DOGS, DISEASES FROM
Diverticulosis of the colon
Diverticula (pouches) are clearly visible in this
endoscopic view of the wall of the colon. The
condition is thought to be due to a low-fibre diet.
Complications of diverticulo-
sis may include intestinal bleeding and
The cause is believed to be
a lack of fibre in the diet (see
Diverticulosis is very rare in
developing countries, where high-fibre
foods make up much of the diet.
Symptoms occur in only a m inority
of people w ho have diverticulosis. They
usually result from spasm or cramp of
the intestinal muscle near diverticula.
Many patients have symptoms similar
irritable bowel syndrome
including abdominal pain, a bloated
sensation, and changes in bowel habits.
In severe cases of diverticulosis, intesti-
nal haemorrhage can lead to bleeding
from the rectum.
In people with cramps, a high-fibre
diet, fibre supplements, and
may relieve the symptoms.
A high-fibre diet also reduces the inci-
dence of complications. Bleeding from
treatment, but surgery is an option.
A brand name for
that is also used in the
and, in meno-
A sensation of unsteadiness and light-
headedness. Dizziness may be a mild,
brief symptom that occurs by itself, or
it may be part of a more severe, pro-
longed attack of
typified by a spinning sensation) with
nausea, vomiting, sweating, or fainting.
Most attacks are harmless and are due
to a fall in the pressure of blood to the
brain. This can occur when getting up
quickly from a sitting or lying position
symptoms may result from a
in w hich there is a
temporary, partial blockage in the arter-
ies that supply the brain.
Other possible causes include tired-
ness, stress, fever,
(impairment of electrical activity in the
sugar levels), and
(bleeding between the outer two mem-
branes that cover the brain).
Dizziness as part of vertigo is usually
due to a disorder of the inner ear,
principal disorders of the inner ear
that can cause dizziness and vertigo
Disorders of the acoustic nerve, such
are rare causes of
dizziness and vertigo. Brainstem dis-
orders that can cause
vertigo include a type of
Brief episodes of m ild dizziness usually
clear up after taking a few deep breaths
or after resting for a short time.
Severe, prolonged, or recurrent dizzi-
ness should be investigated by a doctor.
Treatment depends on the underlying
cause. For example, certain cases of
dizziness and vertigo due to a disorder
of the inner ear are treated w ith
also called fraternal
twins. Dizygotic twins are the result of
of two egg
They each have a
of their own and may be of different
sexes. (See also
disease-modifying anti-rheumatic drugs
A type of
The abbreviation for deoxyribonucleic
acid. DNA is the principal molecule
carrying genetic information in almost
all organisms; the exceptions are cer-
tain viruses that use
DNA is found in the
cells; its double-helix structure allows
the chromosomes to be copied exactly
during the process of cell division. A
special form of DNA exists in m ito-
structures within cells (see
Sections of DNA can also be cre-
ated artificially (see
during genetic engineering. (See also
A drug that is used in the treatment of
(a halt in the pum p-
ing action of the heart). The drug may
be given by intravenous drip.
Dobutamine stimulates nerve cells in
the heart to increase the heart rate and
raise the blood pressure. For this rea-
son, the drug may be used in a
to investigate potential
nary artery disease
in cases where the
patient is unable to exercise on a tread-
m ill (see
A qualified medical practitioner who is
licensed to practise by the appropriate
medical authority in his or her country,
such as the General Medical Council in
dogs, diseases from
Infectious or parasitic diseases that are
acquired from contact with dogs. They
may be caused by viruses, bacteria,
mites living in or on a dog.
Many parasites that live on dogs can
be transferred to humans, for example
through stroking the dog’s fur.
The most serious disease from dogs
is the viral infection
The UK is
free of rabies, but travellers to countries
in w hich rabies exists should treat any
dog bite w ith suspicion. Dog bites can
cause serious bleeding and shock and
may become infected.
potentially serious diseases caused by
the ingestion of worm eggs from dogs.