Necrosis of the collateral cartilage of the distal phalanx in horses: 16 cases (1970-1985)

The medical records of 16 horses with necrosis of the collateral cartilage of the distal phalanx were reviewed. Typical history included a laceration or puncture wound over the affected cartilage, resulting in persistent drainage proximal to the coronary band. All horses had signs of lameness. The duration of drainage prior to admission to the hospital ranged from 5 days to 5 months. The involved cartilages were left front lateral (n = 4), right front lateral (n = 5), left rear lateral (n = 1), right rear lateral (n = 4), left front medial (n = 1), and left rear medial (n = 1). The affected cartilage was curetted or resected in 13 horses, and conservative treatment was used in 3 horses. Follow-up information on 15 horses (2 to 72 months after discharge) revealed that 66% were sound and able to perform at their previous level. One horse was euthanatized 2 months after discharge from the hospital because it had septic arthritis of the distal interphalangeal joint. The outcome of treatment for each horse was evaluated with respect to the duration of drainage and the method of treatment. Horses with drainage of less than 1 month's duration had a better prognosis for eventual soundness, compared with horses with drainage of greater than or equal to 1 month's duration prior to initiation of treatment. Nine of the 13 horses managed surgically and 1 of the 3 horses managed conservatively were sound at follow-up evaluation.     

Equine basal cell tumors: 6 cases (1985-1999)

Basal cell tumors are rare benign tumors in horses. Over a 15-year period, 6 horses were diagnosed with basal cell tumors. The tumors were well-circumscribed. freely moveable, firm, raised papules, nodules, or masses that ranged from 0.6 to 5 cm in diameter. Five of the 6 tumors were ulcerated. Based on gross appearance, the tumors were diagnosed as sarcoids, and 1 was diagnosed as a melanoma. The range of age of affected horses was 6-26 years. The tumors were identified clinically 1 week to 3 years before excision. In 4 horses for which information was available, complete surgical excision was curative with no recurrence 4 months to 2 years after removal.     

Septic osteitis of the distal phalanx in foals: 22 cases (1995-2002)

OBJECTIVE: To determine the clinical characteristics and outcome of foals with septic osteitis of the distal phalanx. DESIGN: Retrospective case series. ANIMALS: 22 foals. PROCEDURES: Information obtained from medical records included signalment; clinical, laboratory, and radiographic findings; treatment method; and outcome. Foals included in the study had lameness referable to the foot, radiographic evidence of localized lysis or focal loss of bone density of the distal phalanx, and suppurative discharge or necrosis of the affected bone evident at surgery. Foals with a history or evidence of penetrating wounds or subsolar abscessation were excluded. RESULTS: Mean age of foals at initial evaluation was 40.8 days (range, 3 to 122 days). Twenty-one (95%) foals had lameness as the primary complaint. Lesions consistent with septic osteitis of the distal phalanx localized to specific areas of the bone on the basis of radiographic and surgical findings were located on the solar margin or toe (14/22 [64%]), extensor process (5/22 [23%]), and palmar or plantar process (3/22 [13%]). Hind limbs (18/26 [69%] affected limbs) were more frequently affected. Two foals had > 1 affected limb, 2 had additional sites of osteomyelitis, and 4 had concurrent septic arthritis. Surgical debridement and regional antimicrobial perfusion were performed during general anesthesia. Extensor process lesions were not debrided. Nineteen of 22 (86%) foals survived to be discharged from hospital, and 16 horses reached racing age. Eleven of 16 had race starts, of which 8 had official race starts and 3 had unofficial race starts. CONCLUSIONS AND CLINICAL RELEVANCE: Septic osteitis of the distal phalanx should be considered as a source of lameness in foals with signs referable to the foot and does not necessarily preclude a career in racing. Although infection may occur secondary to bacterial penetration of the hoof or sole, the distal phalanx should also be considered as a potential site for hematogenous septic arthritis or osteomyelitis in foals.     

Use of splenectomy in the management of lymphoma in dogs: 16 cases (1976-1985)

Sixteen dogs with lymphoma underwent splenectomy to relieve signs of massive splenomegaly including splenic rupture. The most common preoperative hematologic abnormalities, anemia and thrombocytopenia, were reversed in all dogs surviving the initial postoperative period. Within 6 weeks after surgery, 5 dogs died because of disseminated intravascular coagulation and sepsis. The remaining 11 dogs underwent chemotherapy. These 11 dogs had a complete response rate of 66% at one month after surgery; the mean and median survival times were 9.3 and 5 months, respectively. In 7 dogs evaluated until death, the mean and median survival times were 13.4 months and 14 months, respectively.     

