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Cats: Health, Disease and Physiology: Vaccination, infections
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Cat ‘Flu Information for breeders
What breeders need to know about cat flu
source: Feline Advisory Bureau Volume 39 (1) 2001
starts page 11, 3 pages long
Cat flu is a respiratory tract infection and is problematical in breeding colonies in spite of vaccination. The symptoms can be mild or severe and causes include feline herpesvirus (FHV), feline calicivirus (FCV) and Bordetella bronchiseptica. FHV is usually more severe and some kittens or immunocompromised adult cats may die. Recovered cats may go on to develop problems such as chronic rhinitis and will also be carriers, shedding the virus at times of stress. FCV is often milder than FHV, but there are several strains and these can cause conjunctivitis and oral ulcers, as well as ‘limping syndrome’. Many pedigree cats infected with FCV are found to have gingivitis. FCV is shed continuously, although the infection is eventually eliminated in most cats. Bordetella bronchiseptica (BB) infection usually causes a mild nasal discharge and possibly a cough, but can lead to fatal pneumonia if FHV/FCV are also present. There have been a few cases of transmission of BB from dogs to cats.
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Chronic nasal discharge in the cat
Runny noses in cats
source: Feline Advisory Bureau Volume 39 (1) 2001
starts page 15, 2 pages long
Idiopathic rhinitis is a common form of chronic upper respiratory tract (URT) disease caused by a bacterial infection in the nose secondary to a virus such as cat flu. Other forms are rare, but can include fungal infection, polyps, cancer and physical damage from foreign objects. The symptoms include nasal discharge, which may affect one or both sides of the nose, sneezing, runny eyes, facial swelling and enlarged lymph nodes. Diagnostic tests include haematology, biochemistry and nose and throat swabs, as well as more extensive investigations such as x-rays and surgical rhinotomy. Treatment for URT disease usually involves controlling the clinical signs with antibiotics, steam inhalation and flushing the nasal passages.
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Efficacy of a canarypox virus-vectored vaccine against feline
leukaemia
New canarypox virus-feline leukaemia vaccine found to be effective
source: H. Poulet et al
Veterinary Record vol 153 no 5, August 2 2003
starts p141, 5 pages long
Feline Leukaemia virus (FeLV) causes significant illness and deaths among
domestic cats world wide, and there is a need for more effective vaccines,
as well as more evidence of the efficacy of FeLV vaccines. Live virus vaccines
give rise to a broader immune response than inactivated virus vaccines, but
there are safety concerns relating to live attenuated FeLV vaccines. Live
viral vectors offer an alternative. The canarypox virus vector (ALVAC) offers
possibilities because it multiplies in birds, not mammals, but is able to
give mammals a protective immune response by expressing foreign immunogens.
This study used a canarypox-vectored live vaccine to give protection against
FeLV. The vaccine was tested on FeLV-free and seronegative kittens aged between
seven and nine-weeks-old. The vaccine was found to be effective against very
severe challenges, and was solid twelve months following the initial vaccination.
Most diseases relating to FeLV are suffered by cats with persistent FeLV
infections, so it is important that a vaccine can prevent such infections.
Cats may, however, suffer latent infections, with the virus hosted in their
bone marrow. This latent infection may become active when cats are given corticosteroids.
There was no latent infection detected for most of the cats given the ALVAC-FeLV
vaccine.The vaccine appears to have induced a broad enough immunity to lower
infections with FeLV to levels at which they could not be detected.
The vaccine also proved efficacious with no adjuvant. This helped to achieve
local tolerance, and there was no inflammation when samples from the site
of the injection were examined. The vaccine has an advantage in not provoking
reactions, since it is possible that chronic inflammation at sites of injections
could be linked to fibrosarcomas in vaccinated cats. The vaccine is also compatible
with other vaccines. The article examines methods and results of this study
in further detail.
