M 



ASTITIS drops off rapidly right after the first 

 killing frost, a veterinarian with 30 years experience 

 in Illinois, said to me the other day. "This would 

 appear contrary to the old belief that mastitis is 

 much more common in winter. 

 "You probably have noticed that a drop of milk is al- 

 ways left on the end of the cow's teat after milking," he 

 continued. Flies soon settle on this milk. 



"Now if the milk from the cow has mastitis organisms 

 in it, you can easily see what the flies do as they follow the 

 milker down the line. They carry millions of bacteria 

 from cow to cow." 



I hadn't thought too much about that angle of mastitis 

 spread until he called it to my attention. After discussing 

 it with other veterinarians and dairymen, I decided his 

 explanation made good sense. Later, I learned about an 

 experiment designed to prove whether or not bacteria 

 could get into the cow's udder through the teat openings. 

 The evidence, I believe, was very conclusive. Let's see 

 if you agree. j 



A mechanical milker was placed on a cow. When a 

 good flow of milk came from the cow a dye was injected 

 into the milk tube. After the cow was milked, she was 

 killed and the udder was carefully dissected and examined. 

 The dye was well up into the quarter. The dye had gone 

 "against the stream" so to speak and up into the gland. 

 If dye does it, bacteria will too! 



Most mastitis is caused by bacteria called streptococci. 

 The particular group of streptococci which most often 

 causes mastitis is probably not dangerous to humans. One 

 streptococcus is primarily associated with septic or "strep" 

 sore throat in humans. This particular germ can cause 

 mastitis in cows, but it doesn't often cause what we would 

 consider a serious case. It is a source of danger to humans 

 drinking raw (unpasteurized) milk from these cows. 



There are two ways to prevent this spread. One is to 

 remove the milk from the teat by wiping and disinfecting. 

 The other way is to get rid of flies! I have more faith in 

 the latter method. It is so easy to let the "little things" 

 go when you're in a hurry at milking time. 



This is only one of the diseases of animals that may be 

 spread by flies. This is only one way which flies spread 

 disease. Another common way for them to carry infected 

 blood from one animal to another. Take anaplasmosis for 

 example. '^■'.■■■- :'-^'- -yS'- -"-.''■. :■:■"■■ -'-■'■ 



You probably haven't heard much about anaplasmosis 

 unless you have been one of the relatively few unfortunate 

 ones in Illinois who have had this disease on your farm. 

 In this part of the U. S., it is not a common disease; but 

 there are some parts where it is very prevalent. Most of our 

 feeder cattle come from these areas. It causes a break- 

 down of the red blood cells of the animal infected and 



most of them die. One county in Illinois had an extensive 

 outbreak last summer. This organism that destroys the 

 red blood cells is carried from one animal to another by 

 flies and other blood sucking insects. 



It has been demonstrated that one of the most eflfective 

 ways to check the spread of this diseasase is to eliminate 

 flies. Isolation of infected animals and the elimination of 

 flies is about the only means known to control anaplasmo- 

 sis. After a killing frost, this disease ceases to spread al- 

 though animals that are infected and have recovered con- 

 tinue to be carriers of the disease for a long time. They 

 may even remain carriers until the next fly season and 

 again be a source of the infection. 



Equine encephalomyelitis (quite a name for horse sleep- 

 ing sickness, isn't it?) is another animal disease proven to 

 to be transmitted by some flies, ticks, mosquitos, and other 

 biting insects. Although we haven't had a serious epidemic 

 of sleeping sickness in Illinois for several years, scientists 

 tell us it is one of those diseases that run in cycles. Accord- 

 ing to past experiences, we can expect this disease this 

 summer. Most of you can remember the seriousness of 

 the widespread epidemics of sleeping sickness during the 

 late thirties. - (Continued on page 34) 



By DR. DON VAN HOUWELING, director iaa veterinary Medical relahons department 



ANIMAL DISEASES ,^f --^^ 

 ARE SPREAD RY fLIfcS 



JUNE. 1948 



