A serological and clinical follow-up in horses with confirmed equine granulocytic ehrlichiosis

For diagnosis of equine granulocytic ehrlichiosis (EGE) serological testing of antibodies to Ehrlichia equi is frequently used. An elevated antibody level is often misinterpreted as confirmative of active infection and results in treatment with antibiotics. If only seropositivity is considered as the diagnostic criterium, many horses showing convalescence titres will be treated. This study was undertaken to obtain information about the kinetics of antibodies during the course of infection and, for this purpose, 45 horses with clinical signs of EGE and confirmed ehrlichiaemia were monitored serologically and clinically over time. For a correct handling of cases with suspected EGE, the following results should be helpful: (i) 44% of the horses in the acute ehrlichiaemic stage were found to be serologically positive to E. equi; (ii) all horses showed a rapid increase in antibody titre, reaching maximum value within a month after the ehrlichiaemic stage; (iii) when 8 months had passed, titres had decreased, but 18 of 24 examined horses were still serologically positive; (iv) after 12-15 months most of the horses (n = 10) were serologically negative; and (v) the period required for complete clinical recovery varied from one day up to 6 months after antibiotic treatment.     

Treatment of proliferative colitis in ferrets

Proliferative colitis associated with intracellular Campylobacter sp was diagnosed in 10 ferrets. The ferrets had a history of diarrhea (often blood-tinged or mucoid), dehydration, and chronic weight loss. Additional clinical signs included rectal prolapse, lethargy, fever, and a palpably thick colon. In 5 ferrets, the diagnosis was confirmed by colonic biopsy, via endoscopy. Supportive treatment in 5 ferrets did not alleviate the clinical signs or the proliferative intestinal disorder. oral chloramphenicol treatment (50 mg/kg of body weight, q 12 h for 10 to 21 days) resulted in marked clinical improvement and eradication of proliferative intestinal lesions in 5 ferrets.     

Surgical treatment and long-term outcome of ferrets with bilateral adrenal tumors or adrenal hyperplasia: 56 cases (1994-1997).

OBJECTIVE: To determine signalment, clinical signs, concurrent diseases, response to surgical treatment, and long-term outcome of ferrets with bilateral adrenal tumors or adrenal hyperplasia. DESIGN: Retrospective study. ANIMALS: 56 ferrets with bilateral adrenal tumors or adrenal hyperplasia confirmed histologically following subtotal bilateral adrenalectomy. PROCEDURE: Medical records of all ferrets with bilateral adrenal tumors or hyperplasia examined between 1994 and 1997 were reviewed. Ferrets underwent a subtotal bilateral adrenalectomy or a unilateral adrenalectomy initially, followed by a unilateral subtotal adrenalectomy when tumors or hyperplasia later developed on the contralateral adrenal gland. A long-term follow-up of a minimum of 18 months after final adrenal gland surgery was obtained by examination of medical records and follow-up telephone conversations. RESULTS: Clinical signs of hyperadrenocorticism included bilaterally symmetric alopecia, return to male sexual behavior in castrated male ferrets, or swollen vulva in spayed female ferrets. Surgical treatment of bilateral adrenal disease by subtotal bilateral adrenalectomy (or unilateral adrenalectomy followed by contralateral unilateral subtotal adrenalectomy) was effective with a mortality rate of < 2%. Only 3 (5%) ferrets required glucocorticoid or mineralocorticoid replacement following subtotal bilateral adrenalectomy. Recurrence after bilateral adrenalectomy was 15% with a mean long-term follow-up period of 30 months. CONCLUSIONS AND CLINICAL RELEVANCE: Bilaterally symmetric alopecia, return to male sexual behavior in castrated male ferrets, or swollen vulva in spayed female ferrets are indicative of adrenal tumors or adrenal hyperplasia in ferrets. Surgical treatment of bilateral adrenal disease by subtotal bilateral adrenalectomy is effective, with a low rate of complications and postoperative recurrence rate.     

