Download Snorter Dwarf Calf with Brachygnathia Inferior Condition

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Indian Vet. J., September 2013, 90 (9) : 58 - 59
Snorter Dwarf Calf with Brachygnathia Inferior Condition
A.Velavan, S. Sivaraman, K. Krishnakumar and J. Rajagopal
Veterinary College and Research Institute, Orathanadu, Thanjavur – 614625
(Received : 03-09-2012;
The congenital defects were recorded as 0.5 to
1.0 per cent in cattle population (Newman et al.,
1999). The calves with congenital anomalies are
often a result of environmental factors, genetic
factors or both. Among congenital anomalies,
dwarsm is a rare condition. Snorter dwarsm
in calves is one of the congenital defects with
short, blocky appearance with deformed bone
growth in the nasal passages (parrot mouth)
and have difculty in breathing (Grifth et al.,
1987; Woollen, 1993). Snorter dwarf calf is rarely
reported in Tamil Nadu. This paper describes
the congenital defects of Snorter dwarf calf
and its occurrence in Thanjavur district, Tamil
Nadu, India.
Case History and Observations
A ten days old female Jersey cross calf was
presented to Teaching Veterinary clinical
complex, Veterinary College and Research
Institute, Orathanadu with the complaint of
not taking milk properly since birth. Clinical
examination revealed that the calf was stunted
in growth. The history revealed that a normal
Jersey cross cow was allowed for natural service
with a non-descriptive bull and delivered a dwarf
calf. Past breeding histories of both dam and sire
revealed no dwarf calves. There was no further
breeding history of the bull since it was castrated
immediately after the birth of this dwarf calf.
The calf had normal posture and gait. Defection
and urination were normal. Detailed musculo
skeletal system examination revealed stunted
growth of both appendicular and axial skeletal
bones. Mandibular bone showed brachygnathia
inferior or parrot mouth (Fig ). The calf had 9.5
kg bw and 43 cm height at shoulder level. Due to
improperly developed mandible, the calf was not
able to suckle the milk. So, the poor prognosis
was explained to the owner.
1
Corresponding author : Email : [email protected]
Accepted : 19-12-2012)
Treatment and Discussion
There are three common types of dwarsm
as Snorter, long head and compress dwarfism caused by both environment and genetics
(Pahnish et al., 1995a). Snorter dwarsm causes
short, blocky appearance with deformed bone
growth in the nasal passages which causes difculty in breathing. This dwarsm is inherited
as a simple recessive trait. Long head dwarsm
causes small size but does not affect the bone
growth in nasal passages. This dwarsm is
inherited as a simple recessive trait. Compress
dwarsm is inherited as incomplete dominance.
An individual with one compress gene and one
normal gene has an extremely compressed body
conformation. The individual with two compress
Fig. 1: Snorter dwarf calf showing its parrot mouth (Note :
incomplete development of mandible and protrusion of tongue
outside the mandible).
The Indian Veterinary Journal (September, 2013)
A.Velavan et al.
genes is a dwarf and the calf dies at or soon after
birth. The cause for these abnormalities could
not be determined. The typical brachynathia
inferior (parrot mouth) was identied in Holstein
and Simmental breed calves due to polygenic
inheritance (Girfth et al., loc. cit; Woollen, loc.
cit). Based on the above ndings the present
case could be classied as Snorter dwarf calf.
Viral infection, teratogenic drugs and
alkaloids of plants often lead to craniofacial
malformations associated with brachgnathia
inferior. Schalles et al., (1914) reported that
parrot mouth (brachygnathia inferior) in cattle
was inherited as a simple recessive trait. The
more common cause of teeth and denture pads
not meeting is a quantitative trait caused by
several sets of genes. This can cause either an
under or over shot jaw with varying degrees of
expression. Progeny testing done by Pahnish
et al., (1995) reported that dwarsm must be
considered as a breeding problem. It cannot
be eliminated by changing basic rations or
introducing feed supplements. So, considering
all these above ndings, we could conclude that
this particular calf dwarsm was purely due to
genetic effect and not environmental effect.
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Summary
A ten days old Jersey cross calf was presented
for improper milk intake. Clinical examination
revealed improper development of mandible
(brachygnathia inferior) and stunted growth of
the calf. So the calf was identied as Snorter
dwarf calf. To prevent further dwarsm from
the same parents, both the sire and dam were
stopped from further breeding.
References
Grifth, J.W., Hobbs, B.A. and Manders, E.K. (1987) Cleft
palate, brachygnathia inferior and mandibular oligodontia in a
Holstein calf. J. Comp. Pathol., 97 : 95-99.
Newman, S.J., Bailey, T.L., Jones, J.C., DiGrassie, W.A. and
Whittier, W.D. (1999) Multiple congenital anomalies in a calf.
J. Vet. Diagn Invest., 11 : 368-371.
Pahnish, O.F., Stanley, E.B. and Saey, C.E. (1955) The
inheritance of a dwarf anomaly in beef cattle. Jour. Anim. Sci.,
14 : 200.
Pahnish, O.F., Stanley, E.B., Saey, C.E. and Roubicek, C.B.
(1955) Dwarsm in beef cattle. The description, cause and
control. Agricultural Experiment Station, University of Arizona,
Tucson, Bulletin, 268 : 1-21.
Schalles, R.R., Leipold, H.W. and McCraw, R.L. (1914) Congenital defects in cattle. In : Beef Cattle Handbook, pp 1-4.
Woollen, N.E. (1993) Brachynathia in Simmental cattle. Agric
Res. Serv., 71 : 183.
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