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Rabbit Health
Like all pets Rabbits
can get ill. The most common symptom that is presented in
a veterinary clinic is due to heat stroke.
Heat stroke
If the temperature reaches above 25 degrees Celsius, then you
need to take action to prevent your rabbit suffering heat
exhaustion Though this is a legitimate concern for all
rabbits, rabbits with thick or long coats of hair, overweight,
and young or old are at an even greater risk. Temperature,
humidity and air ventilation are all factors that contribute to
heatstroke in a rabbit. Like people, rabbits are individuals and
could respond to these conditions somewhat differently. It is
important to check your rabbit consistently to insure they are
comfortable and do not overheat. Early detection of heatstroke
and proper corrective steps could mean the difference between
life and death for your beloved companion.
Signs to look out for:
Fast, shallow breathing
Hot ears
Listlessness
Wetness around the nose area
Tossing back of head while breathing rapidly from open mouth.
If your rabbit shows signs of heatstroke?
You need to move your rabbit immediately in to a cool place away
from any sun. Dampen the ears with cool (not cold) water as this
will help to bring down his/her body temperature. Rabbit’s ears
are his/her air conditioner. Give your bunny plenty of fresh,
cold water with a few ice cubes in it. Another way is what
we do here at Melbourne Pet Minders and that is fill up empty
plastic coke bottles with water and freeze them, cover them in a
cotton cloth and place near the rabbit.
Teeth
Dental disease has several causes, namely genetics, inappropriate
diet, injury to the jaw, infection, or cancer.
Malocclusion: Rabbit teeth are open-rooted and continue to grow
throughout their lives. In some rabbits, the teeth are not
properly aligned, a condition called malocclusion. Because of
the misaligned nature of the rabbit's teeth, there is no normal
wear to control the length to which the teeth grow. There are
three main causes of malocclusion, most commonly genetic
predisposition, injury, or bacterial infection. In the case of
congenital malocclusion, treatment usually involves veterinary
visits in which the teeth are treated with a dental burr (a
procedure called crown reduction or, more commonly, teeth
clipping) or, in some cases, permanently removed.
Molar spurs: These are spurs that can dig into the rabbit's
tongue and/or cheek causing pain. These can be filed down by an
experienced veterinarian with a dental burr.
Signs of dental difficulty include difficulty eating, weight
loss and small stools, anorexia, and visibly overgrown teeth.
However, there are many other causes of ptyalism, including pain
due to other causes. A visit to an experienced rabbit
veterinarian is strongly recommended in the case of a wet chin,
or excessive grooming of the mouth area.
Worms
Some vets now
recommend worming all rabbits against the parasite
Encephalitozoon Cuniculi. Some studies have indicated that over
50% of rabbits may be infected with this parasite. Fenbendazole
is used as a deworming agent in other species of animal and has
shown to be effective in treating rabbits. In the UK it is now
sold in paste form as a treatment for rabbits under the brand
name Panacur. It is particularly recommended for rabbits kept in
colonies and before mixing new rabbits with each other
Gastrointestinal Stasis
Gastrointestinal stasis is a serious and potentially fatal
condition that occurs in some rabbits in which gut motility is
severely reduced and possibly completely stopped. When untreated
or improperly treated, GI stasis can be fatal in as little as 24
hours.
GI stasis is the condition of food not moving through the gut as
quickly as normal. The gut contents may dehydrate and compact
into a hard, immobile mass (impacted gut), blocking the
digestive tract of the rabbit. Food in an immobile gut may also
ferment, causing significant gas buildup and resultant gas pain
for the rabbit.
The first noticeable symptom of GI stasis may be that the rabbit
suddenly stops eating. Treatment frequently includes
subcutaneous fluid therapy (rehydration through injection of
saline solution under the skin), drugs for treatment of the
buildup of gas in the digestive tract, massage to promote gas
expulsion and comfort, possible drugs to promote gut motility,
and careful monitoring of all inputs and outputs. The rabbit's
diet may also be changed as part of treatment.
