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ABSTRACTS
The only streptococcal disease of bovines is the common chronic mastitis caused by
Group B haemolytic streptococci (Str. agalactiae). Other streptococci, viz. Str. dysgalactiae
and Str. Uberis (Diernhofer) designated respectively as Group II and III of mastitis
streptococci, have been isolated from acute and sporadic cases of mastitis. Group A
haemolytic streptococci (Str. pyogenes) and those of Group C have also, though rarely,
caused mastitis in cows and the former, through contaminated milk, is mainly respon-
sible for epidemics of scarlet fever and septic sore throat in man.
In equines, the haemolytic streptococci are commonly associated with strangles,
pneumonia, nasal sinus infections, joint ill, metritis, abortion and various wound in-
fections. So far all equine strains have fallen into one serological group (Group C), and
streptococci from infections other than strangles forming a sub-group distinct from the
streptococci of strangles.
A variety of canine affections have been shown to be caused by haemolytic strepto-
cocci, namely septicaemia, tonsillitis, adenitis, otitis media, sterility, puerperal fever
and cellulitis. Most canine strains have fallen into Group G and some into Group C.
Whilst it is presumed that streptococci are responsible for some disease conditions
in other animals, there is as yet little evidence of their nature and incidence.
Apart from symptomatic and palliative measures, the control and treatment of
streptococcal diseases lie in segregation, vaccination and chemotherapy. Segregation
has proved a measure of decided value in dealing with chronic Str. agalactiae mastitis of
dairy cows, but much information is required before it can be regarded as a sound means
of control of streptococcal infections of other animals. Vaccines on the whole have been
disappointing. Acridine dyes (rivanol, entozon) and the flavines (acriflavine, euflavine,
and proflavine) have been found to exercise a marked bactericidal action against strepto-
cocci when used locally, especially in mastitis. Substances of the prontosil-sulphanilamide
type, which have given strikingly encouraging results in combating human infections
caused by Group A streptococci, have proved beneficial against Group C when used orally
or parentally. Clinical reports suggest the use of sulphanilamide in streptococcal diseases
of dogs due to streptococci of Group G. The drug is well tolerated by all animals (J. A. I.
A new prophylaxis for wound myiasis in domestic animals. M. A.
STEWART (1939), J. Econ. Ent. 32, 404-7
T HE author reports that the annual loss from the screw-worm in Texas alone has
been estimated at from $4,000,000 to $10,000,000 and that some more millions of
dollars can be added to this on account of loss caused through the attacks of other myiasis¬
producers. Various substances have been recommended for the prevention of wound
myiasis in domestic animals ; tannic acid followed by an application of pine tar or some
of the cresol dips ; one part furfural and four parts pine tar oil; acid-free, dehydrated
pine tar oil with a specific gravity of 1.065 to 1.085 ; and bone oil. Of these, the
acid-free dehydrated pine tar oil has been the most efficient. However, this material
has not been particularly satisfactory in the interior valleys of California and similar
places where high temperatures and low atmospheric humidities prevail during the periods
of maximum fly activity. The author, therefore, undertook an investigation into the
possibility of finding out a more efficient and economical substance which would repel
flies from wounds, stimulate wound repair and successfully withstand high temperatures,
low atmospheric humidities and relatively low temperatures and heavy rains. The last
was necessary, because in California there is no season of the year when one can be certain
that myiasis will not occur.
After a series of experiments with different combinations of various chemicals and
also with bone oil alone, the author obtained satisfactory results with a mixture of pine
tar oil, paraffin and viscous oil. The proportions and specifications of these chemicals
were as follows :—
Acid-free dehydrated Stockholm pine tar oil with a specific gravity
of
1.075
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Amorphous paraffin wax with a U. S. P. melting point of 160-170°F.
Viscous oil
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Per cent
25
12.5
62.5