Pancreatic endocrinopathies in ferrets.

Pancreatic endocrinopathies, especially insulinomas, are a common finding in ferrets. Surgical resection remains the treatment of choice for insulinomas because it can provide longer disease-free intervals and survival times. Because of the high rate of metastasis, owners should be advised that treatment is rarely curative and is aimed at controlling the clinical signs of hypoglycemia by stopping or slowing the progression of the insulinoma. Although less common, diabetes mellitus can occur in ferrets, but is often a postsurgical sequela to insulinoma resection. Current advancements in diabetes management can be applied to ferrets with diabetes mellitus.     

Leuprolide acetate treatment of adrenocortical disease in ferrets

OBJECTIVE: To determine the effects of leuprolide acetate, a long-acting gonadotropin-releasing hormone analog, in ferrets with adrenocortical diseases. DESIGN: Case series. ANIMALS: 20 ferrets with adrenocortical disease diagnosed on the basis of clinical signs and plasma sex hormone concentrations. PROCEDURE: Ferrets were treated with leuprolide (100 microg, IM, once), and plasma hormone concentrations were measured before and 3 to 6 weeks after treatment. RESULTS: Leuprolide treatment resulted in significant reductions in plasma estradiol, 17 alpha-hydroxyprogesterone, androstenedione, and dehydroepiandrosterone concentrations and eliminated or reduced clinical signs associated with adrenocortical disease. Decreases in vulvar swelling, pruritus, and undesirable sexual behaviors and aggression were evident 14 days after treatment; hair regrowth was evident by 4 weeks after treatment. The response to treatment was transitory, and clinical signs recurred in all ferrets. Mean +/- SEM time to recurrence was 3.7 +/- 0.4 months (range, 1.5 to 8 months). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that leuprolide can be safely used to temporarily eliminate clinical signs and reduce sex hormone concentrations in ferrets with adrenocortical diseases. However, the safety of long-term leuprolide use in ferrets has not been investigated, and the long-term effects of leuprolide in ferrets with nodular adrenal gland hyperplasia or adrenal gland tumors are unknown.     

Ranitidine bismuth citrate and clarithromycin, alone or in combination, for eradication of Helicobacter mustelae infection in ferrets

OBJECTIVE: To determine whether ranitidine bismuth citrate, clarithromycin, or a combination of ranitidine bismuth citrate and clarithromycin would be efficacious in eradication of Helicobacter mustelae infection in ferrets. ANIMALS: 60 seven-month-old ferrets. PROCEDURE: To determine dosages of clarithromycin and ranitidine bismuth citrate that would suppress growth of, but not eradicate infection with, H mustelae, ferrets (n = 6/group) were treated p.o. with clarithromycin or ranitidine bismuth citrate at various dosages. Efficacy of treatment was then determined by treating ferrets with clarithromycin alone, ranitidine bismuth citrate alone, or clarithromycin and ranitidine bismuth citrate. Gastric biopsy specimens were obtained before, during, and at various times after treatment and submitted for quantitative bacterial culture and histologic evaluation. Minimum concentrations of clarithromycin that inhibited 90% of the growth of isolates obtained before and after treatment were determined. RESULTS: Dosages of clarithromycin and ranitidine bismuth citrate that suppressed growth of H mustelae were 12.5 and 24 mg/kg of body weight, p.o., every 8 hours, respectively. Infection was not eradicated in ferrets treated with ranitidine bismuth citrate alone but was eradicated in all 6 ferrets treated with clarithromycin and ranitidine bismuth citrate and in 4 of 6 treated with clarithromycin alone. A decrease in susceptibility to clarithromycin was detected for H mustelae isolates obtained after treatment. Mild or moderate antral gastritis was observed even in ferrets from which infection was eradicated. CONCLUSIONS AND CLINICAL RELEVANCE: A combination of ranitidine bismuth citrate and clarithromycin was efficacious in eradicating H mustelae infection from ferrets.     

