There are two types of bloat. One type is known as frothy bloat and sometimes commonly referred to as pasture bloat. Another type is known as gas bloat and is sometimes referred to as feed lot bloat. Bloat is normally caused by nutrition problems, such as increased pressure in the rumen due to too many gases being built up. These gases could include carbon dioxide (CO2) and methane gas (CH4). Prevention is the best method in controlling this disease. One method is providing constant grazing instead of feast and famine, as long as the pasture doesn't contain a lot of legumes, which can cause bloat easily. The symptoms of bloat can include the skin on the left side of the animal behind the last rib may appear distended (see picture). Bloated sheep should be treated with great care, due to the condition of their body, and the possibilities of greater damage can occur. These can include collapsed lung due to pressure build-up, blood is pushed out of the body cavities, and can cause a type of acidosis. There are a few different options for treatment, depending on the time of diagnosis. You can use a stomach tube to release pressure of the gas, agitation of the rumen will also release trapped air bubbles, commercial anti-bloat medicines, and in severe cases a rumenotomy can be performed in life-or-death cases by puncturing a hole in the rumen, but will need to be sutured afterwards.



Bluetongue
Bluetongue is an insect-transmitted disease that is transmitted by biting gnats. It is a viral disease, and other animals cannot directly contract the disease from infected animals. This disease affects domestic ruminants such as sheep, cattle, goats, as well as wild ruminants. These wild ruminants serve as the reservoir for the virus. It is reported that this virus killed 179,000 sheep in 4 months, so it has affected the industry tremendously. Bluetongue is very prevalent in Southwest and Southern parts of the United States . Symptoms of the disease include inflammation, swelling, and hemorrhage of the mucous membranes of the mouth, nose, and tongue. Sheep show clinical signs, where as other domestic ruminants rarely show clinical signs of the disease. There are no known prevention methods. Veterinarians are more aware of the disease and look for symptoms and clinical diseases when doing herd checks. There are two types of viral antigens for bluetongue virus testing. This testing is not very accurate due to low numbers of antibodies correlated to bluetongue viremia. Virus isolation from blood samples is the only soundproof method of detection. There is a vaccine to help with treatment, but only certain serotypes are available with a vaccine. The vaccine comes with adverse side effects and you cannot use the vaccine on pregnant ewes.



Copper Toxicity
Copper toxicity is a big concern for sheep, because it is a required mineral but is also toxic to them as well. This can vary based on breed, age, health status, levels of other minerals in body and in diet, and levels of ionophores in the diet. Copper is found in the feeding supplement for cattle and swine diet. If mixed with or fed to sheep, it can have drastic effects. There are two types of copper toxicosis; acute and chronic. Acute is when a high level is ingested in a short period of time. Chronic is when a low level is ingested over a long period of time, and exceeds the threshold level and escapes into the bloodstream. Excess copper is stored in the liver. Eventually hemolytic crisis occurs due to the destruction of red blood cells. Prevention is key in this disease. There are several key factors in prevention which include no feeding swine or poultry diets to sheep, communicating with your feed suppliers, testing your feed for levels of copper, molybdenum and sulfate, avoidance of pasture that has been treated with swine or poultry manure, and doing post-mortems on dead animals from your flock. The major symptom of copper toxicity is death in your herd. But symptoms may include animals go off feed and become weak, mucous membranes and skin are yellowish-brown, and/or urine will be reddish-brown and hemoglobin will be present. Treatment should involve your veterinarian. Treatment includes feeding or drenching with ammonium molybdenum, sodium sulfate, and penicillamine.



McDill, Lisa. "Bluetongue Virus". Animal Disease Diagnostic Laboratory. 2001. Purdue University . 27 Feb. 2007
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Neary, Michael. " Preventing Pasture Bloat in Sheep". Purdue University Sheep Extension. 1997. Purdue University . 27 Feb. 2007.
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Schoenian, Susan. "Sheep Diseases A-Z." Sheep 201; A Beginner's Guide to Raising Sheep. 26 Sept. 2006. Maryland Cooperative Extension. 6 Feb. 2007
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Ovine Progressive Pneumonia
Ovine Progressive Pneumonia, or OPP, is caused by a virus and is prominent in the United States . This type of virus is very similar to Maedi-Visna, a retrovirus found in different parts of the world. A study found that 26% of sheep in the United States are infected with OPP, but the prevalence of the virus is largely dependent on flock management, the strain of the virus, and the genetics/breed of sheep. In fact, sheep and goats seem to be the only species that can naturally contract the OPP virus. Breeds which have been found to be highly susceptible to the OPP virus in the United States include Border Leicester, Finnsheep, Finn-crosses, Corriedales, Dorsets , and North Country Cheviots. Texel sheep are only susceptible in Europe , and the Ile de France has even been shown to be resistant to infection and disease. This suggests a difference between the pathological potency of the OPP virus rather than just the genotype of the sheep.

Transmission of OPP is mainly by ingesting contaminated milk/colostrum, like if a lamb receives milk from an infected ewe. Respiratory fluids, like from coughing, can also be transmitted between closely confined sheep. Signs and symptoms of OPP can begin to be noticed around two years of age or older because the disease progresses very slowly. Unfortunately, once signs are spotted, it is often too late to fix the problem. Two common signs are weight loss and lethargy when required to exercise more than usual. Breathing becomes very laborious and difficult for the sheep. OPP can be diagnosed by the presence of the virus or antibodies in the blood. A perfect diagnosis can only be made during necropsy, where the lung is covered in large lesions and discolored to grayish-blue. There are currently two different tests that can be used to detect the virus in live animals: Agar Gel Immunodiffusion Test (AGID) or the Enzyme Linked Immunosorbent Assay (ELISA) test. AGID is able to detect circulating antibodies in the blood, but it should only be tested after six months of age, once the colostrum-derived antibodies are no longer present. The ELISA test is more sensitive than AGID as it can detect OPP only two weeks after infection. There is no treatment for such a virus. There are, however, two methods to prevent future exposure of OPP. One method of prevention would be to remove lambs from infected mothers before they have the chance to nurse from them. This is the start of an OPP-free flock and should never come in contact with infected sheep. The second method would be to test and remove all infected sheep and lambs that test positive for OPP.



*More information on OPP and the Maedi visna virus:
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This information was used with permission from: Neil Anderson, Copyright Coordinator, University of Minnesota Extension

Pictures were used with permission from: Dr. Paula I. Menzies , Associate Professor, Department of Population Medicine, Ontario Veterinary College [عزيزي الزائر يتوجب عليك التسجيل للمشاهدة الرابطللتسجيل اضغط هنا]



Scrapie
Scrapie is a disease that severely affects the nervous system of sheeps and goats. This disease is fatal and degenerative. It is just one of the several diseases classified under the transmissible spongiform encephalopathies (TSE) and can cause significant production losses in a flock. Scrapie can be spread when female animals are sold from infected flocks to other flocks. Because of this hazard, the export of breeding stock, semen, and embryos to other countries is prohibited. Scrapie is caused by a minuscule virus that has not been completely characterized. So far, we know that disease is caused by a prion, or an abnormal form of a cellular protein. Also, the cause, or agent, is a virus with unusual characteristics. Finally, the agent is a virino, a tiny piece of DNA that acts like a virus. Unfortunately, the scrapie agent is unaffected by heat and sterilization processes. There is also no detectable immune response in sheep and goats.

Scrapie is mainly spread from a mother to her offspring or through contact with placental fluids. Signs of the disease usually do not appear until 2-5 years after the animal

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