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Common questions from goat producers (Proceedings)
There are many causes of external lumps and masses in sheep and goats, yet many producers assume that all external masses are abscesses.
Dealing with lumps and bumps
There are many causes of external lumps and masses in sheep and goats, yet many producers assume that all external masses are abscesses. Not all lumps are abscesses and not all abscesses are caused by Corynebacterium. The veterinarian should not assume that all masses in the herd have the same cause, and the veterinarian should obtain a detailed herd history, thoroughly examine the animal or animals in question, and then aspirate or biopsy the mass in question to obtain a diagnosis. Once a diagnosis has been made, appropriate therapy can be administered and a prognosis for recovery can be determined.
Small, round bumps in the superficial skin that exude a cheesy white exudate when compressed are characteristic of demodectic mange in goats. The demodex mite is distributed world-wide and most frequently infests young dogs. Goats with compromised immune systems or those from specific families are more susceptible to demodex. The non-pruritic small bumps are frequently discovered in the late spring when producers clip their goats for show. Microscopic examination of the exudate reveals the characteristic cigar-shaped mites. No miticides are currently labeled or licensed for use in goats; however injectable or topical avermectins are commonly used to treat mange in goats.
Goiters are firm, symmetrical solid masses extending from the center of the neck to the angle of the jaw and are usually present at birth. They are quite variable in size and may interfere with swallowing in some kids. Goiter is more common in the offspring of young does, goats on high calcium diets, does consuming water with a high mineral content, or those goats eating high calcium vegetables such as cabbage, brussel sprouts, broccli and rape seed. Most goiters are caused by iodine deficiency and can be prevented and treated by feeding iodized salt. Topical application of 7% iodine to the dorsal spine of pregnant does has been reported to successfully prevent goiter in later kids when iodine deficiency goiters have been observed in early kids. A heritable form of goiter associated with congenital alopecia or abnormal hair coat, sluggish behavior and retarded growth does not respond to dietary iodine. All goats in the continental USA require iodine in the diet to prevent thyroid dysfunction.
Small, round, firm swellings at the base of the wattles that vary in size are wattle or branchial cleft cysts. The benign, golf-ball sized lumps are filled with a clear fluid and result from an error in development. The branchial cysts are deeply attached to cervical structures and not easily removed surgically. Some veterinarians and producers consider them to be a heritable trait.
Dermoid cysts also appear as round masses in the skin that gradually increase in size. Dermoid cysts also result from an error in development and occur when an island of epidermis develops in the wrong place. Often no fluid is obtained when a dermoid cyst is aspirated, but biopsy or lancing of the mass reveals a clump of hair and sebaceous fluid. Dermoid cysts recur unless surgically removed, but surgery is only performed for cosmetic reasons.
Goats who have suffered head or neck trauma may develop large soft tissue masses that change in size, especially when eating. Salivary mucocoeles develop when the ducts to the various salivary glands are traumatized and saliva leaks into the soft tissue. If the duct tear is large enough, saliva continues to leak repeatedly at each feeding. Salivary mucocoeles are easily diagnosed by aspiration of the mass yielding stringy, viscous, clear fluid. Most mucocoeles are benign and do not require treatment although surgical correction may be attempted in a show animal.
Blunt trauma may also cause hematomas or seromas. Sudden development of swellings that are dense masses raising out of tissue much like mountains out of prairie indicate development of a hematoma. Hematomas result from severe trauma that tears major blood vessels allowing escape of large volumes of blood into surrounding tissue. Depending on their size or location, hematomas may interfere with function or movement. If a hematoma is suspected, the mass should be clipped and aseptically prepared prior to aspiration to prevent infection. Most hematomas resolve uneventfully over time without treatment. As the hematoma heals, the solid blood clot shrinks and is absorbed before the serum. Occasionally the hematoma capsule continues to secrete serum and a seroma develops. Seromas may require surgical removal to prevent recurrence.
Hernias may result from developmental defects or blunt trauma to the abdomen. A young male kid may exhibit a grossly enlarged scrotum if abdominal contents are herniated through the inguinal canal. Umbilical hernias result when the abdominal muscles fail to close properly along the midline during development. Ventral abdominal hernias may follow severe blunt trauma particularly in pregnant does. Large abdominal or scrotal masses should be carefully palpated prior to aspiration to determine whether or not the mass might be a hernia. Hernias should not be aspirated to prevent infection. All hernias require surgical correction and the severity of the hernia and its location determine prognosis. Umbilical hernias are considered a heritable fault and animals exhibiting them should not be used for breeding.