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Disease risks for the travelling pet: Leishmaniasis
Diagnosing and treating leishmaniasis in cats and dogs
source: Lise Trotz-Williams and Luigi Gradoni
In Practice vol 25 no 4, April 2003
starts p190, 6 pages long
Several thousand pets have travelled between mainland Europe and Britain
since the Pet Travel Scheme (PETS) was introduced in 2000. Pets are treated
for ticks, tapeworms, and rabies, but can still contract other diseases, including
leishmaniasis, which can be fatal, and can also affect humans.
Leishmaniasis refers to syndromes in animals affected by Leishmania protozoan
parasites. Leishmania infantum is more common in the Mediterranean, and has
also been found in North America. Leishmania chagasi is more common in Latin
America. Dogs are the main reservoir for both types of Leishmania, since it
is rarer for cats to be affected. Animals become infected through being bitten
by sandfly carrying the parasite. The infection can spread to several organs
in cats and dogs that do not have a strong enough immune system to protect
them. Around half of dogs that become infected will go on to develop clinical
leishmaniasis. The disease has a reported incubation period of between a month
and seven years. Symptoms vary according to which organs and tissues have
been invaded, and some animals may simply show dermatitis. Pets may develop
'spectacles' as the skin round the eye is affected, and their muzzles may
also show signs of the disease. Cats and dogs that are seriously affected
can lose their appetites, lose weight, and become depressed. The variety of
possible clinical signs is wide, and includes osteomyelitis, colitis, and
pericarditis, so diagnosis is not easy, but leishmaniasis should be considered
when pets have travelled to areas where it is endemic.
Diagnosis can be carried out in a number of ways, including smears from skin
lesions. Parasites may not be easily detectable in some cases, and diagnosis
may also be carried out through testing for antibodies to leishmania. Such
tests may not be accurate until a while has elapsed after the pet has become
infected.
There is some risk to humans, especially children and people with HIV. However,
humans in southern Europe generally appear to be at low risk of acquiring
clinical leishmaniasis, despite high risks of infection.
Treatment tends to suppress clinical signs, and pets may suffer relapses,
since parasitological cures are difficult to achieve. Euthaniasia may be recommended
in areas where leishmaniasis is endemic, due to the risk of the disease being
passed on, and of drug resistance developing. However, since sand flies and
other vectors are unknown in the UK, treatment is more of an option there.
Megaglumine antimoniate and allopurinal are usually given, with allopurinol
continuing over the longer term, though there are other treatments, such as
allopurinol given alone. Long-term intermittment treatment appears to be the
best option to prolong survival rates.
Cats appear to be more resistant to leishmaniasis than dogs, and they tend
to be less severely affected when they are infected. Most affected cats simply
suffer from skin conditions. Treatment is the same for cats and dogs.
Leishmaniasis is especially common in Mediterranean countries, such as France,
Spain and Portugal. The highest rates have been found in the Balearic Islands,
Crete, Malta and Corsica. The risk varies from one locality to another, and
from one season to the next. The risk is highest when there are most sand
flies about, especially between May and September. Sandflies tend to be especially
active from dusk to dawn, so an important precaution is to keep pets indoors
at this time. Collars impregnated with deltamethrin (Scalibar collars from
Intervet) can also help to protect dogs from sandfly bites and infection.
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Preliminary results of the dog and cat exotic disease surveillance
scheme
Cats in Britain appear to be less vulnerable to exotic diseases
than dogs
Source: Paul Mauser
Veterinary Record vol 153 no 7, August 16 2003 p220
The British government launched its Dog and Cat Travel Risk Scheme (DACTARI)
in March 2003, for voluntary reporting of cats and dogs with exotic diseases,
especially if they have been abroad under the Pet Travel Scheme. Cats appear
to be less vulnerable than dogs, since no cases of exotic diseases were reported
from March to July inclusive, while 12 dogs were reported, one with two conditions.
There were eight diagnoses of leishmaniasis, four of babesoisis, and one of
ehrlichiosis. Two diagnoses of leishamniasis and one of babesoisis were also
reported prior to the start of DACTARI. Ten of these cases involved dogs that
had travelled to France and Spain. Leishmaniasis is a disease that humans
can suffer from too, and it is not easy to treat.
