© 2007 The Authors

Australian Veterinary Journal

Volume 85, No 10, October 2007Journal compilation © 2007 Australian Veterinary Association

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Blackwell Publishing Asia

In this issue

Small animals

The influence of the full moon on the number of accessions to an animal emergency centre

There is a common belief that human and animal behaviour isinfluenced by the full moon. The aim of this study from theUniversity of Melbourne Animal Emergency Centre was toinvestigate if they had more clients at times of the full moon, sothat they could adjust staffing levels accordingly. All the12,102 accessions to the Centre between February 2003 andJanuary 2006 were classified as full-moon or new-moon days,identified as the date of the occurrence plus one day each side.There were 12.1 consults per day on the 111 full-moon days and10.9 on 985 non-full moon days, and these were not statisticallysignificantly different. There was also no difference on newmoon days.

The authors discuss the possible reasons for the long held beliefin the effects of the moon and suggest that it had a much greatereffect before electricity and modern lighting. Increased light atthe full moon may have caused sleep deprivation, alterations inreproductive performance, decrease activity in nocturnal preyanimals and so changes in predator performance. They concludethat although their results do not support their original hypothesisthat the full moon affects clinic accessions, human nature beingas it is, staff will still most likely blame the full moon on busy days.

Genetic analysis of canine parvovirus from dogs in Australia

Canine parvovirus (CPV-2) causes severe haemorrhagic diarrhoea,vomiting, dehydration and immunosuppression in susceptibledogs, and has a high mortality rate. Reports from several countrieshave suggested development of different genetic variants (CPV-2a,2b and 2c) but there is no data on the variants currently circulatingin Australia. This has implications for vaccine efficacy. Thisstudy assessed the CPV-2 genotype of 43 samples, including 16viruses isolated from samples collected between 1980 and 2001,33 faecal or intestinal samples collected between 2001 and 2005(26 of which from cases of possible vaccine failure), and 2 vaccinesamples.

Results showed that 41 of the 43 samples contained CPV-2a, incontrast to many other countries where CPV-2b/2c has displacedCPV-2a. The reasons for this are not known, but the authorsspeculate that some may be due to mis-typing. They consideredthat the cases of possible vaccine failure were most likely to bedue to interference by maternal antibodies. There is a short timewhen maternal antibodies have declined and are no longer protective,but newly vaccinated pups have not had time to produce theirown immunity. The authors stress the recommendations thatrisk of exposure to CPV in the environment should be minimiseduntil 2 weeks after the final vaccination.

Gall bladder mucocoele and concurrent hepatic lipidosis in a cat

In the dog, gallbladder mucocoele presents with abdominal pain,jaundice and inappetance, and there are characteristic striatedpatterns seen in immobile bile on ultrasound examination. Inthe 3-year old cat of this report, presented for severe weight loss,icterus and anorexia of 6 weeks duration, there was thickeningof the gall bladder wall ultrasonographically, and the gallbladderwas distended and firm when examined on exploratorycoeliotomy, but no striated pattern was evident in ultrasoundimages. Subsequent histological examination of the gallbladderwall showed mucous gland hyperplasia of the epithelium. Acholecystojejunostomy was successful in treating the gallbladdermucocoele in the cat, despite transient signs of hepatic encephal-opathy in the days following the surgery. Feline hepatic lipidosis,found on histological examination of a liver biopsy sample,was not thought by the authors to be related to the developmentof gallbladder mucocoele, a condition that has not previouslybeen described in cats.

Flexor carpi ulnaris tendonopathy in a Weimaraner

There are no published reports of injuries to the tendon ofinsertion of the flexor carpi ulnaris in dog breeds other than racingGreyhounds. In this case report, a 6-year-old Weimaraner withmild thoracic limb lameness of 3 weeks duration had pain andswelling of the caudal carpus, apparently involving the distalantebrachial flexor tendons. Radiographs showed osteophyte forma-tion on the normally positioned accessory carpal bone and softtissue thickening of the palmar aspect of the carpus. The dog wasstill lame after the limb was placed in a palmar fiberglass splint for3 weeks. Ultrasound examination after splint removal lead to aretrospective diagnosis of inflammation associated with the flexorcarpi ulnaris tendon of insertion on the accessory carpal bone. Thedog recovered with topical flumethasone and diemethyl sulfoxideand rest. The possible reasons for the course of the dog’s lamenessand response to the treatments employed are discussed.

Production animals

Lesions in the central nervous system associated with perinatal lamb mortality

Perinatal lamb mortality immediately before or up to 28 daysafter birth, is a major intractable economic problem to the sheepindustry. It is usually categorised as being caused by dystocia/birthinjury or a starvation/mismothering/exposure complex. There arefew reports of the importance of central nervous system effects.Hypoxic/ischaemic encephalopathy, secondary to asphyxia,is a cause of morbidity and mortality in many other species. Thisstudy from Uruguay investigated perinatal mortality in 2002, 2004and 2005 in flocks of Corriedale ewes lambing in September. All96 dead lambs had a necropsy examination, and 72 had a light

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Australian Veterinary Journal

Volume 85, No 10, October 2007 © 2007 The AuthorsJournal compilation © 2007 Australian Veterinary Association

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microscopic examination. Lamb mortality was 27.3%, 15.6%and 17% in 2002, 2004 and 2005, and overall was 26.4% in twinsand 15% in singletons. The paper gives detailed descriptions andphotographs of the neurological lesions found, and they suggest thatthe central nervous system lesions may be a major component ofperinatal lamb mortality, as there were few such lesions in thosedying antemortem or after 6 days post partum.

