Serum Trypsinlike Immunoreactivity Measurement for the Diagnosis of Subclinical Exocrine Pancreatic Insufficiency

Dogs (n = 158) with serum trypsinlike immunoreactivity (TLI) concentrations < or = 5.0 microg/L were studied. The diagnosis of clinical exocrine pancreatic insufficiency (EPI) was made in 114 of 158 dogs based on TLI concentration < 2.5 microg/L and clinical signs typical of EPI (eg, polyphagia, voluminous feces, weight loss). In 44 of 158 dogs, a single TLI measurement and clinical signs were not diagnostic. In 9 of 44 dogs, TLI was < 2.5 microg/L, indicating EPI, but the gastrointestinal signs were atypical or the dogs were asymptomatic. In 35 of 44 dogs, TLI was 2.5-5.0 microg/L. All 44 dogs were retested for TLI within 1-27 months (mean, 11.9 months). In 20 of 44 dogs, the retested TLI was normal (> 5.0 microg/L). In 4 of 44 dogs with clinically diagnosed EPI, the retested TLI was < 2.5 microg/L. In the remaining 20 of 44 dogs, TLI was persistently < 5.0 microg/L (range, 1.0-4.9 microg/L; mean, 3.1 microg/L). Of these dogs, 15 had no clinical signs of gastrointestinal disease, and 5 had occasional clinical signs atypical for EPI. Gross examination of the pancreas (12 dogs) showed that the amount of normal pancreatic tissue was remarkably diminished. These dogs were diagnosed with subclinical EPI. The TLI-stimulation test, in which TLI is measured before and after stimulation with secretin and cholecystokinin, showed a significant response (P < .05) both in dogs with subclinical EPI and in control dogs, but showed no response in dogs with clinical EPI. In this study, EPI was diagnosed in its subclinical phase by TLI concentrations persistently < 5.0 microg/L, and a single TLI concentration < 5.0 microg/L was not diagnostic. Retesting after TLI concentrations < 5.0 microg/L is recommended even in clinically normal dogs, because of the possibility of subclinical EPI.     

Serum lipase activities and pancreatic lipase immunoreactivity concentrations in dogs with exocrine pancreatic insufficiency

OBJECTIVE: To determine serum lipase activities and pancreatic lipase immunoreactivity (PLI) concentrations in dogs with exocrine pancreatic insufficiency (EPI). ANIMALS: 74 healthy dogs and 25 dogs with EPI. PROCEDURES: A diagnosis of EPI was made on the basis of clinical signs, low serum trypsin like immunoreactivity (TLI) concentration, and response to treatment with enzyme replacement. Median values for fasting serum lipase activity and serum PLI concentrations were compared between the 2 groups with a Mann-Whitney U test. RESULTS: Median fasting serum lipase activity was not significantly different between dogs with EPI (366.0 U/L) and healthy dogs (294.5 U/L), and only 1 dog with EPI had a serum lipase activity less than the lower limit of the reference range. Median serum PLI concentration was significantly lower in dogs with EPI (0.1 microg/L) than in healthy dogs (16.3 microg/L). All dogs with EPI had serum PLI concentrations less than the lower limit of the reference range. CONCLUSION AND CLINICAL RELEVANCE: Serum lipase activity is not limited to the exocrine pancreas in origin, whereas serum PLI is derived only from the exocrine pancreas. Unlike in serum TLI concentrations, there was a small degree of overlap in serum PLI concentrations between healthy dogs and dogs with EPI. Serum TLI concentration remains the test of choice for diagnosis of EPI.     

Diagnosis of canine exocrine pancreatic insufficiency by the assay of serum trypsin-like immunoreactivity

A radioimmunoassay for canine serum trypsin-like immunoreactivity (TLI) has been developed and evaluated for use in the diagnosis of exocrine pancreatic insufficiency (EPI). The maximum fasting TLI concentration in 14 dogs with EPI was 1.8 μg/l, compared with a minimum value of 7.0 μg/l in a control group of 75 dogs. The measurement of serum TLI therefore provides a sensitive test for the diagnosis of EPI in the dog.     