Clinical and endocrine responses to treatment with deslorelin acetate implants in ferrets with adrenocortical disease

OBJECTIVE: To evaluate the clinical and endocrine responses of ferrets with adrenocortical disease (ACD) to treatment with a slow-release implant of deslorelin acetate. ANIMALS: 15 ferrets with ACD. PROCEDURE: Ferrets were treated SC with a single slow-release, 3-mg implant of deslorelin acetate. Plasma estradiol, androstenedione, and 17-hydroxyprogesterone concentrations were measured before and after treatment and at relapse of clinical signs; at that time, the adrenal glands were grossly or ultrasonographically measured and affected glands that were surgically removed were examined histologically. RESULTS: Compared with findings before deslorelin treatment, vulvar swelling, pruritus, sexual behaviors, and aggression were significantly decreased or eliminated within 14 days of implantation; hair regrowth was evident 4 to 6 weeks after treatment. Within 1 month of treatment, plasma hormone concentrations significantly decreased and remained decreased until clinical relapse. Mean time to recurrence of clinical signs was 13.7 +/- 3.5 months (range, 8.5 to 20.5 months). In 5 ferrets, large palpable tumors developed within 2 months of clinical relapse; 3 of these ferrets were euthanatized because of adrenal gland tumor metastasis to the liver or tumor necrosis. CONCLUSIONS AND CLINICAL RELEVANCE: In ferrets with ACD, a slow-release deslorelin implant appears promising as a treatment to temporarily eliminate clinical signs and decrease plasma steroid hormone concentrations. Deslorelin may not decrease adrenal tumor growth in some treated ferrets. Deslorelin implants may be useful in the long-term management of hormone-induced sequelae in ferrets with ACD and in treatment of animals that are considered at surgical or anesthetic risk.     

Adrenal gland disease in ferrets.

Adrenal gland disease in ferrets is unique to this species, with clinical signs and pathophysiology different from those seen in the dog. Its prevalence is increasing; 70% of pet ferrets in the United States were affected in 2003. The exact causes of the adrenal gland changes that lead to the disease are not known. Early oophorohysterectomies and neutering, combined with the artificially prolonged photoperiod experienced by indoor pet ferrets, and a possible genetic component, may be contributing factors. Signs of adrenal gland disease include progressive hair loss, pruritis, lethargy, atrophy, and, in female ferrets, vulvar swelling. An understanding of the signs and physiologic changes is necessary for diagnosis and treatment. A review of anatomy, physiology, and current surgical and medical options is presented.     

Effects of melatonin administration on the clinical course of adrenocortical disease in domestic ferrets

OBJECTIVE: To evaluate the effect of oral administration of melatonin on clinical signs, tumor size, and serum steroid hormone concentrations in ferrets with adrenocortical disease. DESIGN: Noncontrolled clinical trial. ANIMALS: 10 adult ferrets with clinical signs of adrenocortical disease (confirmed via serum steroid hormone concentration assessments). PROCEDURES: Melatonin (0.5 mg) was administered orally to ferrets once daily for 1 year. At 4-month intervals, a complete physical examination; abdominal ultrasonographic examination (including adrenal gland measurement); CBC; serum biochemical analyses; and assessment of serum estradiol, androstenedione, and 17alpha-hydroxyprogesterone concentrations were performed. Serum prolactin and dehydroepiandrosterone sulfate concentrations were evaluated at the first, second, and last examinations, and serum cortisol concentration was evaluated at the first and last examinations. RESULTS: Daily oral administration of melatonin greatly affected clinical signs of adrenocortical disease in ferrets; changes included hair regrowth, decreased pruritus, increased activity level and appetite, and decreased vulva or prostate size. Mean width of the abnormally large adrenal glands was significantly increased after the 12-month treatment period. Recurrence of clinical signs was detected in 6 ferrets at the 8-month evaluation. Compared with pretreatment values, serum 17alpha-hydroxyprogesterone and prolactin concentrations were significantly increased and decreased after 12 months, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that melatonin is a useful, easily administered, palliative treatment to decrease clinical signs associated with adrenocortical disease in ferrets, and positive effects of daily treatment were evident for at least an 8-month period. Oral administration of melatonin did not decrease adrenal gland tumor growth in treated ferrets.     