The authors suggest that hyperextension of the neck at deliverymay cause impairment of the posterior circulation, and thatlaxity of atlanto-axialis and atlanto-occipitalis joints, elasticity ofthe vertebral column and low muscle mass in the neck may bepredisposing factors.

Equine

Comparison of tracheal aspirates before and after high-speed treadmill exercise in racehorses

Tracheal aspirates are often obtained from racehorses thathave been performing poorly, to investigate the presence ofinflammatory airway disease. Samples may be collected before orfollowing exercise, but there is some doubt over the effect of theexercise itself on neutrophil numbers. In this study, tracheal aspirateswere obtained from 40 poorly performing racehorses before andafter high-speed treadmill exercise. The median percentage ofneutrophils in the aspirates was significantly higher after exercise,increasing by more than 20% in 15 of the horses, and by morethan 50% in six of those. A pilot study showed that there was noeffect of the collection procedure on neutrophil numbers. Theauthors speculate that a more diagnostically useful sample maybe obtained 1 to 2 h after exercise, because exercise could movedisparate secretions from distal airways into the trachea.

Wildlife and zoos

Distributions of the paralysis ticks

Ixodes cornuatus

and

Ixodes holocyclus

in south-estern Australia

The hosts, seasonal occurrence and geographical distribution of

Ixodes cornuatus

and

I holocyclus

in Victoria were examined inthis study. Although these ticks have been studied extensively inNSW and Queensland, similar data from Victoria is lacking.Ticks were collected from rodents and other small mammalscaught in baited traps or killed on roads in central Victoriaand east Gippsland over a 2 to 2.5 year period. The potentialgeographical distribution was also predicted using climaticparameters. Rodents appear to be significant hosts for both tickspecies; neither species was found on antechinuses, but the roleof possums, koalas and bandicoots is uncertain because ofinsufficient numbers examined. Ticks were more frequent in thewarmer months, with peaks in

I holocyclus

between Septemberand December, and again in March.

I holocyclus

was restricted tocoastal east Gippsland, while

I cornuatus

occurred in the ranges

around Melbourne. There were significant discrepancies betweenthe known and predicted distributions, suggesting the presenceof unspecified geographical barriers to host species. The apparentsuitability of the area surrounding Melbourne for

I holocyclus

suggests that, if the tick were introduced, it may persist there ona suitable native mammalian host.

Semen collection in an Asian elephant

(Elephas maximus)

under combined physical and chemical restraint

To maintain captive breeding populations of elephants, semencollection and ultrasound of secondary sexual glands is needed toassess reproductive function, especially for artificial inseminationprograms. This case report is of semen collection using physicaland chemical restraint in a standing Asian elephant that wassedated three times for treatment of a toenail abscess. It was putinto a purpose built elephant restraint chute, and xzylazine andbutophanol injected manually into the triceps muscles. Oxygenwas give via nasal insufflation. Once it was restrained withstraps, faecal material was evacuated and it was given a warmwater enema. After ultrasound examination, accessory gland andthe pelvic urethra were massaged and ejaculation occurredwithin 10 minutes. On the third occasion, ejaculation occurredwithin 2 minutes, and massage continued for 15 minutes andfour fractions were collected. The authors do not recommendthis technique for routine and repeated collections because of therisks associated with chemical restraint, but note that it is apotential method for unconditioned bulls or those in musth.

Fatal encephalitozoonosis in two koalas

The enteric protozoan parasite

Encephalitozoon intestinalis

is associ-ated with chronic diarrhoea and enteritis in human patients withHIV/AIDS and with ‘travellers diarrhoea’ in immunocompetenthumans. It is rarely reported in animal hosts. After a series ofunexplained deaths in young koalas at a fauna park in Queenslandover a 3 year period, two joeys found dead with no previous clinicalsigns were necropsied. There were no gross lesions, but histo-logical examination showed numerous oval organisms in villustips of the small intestinal mucosa and in sloughed enterocytesin the small intestinal lumen. Molecular analysis of the parasitesshowed 100% sequence homology with a previously publishedhuman isolate of

Encephalitozoon intestinalis

. The speculatedsource of the pathogen was from dipping eucalyptus leavesfed to the koalas into a dam contaminated with human faecalwaste. Veterinarians should be aware of this disease becauseof its zoonotic potential and for its potentially fatal effects inanimals.

A Jackson and M Revington

doi: 10.1111/j.1751-0813.2007.00219.x

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