Development of a canine trypsin-like immunoreactivity assay system using monoclonal antibodies

The radioimmunoassay (RIA) for trypsin-like immunoreactivity (TLI) is one of the most sensitive and specific tests for detecting exocrine pancreatic insufficiency (EPI). An abnormally low serum TLI concentration (<2.5 ng/ml) indicates end-stage EPI. Although RIA methods can be used to detect canine serum TLI, these procedures are beyond the capabilities of most veterinary clinics and general laboratories. Using monoclonal antibodies (mAbs), we developed an enzyme-linked immunosorbent assay (ELISA) for canine TLI and incorporated it into an immunochromatographic test (ICT) for the diagnosis of EPI. The ELISA was linear over TLI concentrations of 1-100 ng/ml. Levels of intra-assay coefficients of variance (CVs) were 1.8-6.1%, inter-assay CVs were 5.1-9.8%, and the recovery of TLI added to two samples of canine serum ranged from 89 to 111 and 93 to 108%, respectively. Good correlation (correlation coefficient, 0.974) occurred between the TLI values obtained by the ELISA method and those by RIA from 56 clinical samples. Serum TLI values in clinically healthy dogs ranged from 7.8 to 29.2 ng/ml by ELISA, and those from dogs with EPI were 0.0-0.6 ng/ml. The values were 0.0-287.4 ng/ml for dogs with pancreatitis, and those from dogs with gastrointestinal disease were 5.5-58.9 ng/ml. The only statistically significant difference (P<0.01) occurred between the TLI level of healthy dogs and those with EPI. The ICT kit showed high reproducibility, and the TLI values yielding negative results differed significantly (P<0.01) from those returning positive results. The ICT kit yielded negative results (indicating EPI) from clinical serum samples with TLI concentrations of 0.0-4.1 ng/ml by ELISA. Both the ELISA and ICT kit are useful tools in the diagnosis of canine EPI.     

Subclinical exocrine pancreatic insufficiency in dogs

OBJECTIVE: To study progression of autoimmune-mediated atrophic lymphocytic pancreatitis from the subclinical to the clinical phase (exocrine pancreatic insufficiency [EPI]) and determine whether progression of the disease could be halted by treatment with immunosuppressive drugs. DESIGN: Randomized controlled trial. ANIMALS: 20 dogs with subclinical EPI. PROCEDURE: Diagnosis of subclinical EPI was determined on the basis of repeatedly low serum trypsin like-immunoreactivity (TLI) in dogs with no signs of EPI. Laparotomy was performed on 12 dogs with partial acinar atrophy and atrophic lymphocytic pancreatitis. A treatment group (7 dogs) received an immunosuppressive drug (azathioprine) for 9 to 18 months, and a nontreatment group (13) received no medication. RESULTS: During the subclinical phase, serum TLI was repeatedly low (< 5.0 microg/L). Although a few dogs had nonspecific gastrointestinal tract signs, they did not need diet supplementation with enzymes. While receiving immunosuppressive medication, treated dogs had no clinical signs of EPI, but within 2 to 6 months after treatment was stopped, 2 dogs had signs of EPI, and diet supplementation with enzymes was started. Five of the 13 untreated dogs needed diet supplementation with enzymes within 6 to 46 months. During follow-up of 1 to 6 years, 3 of the 7 treated dogs and 8 of the 13 untreated dogs did not need continuous diet supplementation with enzymes. CONCLUSIONS AND CLINICAL RELEVANCE: Progression of atrophic lymphocytic pancreatitis varied widely. The subclinical phase may last for years and sometimes for life. The value of early treatment with an immunosuppressive drug was questionable and, because of the slow natural progression of the disease, cannot be recommended.     