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Government response on cat and dog vaccination
British government responds to report on cat and dog vaccines
source: Veterinary Record vol 153 no 2, July 12 2003
starts p35, 2 pages long
The British government has backed recommendations made by a working group
on vaccination for cats and dogs. The group was set up in 1999 to assess health
risks arising from vaccinations. The government supports 15 of the 19 recommendations
made by the group, including a recommendation that more research be carried
out into links between upper respiratory tract problems in cats, and feline
calcivirus vaccination. The working group called for product literature to
carry statements that the duration of immunity used for booster vaccination
regimes is a minimum, rather than a maximum period. The group also called
for a risk-benefit analysis to be carried out for individual pets, by vets
together with the pets' owners. The government sees professional development
among vets as the best way to spread information, rather than through product
literature. The government also claims that it encourages voluntary disclosure
of information to vets and the public. The government rejected a recommendation
for generic warnings to be put on injectable vaccines for cats, relating to
the possible higher risk of sarcomas developing after aluminium-adjuvanted
vaccines. The government argues that there is not yet enough evidence to link
specific vaccines, or types of vaccines to fibrosarcomes.
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Vaccination and fibrosarcomas in cats
Risks of fibrosarcomas from vaccinating are less than risks
of not vaccinating cats
source: Veterinary Record vol 148 no16, April 21 2001 p493
Jane Dobson from Cambridge University's Department of Clinical Veterinary
Medicine, has reviewed literature on links between vaccination and fibrosarcomas
in cats. She presented her report to the 2001 BSAVA Congress. She noted that
there was a study in California which found cats vaccinated against rabies
to be more likely to suffer from fibrosarcomas that were often larger and
more aggressive, and affecting younger cats, than traditional fibrosarcomas.
Sarcomas also seem more likely to occur if a cat is always vaccinated in the
same spot, possibly because the injection site could become affected by chronic
inflammation. There is evidence for some sort of link between vaccinating
and
fibrosarcomes, but no actual proof. The development of cancers probably involves
a number of factors, she argues. Reported cases in the UK that fit a diagnosis
of fibrosarcomas induced by vaccination are rare. Cats are exposed to greater
health risks if they are not vaccinated, compared to the risk of their developing
a tumour.
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Kitten mortality in the United Kingdom: a retrospective analysis
of 274 histopathological examinations (1986 to 2000)
Study of 274 kitten deaths in the UK between 1986 and 2000
source: T.A.Cave et al
Veterinary Record vol 151 no 17, October 26 2002
starts p497, 5 pages long
A retrospective study has examined the deaths of 274 kittens from the UK.
Private homes accounted for 211 of the kittens, and 56 kittens came from shelters,
while a further seven kittens were of unknown origin. Pedigrees accounted
for 56% of the sample, and this high proportion may be because owners were
keener to find out why the kitten had died. Infectious diseases were found
to have affected 55% of the kittens, with viral infections accounting for
71% of infections. Feline parvovirus (FPV) accounted for 25% of the total
deaths. Feline herpesvirus and calcivirus were the most important viral infections
for neonatal and pre-weaning kittens, while 17 postweaning kittens died from
feline infectious peritonitis.
The median age at death of rescue shelter kittens was 49 days compared to
56 days for kittens from private homes. Shelter kittens were also more likely
to have suffered from FPV. Pedigree kittens were more likely to have come
from private homes rather than shelters, and their median age at death was
56 days compared with 42 days for non-pedigree kittens. Little difference
was found between age at death of male and female kittens. There was no diagnosis
for 33% of the total, and lack of diagnosis was more
likely if only a sample of tissue was submitted, rather than the kitten's
whole carcass.
More research is needed on how common FPV is in shelters. Measures to control
infection can reduce kitten mortality in shelters.
