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All rights reserved. Its no secret that acral lick granulomas are irritating for veterinary clients, their pets and you. Heres everything you need to know about this dermatologic condition, from what causes it to how to diagnose it. While acral lick granuloma is rarely a life-threatening condition, it's irritating for both the dog and owner. Acral lick granulomas also known as acral lick dermatitistypically seen on the front part of the lower leg in dogs, are lesions that develop as a result of chronic and compulsive licking. Constant licking causes hair loss and erosion or ulceration of the superficial skin layers, leading to marked inflammation of the skin and focal infection.
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So you’ve got a little headbanger
Learn More. Performed the experiments: TM. Analyzed the data: TM NK. Wrote the paper: TM NK. Many social animals have a species-specific repertoire of affiliative behaviours that characterise individualised relationships within a group. To date, however, quantitative studies on intragroup affiliative behaviours in social carnivores have been limited.
Here, we investigated the social functions of the two most commonly observed affiliative behaviours in captive African lions Panthera leo : head rubbing and licking. We conducted behavioural observations on a captive group of lions composed of 7 males and 14 females, and tested hypotheses regarding three social functions: tension reduction, social bonding, and social status expression.
In accordance with the social bond hypothesis, and in disagreement with the social status expression hypothesis, both head rubbing and licking interactions were reciprocal. After controlling for spatial association, the dyadic frequency of head rubbing was negatively correlated with age difference while licking was positively correlated with relatedness.
Group reunion after daily separation did not affect the frequencies of the affiliative behaviours, which was in disagreement with the predictions from the tension reduction hypothesis. These support the social bond hypothesis for the functions of head rubbing and licking. Different patterns of affiliative behaviour between the sexes may reflect differences in the relationship quality in each sex or the differential predisposition to licking due to its original function in offspring care.
Many social animals have a species-specific behavioural repertoire of affiliative interactions. These behaviours are usually non-randomly distributed within a group and are affected by factors such as individual traits e. Animals across a wide range of taxa use ritualised non-agonistic behaviours to manage intragroup social relationships to maintain social bonds with valuable partners  — reduce tension  — and express social status submission and dominance within a group  — .
Acral lick granuloma: stopping the itch-lick cycle
To date, quantitative studies of intragroup affiliative behaviours based on fine-scale behavioural observations of social carnivores have been limited to a few species, such as spotted hyenas coatis and meerkats . Studies on social interactions in felids are even scarcer due to their solitary nature.
Inconsistent reports exist regarding the function of allogrooming in domestic cats. Curtis et al. On the other hand, in a similar captive setting, van den Bos  observed that dominant cats mostly males groomed subordinates more frequently than they received grooming from subordinates, often with aggression and regardless of kinship, which suggests that allogrooming can be a mild form of aggression. In long-term coalitions of wild male cheetahs composed of brothers or unrelated individuals, allogrooming is distributed equally .
In captivity, many other felid species, despite having solitary lifestyles in the wild, express rubbing and licking behaviour toward their keepers which indicates that rubbing and licking are common in the felid behavioural repertoire. Lions, which live in groups with a unique social structure and express a set of social interactions, have not been the subjects of such behavioural studies.
Lion sociality has been well documented by a long-term field research project in the Serengeti ecosystem e. A pride, the basic social unit of lions, is typically composed of 2—9 maximum 21 related females, their offspring, and a coalition of 1—6 maximum 9 males that are unrelated to the females .
Unrelated males can form coalitions of two to three individuals, but larger coalitions are composed of close kin . Lions form a fission—fusion society in which members travel in subgroups of variable composition . Multiple females in a pride give birth simultaneously and young cubs are nursed communally . Dispersal is male-biased, with most females remaining in the natal pride while cohort males form a coalition and leave the natal pride to become nomadic.
Nomadic male coalitions may fight with resident males to acquire a territory and reproductive opportunities. Takeover of a pride is usually followed by infanticide . Male reproductive success is evenly distributed in small coalitions, but becomes skewed as coalitions become larger . research on lion social behaviour has mainly focused on intergroup conflict e.
Ask a vet: why is my dog licking ears?
The two most conspicuous affiliative behaviours are head rubbing and licking  ; Figure. Head rubbing can last for more than 1 min, but it can also occur in an abbreviated form with a slight bending of the head toward the other lion. In addition to providing tactile stimulation, head rubbing may also act as an olfactory form of communication i. Odours play an important role in the social life of lions and felids in general . When scent marking with urine, a lion either scratches the ground immediately after squatting down to urinate, or sprays urine over objects while in an upright position and with a vertically raised tail .
Why does my dog lick the baby’s face?