Serum immunoglobulin E concentrations in West Highland White Terrier puppies do not predict development of atopic dermatitis

Sera from 154 West Highland White Terrier puppies between 6 and 12 weeks of age were assayed for total IgE using a sandwich ELISA method. Development of clinical signs of atopic dermatitis in these dogs was monitored by use of an annual owner questionnaire, until the dog reached 3 years of age. Of 114 evaluated dogs, skin disease severe enough to warrant veterinary examination was reported in 52 (46%) during the three study years. A diagnosis of atopic dermatitis was made by the attending veterinarian in 28 dogs (25%). Certain litters had an especially high prevalence of apparently atopic dogs, consistent with the genetic predisposition towards atopy in this breed, but clear evidence of consistent heritability was not present. The median IgE concentration in 154 puppies at 6–12 weeks of age was 0.9 units mL⁻¹, with a skewed distribution. Significant ( P < 0.01) variation in serum IgE concentrations was observed between litters, with median serum IgE concentrations for a litter ranging from 0 to 27.7 units mL⁻¹. The median serum IgE concentration in puppies that later developed clinical signs of atopic dermatitis was not significantly different from that of puppies that remained healthy. There were no apparent correlations or significant differences found between serum IgE concentration as a puppy, parental history of skin disease, and subsequent emergence of clinical signs of atopic dermatitis. We conclude that early total serum IgE determinations seem to have little usefulness in predicting the later onset of atopic dermatitis in this breed.     

Evaluation of Fecal Elastase and Serum Cholecystokinin in Dogs with a False Positive Fecal Elastase Test

Background: An assay for the measurement of pancreatic elastase in dog feces has been introduced. Hypothesis/Objectives: The goal of this study was to evaluate the rate of false‐positive fecal‐elastase test results in dogs with suspected exocrine pancreatic insufficiency (EPI) and to assess serum cholecystokinin (CCK) concentrations in dogs with a false positive fecal elastase test result. Animals: Twenty‐six fecal and serum samples from dogs suspected of EPI, for which samples had been submitted to a commercial laboratory (Vet Med Labor) for analysis. Methods: Prospective study. Serum trypsin‐like immunoreactivity (TLI) was measured in 26 dogs with a decreased fecal elastase concentration of <10 μg/g feces. Serum CCK concentrations were measured in 21 of these dogs. Results: Of 26 dogs with a decreased fecal elastase concentration, 6 (23%) had serum TLI concentrations within or above the reference range. Serum CCK concentrations were significantly higher in dogs with a true positive fecal elastase test result (median: 1.1 pmol/L; range: 0.1–3.3 pmol/L) than in those with a false positive fecal elastase test result (median: 0.1 pmol/L; range: 0.1–0.9 pmol/L; P value = .0163). Conclusions and Clinical Importance: The rate of false positive fecal elastase test results was high in this group of dogs, suggesting that diagnosis of EPI must be confirmed by other means. The decreased CCK concentration in dogs with a false positive fecal elastase test result could suggest that false positive results are because of decreased stimulation of exocrine pancreatic function caused by other conditions.     

Sensitivity and specificity of radioimmunoassay of serum trypsin-like immunoreactivity for the diagnosis of canine exocrine pancreatic insufficiency

Concentrations of serum trypsin-like immunoreactivity (TLI) measured by radioimmunoassay were low (less than 1.9 micrograms/L) in 25 dogs with exocrine pancreatic insufficiency (EPI), compared with 100 clinically normal (control) dogs (5.2 to 34.0 micrograms/L; P less than 0.001; sensitivity, 100%). Serum TLI concentrations (5.5 to 35.0 micrograms/L) in a group of 50 dogs with small intestinal disease (SID) were not significantly different from those of control dogs, values being greater than the lower limit of the control range in all cases (specificity, 100%). Results of bentiromide (N-benzoyl-L-tyrosyl-p-aminobenzoic acid [BT-PABA]) tests and fecal proteolytic activity (determined by use of an azocasein substrate) were abnormal in 21 of 22 dogs with EPI (sensitivity, 95%). Bentiromide test results were subnormal in 13 of 35 dogs with SID (specificity, 63%), whereas fecal proteolytic activity was subnormal in 7 of 34 dogs with SID (specificity, 79%). It was concluded that assay of serum TLI is a highly sensitive and specific test for the identification of dogs with EPI.     