Lameness attributable to osteochondral fragmentation of the plantar aspect of the proximal phalanx in horses: 19 cases (1981-1985)

Osteochondral fragmentation of the plantar aspect of the proximal phalanx was diagnosed as a cause of hind limb lameness in 19 horses. The lameness was evident at the upper levels of the horses' performance capabilities, and was isolated to the metatarsophalangeal joints by use of intra-articular or regional anesthesia. Fragments were surgically removed from 10 horses that later returned to full use. Seven horses were treated intra-articularly with polysulfated glycosaminoglycans or corticosteroids; only one horse was able to return to full use. One horse was retired from work at the time of diagnosis. Surgery appeared to be the most effective treatment for osteochondral fragmentation of the plantar aspect of the proximal phalanx, although medical treatment combined with a decrease in the horses' expected performance also was believed to be useful.     

Sagittal fractures of the third carpal bone in horses: 12 cases (1977-1985)

Third carpal sagittal fractures were found to be related to racing injuries in 10 of 12 horses. These fractures occurred most commonly on the medial aspect of the bone. A dorsoproximal-dorsodistal view of the carpus was required to visualize the fracture in all cases. Healing of the fracture required periods of rest of up to one year. Conservative management of these fractures resulted in return to function in 7 of 12 horses.     

Use of phacofragmentation for cataract removal in horses: 12 cases (1985-1989)

The medical records of 12 horses that had cataracts removed by use of phacofragmentation were reviewed. Cataracts were removed from 16 eyes in horses ranging in age from 2 months to 15 years. Complications after surgery included corneal ulcers in 13 eyes, diffuse corneal edema in 5 eyes, and uncontrollable uveitis in 3 eyes. Follow-up information was obtained in all horses from 1 month to 3.5 years after surgery. Visual results were judged good by owners or veterinarians in 10 of the horses.     

Removal of large fragments of the extensor process of the distal phalanx via arthrotomy in horses: 14 cases (1992-1998)

OBJECTIVE: To evaluate the outcome of horses with large fragments of the extensor process of the distal phalanx that were removed by use of arthrotomy. DESIGN: Retrospective study. ANIMALS: 14 horses with large fragments of the extensor process of the distal phalanx. PROCEDURE: Medical records for horses with large fragments of the extensor process that were removed by use of arthrotomy were reviewed. Data retrieved from medical records included signalment, use of horse, affected limb, lameness history, lameness examination findings, radiographic findings, surgical technique, and outcome. Follow-up evaluation was obtained by telephone interview. RESULTS: Most affected horses were < 5 years old and had a history of chronic lameness. Lameness grade ranged from 1/5 to 4/5. Fragments involved 20 to 45% of the dorsopalmar articular surface of the distal phalanx. Eight of 14 horses had a successful outcome. Outcome was not associated with age, duration or severity of lameness, or fragment size. CONCLUSIONS AND CLINICAL RELEVANCE: Despite involvement of a large portion of the articular surface and use of arthrotomy, joint instability and permanent soft tissue injury was not a problem in most horses. Outcome may be improved by selection of horses with lameness of < 2 years' duration and careful management after surgery. A fair prognosis may be anticipated for removal of large fragments of the extensor process via arthrotomy.     

Balloon-tipped catheter arterial occlusion for prevention of hemorrhage caused by guttural pouch mycosis: 13 cases (1982-1985)

Epistaxis, caused by guttural pouch mycosis, was treated by balloon-tipped catheter and ligature occlusion of the involved arteries in 13 horses. In 7 horses, more than one artery was catheterized. Serious postoperative hemorrhage was prevented in all horses. Long-term endoscopic follow-up examination was possible in 8 horses, and all had complete regression of the fungal lesion as early as 5 weeks after surgery. Six of the 8 horses did not receive medical treatment. Problems related to the use of the balloon-tipped catheter technique were rare. There were incisional infections in 3 horses, catheter breakage during removal occurred twice, and in one horse, a catheter was inappropriately placed.     