Tumors may also present as firm, solid tissue masses. The two most common tumors that appear as external masses in goats are thymoma and lymphosarcoma. Thymomas are usually firm, encapsulated masses on the ventral neck that slowly enlarge in size and may extend into the thorax. They do not usually cause clinical symptoms unless their location or size interferes with respiration or digestion. Lymphosarcoma is characterized by localized or generalized enlargement of lymphoid tissue. Affected external lymph nodes are large, firm and interfere with organ function. Lymphosarcoma is more invasive than thymoma and few animals survive long with lymphosarcoma. Squamous cell carcinomas often occur in goats with light skin color and are frequently located on the udder or around the perineum. Treatment for each of these tumors is often unsuccessful at this time.
Abscesses caused by a wide variety of bacteria are the most common cause of external masses in goats. Numerous bacteria live on the surface of healthy skin and mucous membranes and can be introduced into body tissues through small ulcers and puncture wounds. Coarse hay, grass awns, wood splinters, unsanitary injection needles and accidental trauma can introduce bacteria into soft tissue. Once introduced into tissue and deprived of oxygen, bacteria replicate rapidly, destroy healthy tissue and attract an inflammatory response. Fibrous connective tissue forms around the infection to wall off the bacteria leading to an encapsulated abscess. In most cases, the immune system functions properly to destroy the bacteria, and the abscess is either absorbed or breaks through the skin to the outside where it drains and heals on its own. Occasionally, due to location, an abscess will interfere with body function and may need to be surgically drained or removed.
As with other external masses, the hair over the abscess should be clipped and the skin should be cleaned with iodinated soap and alcohol prior to aspiration. Culture of the causative agent helps determine if treatment is indicated and allows a more accurate prognosis for recovery. Abscesses caused by Staphylococcus, Streptococcus or Pasteurella do not require further treatment once the abscess opens unless symptoms of systemic involvement such as swelling, anorexia or fever develop. Abscesses caused by these bacteria occur commonly about the mouth, lips, cheeks, and injection sites and do not spread between animals. Contagious abscesses or caseous lymphadenitis are caused by Corynebacterium pseudotuberculosis and are spread from animal to animal.
Careful physical examination, aspiration and biopsy can be used to determine the cause of external masses in sheep and goats. Accurate diagnosis can lead to correctly chosen treatment and prevention programs. Although not all causes of external masses can be prevented, their incidence can be markedly reduced through adoption of good management practices.
Working with shows and sales
Providing veterinary services for livestock shows and sales presents several interesting challenges for veterinarians especially if they are unfamiliar with showing or selling livestock. Veterinarians may be asked to examine and certify the health of animals presented for exhibit or for transport across state lines or country borders. Animals accepted for livestock sales may require veterinary examination for specific defects or may require official testing for certain diseases. Breeding goats, all goats on exhibit and those traveling across state lines require individual animal identification linked to the premise of origin under the federally mandated National Scrapie Eradication Program. Veterinarians also play an important role in educating producers about withdrawal times for drugs to ensure that goats offered for sale or slaughter are free of drug residues. Good communication between sponsoring committees, the participants, the veterinarian and both state and federal regulatory officials can make the process go more smoothly.
Veterinarians are frequently involved in the movement of animals across states lines and country borders. All goats transported across state lines for the purposes of exhibition or sale require a Certificate of Veterinary Inspection issued by the examining veterinarian and occasionally permission to enter by the state veterinarian in the receiving state. The regulations for entry differ from state to state and change over time with emergency notices posted as disease outbreaks occur. Individual state requirements can be found at www.aphis.usda.gov/us/sregs but veterinarians should call the state veterinary office in the receiving state to insure that the information is current. The published state regulations are the minimum requirements that a goat producer must meet as shows and sales may have additional requirements for participants. Practitioners should read the show or sale requirements carefully to ensure that their clients meet all requirements.