Exocrine pancreatic atrophy in German Shepherd Dogs and Rough-coated Collies: an end result of lymphocytic pancreatitis

Previously published studies of the pathology of canine exocrine pancreatic insufficiency (EPI) have been based on morphological findings during the clinical phase of the disease, when atrophy of acinar parenchyma occurs. Recently, low serum trypsinlike immunoreactivity (TLI) concentration has been shown to precede clinical signs, making it possible to diagnose EPI prior to onset of the clinical disease. This study presents histological and ultrastructural findings of pancreatic biopsies from 11 German Shepherd Dogs and 2 Rough-coated Collies with subclinical EPI (SEPI). These findings were compared with those from dogs with clinical EPI (n = 11) and healthy control dogs (n = 5). Biopsied tissue from dogs with SEPI typically contained both normal and atrophied acinar parenchyma. The most significant finding was the marked lymphocytic infiltration, which was most prevalent at the border zone of affected and nonaffected parenchyma but had spread into the normal acinar tissue. Numerous intraacinar lymphocytes were found. Most of the lymphocytes were positive by immunostaining for CD3. In more advanced stages of destruction, the findings were characteristic of pancreatic acinar atrophy. In the atrophied parenchyma, the inflammatory reaction, if present, was less prominent. Ultrastructural changes were in accordance with those of the histological study showing infiltration of lymphocytes both in affected acini and in acini that revealed no obvious ultrastructural changes. Progressive degenerative changes of acinar cells were considered a nonspecific finding. Apoptotic death of acinar cells was occasionally found. The inflammatory reaction was clearly shown to precede the pancreatic acinar atrophy, and the findings suggested that lymphocytic pancreatitis leads to atrophy of the pancreas. The possibility that EPI is an immune-mediated disease in German Shepherd Dogs and Rough-coated Collies is discussed.     

Goiter with vascular anomalies in a litter of Polish Lowland sheepdogs

At approximately 4-5 mo of age, three Polish Lowland sheepdog puppies from a single litter of eight puppies presented to their respective primary veterinarians with bilateral subcutaneous masses in their ventral cervical regions. Evaluation, including thyroid function testing, surgical exploration with resection, computed tomography, and angiography, identified the masses as enlarged thyroid glands with severely dilated and abnormal vasculature in the regions of the glands. The dogs were also found to have serum concentrations of thyroid hormones that were below the reference ranges. None of the three dogs showed clinical signs of hypothyroidism, except for the presence of goiter. One dog also had a patent ductus arteriosus that was surgically repaired. All dogs were clinically normal at 2 yr of age. This is the first report of major vascular anomalies associated with goiter in any species. The mechanism is unknown.     

Preliminary clinical pharmacological investigations of tylosin and tiamulin in chickens

Summary The minimal inhibitory concentrations (M1C) of tiamulin and tylosin for mycoplasma. Gram-positive, and Gram-negative micro-organisms isolated from chickens were determinated by the agar dilution method. Median M1C values for tiamulin against Mycoplasma gallisepticum (0.05 μg/ml) and Mycoplasma synoviae (0.10 μg/ml) were 2 to 4 times lower than the corresponding values for tylosin. Tiamulin was also slightly more effective in vitro in inhibiting Escherichia coli, Pasteurella multocida, and beta-haemolytic streptococci than was tylosin. Groups of chicken were offered tiamulin medicated drinking water at rates of 125 and 250 mg/litre for 48 hours. Average serum tiamulin concentrations were 0.38 and 0.78 μg/ml, respectively. When tylosin tartrate was added to the drinking water at 500 and 700 mg/litre, average serum drug levels were 0.12 and 0.17 μg/ml, respectively. Tiamulin was 45% bound in chicken serum, as against 30% serum protein binding or tylosin. Correlations were made between free (non protein bound) serum drug levels and the MIC values of the two drugs. Such comparisons suggest that when tiamulin is given in the drinking water at rates of 125 to 250 mg/litre, better antimycoplasmal activity is to be expected in vivo than by giving tylosin tartrate in the drinking water at 500 to 700 mg/litre. Based on these data, no clinical efficacy of these dose rates can be expected in flocks infected by gram-negative microorganisms such as E. coli or P. multocida. The tylosin tartrate rate of 500 to 700 mg/litre, may be clinical ineffective the treatment of Staphylococcus aureus infections.     