Pheochromocytoma in dogs: 13 cases (1980-1985)

Thirteen cases of canine pheochromocytoma seen at the University of Minnesota Veterinary Teaching Hospital between 1981 and 1985 were reviewed. In 8 cases, the neoplasms were locally invasive; in the remaining cases, they were confined to the adrenal gland. Clinical signs compatible with fatal cardiovascular collapse secondary to a hypertensive or arrythmic episode were observed in 6 of 8 dogs with invasive neoplasms that died during examination or shortly thereafter. The remaining 2 dogs with invasive neoplasms had antemortem diagnoses of adrenal gland neoplasm with metastases and were euthanatized. Invasion or encroachment of the caudal vena cava in 6 dogs and encroachment of the aorta and other regional vasculature in 2 dogs were discovered at necropsy. In 5 dogs, the noninvasive pheochromocytoma was found incidentally during necropsy.     

Evaluation of heparin for prophylaxis of equine laminitis: 71 cases (1980-1986)

The records of 71 horses with small intestinal disorders requiring surgical correction were disorders requiring surgical correction were reviewed to compare the prevalence of laminitis in those horses treated prophylactically with heparin and the prevalence of horses not treated with heparin. The prevalence of laminitis was 13% (9/71), and there was no significant difference (P less than 0.05) in the prevalence of laminitis between the 2 groups. The lack of significant benefit after treatment with heparin indicates that further work needs to be done on the equine coagulation system before heparin can be advocated for prevention of laminitis.     

Complications of blind-stitch abomasopexy: 20 cases (1980-1985)

Over a 5-year period, 20 adult Holstein cows were admitted to the New York State College of Veterinary Medicine because of complications following blind-stitch percutaneous abomasopexy for correction of left-displaced abomasum. Of the 20 cows, 16 were treated surgically, 2 were treated medically, and 2 were admitted to the pathology service for necropsy. Complications associated with the blind-stitch technique included peritonitis, cellulitis, abomasal displacement or evisceration, complete forestomach obstruction, and thrombophlebitis of the subcutaneous abdominal vein. Because of the various complications associated with blind-stitch percutaneous abomasopexy, we concluded that it is not an appropriate procedure for correction of left displaced abomasum in valuable cattle, but may be used as an alternative for salvage in less valuable cows.     

Portosystemic shunts in cats: seven cases (1976-1984)

Congenital portosystemic venous shunt causing signs of hepatic encephalopathy was diagnosed in 7 cats. The left gastric vein served as the shunt in four of these. Increases in blood ammonia and postprandial serum bile acids were the most consistent serum biochemical abnormalities. Excessive variation in red blood cell shape was a common but nonspecific hematologic finding. The jejunal-mesenteric venous injection of contrast material was the preferred method of portography to diagnose portosystemic shunts. Two cats were treated successfully by partial surgical occlusion of their shunts.     

Idiopathic gonitis in heifers: 34 cases (1976-1986)

Acute suppurative arthritis of the stifle joint was diagnosed in 34 Holstein heifers between 1976 and 1986. Only 1 stifle joint was affected in each heifer; however, 1 heifer also had involvement of the contralateral radiocarpal joint. In each heifer, there was marked lameness and synovitis characterized by an effusion with high synovial fluid nucleated cell counts and total protein concentration. Seventy-four percent (25/34) of the heifers had radiographic evidence of an osteolytic lesion involving the lateral tibial plateau. Bacteriologic cultures of synovial fluid, synovial membrane, and bone yielded no growth. Eighteen of 23 (78%) affected heifers for which follow-up data was obtained became productive herd members after treatment.     

Equine laminitis: cryotherapy reduces the severity of the acute lesion

REASONS FOR PERFORMING STUDY: The hypometabolic and vasoconstrictive effects of cryotherapy could prevent the development of laminitis. OBJECTIVES: To use distal limb cryotherapy to prevent laminitis induced by alimentary carbohydrate overload. METHODS: Laminitis was induced in 6 Standardbred horses that had one front limb continuously cooled in an ice/water mixture. Lameness evaluation, blinded lamellar histological grading and analysis for lamellar matrix metalloproteinase-2 (MMP-2) mRNA expression were used to evaluate the severity of laminitis. RESULTS: Cryotherapy was well tolerated and effective in cooling the feet. In each horse no lameness was observed in the treated limbs. Laminitis histology scores in the treated limbs were significantly less than those of the corresponding untreated forelimbs (P < 0.05). Laminitis histology scores in the treated limbs were also significantly less than those of the untreated limbs (fore- and hind) as a group (P < 0.05). Expression of MMP-2 mRNA in the iced feet was significantly (P < 0.05) less than that detected in the untreated feet. CONCLUSIONS: Cryotherapy, when applied to one foot, markedly reduced the severity of acute laminitis in this study. We propose that vasoconstriction (preventing delivery of haematogenous trigger factors) and hypometabolism (reduction in lamellar MMP activity) were the primary therapeutic mechanisms. POTENTIAL RELEVANCE: Although further research is needed, we suggest cryotherapy as a potentially effective prophylactic strategy in horses at risk of developing acute laminitis.     

