Vet on call: The triple threat to your dairy cattle

The call came at 7pm last week as I settled to watch the day’s news. Gabriel registered his frustration outright stating that he had lost two calves and two cows in the past two weeks.

The farmer said the last animal had died an hour before he called. He wanted me to visit the farm the following day to find out what was killing his cattle.

I got another call soon after from Gabriel’s farm manager, Eddy, explaining that another cow which had been treated two days earlier was also weakening. He feared it would also die.

The two reports meant I would have to visit the farm in Matuu by 8am the following day. From Eddy’s description, I determined there was no emergency in the cow he feared could die because it still had some appetite.

I had visited the farm in December last year and advised on dairy cattle management and disease control. During the visit, ticks had been many on the farm that they were visibly crawling from the grass and bushes into the cattle pens.

I wondered whether they could be the ones causing the animal losses that Gabriel had described as a disaster.

I stopped theoretical disease diagnosis and waited to carry out a post-mortem examination and diagnose the disease with first-hand observations.

Disease history as given by the farmers can be deceptive but direct observation by the doctor tells the whole story in most cases.

I arrived on the farm at 7.45am the next day. Eddy took me round the dairy unit explaining in details how the four animals had got sick, the way they were treated by two different paravets and how they had failed to recover and died.

The farm manager’s story was precise and consistent. All the animals had shown the same set of signs, behaved the same way and died between two and four days after treatment.

The cows had suddenly dropped milk production, stopped eating and became slow in movement. They were all treated on the same day they stopped eating.

Both the cows and calves did not regain appetite and they proceeded to have difficulties in breathing and died.

EXAMINING RECORDS

Save for the new death, none of the others had been reported to me or any other veterinary doctor and no post-mortem had been carried out. I advised Eddy that was a bad practice in livestock farming.

It is recommended that a veterinary doctor carries out post-mortem on any animal dying on a farm to diagnose the cause of death to safeguard the health and safety of the other animals and people.

Upon examining records by the two animal health service providers, I observed they had diagnosed east coast fever (ECF) in all the cases and treated as required.

I told Eddy to restrain the cow that he had reported sick so that I could examine and treat it before carrying out the post-mortem on the dead one.

The cow walked slowly with the head lowered and the sides of the lower abdomen were heavily sunken indicating that it had been eating poorly.

Flies were feasting on its nasal and eye secretions because the animal could not fend them off with the tail or head shaking.

It had a fever of 40.7 degrees centigrade, a wildly racing and pounding heart and very pale mucous membranes. The breathing was shallow and rapid.

There were brown disappearing blood spots on the mucous membranes of the gums and vulva. The external lymph nodes were slightly swollen.

I diagnosed babesiosis, commonly called red water. The disease is caused by blood parasites that are spread by ticks.

It was also evident to me that the cow initially had a mixed infection with ECF, the deadliest of the common tick-borne diseases.

ECF had responded well to treatment and was no longer a threat as shown by the brown blood spots, the slightly swollen lymph nodes and the moderate fever.

I injected the cow with medicine specific for babesia parasites and also gave antibiotic, multivitamin and iron injections.

The antibiotic would help prevent bacterial infection due to weakened immunity. Multivitamin would stimulate appetite while the iron would enhance blood formation to replace the red blood cells destroyed by the disease.

VICIOUS TRIAD OF BLOOD PARASITES

I advised Eddy to feed the cow a balanced diet, lots of water and keep her in the shade. I then proceeded to the dead cow for post-mortem.

The cow was a replica of the live one I had just treated, save for the life. The mucous membranes had progressed from pale to yellow in the terminal stage of the disease. The lungs were full of fluid and the bladder had bloody urine.

The disappearing brown blood spots were evident on the lining of the rumen and other internal organs.

As I concluded the post-mortem examination, one of the farm workers asked me why all the cows that died initially had very hard dung which reverted to normal after treatment for ECF.

I explained the stool was a sign of infection by another blood parasite called anaplasma. The parasite is quickly killed by the antibiotic recommended for use with ECF treatment.

With the examination of the sickly cow, history of hard dung in sick animals and the post-mortem findings, I uncovered the mystery of the dying cows.

The farm had an attack of what I called “the three musketeers” in my article of July 15, 2017 available online. Gabriel’s cattle had been infected with a combination of ECF, anaplasmosis and babesiosis.

The three diseases are a vicious triad of blood parasites spread by ticks. In the article, I exhaustively explained about the diseases.

In Gabriel’s case, ECF would be diagnosed and treated as it was most evident and impactful. The tetracycline antibiotic used as supportive therapy for ECF medicine would also treat the anaplasmosis but red water would be left untreated because it was not detected. The disease would progress to kill the cattle.

Only a veterinary doctor can make the full diagnosis of all the diseases when they occur combined.

Farmers should always call in a veterinary doctor if treatment by a paravet does not show good recovery within 24 hours. Gabriel’s cow has since recovered.