Submitted by: Patricia Shea, DVM
Sci Rep 2020;10:16503. DOI: 10.1038/s41598-020-73426-0
The role of cat eye narrowing movements in cat–human communication.
Humphrey T, Proops L, et al.
Many domestic animal species including dogs, horses, pigs, and goats, are known to respond to cues given by humans in performing tasks. Dogs and puppies as well as horses and goats also an engage in gazing behavior towards people as a form of communication. As is common, socio-communicative abilities of domestic cats towards humans have been less well studied than those in dogs and horses due to the solitary and perceived secretive nature of the cat.
Studies performed over the past two decades have demonstrated that cats faced with an ambiguous situation will look to their owners, and will, like dogs, correctly perform object choice tasks involving human pointing. They also can recognize their name from other words spoken by people, even when the persons speaking their name are unfamiliar to them.
Almost everyone who has been attentive to a cat in any setting has noticed the slow blink sequence. The slow blink sequence comprises a series of half-blinks (eyelids partially approach each other without full eye closure), which are followed by either a prolonged narrowing of the palpebral fissure or full eye closure. Generally, the slow blink sequence is observed when human and cat are both present in a calm, positive setting. Narrowing of the palpebral fissure can also be observed in positive emotional displays of other species, including dogs, horses, and cows, and in the human Duchenne smile, considered to be the most genuine in some cultures, because of the perceived warmth and joy conveyed when the eyes are also involved, through constriction of the orbicularis oculi muscles.
In this study, two experiments were performed to assess the communicatory significance of the slow blink in human-cat interactions. The first experiment sought to determine if cats would respond to humans directing a slow blink stimulus by engaging in slow blink responses of their own. The second experiment investigated whether a cat would approach an unknown human after a slow blink interaction.
The first experiment included 21 cats from 14 different households. Fourteen owners participated in this experiment, conducted in a familiar room within the cat’s home. The cats represented a variety of ages from 0.45 to 16 years; 10 were male and 11 were female; all cats involved had healthy, visual eyes. The owners were instructed in the slow blink technique by the experimenters. Each cat was presented with a slow blink condition, and a control condition consisting of no human interaction.
In the second experiment, 24 cats ranging in age from 1-17 years, twelve males and twelve females, were recruited from local online advertisements. Only cats with healthy, visual eyes were included, as in the first experiment. These cats, who were not the same individuals as the cats in the first experiment, were given a slow blink stimulus in one condition and a neutral human face with no direct eye contact being made as a control condition.
This paper is the first report of an experimental investigation designed to understand the role of slow-blinking as a form of communication between cats and humans. The feline subjects in the first experiment responded with more eye narrowing movements when they received a slow blink from their owners than when the owner was simply present in the room but not slow blinking at the cat. In the second experiment, when a person unfamiliar to the cat (the experimenter) slow blinked at the animal, cats responded with a higher frequency of eye narrowing movements than when the experimenter showed a neutral face not involving direct eye contact with the cat. Also, cats enrolled in the study appeared to perceive slow blinking by humans as a positive interaction, as they were more likely to approach the experimenter following a slow blink by this person than when the experimenter avoided direct eye contact with the subject and adopted a neutral facial expression. The slow blink sequence therefore may represent an indicator of positive emotion in cats and may promote relaxation in this species.
In the past several decades, a growing amount of attention has been paid to the emotional welfare of domestic animal species, including the cat. The “Cat Friendly” movement, spearheaded by the American Association of Feline Practitioners and the International Society of Feline Medicine/International Cat Care, have at their core a concern for the emotional well-being and comfort of domestic animal species. The slow blink is an easy technique to learn for cat care professionals and volunteers in the veterinary, shelter, and rescue arenas, as well as for cat owners, and can be helpful in assessing the welfare of cats in their care and enhancing cat-human communication and bonding.
J Small Anim Pract 2020;61: 467-474. DOI: 10.1111/jsap.13178
Is there a link between bacteriuria and a reversible encephalopathy in dogs and cats?