Breeding goats and wethers for exhibition purposes must have unique individual animal identification conforming to the National Scrapie Eradication Program. Information on specific identification requirements is available at http://www.animalagriculture.org/scrapie. Registration ear or tail tattoos may be used as official identification for goats enrolled in the Scrapie Flock Certification Program or the National Scrapie Eradication Program as long as each tattoo contains a unique premises designation and a unique individual animal identification number. APHIS has approved registry tattoos from the American Dairy Goat Association, the Nigerian Dwarf Goat Association, the American Goat Society, Pedigree International and the National Pygmy Goat Association. Wethers and non-registered goats must have official NSEP or SFCP eartags for identification. The American Dairy Goat Association offers a certificate of identification that can be used with individual unique animal tattoos as scrapie identification for wethers that are offspring of ADGA registered stock. The necessary individual animal identification required must be listed on the Certificate of Veterinary Inspection.
Veterinarians examining goats for health certificates or screening animals for sales or shows should be aware of the infectious, contagious and communicable diseases of goats. Sale committees and show sponsors should work with exhibitors to define and describe what standards exhibited goats must meet. These requirements should be part of the show or sale entry forms so that all involved are aware of what standards must be met. Animals exhibiting clinical symptoms such as pinkeye, soremouth, ringworm, or open abscesses should not be allowed to travel, show or sell and cannot be listed on a health certificate. Not all swellings are abscesses, so veterinarians should distinguish between vaccine reaction sites and abscesses. Animals with zoonotic diseases such as pinkeye, soremouth, and ringworm should not be exhibited to prevent transmission from the affected goats to the humans attending the event. Occasionally goats that are close to kidding may be on display. Placental fluids are a potential source of zoonotic organisms such as Coxiella burnetti, Toxoplasma gondii, or Chlamydiophylla. Goats that kid while at a show or sale should be housed in such a manner that the public does not have exposure to placental membranes or fluids, and handling of the neonates by the public should be minimized.
Once the Certificate of Veterinary Inspection has been written and an entry permit has been obtained, different goats may not be substituted for animals already listed on the health certificate. If other animals must be substituted or if other animals are to be added to the ones already listed on the certificate, the first certificate should be destroyed and a new certificate should be issued after the new animals are inspected and meet the requirements for shipment. The list of animals individually identified on the Certificate of Veterinary Inspection must match the animals in the shipment.
When veterinarians are asked to inspect goats on arrival for a show or sale, there should be a designated area for the veterinarian to examine each animal upon arrival before it is allowed to be housed at the show or sale facility. A quarantine area should be provided to house goats that fail inspection until they can be removed from the sale or show facility. The sponsoring committee should provide both the exhibitors and examining veterinarian with clear guidelines regarding the health and condition of eligible animals. Veterinarians may be asked to examine goats for specific defects such as extra or abnormal teats, umbilical hernias, malocclusion or scrotal abnormalities. Registry guidelines and show or sale committee requirements will then decide what recourse will be taken if abnormalities are found.
Veterinarians play a vital role in educating producers about management practices associated with transport, housing, and selection of suitable animals for show or sale. Goats must be transported in appropriate crates or trailers with adequate space and protection from wind and weather. When traveling long distances, goats must be off-loaded at suitable intervals and should be allowed to exercise before drinking fresh water and being fed their normal diet. Lactating goats should be milked at normal intervals and should be observed carefully for signs of transit tetany or hypocalcemia associated with transport across long distances. The stress associated with transport and exposure to new facilities and new animals may cause diarrhea, mastitis or pneumonia and may cause previously subclinical disease to manifest. Dairy goats are frequently shorn or clipped prior to show or sale and coats should be available to protect against adverse weather or sunburn. Producers should make sure the facilities are clean upon arrival and the pens should be disinfected before the goats are unloaded. Producers should take adequate amounts of the normal roughage and concentrate diets to prevent digestive upsets such as enterotoxemia and acidosis. Proper preparation may make the difference between a successful show or sale and loss of a valuable animal.
Goat producers may seek veterinary advice regarding evaluation of defects and possible correction or removal of defects. While it may be a common practice to remove extra teats in dairy cattle, it is unethical to surgically correct teat faults in dairy goats. Extra teats or surgically removed teats are a serious fault in dairy females and a disqualification in males. Potentially heritable traits such as hernias, entropion, or limb deformities should not be corrected unless the animal is removed from the breeding program.
