Common questions from goat producers (Proceedings)
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.