Download Infectious and parasitic diseases of dogs in New Zealand

Surveillance Vol.26 No.1 1999
Infectious and parasitic
diseases of dogs in
New Zealand
Page 3
This article comments on infectious and
parasitic diseases of dogs in New Zealand as
recorded by Animal Health Laboratories over the
last 10 years. Some viral infectious
diseases initially caused epidemics
before being controlled by vaccination.
Fraser Hill, author
Endemic Bacterial diseases
Actinomyces species: These can cause a fibrinopurulent
visiting northern regions, but some infection appeared to have been
pleuropneumonia in dogs. Large bacterial colonies containing
contracted locally, and were associated with the presence of the rat
branching filamentous Gram-positive bacteria can be identified in
(Rattus norvegicus) on their properties. The niche occupied by
thoracic aspirates of infected dogs with dyspnoea.
serovar copenhageni in the brown rat in the upper half of the North
Campylobacter jejuni: C. jejuni has been isolated from the faeces of
dogs with recurrent bloody diarrhoea - especially puppies.
Leptospira: Overseas, classical canine leptospirosis is associated with
the serovars copenhageni and canicola. In New Zealand, only one
weak serovar to L interrogans serovar canicola has been recorded from
5,800 dogs tested, and there has been no evidence of disease due to
serovars ballum or canicola.
Island is thought to be occupied by serovar ballum in the lower half
of the North Island - hence fewer canine cases in this region. One
survey found serological evidence of serovar ballum infection in
0.7% of dogs sampled(5).
Mycobacterium species: Tuberculosis caused by Mycobacterium bovis
has been recorded a number of times, usually associated with the
consumption of tuberculous possums. Cases have been seen in two
dogs from the West Coast of the South Island. Acid-fast organisms
Between 1987 and 1996, 121 cases of canine leptospirosis were
were seen in tissues from both dogs, and culture of infected tissue
diagnosed at the Ruakura Laboratory(1). Most of these were caused by
from one of the dogs was positive for M. bovis. Dogs are relatively
L. interrogans serovar copenhageni. Prior to 1990, serovar copenhageni
resistant to M. avium complex, but infection was identified in
infections were recorded almost exclusively in the upper half of the
aspirated lymph node from a 10-month-old Labrador retriever. The
North Island(2)(3). Subsequent serological confirmation of
clinical history included thrombocytopenia, lymphocytosis, and
L.interrogans serovar copenhageni infection in the lower half of the
regenerative anaemia, with subsequent generalised
North Island was made in dogs presenting with severe hepatic and
lymphadenopathy and splenomegaly(6).
(4)
renal disease . Some of these dogs had probably been infected whilst
3.
Surveillance Vol.26 No.1 1999
4.
Nocardia species: Proliferative pleuritis with
with Toxascaris leonina, Dipetalonema caninum, and Taenia species
abundant red-brown fluid and sulphur granules is suggestive of
was uncommon(13). Oslerus (Filaroides) osleri has been found in
Nocardia infection. The thoracic cavity, abdominal cavity and skin
dogs, but with a low prevalence(14). Dipetalonema reconditum
are the most frequently reported sites of infection. The presence of
infection is endemic in New Zealand dogs, but it causes no clinical
chains of Gram-positive branching rods strengthens the diagnosis.
disease. It is therefore important to differentiate microfilariae seen
Culture confirms it.
on blood smears from the clinically significant Dirofilaria immitis
Salmonella species: Diarrhoea, pyrexia and abdominal pain may be
infection.
the presenting signs of salmonellosis. A number of serotypes have
D. immitis has not been detected in dogs resident in this country -
been isolated from dogs.
only in those recently introduced(15).
Exotic bacterial diseases
Cestodes: At one time, Echinococcus granulosus, Taenia hydatigena
and Taenia ovis were important causes of livestock disease in New
New Zealand is free of Brucella canis and Borrelia burgdorferi
Zealand, with the dog as the definitive host. A national eradication
infections, as shown by recent serological surveys(7)(8). Ninety clinical
scheme has almost eradicated E. granulosus(16).
cases that could have included Br. canis in the differential diagnosis
were subjected to bacteriological examination, and no Br. canis was
isolated(8). Canine ehrlichiosis caused by Ehrlichia canis and Rickettsia
rickettsii are not present in New Zealand, and the tick intermediate
hosts have not established here.
Fungal diseases
Dermatophytoses: Dermatophytosis is uncommon. Microsporum canis
is responsible for 70-95% of dermatophyte infections, and M. gypsum
and Trichophyton mentagrophytes account for between 10 and 16%(9).
Protozoa
Coccidia species: In a 1978 survey of 481 faecal samples(17) the
prevalence of coccidia species in dogs was found to be 4% for
Isospora canis, 9.2% for I. ohioensis, 58.8% for Sarcocystis species,
and 2.7% for Hammondia heydorni.