Common procedures in the pet ferret.

The domestic ferret is an increasingly popular pet in North America and Europe and may easily be incorporated into the structure and workings of most small animal hospitals. Not only does treatment of ferrets provide case diversity and intellectual challenges to the veterinarian but it may increase revenue, because most ferret owners have several ferrets. The diagnostic and supportive care procedures used commonly in ferrets are similar to those used in dogs and cats. This article presents the common diagnostic and supportive care procedures used in ferrets, with special emphasis on some of the unique aspects that make these procedures easier to learn and perform.     

Urinary glucocorticoid excretion in the diagnosis of hyperadrenocorticism in ferrets

Hyperadrenocorticism in ferrets is usually associated with unaltered plasma concentrations of cortisol and adrenocorticotropic hormone (ACTH), although the urinary corticoid/creatinine ratio (UCCR) is commonly elevated. In this study the urinary glucocorticoid excretion was investigated in healthy ferrets and in ferrets with hyperadrenocorticism under different circumstances. In healthy ferrets and in one ferret with hyperadrenocorticism, approximately 10% of plasma cortisol and its metabolites was excreted in the urine. High-performance liquid chromatography (HPLC) revealed one third of the urinary corticoids to be unconjugated cortisol; the other peaks mainly represented cortisol conjugates and metabolites. In 21 healthy sexually intact ferrets, the UCCR started to increase by the end of March and declined to initial values halfway the breeding season (June). In healthy neutered ferrets there was no significant seasonal influence on the UCCR. In two neutered ferrets with hyperadrenocorticism the UCCR was increased, primarily during the breeding season. In 27 of 31 privately owned ferrets with hyperadrenocorticism, the UCCR was higher than the upper limit of the reference range (2.1 x 10(-6)). In 12 of 14 healthy neutered ferrets dexamethasone administration decreased the UCCR by more than 50%, whereas in only 1 of the 28 hyperadrenocorticoid ferrets did the UCCR decrease by more than 50%. We conclude that the UCCR in ferrets primarily reflects cortisol excretion. In healthy sexually intact ferrets and in ferrets with hyperadrenocorticism the UCCR increases during the breeding season. The increased UCCR in hyperadrenocorticoid ferrets is resistant to suppression by dexamethasone, indicating ACTH-independent cortisol production.     

Restoration of fractured canines in ferrets after one-step root canal treatment

This article describes a one-step root canal treatment and restoration of canine teeth in ferrets. Standard brass posts were used for the reconstruction of the teeth. The procedures were performed by dentists according to all rules and procedures used in root canal treatment in humans. The teeth were immediately restored anatomically. The procedures were successfully performed in four ferrets aged between 6 and 20 months of age, in three upper and one lower canines.     

Myofasciitis in the domestic ferret

Since late 2003, an inflammatory disease of muscle and fascia has been diagnosed in several ferrets at Northwest ZooPath, and this report describes the condition in 17 ferrets. It is a disease of young ferrets, characterized by rapid onset of clinical signs, high fever, neutrophilic leukocytosis, treatment failure, and death (or euthanasia). Gross lesions include atrophy of skeletal muscle; red and white mottling and dilatation of the esophagus; and splenomegaly. Histologically, moderate to severe suppurative to pyogranulomatous inflammation is in the skeletal muscle and the fascia at multiple sites, including esophagus, heart, limbs, body wall, head, and lumbar regions. Myeloid hyperplasia of spleen and/or bone marrow also is a prominent feature. Ultrastructural lesions include mitochondrial swelling, intracellular edema, disruption of myofibrils and Z bands. Bacterial and viral cultures, electron microscopy, immunohistochemistry, and polymerase chain reaction were negative for a variety of infectious agents. The clinical presentation and distribution of lesions suggests that polymyositis in domestic ferrets is likely a distinct entity. The etiopathogenesis if this condition is not known.     