A study of bovine and equine immunoglobulin levels in pony foals fed bovine colostrum

As part of a project to raise specific pathogen free (SPF) Welsh Mountain Pony foals, free from exposure to Equid herpesvirus type 1, foals were removed from their dams at birth and fed bovine colostrum. This study characterises the uptake of bovine colostral immunoglobulin and production of endogenous immunoglobulin, in 10 SPF foals. An enzyme-linked immunoadsorbent assay was developed to measure serum concentrations of bovine IgG1 (boIgG1) to assess the efficiency of transfer, and rate of elimination of boIgG1 by the foal. The endogenous production of equine IgG was studied using a single radial immunodiffusion test. Foals were given 1.2 to 2 litres of bovine colostrum achieving peak serum boIgG1 concentrations of 18.9 to 34.2 g/litre (mean 28.0). The mean half-life of boIgG1 in the foals was 7.4 days. Endogenous immunoglobulin production resulted in equine IgG concentrations greater than 2 g/litre in six of 10 foals by 14 to 19 days of age, and greater than 7 g/litre in eight of 10 foals by 37 to 50 days of age. All foals had equine IgG serum concentrations greater than 10 g/litre by 102 to 135 days of age.     

Production of volatile fatty acids in the rumen of calves during dietary-microbial stimulation and early weaning

The contents of volatile fatty acids in the rumen fluid were studied in calves at an early (seven weeks of age) and traditional weaning term (nine weeks of age). Weaning at the age of seven weeks enabled to save 16.2 kg of milk replacer per calf; there was also a lower content of concentrates in the starter feed with a supplement of Amylastim. The health condition of the calves was good in both groups. The average daily weight gains for the period from the second to the ninth week of age were 0.550 kg in the early weaned calves and 0.690 kg in the calves weaned at a normal time. Early weaning had a positive influence on the development of rumen metabolism. Calves weaned at the age of seven weeks, compared with those weaned at the age of nine weeks, had much higher concentrations of VFA (p less than 0.05) in rumen fluid (at the age of seven weeks: 130.49 mmol per litre vs. 111.53 mmol per litre; at the age of eight weeks: 119.74 mmol per litre vs. 96.98 mmol per litre). Early weaned calves had the statistically significantly (p less than 0.05) higher proportions of propionic acid, butyric acid, i-butyric acid, and valeric acid. Later-weaned calves had the significantly higher (p less than 0.05) contents of acetic acid and i-valeric acid.     

Dilated cardiomyopathy in juvenile Portuguese Water Dogs

Dilated cardiomyopathy recently has been recognized in juvenile Portuguese Water Dogs. The purpose of this study was to evaluate unaffected and affected puppies by physical examination, electrocardiogram (ECG), echocardiogram, specific biochemical assays, and ultrastructure to document disease progression and to develop a method of early detection. Results of segregation analysis were consistent with autosomal recessive inheritance. Of 124 puppies evaluated clinically and echocardiographically, 10 were affected. No significant differences were found between unaffected and affected puppies for blood and myocardial carnitine or taurine concentrations, serum chemical variables, results of ophthalmological examinations, ECGs, or measurement of urine metabolites. Ultrastructural examination of myocardium from affected dogs revealed myofibrillar atrophy and small regions of myofibrillar degeneration, most prominently at the region of the intercalated discs. Only echocardiography allowed detection of affected puppies before clinical signs became evident. Echocardiography revealed a significant difference in the shortening fraction, E point to septal separation, and the end systolic and diastolic left ventricular internal diameters. Affected puppies were detected 1-4 weeks before the development of acute congestive heart failure.     

Exocrine pancreatic insufficiency in dogs.

