2021 April Timely Topics

Submitted by: Patricia Shea, DVM

J Vet Behav 2020;39:47-56. DOI: 10.1016/j.jveb.2020.07.007
The effects of the frequency and method of gentling on the behavior of cats in shelters
Liu S, Paterson M, et al.

Almost any change in environment, routine, or human and/or animal affiliates can be stressful for a cat. One situation that can be extremely stressful for a cat is shelter confinement; others are hospitalization or boarding. Veterinary behavioral research regarding stress reduction strategies for cats has burgeoned in recent years, as this has been found to be crucial in improving the health and welfare of cats, and in the case of shelter cats, enhancing adoptability.

Gentling is a term used to refer to friendly interaction between humans and cats, and can include a variety of such interactions: long body strokes, soft vocalization, head patting, or placing a hand on the animal. These investigators designed a study which allowed them to learn more about techniques and duration of gentling that would receive the best response from shelter cats.

In a shelter in Australia, two experiments were performed. In both, cats were confined to cages that had a large living space with several shelves of different heights attached to a separate, closed-off litterbox area. In the first experiment, 60 cats received gentling for 5 days. The gentling sessions were either one 6-minute session per day, or 3 two-minute sessions per day, or no sessions, both with and without soft human vocalizations. Gentling in these sessions involved single-direction, head to tail petting.

The second experiment, involving 15 cats, was specifically aimed at identifying an optimum length of gentling time. Each cat received gentling treatments of 0, 3, 6, or 9 minutes/day with a different treatment each day, once daily for 4 days.

Results of the first experiment demonstrated that a single daily gentling period of 6 minutes without human vocalization produced the best results, in that those cats receiving this treatment spent more time at the front of their cage, more time on the floor rather than on a perch, and pawed less at the cage walls. When human vocalizations were a part of the session, cats spent more time in the secluded litterbox area or lying down.

In the second experiment, cats receiving 6- or 9-minute treatments spent more time on the cage floor. They also purred, ate, and drank more than those receiving 3-minute treatments.

The study cats did not display positive behavioral effects (remaining on the floor or near the front of the cage) when their cage was approached by a stranger (a potential adopter), but only when the handler with whom they were familiar was present. Therefore, the gentling may not directly improve adoptability of shelter cats, but is still likely to enhance their health and well-being. Another very worthwhile experiment could be to have a stranger approach with the cat’s regular handler to see if the cat spends more time near the front of their cage when the handler is present along with the stranger. Gentling of the kind performed in the experiments, i.e., a 6-9 minute/day long stroking session without human vocalization, is likely to be of significant benefit to hospitalized or boarded cats, especially if the cat has the same handler throughout their stay.


Vet Dermatol 2021;32:13-e4. DOI: 10.1111/vde.12928
Immunopathogenesis of the feline atopic syndrome
Halliwell R, Banovic F, et al.

In the paper by Halliwell et al. summarized in the February 2021 issue of The Scratching Post, the classification of three major feline allergic diseases: asthma, skin diseases associated with environmental allergens, and food allergy, as atopic, was proposed. These diseases, but not flea allergy dermatitis and mosquito-bite hypersensitivity, are now considered components of the Feline Atopic Syndrome (FAS). Feline Atopic Skin Syndrome (FASS) is the recommended new term for allergic skin disease of cats associated with environmental allergens, formerly called “non-flea non-food hypersensitivity dermatitis.”

In the present paper, the second in a series of four review articles on the feline atopic syndrome published this year in Veterinary Dermatology, the authors summarize and discuss the published literature regarding the immunopathogenesis of the FAS family of diseases.

Published evidence for the involvement of antibodies in the pathogenesis of FASS was reviewed. Early studies, published in the second half of the 20th century, identified feline immunoglobulin E (IgE) as a major mediator in allergic diseases of the cat. Subsequent research, including studies of intradermal skin test reactivity, serologic assays of IgE levels in allergically affected cats and normal cats, clinical response of allergic feline patients to allergen-specific immunotherapy (ASIT), and atopy patch test results, all support the involvement of IgE in FASS. However, interpretation of intradermal test reactions in cats is difficult, as the wheals resulting from such reactions are not readily visualized. Recent research has determined that healthy cats tolerate higher concentrations of allergens than do dogs. The nonirritant thresholds for allergens used in feline IDTs were only identified and published less than five years ago.

With regard to the role of antibodies in asthma, evidence for the pathogenic involvement of IgE in feline asthma is stronger in studies of experimental models of this disease in cats, than in cats with spontaneous feline asthma. Both the experimental models, which were developed using ovalbumin, Ascaris suum, house dust mites (HDM), or Bermuda grass allergens, and the natural, spontaneous disease, have very similar responses to irritation, including airway hyperreactivity, eosinophilic inflammation, and airway remodeling. Similar changes are found in human asthma.

In cats experimentally sensitized to Bermuda grass aeroallergen and subsequently challenged, mild eosinophilic inflammation, mostly in the rostral nasal cavity, and a significant increase in tissue mast cells in the nasal airways compared to control cats, has been noted. This finding is also present in people with allergic rhinitis. Upregulation of the gene encoding interleukin-4, a Th2 dominant pro-allergic cytokine, has been found in cats with experimentally induced asthma.

In the only study of the efficacy of ASIT for spontaneous asthma in the cat, 15 out of 20 cats with the disease had positive results on intradermal allergy testing (IDT), mostly to household dust mites and sometimes to pollens. Twelve of the cats received ASIT and it was completely effective in 8 of these animals (67%). The other 4 cats experienced some improvement in clinical signs, but still had to use an inhaled corticosteroid or bronchodilator several times a week. In experimental studies, cats sensitized to HDM and/or Bermuda grass allergen, and then challenged with the same inhaled allergen(s), had a reduction in clinical signs of asthma as well as reduced airway eosinophilia when given ASIT after challenge. Therefore, ASIT could be a rewarding treatment for spontaneous feline asthma, as long as the triggering allergen(s) are first identified by IDT or allergen-specific IgE serology.

Few studies have been published regarding the role of cells and mediators of inflammation in FASS diseases. The inflammatory cellular infiltrate in the epidermis and dermis of cats with FASS, similar to that in atopic humans and dogs, includes mast cells, T cells (the majority expressing CD4 rather than CD8), Langerhans cells, and macrophages. Even fewer studies exist that provide information regarding the pro-inflammatory mediators in the skin or blood of cats with hypersensitivity dermatitis, and these studies are small or have inconclusive results. In some, but not all cats with FASS diseases and asthma, cytokine expression suggests Th2 immune dysregulation, which is a feature of atopic dermatitis in humans and dogs.

Both human and feline allergic skin diseases and asthma likely comprise a variety of phenotypes with significant histological overlap. Almost all of the research on pathogenesis of feline asthma has utilized experimental models rather than cats with natural, spontaneous disease. The authors recommend additional research on the immunopathogenesis of FAS diseases, including both dermatological diseases and asthmatic diseases, and each individual disease needs to be characterized and investigated separately to determine if they represent parts of a continuum or are separate entities with different clinical signs and pathogeneses.