Equine ehrlichiosis in northern California: 49 cases (1968-1981)

Case records of horses with equine ehrlichiosis (Ehrlichia equi) at the University of California Veterinary Medical Teaching Hospital and Ackerman Creek Large Animal Clinic were analyzed for evaluation of clinical signs, time of onset, hematologic values, response to treatment, and recovery. Equine ehrlichiosis was found to be seasonal in horses in the foothills of northern California, with higher incidence than reported previously. The horses developed fever, anorexia, depression, limb edema, icterus, and ataxia. Hematologic changes were leukopenia, thrombocytopenia, icterus, anemia, and inclusion bodies in the neutrophils and eosinophils. Diagnosis was made by observing the characteristic inclusion bodies, using a standard Wright's stain. Mortality was low, although complications of opportunistic secondary infection and injury due to ataxia did develop. Treatment with tetracycline resulted in prompt clinical improvement within 24 hours. Chronic cases were not detected. Equine ehrlichiosis should be differentiated from diseases with similar clinical signs including encephalitis, liver disease, purpura hemorrhagica, equine infectious anemia, and equine viral arteritis.     

Coxofemoral luxations in cattle: 22 cases (1980-1985)

Traumatic, unilateral coxofemoral luxation was diagnosed in 22 female dairy cattle (12 calves less than or equal to 13 months old, 10 adults). Physical examination differentiated between dorsal and ventral luxations, but could not distinguish luxations from fractures of the proximal aspect of the femur that occurred in 2 additional adults. Luxations were confirmed by radiography in 5 animals. Closed reduction was accomplished in only 1 calf. A craniolateral surgical approach to the hip, using mechanically assisted traction, was successful in reducing 95% (20/21) of the luxations. Craniodorsal luxations (16) were most common. Ninety-four percent of the animals were ambulatory before surgery. None had concomitant musculoskeletal injuries and 75% (12/16) survived for a long period. Five of 6 animals with ventral luxations arrived recumbent, with serious complicating musculoskeletal injuries, and only 2 of these animals survived for a long period. Calves had a better long-term survival rate (75% vs 50%) and a lower reluxation rate (17% vs 40%), compared with adults.     

Cutaneous vasculitis in horses: 19 cases (1978-1985)

The medical records of 19 horses with cutaneous vasculitis were reviewed. Most (73.7%) affected horses were between 3 and 10 years old, and there were significantly more mares (14) than stallions or geldings (5) (P less than 0.01). Subcutaneous edema of the limbs, body, and/or head was the predominant clinical sign (18/19 horses; 94.7%). The single most prevalent laboratory abnormality was neutrophilia (greater than 7,000 neutrophils/microliter), which was detected in 10 horses (52.6%). Leukocytoclastic vasculitis was evident in skin biopsy specimens from 12 of 14 horses (85.7%). All horses were treated with corticosteroids and supportive care, and the overall survival rate was 63.1% (12/19). The mean duration of treatment with corticosteroids in surviving horses was 14 (+/- 5.3) days. Of the 7 horses that died, 5 failed to respond to treatment (4 were euthanatized, 1 died), and 2 others had persistent debilitating sequelae (euthanatized). The only significant clinical or laboratory abnormality predictive of poor prognosis was fever (odds ratio, 17.81; P less than 0.05). Seven horses had history of, or were exposed to horses with, abscessed peripheral lymph nodes and likely were suffering from equine purpura hemorrhagica. In spite of histopathologic evidence of hypersensitivity-vasculitis and/or the clinical suspicion that the cause for vasculitis was immune mediated, 7 of 19 horses (36.8%) had no history of bacterial or viral infection nor a history of current drug administration.