Veterinarians play a pivotal role in preventing illegal drug residues in animals presented for show or sale. Few drugs are legally available for use in goats, but producers often use whatever drugs are accessible without veterinary advice concerning dosage, route or frequency of administration, duration of treatment or withdrawal of treatment prior to consumption of dairy products or sale and slaughter of the animal. Establishment of a valid veterinary-client-patient-relationship allows veterinarians and producers to use pharmaceuticals in goats in a manner different than the label. Veterinarians can educate producers about proper use and administration of necessary drugs and can determine adequate withdrawal times for both meat and milk through access to the Food Animal Residue Avoidance Databank and the Compendium of Veterinary Products. Both veterinarians and producers must be aware of withdrawal times prior to administering pharmaceuticals to market goats prior to a show or sale. The purchasing public demands wholesome meat and dairy products, so veterinarians and producers must work together to ensure that goat products are free of illegal drug residues.
Emergency preparedness for small herd owners
Natural disasters such as tornadoes, hurricanes, floods, fires and blizzards affect some part of our country every year. Livestock owners can reduce their losses by planning for these unfortunate events in advance. The American Veterinary Medical Association has developed the pamphlet "Saving the Whole Family" to help guide pet owners and producers in preparing for emergencies. More detailed information for use during emergencies can be found in the AVMA manual for veterinarians entitled "Disaster Preparedness and Response".
No one knows when or where the next natural disaster will occur, but the time to prepare for these events is in advance. Most pet owners and producers do not plan for emergencies when they obtain their animals. However, protecting livestock and defending facilities against disaster begins with the original site selection of the property and the design of the facilities. Before any structures are built, the producer should note wind patterns, water drainage, vegetation and climate, and plan the livestock facilities to withstand the problems specific to that environment. The producer should use common sense and not build in a flood plain, on top of the only hill, or in a dense forest. The property and access roads must be kept clean and free of debris, and the producer should clear a defensible space around the property to give emergency personnel access and an area to work.
The herd owner should maintain an inventory of all livestock and pets and decide whether it is more logical to evacuate during an emergency or to stay and defend the property. Large commercial operations should develop disaster plans and train personnel on what to do during an emergency. Commercial livestock operations need back-up generators that work and independent sources of energy to run those generators: gas, oil, wood or water. At least once yearly, every fence and barn should be inspected and repaired before emergencies occur, as poorly maintained facilities serve as sources of flying debris. The herd owner should decide in advance whether to confine livestock to enclosures or to turn them loose. In many emergencies, the livestock have a higher rate of survival and lower incidence of injury if they are turned loose or moved away from buildings prior to the disaster. The herd owner should plan in advance to provide adequate food and water throughout the emergency, and producers must realize that aid may not arrive for several days following the emergency. Producers should maintain emergency supplies, develop lists of contacts and livestock with complete descriptions, photograph livestock and pets, and identify emergency evacuation routes and destinations. Written directions to the property should be kept next to the telephone.
Smaller operations with lower livestock numbers and fewer pets should plan on evacuating during emergencies. Small herd owners should plan ahead for the type of emergencies common to the area and develop evacuation plans with routes, destinations and emergency contacts. The producer should keep trailers maintained and vehicles full of gas while having adequate transportation and carriers for the types of pets and livestock that will need to be evacuated. All the animals should be clearly identified by tag, tattoo or microchip. The small herd owner should keep copies of ownership, proof of rabies vaccination, and contact numbers near the telephone. With today's communication capabilities, advance warning is often given hours and even days before disaster strikes. The small herd owner should not wait until it is too late to evacuate, and the owner should take all animals with them even if they think they will only be gone for a short time.
Human life must always take precedence over livestock. Sudden emergencies may arise when it makes more sense to turn livestock loose and evacuate the family. Livestock spray paint can be used to quickly "brand" animals for identification and later reclamation. Emergency authorities should be notified that the animals have been released and how they are identified so that they can be relocated quickly following the emergency.
After the emergency is over, the producer should survey the facilities to identify hazards such as sharp objects, dangerous materials, wildlife, contaminated water and downed power lines before the livestock returns. Pets and livestock will be frightened and may not behave normally, so the small herd owner should be careful when handling them. Relocated or returned livestock should be released into enclosed areas such as intact barns or fenced areas. Likewise, pets should be released inside the home and should not be let outside unless leashed until they have calmed down after the disaster. The small herd owner should provide small amounts of familiar food upon return and should make sure that the water is clean and not contaminated. The family, livestock and pets should allow a period upon return to rest and recover from stress of the emergency. Upon return home, small herd owners should examine all pets and livestock for injuries and aggressively search for missing animals. Small herd owners can minimize their losses from emergencies and natural disasters through detailed advance planning and preparation. Veterinarians can provide information on a variety of subjects that would assist their clients in preparing for emergencies.