March 2011

Calf Scours - Preventing & Treating the common causes

Believe it or not, spring is fast approaching, and with it comes calving season. One of the most common calf problems we en- counter is diarrhea. This can be a serious problem and can cause the death of the calf if not treat- ed properly.

Common causes of calf diar- rhea are: E. coli, Salmonella, Clostridium, Coccidia, Crypto- sporidia, Rotavirus and Coro- navirus. E. coli, Salmonella, and Clostridium are bacterial diseases, Coccidia and Crypto- sporidia are parasitic diseases while rotavirus and coronavirus are viral diseases. E.coli usually occurs in the first 5 days of life, rotavirus and coronavirus within the first few weeks, Clostridium from 5-10 days of age, Crypto- sporidia from 5 days to about one month old, Salmonella from 2-6 weeks and Coccidia from 3 weeks to any age. Ensuring all calves get 3-4 liters of colostrum within the first 6 hours of life is an important .way to help prevent calf illness. If the calf doesn't nurse on it's own, assisting it to nurse or us- ing a bottle or esophageal feeder will be necessary.

It is also important to clean the calving area between cows to decrease the amount of contami- nation the calves are exposed to at birth. It also helps to keep any pens the calves are in as clean as possible.

Depending on the cause of the diarrhea on your farm, scours vaccines are very helpful to de- crease the incidence and severity disease in calves. These vaccines are usually given 2 months prior to calving and then again at 1 month prior to calving.

Potomac Horse Fever

Port Perry Veterinary Services had six confirmed cases of Po- tomac Horse Fever last sum- mer. This was a significant in- crease in the number of cases seen in this area and it is im- portant to recognize the symp- toms to ensure your horse receives appropriate care as soon as possible.

Definition: A potentially fatal illness caused by the bacteria Neoricketsia ristticii. The course of the disease is not completely understood, but Potomac Horse Fever (PHF) is characterized by severe diarrhea, fever and subse- quent laminitis.

Causes: PHF was originally de- scribed in horses living along the Potomac River in Maryland and Virginia. It is believed the dis- ease is transmitted by mayflies and other insects, but freshwa- ter snails are also believed to be involved in the life cycle. Routes of infection include bites from and ingestion of infected snails or water contaminated by the infected snails.

Signs: Initial symptoms are vague and may go unnoticed. Horses go off feed as they spike a fever, often as high as 104oF or 40oC. The affected horse be- comes colicky due to a brewing colitis and may have red mucus membranes. Within 24-48 hours, severe diarrhea develops and secondary dehydration and electrolyte changes occur. Toxins are released into the blood- stream (septicemia), raising the heart rate and beginning a cascade of reactions in the body. Bounding digital pulses can then be detected, the first sign of im- pending laminitis. Loss of pro- tein from the diarrhea is often severe and causes swelling in the limbs and under the belly, which may take weeks to disappear.

Treatment: Your veterinarian should be called immediately should you suspect your horse is showing signs of PHF. Treat- ment with oxytetracycline is effective when administered very shortly after the onset of clinical signs. If diarrhea is severe large volumes of IV fluids are required. Banamine is often administered to protect against septicemia. Septicemia is a severe consequence of infection with PHF and diarrhea/ colitis, and may require referral to a clinic that can provide intensive care and plasma transfusions.

Prevention: Vaccination de- creases the incidence and sever- ity of the disease, but as with all vaccines, it is not entirely preventative. Mortality rates are significantly lower in vaccinated horses. Vaccination is recom- mended in spring, like vaccines for other insect-born diseases. It is recommended that barn lights be turned off at night so as not to attract insects. Standing water should be eliminated or changed regularly as well.

Small Ruminant Ultrasound

It can be useful to ultrasound your sheep or goats to determine if they are pregnant and how many fe- tuses they are carrying. This will allow you to better manage the dietary needs of the pregnant animals to avoid complications such as pregnancy toxemia. The best time to do the ultrasounds is when they are between 40 and 90 days gestation. Call now to book an appointment for an ultrasound.