Comparison of the lesions of Aleutian disease in mink and hypergammaglobulinemia in ferrets.

Gross and microscopic lesions of Aleutian disease (AD) in mink and hypergammaglobulinemia in ferrets were compared. Both conditions were characterized by widespread proliferation of plasma cells, but proliferation was more prominent in mink infected with AD. Arteritis did not occur in hypergammaglobulinemic ferrets. Minimal or no glomerular alterations occurred in infected ferrets, but were severe in mink infected with AD. Bile duct proliferation was more prominent in diseased mink. Tissue alterations suggested that AD in Aleutian genotype mink is more rapidly progressive than is AD in ferrets, causing overt clinical disease and death. In contrast, hypergammaglobulinemia in ferrets appeared to progress more slowly, with little clinical evidence of disease. This is probably the result of a paucity of glomerular lesions in ferrets. Possible mechanisms to explain the differences in the development of lesions are discussed.     

ADRENAL NEOPLASIA IN SEVEN FERRETS

Medical records from 7 ferrets presented to the VMTH with histologically confirmed adrenal neoplasia were reviewed. Three neutered female ferrets had adrenal cortical adenoma; four ferrets (2 neutered females, 2 neutered males) had adrenal cortical carcinoma. Ultrasound identified unilateral enlargement or abnormal shape of the adrenal gland in all ferrets. Only 1 ferret had adrenomegaly on abdominal radiographs. Adrenomegaly was identified in 1 ferret by magnetic resonance imaging (MRI). All ferrets were treated by adrenalectomy followed by a tapered dose of prednisone. Surgical complications were limited to fatal hemorrhage from the caudal vena cava in 1 ferret. Remission of clinical signs occurred in all 6 ferrets which survived surgery. The time of follow up varied from 3 to 16 months. The 3 ferrets with adrenal adenomas were still alive 3 to 7 months after surgery. AH 3 ferrets with adrenal carcinoma developed metastasis and were euthanized from 2 to 16 months after surgery.     

The relationship between prevalence of Mycobacterium bovis infection in feral ferrets and possum abundance

AIM: To determine the relationship between the prevalence of macroscopic Mycobacterium bovis infection in feral ferrets (Mustela furo) and the abundance of brushtail possums (Trichosurus vulpecula). METHODS: The predictive power of a previously reported positive association between the prevalence of macroscopic M. bovis infection in ferrets and possum abundance was examined by undertaking surveys of M. bovis infection in ferrets at sites of low and high possum abundance. The association was then tested by a manipulative experiment that measured changes in the prevalence of macroscopic M. bovis infection in feral ferrets after reducing possum abundance. RESULTS: The positive relationship between the prevalence of macroscopic M. bovis infection in ferrets and possum abundance remained valid for new survey data, although the goodness of fit of the relationship was reduced. Experimentally reducing possum abundance reduced the odds of macroscopic M. bovis infection in ferrets by 80% in the years immediately following possum control (Odds Ratio=0.23, p=0.003). CONCLUSIONS: There is a causal link between possum abundance and the prevalence of macroscopic M. bovis infection in feral ferrets in areas in which M. bovis infection is known to occur in ferret populations. This suggests that possum-to-ferret transmission of disease occurs and accounts for most of the disease evident in ferret populations, though does not determine whether ferrets are spillover or maintenance hosts of M. bovis. Management to reduce the prevalence of M. bovis infection in ferrets should consider reducing possum abundance as a control tactic. KEY WORDS: Mustela furo, ferret, Trichosurus vulpecula, brushtail possum, Mycobacterium bovis, bovine tuberculosis.     

Parvovirus-associated syndrome (Aleutian disease) in two ferrets.

