Download Important infectious diseases of cats in New Zealand

Important infectious
diseases of cats in
New Zealand
Bacterial diseases
Mycobacteria: Feline mycobacterial infections have been reviewed
recently(1)(2). Most are caused by Mycobacterium bovis. Infections
This article describes the important feline diseases
diagnosed in New Zealand’s regional animal health
laboratories. Veterinary practitioners do not
always use a regional laboratory when
making a diagnosis, so laboratory
records provide biased estimates of
disease prevalence. They do, however,
usually represent most diseases of
importance.
have been recorded in both feral cats and in a relatively large
number of domestic cats(1)(2)(3). Less common are infections with M
Janice Thompson
tuberculosis, the cat leprosy organism M lepraemurium, M avium, M
fortuitum, M smegmatis, and M thermoresistibile.
The clinical signs caused by M bovis include lymphadenopathy, skin
lesions, weight loss and depression. M lepraemurium causes painless,
firm skin nodules up to 3 cm in diameter. M fortuitum, M
smegmatis, and M thermoresistibile may also cause skin lesions.
positive filaments often breaking up into coccoid forms, but culture
is needed to differentiate between them and they often occur as
mixed infections with other bacteria such as Bacteroides spp.
Rickettsial diseases
Feline infections with Mycobacterium avium are rare but they do
Haemobartonella felis: This common rickettsial parasite is routinely
occur in immunocompromised animals(1).
diagnosed in anaemic cats in New Zealand, and it has been reviewed
Oral bacteria: Cats carry numerous bacteria as flora in their oral
recently(11). It may be present either as a primary infection or
cavities, and these may cause disease. Isolates have included
secondary to immunocompromisation from a variety of causes.
Streptococcus spp, Staphylococcus spp, Klebsiella spp, Enterobacter spp,
Pasteurella spp (including P. multocida), Escherichia coli, Bacteroides
Viral diseases
(4)
spp, CDC Alphanumeric spp, and Mycobacterium spp . Cat scratch
fever of humans often follows cat bites(5). Organisms implicated have
included Afipia spp, Rothia dentocariosa, Bartonella bacilliformis, and
Chlamydia. Recent work has also implicated Rochalimaea henselae(5).
Feline immunodeficiency virus (FIV): FIV appears to be common in
New Zealand, with 66/290 (23%) antibody positive tests having been
detected in one year at AgriQuality Animal Health Laboratory
Palmerston North. Cats early or late in the disease can be antibody
Salmonella: Most cases of salmonellosis are caused by Salmonella
negative. Lymphopaenia is common in serologically positive cats, but
Typhimurium. Salmonella Enteritidis, Salmonella Saintpaul,
neutropaenia, or a combination of both lymphopaenia and
Salmonella enterican subspecies Houtenae, and Salmonella
neutropaenia, are less common. Hypergammaglobulinaemia is
(6)(7)(8)
Hindmarsh have all been isolated from cats with diarrhoea
.
Campylobacter and Yersinia species: Both Campylobacter and
Yersinia spp can cause diarrhoea in cats.
Staphylococcus felis: This organism is commonly associated with
otitis, cystitis, abscesses, wounds and other cutaneous infections of
another common finding. Infected cats may present with reactive
lymphadenopathy, stomatitis, and persistent infections which are
difficult to control due to immunodeficiency(12).
Feline leucaemia virus (FeLV): The FeLV test detects viraemic cats
only, and not those which are infected but not viraemic. Over the
same one-year period during which the FIV positive sera were
cats (9).
detected (above), only 4/248 FeLV positive sera were detected. In
Chlamydia psittaci: This organism can cause conjunctivitis in cats.
New Zealand, FeLV infection appears to be much less common than
Actinomyces and Nocardia species: In cats, actinomycetic bacteria
it is overseas. The reason why is not known, but it presumably
are occasionally isolated from pleural and peritoneal effusions, and
reflects epidemiological factors such as frequency of contact between
from subcutaneous and tissue abscesses . A viscosus and A bovis are
cats and times spent in catteries.
the common isolates, but A odontolyticus may be cultured
Overseas, FeLV infection has been associated with myeloproliferative
occasionally (10). Nocardia may be isolated from skin wounds and
and lymphoproliferative disease(12) in addition to chronic infections
body cavity effusions in cats. Clinically, it is hard to distinguish
caused by immunodeficiency. At AgriQuality Animal Health
between Actinomyces and Nocardia infections but it is important to
Laboratory Palmerston North there has been only one documented
attempt a definitive diagnosis because the treatment regimes for the
solid lymphoma (thoracic) associated with a positive FeLV test.
two organisms differ(9), and Nocardia infections supposedly occur
Recently, cases of sarcoma induced by routine vaccination against
more frequently in immunocompromised animals(10). Both types of
FeLV have been diagnosed.