Prior to this scent marking, they often rub their head over the object, and in a recent study, volatile organic compounds from the faces of lions and other large felids were identified . In addition, lions may acquire information on individual identity and reproductive condition by sniffing the hindquarters of the conspecifics they encounter . Whether olfactory stimuli induce estrus synchrony in females is unknown.
Other affiliative behaviours exhibited by lions include social play in which juveniles and occasionally adults also engage. Less conspicuously, some vocalisation and physical contact while resting may also convey amicable intention although detailed investigations are lacking. In this study, we quantitatively described the distributions of these affiliative behaviours in a captive group of lions and tested three hypotheses regarding their social functions.
These hypotheses are not mutually exclusive, and thus the behaviours could have multiple functions. Social stress caused by instability in relationships may eventually disrupt cooperation among group members. To cope with relationship uncertainty, mammals living in fission—fusion societies exchange greeting behaviours that quickly update relationships chimpanzees:  ; bonobos:  ; spider monkeys:  ; spotted hyenas: .
Although it may be risky for an individual to approach and physically contact a conspecific with which it has an uncertain relationship, according to Schaller head rubbing in lions often occurs after fights and other stressful events, and when dissociated pride members reunite.
We hypothesised that head rubbing functions to moderate tension by reducing the aggressive intent of an interaction partner.
A considerable amount of evidence indicates that grooming in primates, which serves a hygienic function equivalent to licking in lions, promotes tension reduction . The tension reduction hypothesis le to the following predictions:. Prediction 1. Therefore, head rubbing and licking should be frequent during encounters after separation i.
Communal cub rearing by lionesses  is likely to result in frequent affiliation among same- and adjacent-aged cubs, which may develop into lasting bonds.
In contrast, less social interaction is expected in dy with larger age differences. Hence, after controlling for spatial association, the frequencies of head rubbing and licking should correlate positively with age difference. Social bonds between two conspecific animals can be defined by the occurrence of disproportionally frequent affiliative behaviours among them compared to other dy within the group . In addition, affiliative behaviours can be viewed as investments in the development of social bonds .
Schaller  argued that head rubbing functions to unite the pride and strengthen social bonds. In the life history of lions, relationships between adult males and females last for the short period of male residency in a pride while relationships between same-sex individuals last for a lifetime. Male coalitions last through the nomadic period and pride residency. The longer residency of larger coalitions  suggests male bonding may have a positive effect on their reproductive success. In philopatric females, relationships can continue throughout their lifetime unless pride fission occurs.
Since larger prides can maintain higher-quality territories  and more effectively defend cubs against infanticidal males females may also benefit from social bonds with other females. If head rubbing and licking have the function of maintaining these relationships, the following predictions can be made. Prediction 2. Reciprocal relationships should be unaffected even when immediate exchanges are excluded.
A novel device for real-time measurement and manipulation of licking behavior in head-fixed mice
The distributions of intragroup affiliative behaviours are often affected by the difference in dominance rank between individuals. In primates, for example, a general tendency for dominant individuals to receive more grooming than subordinates is observed . There are two possible directions of social status expression: submission and dominance assertion. In carnivores, low-ranking domestic cats approach high-ranking conspecifics with their tails held vertically and subordinate spotted hyenas show submission to dominants by exposing their genitals .
Female lions in a pride lack dominance rank system in relation to access to food and although males in a large coalition have skewed reproductive success they do not have dominance rank expressed by agonistic or submissive behavior . Lions exhibit considerable sexual size dimorphism that gives males an advantage during physical contests with females. Schaller  associated this asymmetry in resource holding potential between the sexes with his observation that females direct more head rubbing to males than to other females.
Submission and dominance predict opposite patterns in the direction of affiliative behaviours as follows.
Prediction 3. This study complies with Japanese regulations regarding the ethical treatment of research subjects.
Research permission to conduct the study was granted by the Tokyo Zoological Park Society. The subject of this study was a group of captive lions kept in the Tama Zoological Park, Tokyo, Japan. The group was composed of two founding adult female siblings that were introduced in and their offspring Figure 2. Individual identification was based on scars, coat colour, physique, and other natural features.
Reproductive control was conducted on this group; all of the group males, including the subadults, were vasectomised and sires not shown in Figure 2 were kept separately from the group and introduced to unrelated adult females for breeding every 2—3 years. The effect of vasectomy on social behaviour of male social carnivores is considered to be limited .
Over the study period, no individuals showed stereotypical or abnormal behaviours. The average relatedness of the group, calculated from the zoo studbook, was 0. The average relatedness values among males and females were 0. Males are indicated by underlined IDs.
Siblings from the same litter are connected by vertical lines. Bold, dashed and double lines represent three different sire males. Birth years are indicated at the bottom.
Depending on their physical conditions e.