Crawford AH, Cardy, TJA
In humans, particularly the elderly, neurological deficits such as delirium, confusion, coma, drowsiness, gait disturbance, and worsening of clinical signs in patients already suffering from neurological disorders such as Parkinson’s disease and stroke, can be associated with bacteriuria. A causal link has been hypothesized in these situations because the neurological deficits improve rapidly when antibiotics appropriate for the bacteriuria and supportive care are initiated. The reasons for bacteriuria, either clinical or subclinical, being a potential cause of neurological deficits are unclear. Forebrain dysfunction, sometimes associated with brainstem involvement in more severe cases that involve stupor, coma, or cranial nerve deficits, is implicated in bacteriuria-associated neurological signs. Systemic inflammation, hyperammonemia, and urine retention are among the phenomena likely to be part of the etiology of bacteriuria-associated neurological deficits in human patients.
The authors note that while there are no reports in the literature documenting a possible link between bacteriuria and neurologic deficits in canine and feline patients, anecdotally such an association is likely to exist. In this case report, the medical records of 11 animals (7 dogs and 4 cats) seen at a veterinary teaching hospital were reviewed. These were patients with neurological signs referable to diffuse forebrain, or forebrain and brainstem, disease. Extracranial and structural and/or inflammatory brain diseases were ruled out in these veterinary patients, but urine bacterial cultures in all of them were positive. Administration of appropriate antibiotics and supportive care in these dogs and cats improved or resolved the neurologic deficits.
All cases reviewed in this report had a positive 48-hour aerobic and anaerobic urine bacteriological culture of a urine sample obtained by cystocentesis. Every subject also had undergone an MRI study of the brain as well as a cerebrospinal fluid analysis, as well as routine hematologic and biochemical testing. Four female spayed cats, ranging in age from 2.5-9 years, were included in the study. Three of the cats presented to the hospital with acute onset of mentation changes, three with seizures (two with generalized seizures, one with focal seizures), two with inappetence, and two with proprioceptive ataxia affecting all four limbs. Duration of clinical signs prior to presentation ranged from two to 14 days, but the median duration of clinical signs prior to hospital evaluation was two days. Two of the cats had neurological signs consistent with diffuse forebrain disease, and two had forebrain and brainstem dysfunction. The brainstem dysfunction in the two cats was associated with a reduced vestibulo-ocular reflex. Dysuria and pollakiuria were observed in one of the cats during its hospital stay. Plasma ammonia levels were elevated in two of the three feline patients who had this measurement performed. Urine from all four cats cultured positive for E. coli, and one of the cats also cultured positive for E. faecalis.
All of the cats received intravenous fluid therapy during hospitalization. Three of the cats received amoxicillin-clavulanate as antibiotic therapy, and the fourth, cephalexin. The duration of antibiotic therapy was 10-14 days. The three cats experiencing seizures received levetiracetam (for 7, 14, or 450 days), and all were seizure-free after starting therapy. Neurologic deficits improved in all four patients within 1-2 days of starting treatment. The patients spent one to six days in the hospital. The canine cases reviewed in this report also experienced sustained resolution of neurologic deficits when their bacteriuria was treated.
It is noteworthy that two of the cats evaluated were young adults: one was a 4-year-old Maine Coon, and the other, a 2.5-year-old Domestic Shorthair (DSH). The other two were a 7-year-old Maine Coon, and an 8.75-year-old Birman. None of these animals were over the age of 12, yet all of them had positive bacterial urine cultures. The only feline patient who did not undergo an abdominal ultrasound study was the 4-year-old Maine Coon, and the only cat with abnormal abdominal ultrasound findings was the 2.5-year-old DSH, who had bilateral mild pyelectasia. In the three cats who had urinalyses as well as urine cultures, low urine specific gravity (USG) was identified; USGs ranged from 1.010-1.022, and two of the cats (the 2.5-year-old DSH and the 8.75-year-old Birman) had inflammatory urine sediment.
In the human field, ongoing studies are attempting to elucidate the pathogenesis of bacteriuria-associated neurologic deficits. Empirically, appropriate antibiotic therapy and intravenous fluid therapy are key to resolving these clinical signs in humans, and result in improvement of abnormal mentation in one to three days. The dogs and cats in this study, with similar treatments, also demonstrated rapid improvement in neurological status in the same time frame. The authors recommend that any cat or dog presenting with acute onset or worsening of neurological signs, especially those associated with diffuse forebrain disease, should have a urinalysis and bacteriological urine culture and sensitivity, even if there are no clinical signs referable to urinary tract disease.