(10)
bacteria are easily recognisable in cytological smears as fine, Gram-
Surveillance 26(2) 1999
3.
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Coronaviruses: Coronavirus infections in cats include the virulent
and avirulent forms of feline infectious peritonitis, feline enteric
coronavirus, canine coronavirus, and possibly coronaviruses of other
Protozoal diseases
Toxoplasma: Toxoplasmosis in New Zealand cats has been reviewed
recently(21). Most cats in New Zealand have titres to Toxoplasma,
(12)(13)
. Routine serological tests do not distinguish between
species
these viruses, so a positive coronavirus result does not provide a
conclusive diagnosis of feline infectious peritonitis. Positive titres
have been reported in healthy cats in New Zealand(13). A serological
diagnosis of feline infectious peritonitis is possible if a positive result
is supported by characteristic clinical pathological findings of
lymphopaenia, polyclonal gammopathy, bilirubinaemia, mildly
increased serum liver enzymes, and an abdominal effusion with a
high gammaglobulin and low cell content. A definitive diagnosis is
possible histopathologically, and occasional seropositive cases have
showing that they have been exposed to the parasite at some time
during their lives(21). Demonstration of a rising or falling titre is
therefore necessary to indicate infection, along with typical clinical
signs as described elsewhere (20). The cats most at risk of infection are
either immunosuppressed adults or kittens which are seronegative
and therefore likely to become infected and undergo a period of
excretion of oocysts(21). In a recently described case, a 5-month-old
Persian cat had a severe generalised subacute pneumonia and severe
multifocal hepatitis in which numerous Toxoplasma trophozoites
were visible(22).
(14)
been confirmed in this way .
Giardia and Cryptosporidia: These protozoa have been diagnosed
Feline panleucopaenia virus: This disease usually manifests as severe
diarrhoea and vomiting in young unvaccinated kittens. Blood
samples typically show severe panleucopaenia and dehydration.
Calicivirus and herpesvirus: Calicivirus and herpesvirus are
commonly implicated in respiratory disease and stomatitis in New
separately by AgriQuality Animal Health Laboratory Palmerston
North in two cats with diarrhoea. Giardia may be a common cause
of gastrointestinal disease in cats(23)(24).
Nematode diseases
Zealand cats. Tests are rarely requested of regional animal health
Toxocara cati and Toxocara leonina: These gastrointestinal
laboratories.
nematodes are common, particularly in young cats(25).
Astrovirus: Astrovirus-like particles have been reported in young
Ollulanus tricuspis: This gastric nematode is diagnosed occasionally
cats with diarrhoea(15). A recent survey has suggested that in New
in vomiting cats, and it may be seen in gastric biopsies taken from
Zealand torovirus infection is not associated with protruding
cats with gastric signs.
nictitating membranes as has been claimed in other articles(16).
Fungal diseases
Aelurostrongylus abstrusus: This respiratory system nematode is
occasionally diagnosed in coughing cats, particularly those which are
good hunters. A diagnosis can be made by finding larvae in faeces, or
Dermatophytes: Ringworm lesions are usually seen on young or
in tracheal or bronchial washes.
immunocompromised cats. Microsporum canis is the most
commonly isolated Microsporum species but M gypseum is cultured
Capillaria aerophila: Capillaria eggs are occasionally seen in tracheal
occasionally(17). Trichophyton mentagrophytes var mentagrophytes is
or bronchial washes.
the most commonly isolated species of Trichophyton but T
Coughing cats often have an allergic bronchitis diagnosed after
mentagrophytes var erinacei (usually associated with hedgehogs) has
cytological examination of tracheal or bronchial washes, and
also been reported(17).
parasitic lung disease remains a differential diagnosis even when
Cryptococcus: Cryptococcosis is diagnosed occasionally, usually by
nematode eggs or larvae are not visible in individual samples.
histology or cytology although culture is sometimes requested to
confirm a morphological diagnosis. Cryptococcosis usually manifests
Ectoparasite Diseases
as a discharging wound around the nose. Infection often extends to
Fleas: Ctenocephalides felis infestation is common in cats. Less
the brain, and it then becomes unresponsive to conventional
commonly diagnosed are Ctenocephalides canis, Pulex irritans, and
Echidnophagia gallinacea. Fleas are responsible for transmitting the
(18).
treatment
Malassezia pachydermatis: This is occasionally diagnosed in ear and
skin infections.
Sporothrix (Sporotrichum) schenckii: This is a dimorphic fungus
found naturally as a saprophyte in rotting vegetation and soil (19)(20).