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Prevalence of feline leukaemia virus and antibodies to feline
immunodeficiency virus and feline coronavirus in stray cats sent to an RSPCA
hospital
UK survey of prevalence of diseases among stray cats
source: A. Muirden
Veterinary Record vol 150 no 20, May 18 2002
starts p621, 5 pages long
Tests for feline coronavirus (FCoV), feline leukaemia virus (FeLV)and feline
immunodeficiency virus (FIV) were carried out on 517 stray cats at an RPSCA
centre in Birmingham, England. 22.4% of cats tested had antibodies to FCoV,
3.5% had antibodies to FeLV, and 10.4% had antibodies to FIV. Feral and semi-feral
cats were more likely to test positive for FCoV, as were cats older than two
years of age. Cats with non-traumatic illness were more likely to test positive
for FeLV and FIV than traumatised or healthy
cats. Semi-feral and feral cats were also more likely to test positive for
FIV, as were older cats, and males, both entire and neutered, though no correlation
was found between tameness, age and sex, and testing positive for FeLV.
FcoV is spread through faeces, and stray cats may be at risk through using
several territories. FeLV appears to be spread through social contact such
as grooming, whereas FIV is linked to fighting, and in this study, with neglected
or old injuries. Previous studies have found links between tumours, gingivitis
and FeLV, and between abscesses and severe oral disease and FIV.
This study should provide useful data for authorities dealing with stray
cats, many of which may need to be rehomed.
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Haemorrhagic fever, oedema and high mortality associated with
FCV infection
Concern about feline calcivirus infection outbreaks in the
US
source: A.D. Radford et al
Veterinary Record Vol 151 no 5, August 3 2002 p155
There is concern about outbreaks of feline calcivirus in the US, where a
new strain affecting both kittens and adults has led to mortality rates often
reaching 50%. Affected cats show a range of symptoms, including pyrexia (90%),
paw and facial oedema (50%) and upper respiratory tract infection (50%). Infection
can be spread by humans and contaminated instruments and cages as well as
by contact between cats. Many cats succumbing to these infections had been
given all their vaccinations. Quarantine and other measures have helped to
limit outbreaks. It takes from between two to four weeks for cats to cease
shedding this virus from the time they are infected. The infection appears
to be confined to the US, but anecdotal evidence suggests a possible case
in the UK. This virulent strain of virus could be the result of a mutation,
so may appear outside the US. UK vets suspecting that cats have this type
of infection should contact A.D. Radford and team at Liverpool University,
where specialist facilities are available for molecular typing and virus isolation.
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Retrospective study of 46 cases of feline haemobartonellosis
in Israel and their relationships with FeLV and FIV infections
Study of cats with feline infectious anaemia
source: S. Harrus et al
Veterinary Record vol 151 no 3, July 20 2002
starts p82, 4 pages long
Feline haemobartonellosis is also called feline infectious anaemia. It is
thought to be the main cause of feline haemolytic anaemia, and is caused by
Haemobartonella felis, which may be mycoplasmal, though it was first thought
of as rickettsial. There are large and small forms of H felis, and the organism
may be transmitted by fleas. This study describes 46 cases, and compares cats
which also suffered from feline immunodeficiency virus (FIV) and feline leukamia
(FeLV) with cats that did not have these additional infections.
The sample comprised 23 intact males, 9 castrated males, 11 intact females
and 3 spayed females. Free roaming cats accounted for 85% of the sample, or
39 cats, and seven were indoor cats. Their ages ranged from two months to
12 years, though 75% were 2.5 years or younger. 34 cats were tested for FeLV,
with 13 positive, and 37 were tested for FIV with eight positive, while two
were positive for both FeLV and FIV. This study found that younger cats, and
intact males are more likely to suffer from feline haemobartonellosis, which
fits with previous research.
The main clinical signs were lethargy, tachypnoea, depression, anorexia,
emaciation, dehydration, splenomegaly, icterus, pale mucus membranes, and
flea infestations. Tachypnoea has not been discussed in most reports of previous
research on H Felis, but was found in 73% of these cats. The main haematological
findings were anaemia and leucocytosis. Key biochemical abnormalities found
were that activites of aspartate aminotransferase (AST) alanine aminotransferase
(ALT) were high for most of the cats tested for this. This could be linked
to hepatic hypoxia as a result of anaemia. Some
of the cats found to be anorexic (65%) may have suffered from hepatic lipidosis,
accounting for the high activity levels.