Some rabbits are more prone to GI stasis than others. The causes
of GI stasis are not completely understood, but common
contributing factors are thought to include:
a lack of fibre in the diet. Many pet rabbits do not get
sufficient fresh grass hay, but are instead mistakenly fed only
commercial alfalfa pellets originally developed for rapidly
increasing mass in rabbits bred for meat.
insufficient moisture in the diet. Fresh, leafy greens are a
critical part of a rabbit's diet in part because of their
moisture content, which helps prevent the gut contents from
becoming impacted.
lack of exercise. Rabbits confined to a cage frequently do not
get the opportunity (or motivation) to run, jump, and play,
which is critical in maintaining gut motility.
In addition, GI stasis can be caused by the rabbit not eating
for other reasons, such as stress, dental problems, or other
unrelated health problems.
GI stasis is sometimes misdiagnosed as cat-like "hair balls" by
veterinarians not familiar with rabbit physiology. However,
unlike cats, rabbits do not have the ability to vomit.
Upper Respiratory/Snuffles
An over-diagnosed ailment amongst rabbits is respiratory
infection. Pasteurella bacteria, known colloquially as
"snuffles," is usually misdiagnosed and has been known to be a
factor in the overuse of antibiotics among rabbits.
A runny nose, for instance, can have several causes, among those
being high temperature or humidity, extreme stress,
environmental pollution (like perfume or incense), or a sinus
infection. Options for treating this is removing the pollutant,
lowering or raising the temperature accordingly, and medical
treatment for sinus infections.
"Runny eyes" can be caused by dental disease or a blockage of
the tear duct. Environmental pollution, corneal disease,
entropion, distichiasis, or inflammation of the eyes are also
causes. This is easy to diagnose as well as treat.
Sneezing can be a sign of environmental pollution (such as too
much dust) or food allergy.
While Pasteurella is a bacterium that lives in a rabbit's
respiratory tract, it can flourish out of control in some cases.
In the rare event that happens, antibiotic treatment is
necessary.
Mites
Cheyletiellosis (also known as "Cheyletiella dermatitis") is a
mild dermatitis caused by mites of the genus Cheyletiella. It is
also known as walking dandruff due to skin scales being carried
by the mites. Cheyletiella live on the skin surface of dogs,
cats, rabbits, and humans. The adult mites are about 0.385
millimeters long, have eight legs that have combs instead of
claws, and have palpi that end in prominent hooks. They do not
burrow into the skin but live in the keratin level. Their entire
21 day life cycle is on one host. They cannot survive off the
host for more than 10 days.Cheyletiellosis is seen more commonly
in areas where fleas are less prevalent, because of the
decreased use of flea products that are also efficacious for the
treatment of this mite.
Cheyletiellosis is highly contagious. Transmission is by direct
contact with an affected animal. Symptoms in animals vary from
no signs to intense itching, scales on the skin, and hair loss.
The lesions are usually on the dorsum of the animal. Symptoms in
humans include multiple red, itchy bumps on the arms, trunk, and
buttocks. Because humans are an irregular host for the mite, the
symptoms usually go away in about three weeks.
Diagnosis is by finding the mites or eggs microscopically in a
skin scraping, combing, or on acetate tape applied to the skin.
The most common treatment in animals is weekly use of some form
of topical pesticide appropriate for the affected animal, often
an anti-flea product. Fipronil works well, especially in cats.
In unresponsive cases, ivermectin is used, Selamectin is also
recommended for treatment. None of these products are approved
for treatment of cheyletiellosis.Other pets in the same
household should also be treated, and the house or kennel must
be treated with an environmental flea spray.
Fly Strike
Fly strike mostly affects rabbits kept in unsanitary conditions
and is more likely to occur during summer months. Fly strike
happens when flies lay their eggs in the damp or soiled fur of a
rabbit. Within 12 hours, the eggs hatch into the larvae stage of
the fly, known as maggots. It is often a secondary condition to
an open wound, extreme faeces accumulation on the fur of rabbits
due to unsanitary living conditions, prolonged contact with
water or other environmental favourable to fly larvae. The
maggots, initially small and almost invisible to the naked eye,
can burrow into the skin of the rabbit and feed on the animals
tissue. Within 3–4 days, the larvae can be large as 15 mm long.
In rare cases, if not treated, the rabbit can pass into shock
and die. Rabbits most susceptible are rabbits living in
unsanitary housing, older rabbits who do not move much, and
those who are unable to clean their bottom areas carefully.