Pancreatic acinar atrophy (PAA) is by far the most common cause for the maldigestion signs of canine exocrine pancreatic insufficiency (EPI). The ability to diagnose PAA in the subclinical phase before the development of total acinar atrophy and manifestation of clinical signs has offered new possibilities to study the pathogenesis of the disease. Marked T-lymphocyte infiltration during the progression of acinar atrophy and the genetic susceptibility of the disease have been taken as a primary evidence of the autoimmune nature of the disease. The term autoimmune-mediated atrophic lymphocytic pancreatitis is preferred to describe pathologic findings. A single abnormally, low serum canine trypsin-like immunoreactivity (cTLI) concentration (< 2.5 mg/L), in dogs with typical maldigestion signs has been shown to be highly diagnostic for clinical EPI and is found in dogs with end-stage PAA. Repeatedly subnormal cTLI values (2.5-5.0 micrograms/L) in dogs with no clinical signs of EPI are valuable markers of subclinical EPI and highly suggestive for partial PAA. The primary treatment of EPI is supplementing each meal with pancreatic enzymes. The long-term treatment response for the nonenteric-coated enzyme supplements has been found to be good in half of these dogs, but the response varied considerably.     

Effects of diet on clinical signs of exocrine pancreatic insufficiency in dogs

OBJECTIVE: To assess the effects of dietary modification on clinical signs of exocrine pancreatic insufficiency (EPI) in dogs. DESIGN: Blinded randomized crossover study. ANIMALS: 21 dogs with EPI. PROCEDURE: Dogs were fed the diet they received at home for 2 weeks. Thereafter, they received 3 special diets (a high-fat diet, a high-fiber diet, and a highly digestible low-residue diet) for 3 weeks each. Owners scored dogs daily for the last 2 weeks of each 3-week period for severity of 6 clinical signs including appetite, defecation frequency, consistency of feces, borborygmus, flatulence, and coprophagia. An EPI index was calculated for each dog by adding the daily scores for each clinical sign. RESULTS: Significant differences in daily EPI indices among diets were observed in 20 dogs. The original diet appeared to be the most suitable in 8 dogs, whereas the high-fat diet was most suitable in 5 dogs, the high-fiber diet was most suitable in 4 dogs, and the low-residue diet was most suitable in 2 dogs. In 1 dog, the lowest EPI index score was the same during the original diet and the high-fat diet feeding periods. One dog did not complete the feeding period for the high-fiber diet. Differences in mean EPI indices among diets were not significant. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that responses to different diets varied among individual dogs. Because responses to the feeding regimens were unpredictable, it is suggested that feeding regimens be individually formulated for dogs with EPI.     

Feline exocrine pancreatic disorders.

Despite the uncommon clinical diagnosis, cats frequently suffer from disorders of the exocrine pancreas. Pancreatitis is the most common feline exocrine pancreatic disorder. Pancreatitis can be acute or chronic and mild or severe. The etiology of most cases of feline pancreatitis is idiopathic. Some cases have been associated with severe abdominal trauma, infectious diseases, cholangiohepatitis, and organophosphate and other drug intoxication. The clinical presentation of cats with pancreatitis is nonspecific. Vomiting and signs of abdominal pain, which are the clinical signs most commonly observed in humans and dogs with pancreatitis, are only uncommonly observed in cats with pancreatitis. Routine laboratory findings are also nonspecific. Abdominal ultrasonography is a valuable diagnostic tool in feline patients with pancreatitis. Serum activities of lipase and amylase are rarely increased in cats with pancreatitis; however, these cats often have elevated serum fTLI concentrations. The goals of management are removal of the inciting cause, provision of supportive and symptomatic therapy, and careful monitoring for and aggressive treatment of systemic complications. Exocrine pancreatic insufficiency is a syndrome caused by insufficient synthesis of pancreatic digestive enzymes by the exocrine portion of the pancrease. The clinical signs most commonly reported are weight loss, loose and voluminous stools, and greasy soiling of the hair coat. Serum fTLI is subnormal in affected cats. Treatment of cats with EPI consists of enzyme supplementation with powdered pancreatic extracts or raw beef pancreas. Many cats with EPI have concurrent small intestinal disease. Most cats with EPI also have severely decreased serum cobalamin concentrations and may require parenteral cobalamin supplementation. Pancreatic adenocarcinoma is the most common neoplastic condition of the exocrine pancreas in the cat. At the time of diagnosis, the tumor has already metastasized in most cases, and the prognosis is poor. Pancreatic pseudocyst, pancreatic abscess, pancreatic parasites, pancreatic bladder, and nodular hyperplasia are other exocrine pancreatic disorders, that are less commonly seen in cats.     