Neospora caninum: A retrospective study of tissue sections using
immunohistochemistry confirmed the presence of N. caninum
infection of dogs, and showed that the infection has been present
here since at least 1972(18). In a recent case, a 13-week-old boxer
Exotic systemic fungal disease: No significant systemic fungal diseases
puppy presented with hind limb ataxia and fibrosis of the left biceps
of dogs are present in New Zealand. Significant exotic organisms
femoris muscle, causing stifle and hock joint fixation. Serology
include Blastomyces dermatitidis, Coccidioides immitis, and
revealed a high Neospora immunofluorescent antibody titre (IFAT of
Histoplasma capsulatum.
1:51,200), and the pup was euthanased. On histopathology,
Ectoparasites
protozoal cysts were visible in the brain and skeletal muscle, and
these were confirmed as N. caninum by immunohistochemistry.
Cheyletiella yasguri: In 1975 this mite was found on dogs imported
Retrospective investigation revealed that this pup was one of five in a
from the UK, but it had been reported previously(10). The dogs were
litter. One pup had lost condition and died at 3 weeks of age, and
in poor condition, with mild pruritus and exfoliative dermatitis
one had begun head pressing and died at 4 weeks of age. Neither
around the ears and head.
death was investigated. Another pup showed no clinical signs and
Ctenocephalides species: All species of fleas are widespread throughout
was negative for Neospora serology. The fifth pup had an IFAT titre
New Zealand, but clinical signs are more common in the warmer
of 1:1,600 that decreased to 1:800 3 months later. The dam of this
northern parts of the country. A recent survey showed that
litter also had an IFAT titre of 1:1,600 (Ron Thornton, pers com).
Ctenocephalides canis, C. felis and Pulex irritans were present on dogs
Toxoplasma gondii: Toxoplasma cysts associated with inflammation
in the Wellington area. C. canis was the most common flea found(11).
in the brain, heart, liver, spleen, tongue, skeletal muscle and intestine
C. canis and C. felis are important as the intermediate hosts of
were observed in dead 8-week-old puppies. The pups were
Dipylidium caninum.
dehydrated, with fever, lymphadenitis, and abdominal pain recorded
Exotic ticks: Rhipicephalus sanguineus, the brown dog tick, and Ixodes
before death. Only one pup was tested for T. gondii and it had a high
holocyclus have been found on dogs imported into New Zealand, but
antibody titre (1:128) in the latex agglutination test(19).
neither tick has established here(12).
Viral diseases
Endoparasites
Canine adenovirus (infectious canine hepatitis): Infectious canine
Ancylostoma caninum and Uncinaria stenocephala: Both are blood
hepatitis was rarely seen because of widespread vaccination. Severe
sucking intestinal parasites that can cause diarrhoea and death in
necrotising hepatitis with characteristic basophilic intranuclear
young pups, and pedal dermatitis in older dogs. A survey of young
inclusion bodies was seen in the liver from a pup that died on a
dogs in 1981 showed that the most common helminth infections
breeding property. Eight puppies died and about 30 become ill.
were Toxocara canis, Trichuris vulpis, and U. stenocephala. Infection
About 80 pups aged from 2-3 months old were being reared on the
Surveillance Vol.26 No.1 1999
property. In another case, three of six 6-week-old pups died with
References
characteristic histological changes in the liver.
(1)
Black A, Orr M. Review of diagnostic cases - July to September 1996. Surveillance 23(4), 3-6, 1996.
(2)
Ellison RS, Hilbink F. Leptospiral infections in New Zealand dogs. Surveillance 17(2), 15-6, 1990.
(3)
Hilbink F. Canine leptospirosis widespread. Surveillance 16(4), 6, 1989.
Canine distemper virus: In 1983 there was a serious outbreak of
distemper in the Auckland and Northland area. Many dogs were
(4)
Black M, Orr M. Review of diagnostic cases - April to June 1997. Surveillance 24(3), 21-3, 1997.
reported to have died. Clinical presentations included nervous signs
(5)
Hilbink F, Penrose M, McSporran K. Antibodies in dogs against L. interrogans serovars copenhageni,
ballum and canicola. New Zealand Veterinary Journal 40, 123-5, 1992.
(6)
Black M. Review of diagnostic cases-July to September 1997. Surveillance 24(4), 21-2, 1997.
(7)
Reichel MP, Penrose M. Survey for specific anti- Borrelia burgdorferi antibodies in dogs. Surveillance
24(2), 20-1, 1997.
severity of the disease, which is now seen only sporadically.
(8)
Gardner E, Reichel MP. No evidence of Brucella canis infection in New Zealand dogs. Surveillance 24(3),
17-8, 1997.