There is a paucity of information regarding natural Aleutian disease, caused by a parvovirus in ferrets. With the increasing popularity of ferrets as household pets and laboratory animals, and with the advent of a USDA-approved rabies vaccine, the occurrence and the etiopathogenesis of naturally acquired diseases in ferrets needs to be documented. We present the clinical and laboratory findings associated with Aleutian disease in 2 domestic ferrets, one with the chronic wasting form of the disease and one with the central nervous system form.     

Correlation between age at neutering and age at onset of hyperadrenocorticism in ferrets

OBJECTIVE: To determine prevalence of hyperadrenocorticism in ferrets in The Netherlands and evaluate age, sex, and age at neutering in affected ferrets. DESIGN: Prevalence survey and retrospective study. ANIMALS: 50 ferrets with hyperadrenocorticism and 1,267 ferrets without hyperadrenocorticism. PROCEDURE: A questionnaire was sent to 1,400 members of a ferret-owners organization in The Netherlands; 492 (35%) owners returned the questionnaire, providing usable data on 1,274 ferrets. Seven of these ferrets developed hyperadrenocorticism during the survey period; medical records for these ferrets and 43 ferrets with confirmed hyperadrenocorticism were reviewed. Hyperadrenocorticism was confirmed by histologic examination of an excised adrenal gland (92% of ferrets) or clinical improvement after excision. RESULTS: Prevalence of hyperadrenocorticism in the survey population was 0.55%. Sex was not associated with prevalence of disease. Median time interval between neutering and diagnosis of hyperadrenocorticism was 3.5 years. A significant linear correlation between age at neutering and age at time of diagnosis was detected. CONCLUSIONS AND CLINICAL RELEVANCE: Age at neutering may be associated with age at development of hyperadrenocorticism in ferrets.     

I plasma concentrations of adrenocorticotrophic hormone and alpha-melanocyte-stimulating hormone in ferrets (Mustela putorius furo) with hyperadrenocorticism

OBJECTIVE: To determine plasma concentrations of adrenocorticotrophic hormone (ACTH) and alpha-melanocyte stimulating-hormone (alpha-MSH) in healthy ferrets and ferrets with hyperadrenocorticism. ANIMALS: 16 healthy, neutered, privately owned ferrets, 28 healthy laboratory ferrets (21 sexually intact and 7 neutered), and 28 ferrets with hyperadrenocorticism. PROCEDURES: Healthy ferrets were used for determination of reference plasma concentrations of ACTH and a-MSH. Diagnosis of hyperadrenocorticism was made on the basis of history, clinical signs, urinary corticoid-to-creatinine ratios, ultrasonography of the adrenal glands, and macroscopic or microscopic evaluation of the adrenal glands. Blood samples were collected during isoflurane anesthesia. Plasma concentrations of ACTH and alpha-MSH were measured by radioimmunoassay. RESULTS: Plasma concentrations of ACTH in 23 healthy neutered ferrets during the breeding season ranged from 4 to 145 ng/L (median, 50 ng/L). Plasma concentrations of alpha-MSH in 44 healthy neutered or sexually intact ferrets during the breeding season ranged from < 5 to 617 ng/L (median, 37 ng/L). Reference values (the central 95% of the values) for ACTH and alpha-MSH were 13 to 100 ng/L and 8 to 180 ng/L, respectively. Plasma concentrations of ACTH and alpha-MSH in ferrets with hyperadrenocorticism ranged from 1 to 265 ng/L (median, 45 ng/L) and 10 to 148 ng/L (median, 46 ng/L), respectively. These values were not significantly different from those of healthy ferrets. Plasma ACTH concentrations of sexually intact female ferrets in estrus were significantly higher than those of neutered females. CONCLUSIONS AND CLINICAL RELEVANCE: Ferrets with hyperadrenocorticism did not have detectable abnormalities in plasma concentrations of ACTH or alpha-MSH. The findings suggest that hyperadrenocorticism in ferrets is an ACTH and alpha-MSH-independent condition.