30 EqUUS 498 AUTUMN 2019
HOW DO
HORSES
PERCEIVE
DEATH?
A sad event provided re-
searchers in Portugal with a
rare opportunity to observe
how feral horses react to the
death of a herd mate and to
collect data that may advance
understanding of emotions
and intelligence in all horses.
Scientists from the
University of Coimbra
in Portugal and Kyoto
University in Japan were do-
ing routine fieldwork, observ-
ing a feral herd, when they
noticed a 2-month-old foal
whose hind legs had been se-
verely injured in a presumed
wolf attack.
“We started to work with
this horse population in the
north of Portugal in 2016,”
says Renata Mendonça, PhD.
“Every year in the breeding
season, from April to July
we conduct fieldwork. We
are almost every day in the
field following and observ-
ing horses’ behavior from
morning to late afternoon.
Additionally, this popula-
tion is subjected to pre-
dation pressure from the
Iberian wolf, and for the
past two years, foal mortal-
ity has reached almost 100
percent and we believe it is
mainly due to wolf predation.
These two factors combined
Owners often overlook difficulty eating, bit
evasions, antisocial behavior and other signs
of dental pain in horses, according to a new
study from Finland.
Researchers at the University of Helsinki
surveyed the owners of 47 horses who had
cheek teeth surgically removed because
of tooth root infections. These infections
can have a number of causes, says Jaana
Pehkonen, DVM, but in this study “most were
due to dental fractures with or without pre-
disposing dental caries.”
The survey respondents answered 23
questions about how their horses behaved
before and after the tooth extractions were
performed. For example, the eating behaviors
that most often disappeared after the den-
tal procedure involved adjusting hay in the
mouth while chewing, dropping hay or
eating unusually slowly. Among the observed
under-saddle behaviors, the one most of-
ten resolved by tooth extraction was evad-
ing the bit by going “above” or “behind” it.
Withdrawn and antisocial behavior toward
people or other horses were the most com-
monly reported general behaviors that dissi-
pated after the procedure.
“In this study, bit-related behavioral
problems seemed to be more common
than signs related to eating and drinking
in horses suffering from periapical dental
pain,” says Pehkonen. “However, bit-related
problems may be easier for the owner to
notice because most of them probably
exercise the horse more often than observe
its eating behavior.”
Indeed, her findings suggest that the
signs of equine dental problems are often
missed. In half of the study horses, the tooth
infections were discovered during routinedental exams, suggesting
that the owners did not
realize the observed
behaviors could be
linked to dental pain,
and only six of the study
horses had external
swellings, sinus drainage
or other obvious signs of
tooth problems prior to
their diagnosis. Almost all of the owners— 96
percent—said their horses benefitted from
having the teeth removed.
“In ‘real life’ this happens a lot,” says
Pehkonen. “Some of the signs the horse is
showing are not regarded as indications of
pain—for example, aggressive behavior,
self-mutilation, introverted gaze—until the
source of pain has been removed or cured.
And usually these signs develop quite slowly,
so knowing the horse is actually experienc-
ing pain is sometimes really difficult or even
impossible before the teeth or other painful
disease have been cured.”
Based on these findings, Pehkonen
recommends routine annual dental exams
to identify problems that may otherwise
go overlooked.WHEN BEHAVIOR
SIGNALS DENTAL PAINReference: “Behavioral signs associated with equine periapical infection in cheek teeth,”
Journal of Equine Veterinary Science, June 2019GETTYIMAGES/ISTOCKP
HOTOSOMETHING
AMISS: Anti-
social behavior
toward people
or other horses
can be a sign of
oral discomfort
in horses.