Rabbits raised on solid floors are more susceptible than rabbits
raised on wire floors. Rabbits exhibiting one or more episodes
of diarrhea are often inspected, especially during the summer
months. Fly strike deaths are quick and extremely painful to the
rabbit, as hundreds of larvae literally eat it alive
Immunization
Rabbit
Calicivirus Disease. CYLAP® HVD vaccine was made available in
Australia under permit by the National Registration Authority in
November 1995. One dose will provide protection against RCD for
twelve months in rabbits older than 10 weeks of age. Only 1 dose
is necessary at 10-12 weeks of age.
An earlier vaccination can also be given in some circumstances
if earlier protection is warranted. Viral
Haemorrhagic Disease
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Viral
Haemorrhagic Disease (VHD) of rabbits is an acute and
usually fatal disease which causes acute necrotic hepatitis
(liver disease) in rabbits over 2 months of age. It is
caused by a Calicivirus and is similar to European Brown
Hare Syndrome which has been present in Europe since 1980.
VHD is a very contagious disease which can be spread
directly between rabbits but can also be carried by birds,
flies and other insects. Infection occurs via the oral,
nasal and conjunctival routes. Unfortunately the virus is
very stable in the environment and can survive for up to 105
days at normal room temperature. Once a rabbit is infected
with VHD the disease is usually incubated for about 1-3
days. Once the rabbit becomes sick and has a fever, death
usually follows in 12- 36 hours.
Signs of VHD in rabbits include elevated rectal temperature
(>41 degrees centigrade), lethargy, loss of appetite,
convulsions, collapse, vocalization, in-coordination,
difficulty breathing and a bloody discharge from the nose.
Because the disease quickly causes death few of these signs
may be noticed. In 5 to 10% of rabbits the disease takes a
more chronic course and here the signs include jaundice,
lethargy and weight loss. Rabbits with the chronic form of
the disease often die from liver failure within 1 to 2
weeks.
If VHD is suspected there are tests which can be undertaken
at Veterinary Laboratories to confirm this, ( other diseases
of rabbits may cause similar signs). The most reliable test
is electron microscopy of frozen liver samples to search for
the viral particles. Testing for antibodies is perhaps
unreliable due to an apparent strain of VHD which causes
antibody production without causing the disease. Post mortem
examination of rabbits which have died from VHD will reveal
haemorrhages throughout the liver and other internal organs.
Is it Zoonotic?
Scientists in
Australia and New Zealand have found antibodies to the virus
present in people who handled rabbits infected with VHD and
in 11 species of animals in those countries. The presence of
antibodies is generally a reaction to infection. However, no
instances of illness or death due to VHD in humans or
animals other than rabbits have been reported.
Vaccine
This disease can
be prevented by vaccinating your rabbit against VHD using a
vaccine called Cylap. This vaccine is a killed vaccine and
is very effective. Rabbits may be vaccinated using Cylap
from 14 weeks of age and they need to have a booster
vaccination every year.
Myxomatosis
Myxomatosis
(sometimes shortened to "myxi" or "myxo") is a disease which
affects rabbits. It is caused by the Myxoma virus. First
observed in Uruguay in the late 1800s, it was deliberately
introduced into Australia in 1950 in an attempt to control
rabbit infestation and population there; see rabbits in
Australia. It was introduced illegally to France in 1952 and
as a result spread to the rest of Europe.
Effects of the disease
In rabbits of the genus Sylvilagus (cottontail rabbits),
myxomatosis only causes localized skin tumors, but the
European rabbit (Oryctolagus cuniculus) is more severely
affected. It is crucial to prevent the misdiagnosis of
myxomatosis with Pasteurellosis. Pasteurellosis is a
bacterial infection which can be treated with antibiotics.
Rabbits treated for Pasteurellosis must often be treated
with antibiotics for several weeks to several months. Some
rabbits may require surgical intervention in order to remove
purulent tissues and abscess. Once Pasteurellosis has become
well entrenched, however, there is no guarantee the animal
will survive. By contrast, at this writing, there is no
treatment for rabbits suffering Myxomatosis, other than
palliative care to ease the suffering of individual animals,
and the treatment for secondary and opportunistic
infections, in the hopes the treated animal will survive.
