 to 4.8 mm depending on the annulus and image used. No significant differences between age and BSA categories were detected, except for AP4 MP%, reduced in the heavier group. TMAD variables showed moderate correlation with longitudinal strain (LSt) and MAPSE, but not with fraction shortening (FS) and ejection fraction (EF). The median time required for the offline calculation was 12.2 s for AP4 and 11.8 s for AP2. The technique showed moderate inter and intraobserver variation, proving a reliable tool for assessing left ventricular longitudinal systolic function in cats.

Characterization of the intrarenal renin-angiotensin system in cats with naturally occurring chronic kidney disease

Background

The role of the renin‐angiotensin‐aldosterone system in cats with chronic kidney disease (CKD) is incompletely understood.

Objective

To characterize components of the intrarenal renin‐angiotensin system (RAS) in cats with CKD.

Animals

Eleven cats with naturally occurring CKD (CKD group) and 8 healthy control cats.

Methods

Renal tissue samples were evaluated by reverse‐transcription polymerase chain reaction for renin, angiotensinogen, angiotensin‐converting enzyme (ACE), and angiotensin II type 1 receptor transcript levels, and by liquid chromatography‐mass spectrometry for quantification of angiotensin I, II, III, and IV concentrations. Linear mixed models were used to compare gene transcript levels and concentrations of angiotensin peptides between groups.

Results

Cats of the CKD group were significantly older (P < .001) and more likely to be neutered (P = .007) than healthy control cats. Kidneys from cats with CKD had significantly higher transcript levels of angiotensinogen (P < .001) and lower transcript levels of ACE (P < .001) than those from control cats. Renal angiotensin I concentrations were increased in CKD compared with control kidneys (P = .001). No other significant differences in renal transcript levels or angiotensin peptide concentrations were noted between groups.

Conclusion and Clinical Importance

The intrarenal RAS might be activated in cats with CKD. Small sample size and differences in age, neuter status, and dietary sodium intake between groups might have limited the ability to identify a significant difference in concentration of renal angiotensin II.

Molecular and Pathological Investigations of Selected Viral Neuropathogens in Rabies-Negative Brains of Cats and Dogs Revealed Neurotropism of Carnivore Protoparvovirus-1

Throughout the year, the Thai Red Cross Society (TRCS), Bangkok, Thailand, received more than 100 animals that died of suspected rabies due to neurological clinical signs. Concerning the role of viral infection in the brain in the outcome of neurological diseases in cats and dogs, a comprehensive study was conducted of 107 brain samples of cats and dogs submitted to the TRCS from August 2019 to August 2020. Selective molecular screening using conventional polymerase chain reaction (PCR) and reverse transcription PCR targeting nine viral pathogens was employed in addition to histopathological investigations. The results showed that carnivore protoparvovirus-1 (CPPV-1) was detected in 18.69% of the cats and dogs sampled (20/107). These results were found in young and old animals; the brain tissue did not show any pathological changes suggesting encephalitis or cerebellar hypoplasia. In addition, feline calicivirus, feline alphaherpesvirus-1, feline coronavirus, and canine distemper virus were also detected, providing a broader range of potential viral infections to consider in the clinical manifestation of neurological disorders in companion animals. The detection of all pathogens was confirmed by the localization of each viral antigen in various resident brain cells using immunohistochemistry. A unique L582S amino acid substitution of the non-structural protein 1 gene coding sequence, speculated to be associated with the neurotropism of CPPV-1 in cats and dogs, was not evident. In conclusion, this study revealed a noteworthy neurotropism of CPPV-1 in both cats and dogs without neurological lesions.