There were significantly lower body temperatures in cats suffering from both
FeLV and H felis infections, possibly because of circulatory collapse and
acidosis from compromised blood perfusion. There have been reported of fever
resulting from co-infections, but cats in this study may have been at more
advanced stages of illness, with temperatures dropping when they were moribund.
Anaemia was also more serious in cats with both infections. FIV infected cats
did not show significant differences from cats without co-infections.
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Feline infectious anaemia
Symptoms of feline infectious anaemia, treatment and prevention
source: Feline Advisory Bureau Journal vol 38:3, July 2000
starts p93, 2 pages long
Feline infectious anaemia (FIA) is caused by Haemobartonella felis (H felis),
a bacterial parasite which damages red blood cells. Young male cats, and those
sick from other diseases such as FIV are especially vulnerable, and the disease
is thought to be transmitted through fighting and fleas, as well as from queens
to their kittens. Urine and saliva are not thought to be infectious, but cats
can catch FIA from infected blood, either from blood transfusions, or from
biting infected cats. Humans cannot catch FIA.
Affected cats tend to show loss of appetite, pale gums, tiredness and depression.
Diagnosis is not easy because levels of bacteria vary in waves. Some infected
cats are carriers and show no symptoms, and anaemic cats are usually able
to produce new red cells. FIA can be treated with antibiotics such as Doxycycline,
which may be used together with corticosteroids to prevent red cell destruction.
Blood transfusions may be needed if anaemia is severe. Rehydration therapy
and help with feeding may also be needed. Cats may still carry FIA for life,
despite treatment with antibiotics, and only
appear ill at times of stress. Preventive measures include controlling fleas,
and reducing aggression between cats, as well as ensuring that blood used
in transfusions is FIA-free.
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Cat jab
Vaccine approved in US for feline AIDS
source: New Scientist April 6 2002 p23
The US Department of Agriculture has approved a vaccine to protect cats from
feline AIDS. The vaccine was developed at Florida University's College of
Veterinary Medicine, by Janet Yamamoto, and uses two strains of FIV virus
that have been inactivated. Cats can obtain some 60% protection for a year.
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Cat HIV jumps species
Macaques infected with FIV
source: Alison Motluk
New Scientist August 25 2001 p8
Researchers from Calgary University, Canada, have infected macaque monkeys
with feline immunodeficiency virus (FIV). Blood was taken from the macaques,
and then injected back into them after being infected with FIV. The macaques
suffered a drop in CD4 immune cells, and lost weight. One macaque that initially
recovered fell ill again following injection with tetanus toxoid, which sets
of latent infections. Usage of FIV and other lentiviruses in gene therapy
should be reconsidered, the researchers argue.
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Grooming and control of fleas in cats
Comparison of grooming behaviour and flea infestation of cats
with and without Elizabethan collars
source: Robert A. Eckstein, Benjamin L. Hart
Applied Animal Behaviour Science 68 (2000)
starts p141, 10 pages long
Two experiments have been carried out on cats to assess the importance of
oral grooming as a method of flea control. In the first experiment, eighteen
long-haired cats were studied in a household plagued by fleas. Nine cats wore
Elizabethan collars which did not allow them to groom effectively. These cats
were compared with nine control cats, with flea samples taken once a week.
After three weeks, the cats with Elizabethan collars were found to have more
fleas than the control cats. In the second experiment, cats were videotaped
in a flea-infested household, and their behaviour was compared with cats in
a flea-free location. The cats in the flea-infested household spent more time
grooming. These two experiments show that cats may groom more when there are
fleas in their environment, and that grooming is a method for cats to remove
fleas.
Cats have cornified spines on their tongues, which can help to remove ectoparasites
like fleas. Cats also use scratch grooming techniques to reach their heads
and necks. Fleas removed from cats by grooming apparently do not survive longer
than one or two days. Grooming may, thus, reduce numbers of fleas in the household,
and there was a reduction in adult flea numbers in the environment where the
control group lived. This drop in numbers of fleas in the environment may
help explain why the control group had fewer fleas than the cats wearing collars.