Though the vectors of communication are similar, either
contact with an infected animal, cage, feeding or water
dishes, and insects, it should be noted, also, that
Pasteurellosis can also be spread through breeding,
specifically infecting the sexual organs of the animal.
Likewise, it is advisable to arrive at the correct diagnosis
for the benefit of both rabbit and owner. In cases of
Myxomatosis and rabbit hemorrhagic disease (RHD) the owner
is often urged to euthanize the animal to ease its
suffering. Often the difference between diagnosing a fatal
viral infection and a complex, but treatable bacterial
infection, like Pasteurellosis, will likely include
medications, X-rays, surgery, convalescent and, follow-up
care. While surgery and antibiotics may successfully treat
Pasteurellosis, they will not treat Myxomatosis or RHD. The
owner and attending veterinarian must quickly discern
between untreatable diseases and treatable conditions.
Myxomatosis and RHD are highly communicable, and untreatable
at any stage, whereas rabbits suffering from
diseases/conditions other than Myxomatosis and RHD, such as
poisoning, heat exhaustion, E. coli or Clostridium
perfringens type E enterotoxemia can benefit from timely
veterinary intervention.
Myxomatosis: At first, normally the disease is visible by
lumps (myxomata) and puffiness around the head and genitals.
It then may progress to acute conjunctivitis and possibly
blindness; however, this also may be the first indication of
the disease. The rabbits become listless, lose appetite, and
develop a fever. Secondary bacterial infections occur in
most cases which cause pneumonia and purulent inflammation
of the lungs. In typical cases where the rabbit has no
resistance death may take place with frightening rapidity,
often in as little as 48 hrs. Death takes an average of 14
days.
Spread of the disease
After its discovery in 1896 in imported rabbits in Uruguay,
a relatively harmless strain spread quickly throughout the
wild populations in South America.
In Australia, the virus was first field-tested for
population control in 1938. A full-scale release was
performed in 1950. It was devastatingly effective, reducing
the estimated rabbit population from 600 million to 100
million in two years. However, the rabbits remaining alive
were those least affected by the disease. Genetic resistance
to myxomatosis was observed soon after the first release and
most rabbits acquired partial immunity in the first two
decades. Resistance has been increasing slowly since the
1970s, and the disease now only kills about 50% of infected
rabbits. In an attempt to increase that number, a second
virus (rabbit calicivirus) was introduced into the rabbit
population in 1996.
Myxomatosis was unintentionally introduced to France by the
bacteriologist Dr. Paul Armand Delille, following his use of
the virus to rid his private estate of rabbits in June 1952
(controversially, he inoculated two of the rabbits on his
land). Within four months the virus had spread 50 km; Armand
suspected this was due to poachers taking infected rabbits
from his estate. By 1954, 90% of the wild rabbits in France
were dead. The disease spread throughout Europe. It reached
the UK in 1953, apparently without human action. Some in the
UK deliberately spread the disease, placing sick rabbits in
burrows, while many others deplored the cruelty and
suffering. The government refused to legislate to make
deliberate spread of the disease illegal. By 1955, about 95%
of rabbits in the UK were dead.
Myxomatosis is spread by direct contact with an affected
animal or by being bitten by fleas or mosquitoes that have
fed on an infected rabbit. The myxomatosis virus does not
replicate in these insect hosts, but can be physically
carried by an insect's mouthparts, i.e. from an infected
rabbit to another susceptible animal. Due to the potential
of insect vector transmission, pet rabbits may be
susceptible in enzootic areas and vaccination is highly
recommended
Use of vaccine
A vaccine is available for pet rabbits (ATCvet code:
QI08AD02) but is illegal in Australia due to fears that the
immunity conferred by the vaccine could be transmitted
through the wild rabbit population, since the vaccine uses a
live virus, the Shope fibroma virus.
Natural resistance
The development of resistance to the disease seems to have
taken different courses. In Australia, the virus initially
killed rabbits very quickly, about 4 days after infection.
This gave little time for the infection to spread. However,
a less virulent form of the virus has become prevalent
there, spreading more effectively by being less lethal. In
Europe, rabbits that are genetically resistant to the
original virus that was spread. The survival rate of
diseased rabbits has now increased to 35% when in the 1950s
it was zero. It is conjectured that this is because the main
transmission vector in Australia is the mosquito, while in
Europe it is the rabbit flea.
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