Clinical
Table 1. Blood glutathione peroxidase activity (GSH-Px) and plasma copper concentrations, faecal
egg count and faecal culture results for 10 animals of mixed age and breed sampled at the time of
the first visit.
mucous membranes, and both had foul-
smelling watery faeces tinged with blood.
Both cows had been inappetent and list-
less prior to becoming recumbent.
A tentative diagnosis of salmonellosis
was made and both cows were treated
with short-acting oxytetracycline by
intravenous injection. One of these cows
died within 24 h but was unavailable for
necropsy.
Because of a previous history of trace
element deficiency on this farm, samples
were collected from eight replacement
heifers and the two recumbent cows:
heparinised blood was submitted for
copper and selenium estimation, and
faecal samples were sent for worm egg
Animal
number
Age
months
Breed
J=Jersey
F=Friesian
Blood
GSH-Pxa
IU/g Hb
Plasma
copper
mg/L
Faecal
egg count
eggs/g
Faecal cultureb
1
2
48
50
15
15
12
16
14
17
14
15
J
F
F
J
27
43
372
693
411
424
725
646
442
674
410
587
< 25
30
Y pseudotuberculosis
Y pseudotuberculosis
3
200
35
< 25
200
50
–
4
–
5
J
44
Y pseudotuberculosis
6
F
F
F
F
F
265
31
150
< 25
50
–
–
–
–
–
7
8
44
9
235
210
100
< 25
10
a
Reference ranges: GSH-Px 60-400 IU/g Hb, plasma copper 500-1100 mg/L (Animal Research Institute,
Queensland Department of Primary Industries, Moorooka, Queensland 4105)
counts and microbial culture. The results
of these tests are shown in Table 1.
b
Faecal culture (–) indicates no Salmonella sp or Yersinia sp isolated
Two days later, a 4-year-old Jersey cow
became recumbent and died after a short
illness. The cow had calved 10 days
previously and had also shown inappe-
tence, dullness, submandibular swelling,
decreased milk production and bloody
diarrhoea.
heifers, although low concentrations of
both were recorded in only one heifer
(animal 4, Table 1).
farm, but the organism was isolated
from one heifer that was not scouring
(animal 5, Table 1). The association
between parturition and Yersinia enteritis
does not appear to have been docu-
mented but may be related to alteration
in immune responsiveness during the
peripartum period.7 It is possible that
the infection in these parturient cows
was introduced to the farm when cattle
were purchased from Kenilworth.
Copper and selenium deficiency have
previously been diagnosed in young
stock on this property.4 At that time
affected cattle were treated with sodium
selenate drench and copper glycinate
injection but the treatment was stopped
when blackleg was induced in treated
unvaccinated cattle (unpublished). The
introduction of selenium bullets and
copper oxide needles has reduced the
likelihood of toxicity associated with
treatment, but an apparent antagonistic
effect of selenium on hepatic copper
concentration was noted in cattle dosed
with copper oxide plus selenium bullets
in South Australia.8,9
These findings suggested that two
conditions coexisted on the property,
Yersinia enteritis in adult cattle and trace
element deficiency affecting cattle of all
ages, with young cattle more severely
affected. All replacement heifer stock 12
months of age or older were dosed
concomitantly with copper capsules and
selenium pellets (Cuprax Sustained
Release Copper Supplement for Cattle
and Permasel Selenium Pellets for Cattle,
Mallinckrodt Veterinary [Coopers
Brand]). The condition of the heifers
was then monitored visually by one of us
(DRK) and was observed to improve,
although actual heifer growth rates were
not recorded. No further cases of enteritis
occurred in adult cows in the herd.
The cow was necropsied in the field,
with the following findings. A clear
yellow fluid infiltrated sub-mandibular
tissues. The abomasal wall was oedema-
tous, thickened to twice normal size and
ecchymoses were present in the mucosa.
The small intestinal contents were
watery and brown-green and the mucosa
showed ecchymotic haemorrhages.
Haemorrhages and mucosal oedema were
present in the wall of the caecum. The
mesenteric lymph nodes appeared
normal. Samples of the gastrointestinal
tract submitted for histological examina-
tion revealed marked submucosal
oedema of the abomasum and small
intestine, and severe erosive purulent
enteritis of the small intestine (Figure 1).
Numerous bacterial microcolonies (of
small Gram- negative rod-shaped
bacteria) were present in the purulent
exudate (Figure 2). A fresh liver sample
from the cow submitted for analysis
revealed a liver copper content of 12
mg/kg dry matter (reference 40-1000).
Blood samples collected at the first
visit revealed low glutathione peroxidase
(GSH-Px, used to assess selenium status)
values in both recumbent cows and a
low plasma copper value in one of these
cows (Animals 1 and 2, Table 1). A low
GSH-Px and/or plasma copper value
was also recorded in six of the eight
Discussion
Three cases of enteritis associated with
Y pseudotuberculosis occurred in cattle on
this farm with clinical and pathologic
features similar to those already
described in Australia.1,2 The occurrence
during the winter months is consistent
with epidemiological features described
in these reports, however yersiniosis has
not previously been described in cattle
in Queensland.
On this farm two of three cows that
developed acute yersiniosis had low
blood selenium concentrations and it is
possible that these low concentrations,
combined with recent calving, predis-
posed them to infection. An association
between selenium deficiency, impaired
polymorphonuclear bactericidal activity
and increased incidence of clinical
mastitis has been noted by several
Subclinical infection with Y pseudo-
tuberculosis is also well-documented 1,2,5,6
.
It was not possible to measure the extent
of subclinical infection in cattle on this
Aust Vet J Vol 78, No 1, January 2000
29
Danilow