Herpesvirus: Cases of Aujeszky’s disease in dogs were reported in
(9)
Carmen M, Gardner E. Dermatophytes of mammals in New Zealand. Surveillance 24(3), 18-9, 1997.
1988, 1989 and 1990. In the 1990 case there was a disease outbreak in
(10) Davis GB, Kyle MG. Cheyletiella yasguri infestation of a dog. New Zealand Veterinary Journal 17, 156,
1969.
and bronchopneumonia. Confirmation was usually based on the
presence of intranuclear and intracytoplasmic eosinophilic inclusion
bodies in brain, bladder and lung. Vaccination has reduced the
a piggery, with an abnormal number of stillbirths and suckling pigs
dying after showing nervous signs. Two bitches on the farm
(11) Guzman RF. A survey of cats and dogs for fleas: with particular reference to their role as intermediate
hosts of Dipylidium caninum. New Zealand Veterinary Journal 32, 71-3, 1984.
consumed dead piglets and exhibited severe neurological signs
(12) Fairley R, Heath ACG. Exotic ticks intercepted in New Zealand since 1980. Surveillance 24(1), 21-2, 1997.
including salivation, ataxia, facial muscle tremor and pruritus
(13) Collins GH. A survey of gastro-intestinal helminths of dogs in New Zealand. New Zealand Veterinary
Journal 29, 163-4, 1981.
leading to self mutilation. Aujeszky’s disease was confirmed by
histopathology and virus isolation(20). Aujeszky’s disease has now
(14) Jones BR, Clark WT, Collins GH, Johnstone AC. Filaroides osleri in a dog. New Zealand Veterinary Journal
25, 103-4, 1977.
been eradicated from New Zealand (Barbara Christensen, pers.
(15) Ellison RS, Townsend KG, McKellow AM, Neilson FJA. Canine heartworm disease. Surveillance 17(4), 9,
1990.
comm).
(16) Pharo H, van der Logt P. Hydatids diagnosed on Arapawa Island. Surveillance 24(2), 8-9, 1997.
Three 11-day-old Boxer pups died with a history of acute respiratory
distress. At necropsy, petechial haemorrhages were found throughout
the parenchyma of the lung, liver and kidney. Histopathology
revealed multifocal necrosis in the kidney, liver, lung, heart and small
intestine. Amphophilic intranuclear inclusion bodies typical of
canine herpesvirus infection were seen in cells of the lung and
kidney.
Parainfluenza virus: Kennel cough is a multifactorial disease
(17) Anon. Coccidia in dogs and cats. Surveillance 5(2), 9, 1978.
(18) Patitucci AN, Alley MR, Jones BR, Charleston WAG. Protozoal encephalomyelitis of dogs involving
Neospora caninum and Toxoplasma gondii in New Zealand. New Zealand Veterinary Journal 45, 231-5,
1997.
(19) Thompson JC. Toxoplasmosis in dogs and cats in New Zealand. Surveillance 20(3), 36-8, 1993.
(20) Lake DE, Hutchings CR, Aalders NG. Aujeszky=s disease in dogs - more confirmed cases. Surveillance
17(2), 24, 1990.
(21) Than KM. Isolation and identification of canine adenovirus type-2 from the upper respiratory tract of a
dog. New Zealand Veterinary Journal, in press
(22) Horner GW. Canine parvovirus in New Zealand: Epidemiological features and diagnostic methods. New
Zealand Veterinary Journal 31, 164-6, 1983.
involving parainfluenza viruses, Bordetella bronchiseptica bacteria
and sometimes Mycoplasma species. Outbreaks can occur in kennels.
Fraser Hill
Canine adenovirus type 2 was isolated from a greyhound dog with
Batchelar Animal Health Laboratory
(21)
tracheitis and tonsillitis in a recent case report .
AgriQuality New Zealand
Parvovirus: Canine parvovirus was first reported in New Zealand in
Email: [email protected]
January 1979, and a subsequent epidemic peaked in 1981. Clinical
Accepted for publication April 1998
disease was usually characterised by enteric signs such as severe
vomiting and diarrhoea, and there was occasional myocardial
necrosis in pups(22). In the early epidemics, most cases died due to
dehydration and secondary infection. Lesions included acute
necrotising enteritis and widespread lymphoid depletion. Once
vaccination became widespread the incidence of disease decreased.
Routine vaccination is still practised and the virus appears to have
become attenuated, so deaths are much less common. They still
occur though in unvaccinated puppies.
Commercial vaccinations are available against canine parvovirus,
distemper virus, canine adenovirus, leptospirosis, parainfluenza
virus and B bronchiseptica.
Exotic viral diseases
New Zealand is free of the rabies virus.
5.