Though oral grooming brings a benefit in terms of effective flea reduction,
one problem that can arise when cats remove fleas by oral grooming is that
fleas can infect cats with tapeworms.
The cats in the flea-infested household in the second experiment, tended
to groom more frequently rather than for longer periods. Increased frequency
of grooming bouts may mean that the cats' central timing mechanism was accelerated
by flea saliva. This fits in with a view of grooming as pre-programmed, rather
than stimulus-driven, since longer periods of grooming would be expected with
a stimulus-driven model of grooming.
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Feline uveitis: a clinical and serological study of 44 cases
French study suggests link between feline uveitis and Toxoplasma
source: M. Roze
The European Journal of Companion Animal Practice Vol IX (2) October 1999
starts p 149, 8 pages long
A study of 44 cats suffering from feline uveitis suggests links between this
condition and Toxoplasma Gondii. The cats underwent both ophthalmologic examination,
and had serological tests for Toxoplasma Gondii, FeLV and FIV. Anterior uveitis
was found in 79.5% of the cases, the most common symptoms being low intra
ocular pressure, and aqueous flare. Posterior uveitis was diagnosed in 22.7%
of the cases. Cataracts were found in nine cases, lens luxation was found
in eight cases, and glaucoma in seven cases.
Changes affecting the iris were noted in 34 cats. The iris often becomes darker
as a result of uveitis. The anterior chamber was cloudy in 27 cats. Feline
uveitis can have a number of causes, such as tumours, traumas, hypertension,
parasitic, bacterial and viral agents, and multiple myeloma, but the precise
cause of a particular case of uveitis is usually unknown. Vets may not always
carry out serological tests, due to the costs involved for the cat owner.
The cats in this study were aged between 2.5 months and 16-years-old, with
those whose uveitis was caused by tumours or trauma excluded from the study.
The average age of the group as a whole was 9.4 years, rising to 13.1 years
for spayed females, 10.8 years for neutered males, 9.5 for entire females,
and falling to 3.5 years for entire males. There were 20 neutered males, 14
spayed females, five entire males and five entire females in the study. A
positive serology was found in 25 cats for toxoplasmosis, while six were
FIV positive, five being positive both to FIV and toxoplasmosis. Four cats
were FeLV positive, with two also positive for toxoplasmosis. The toxoplasma
positive cats had an average age of 10.3 years.
Timing of tests is important in establishing a clear link between toxoplasmosis
and uveitis, but toxoplasmosis does appear to be responsible for some cases.
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Urinary tract infections in small animals: therapeutic options
and management of problem cases
Treating problem UTIs in cats and dogs
source: Mark Dunning and Jo Stonehewer
In Practice vol 24 no 9, October 2002
starts p 518, 7 pages long
The main way of treating urinary tract infections (UTIs) in cats and dogs
is to use conventional antimicrobials, especially injections followed by oral
treatments. The article provides a detailed discussion of selection of antibiotics
and recommended amounts. Cephalexin or amoxycillin may be useful, but culture
and sensitivity is indicated, and this should always be the case where infection
recurs. The therapy should always be completed, even if the cat or dog appears
to have recovered.
Underlying causes have to be investigated if the infection recurs or does
not respond to antimicrobials. Low dose antibacterials may help if an underlying
cause cannot be found. Infections may recur for a number of reasons, such
as drug resistance, too low a dosage, factors that affect how the cat or dog
absorbs the drug, or deep-seated infections. Novel therapies include oestrogen
replacement therapy (which can help women), prophylactic Lactobacillus administration
(effective in mice), and regular consumption of cranberry juice, which is
effective in reducing infections in some humans, though there is only anecdotal
evidence that it may be effective in veterinary species.
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See also:
Cat
Health: Digestive problems, poisoning and kidney disease
Cat
Health: Other health issues
Cats:
General
Cats:
Behaviour and training
Cats:
Effect on human health
Reviews
of Cat books, including books on health and behaviour