Ulcerated, discharging lesions occur at sites of infection, and
infection ascends lymphatic vessels in cats. Cats appear less able than
other species to mount an adequate response against Sporothrix, and
they shed large numbers of the organism in exudates(19).
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tapeworm Dipylidium caninum, and they may also transmit
Haemobartonella felis.
Mites: Otodectes cynotis is commonly associated with otitis externa,
but it may occasionally infect other areas of skin too. Cheyletiella
parasitivorax, C blakei, Notoedres cati, and Demodex cati are more
rarely diagnosed mites. Cats are occasionally infested with mites
from other animals. One example is a 4-month-old kitten that was
infested by the tropical fowl mite Ornithonyssus bursa(26).
Surveillance 26(2) 1999
References
(1) de Lisle GW. Mycobacterial infections in cats and dogs. Surveillance 20(4), 246, 1993.
(2) Gumbrell RC. Tuberculosis in cats. Surveillance 21(1), 21, 1994.
(3) Anon. Surveillance 24(4), 22, 1997.
Foundation for Continuing Education of the NZ Veterinary Association. Pp 616,1987.
(26) Anon. Surveillance 24(2), 23, 1997.
Janice Thompson
AgriQuality Animal Health Laboratory Palmerston North
Email: [email protected]
(4) Weber A. The significance of dogs and cats on the chain of infection in
zoonoses principally in Europe. Veterinary International. An International
Journal of Veterinary Science and Practice 5(3), 27-36, 1993.
(5) Groves MG, Harrington KS. Rochalimaea henselae infections: Newly recognised
zoonoses transmitted by cats. Journal of the American Veterinary Medical
Association 204, 267-71, 1994.
(6) Anon. Surveillance 25(2), 16, 1998.
(7) Anon. Surveillance 22(4), 6, 1995.
(8) Anon. Surveillance 25(3), 17, 1998.
(9) Koneman EW, Allen SD, Janda WM, Schrenkenberger PC, Winn WC (Editors).
The Gram positive cocci: Part I: Staphylococci and related organisms. Chapter II
In: Color Atlas and Textbook of Diagnostic Microbiology. 5th Edition Pp 539576. Lippincott, Philadelphia,1997.
(10) Thompson JC, Gartrell BM, Butler S, Melville VJ. Successful treatment of feline
pyothorax associated with an Actinomyces species and Bacteroides
melanogenicus. New Zealand Veterinary Journal 40, 73-75, 1992.
(11) Thompson J. Blood parasites of animals in New Zealand. Surveillance 25(1), 68, 1998.
(12) Brandon RB. Retroviruses of cats: A review. Australian Veterinary Practitioner
25, 8-17, 1995.
(13) Gruffydd-Jones TJ, Harbour DA, Jones BR. Coronavirus antibody titres in cats
in New Zealand. New Zealand Veterinary Journal 43, 166-167, 1995.
(14) Sparkes AH, Gruffydd-Jones TJ, Harbour DA. An appraisal of the value of
laboratory tests in the diagnosis of feline infectious peritonitis. Journal of the
American Animal Hospital Association 30, 345-350, 1994.
(15) Rice M, Wilks CR, Jones BR, Beck KE, Jones JM. Detection of astrovirus in the
faeces of cats with diarrhoea. New Zealand Veterinary Journal 41, 96-97,
1993.
(16) Smith CH, Meers J, Wilks CR, Rice M, Jones BR. A survey for torovirus in New
Zealand cats with protruding nictitating membranes. New Zealand Veterinary
Journal 45, 41-43, 1997.
(17) Carman M, Gardner E. Dermatophytes of mammals in New Zealand.
Surveillance 24(3), 18-19, 1997.
(18) Anon. Surveillance 22(2), 4, 1995.
(19) Kelly SE, Clark WT. Feline sporotrichosis : A case report with zoonotic
involvement. Australian Veterinary Practitioner 21, 139-42, 1991.
(20) Werner AH, Werner BE. Feline sporotrichosis. The Compendium of Continuing
Education for the Practising Veterinarian 15, 1189-97, 1993.
(21) Thompson J. Toxoplasmosis in dogs and cats in New Zealand. Surveillance
20(3), 36-8, 1993.
(22) Anon. Surveillance 24(3), 22, 1997.
(23) Tonks MC, Brown TJ, Ionas G. Giardia infection of cats and dogs in New
Zealand. New Zealand Veterinary Journal 39, 33-34, 1991.
(24) Anon. Surveillance 25(3), 17, 1998.
(25) Blackmore DK, Humble MW. Zoonoses in New Zealand. Publication No. 112.
Surveillance 26(2) 1999
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