An escalating economic threat to dairy industry
Gul Ghotoo is t echnically known as Hemorrhagi c septicemia (HS). It is a common bacterial disease of buffalo, cattle and many other animal species and is cause of consternation for dairy farmers. It is caused by various serotypes of Pasteurella multocida in Pakistan.
The sick animals show clinical signs such as increased temperature, salivation, serous nasal discharge with labored breathing and sub-mandibular swelling that some time goes to neck and brisket region. Frothy discharge from mouth leads to respiratory distress, animal collapses and dies within 6-48 hours after the first clinical sign appears. Buffalo calves or heifers rarely recover after clinical signs appear.
The disease progression mostly occurs in three forms. In the first form, there is increase in body temperature (40-41oC) and depression. At terminal stage, temperature drops to subnormal level few hours before death.
In second form, there is increased respiratory rate, nasal discharge and salivations with sub-mandibular swelling. In 3rd form, there is 100% fatality.
There is acute respiratory distress and animal becomes recumbent. Terminal septicemia leads to death. In University of Veterinary and Animal Sciences, Lahore, one Higher Education Commission (HEC) funded PhD scholar (Mrs. Noreen Sarwar) established molecular and nucleic acid based techniques for characterization of Pasteurella multocida serotypes.
She also worked on its different aspects for development of its effective and cost effective vaccine. The organism enters and multiplies in the ton- sils. The fulminating septicemia depends upon its capsular material. The septicemia has severe effects on respiratory tract, gastrointestinal tract and heart.
Invasion of bacteria via mucosal epithelial layers causes rapid translocation from respiratory tract to blood, liver, and spleen. Lipopolysaccharides of the bacterial capsule are key virulence molecules along with this other factors e.g. toxin, putative surface adhesions and iron acquisition proteins are also identified by direct and random mutagenesis.
If you treat the infected animal with tetracycline, it usually die within 5-10 minutes post injection.
It is assumed that LPS is released all of sudden due to death of the bacteria, activate the phospholipid molecules of endothelial cytoplasmic membranes and release arachadinic acid that is further hydrolysed through lipoxygenase into thromboxanes or through carboxygenase into prostaglandins PGE.
The both types of end products are responsible for endotoxin shock.
The release of these products can be blocked by NSAID such phenyl butazene, aspirine, etc. Keeping in view the above mentioned pathogensis, the infected animals may be treated as below: Add cold water on the head of the animal; give injection of phenylebutazone or aspirin orally; give injection of the antibiotics of your choice.
After recovery, all animals on the farm can be vaccinated with oil based HS vaccine to induce immunoprophylaxis.
Pakistan has a cattle population of 17.7 million and a buffalo population of 18.8 million, the latter being proportionately higher than most other countries in the region. HS is causing economic loss to dairy farmers that are geared on the basis of mortality, cost of treatment, consternation.
Pakistan ranks HS as a disease of considerable economic importance, with 34.1 % of all deaths in susceptible animals. In 1978, annual economic losses from HS were estimated as Rs 1.89 billion.
Mrs Farhat Nazir Awan a PhD scholar in Department of Microbiology, UVAS, Lahore, conducted a survey and showed that HS, FMD and gastrointestinal diseases were main causes of economic losses.
The infectious diseases cause loss of Rs 19 billion every year. In 1996, HS was causing economic loss of Rs 2.7 billion but currently, it is causing loss of worth Rs 6.8 billion every year.
For effective control of the disease, the causative agent may be isolated from sick or dead animals and be characterized on the basis of cultural, morphological, biochemical characteristics and animal inoculation tests.
The isolate may be further characterized on the basis of multiplex PCR using species, capsular, and somatic antigen specific primers for selecting the serotype for production of commercial vaccines.