Mass screening of Irish wolfhound puppies for portosystemic shunts by the dynamic bile acid test.

Five hundred and sixty-six Irish wolfhound puppies aged six to 15 weeks were tested for congenital portosystemic shunts by the dynamic bile acid method. Plasma ammonia concentration was also measured in 165 of the puppies both fasting and postprandially. Nineteen puppies (3.4 per cent), nine males and 10 females, had portosystemic shunts. Smaller litters appeared to be more likely to contain affected puppies. The postprandial bile acid concentration was a reliable predictor of the presence of a shunt, with the highest concentration in a normal puppy being 38 mumol/litre and the lowest in an affected puppy being 43 mumol/litre. In contrast, fasting bile acid concentrations were normal in the majority of the affected puppies. There was considerable overlap in fasting plasma ammonia concentrations between normal and affected puppies (26 puppies, 15.8 per cent of those tested). Postprandial ammonia concentration appeared to give better separation between the two groups, apart from two individuals which produced bizarre results. It was concluded that the postprandial or dynamic bile acid test is an appropriate test for the mass screening of Irish wolfhound puppies for portosystemic shunts, and guidelines are proposed for the interpretation and follow-up of the test.     

Spongy Degeneration with Cerebellar Ataxia in Malinois Puppies: A Hereditary Autosomal Recessive Disorder?

Background: There is a high incidence of hereditary degenerative diseases of the central nervous system in purebred dogs. Hypothesis: Cerebellar ataxia in Malinois puppies, caused by degenerative changes that predominate in cerebellar nuclei and the granular cell layer, is a hereditary disorder that is distinct from cerebellar cortical abiotrophies. Animals: Thirteen Malinois puppies with cerebellar ataxia. Methods: Retrospective study. Records of Malinois puppies with spongy degeneration of the cerebellar nuclei were analyzed including clinical signs, histopathological changes, and pedigree data. Results: Signs of cerebellar dysfunction were observed in puppies of both sexes from 5 different litters (1995–2009) of phenotypically normal parents. Clinical signs started before the age of 2 months and resulted in euthanasia of all puppies by the age of 13 weeks. Histopathology disclosed marked bilateral spongy degeneration of the cerebellar nuclei and vacuoles in the granular cell layer and foliate white matter of the cerebellum. In some puppies, discrete vacuoles in gray and white matter were present in other parts of the brain. Furthermore, spheroids and dilated myelin sheaths were observed. Pedigree data and segregation frequency support an autosomal recessive hereditary disorder. Conclusions and Clinical Importance: Malinois suffer from a hereditary spongiform degeneration that predominates in the cerebellum and causes an early onset of clinical signs with unfavorable prognosis. Future efforts should increase awareness among veterinarians and breeders and aim to identify underlying metabolic mechanisms and the affected genes.     

Preliminary clinical pharmacological investigations of tylosin and tiamulin in chickens

Summary

The minimal inhibitory concentrations (M1C) of tiamulin and tylosin for mycoplasma. Gram‐positive, and Gram‐negative micro‐organisms isolated from chickens were determinated by the agar dilution method. Median M1C values for tiamulin against Mycoplasma gallisepticum (0.05 μg/ml) and Mycoplasma synoviae (0.10 μg/ml) were 2 to 4 times lower than the corresponding values for tylosin. Tiamulin was also slightly more effective in vitro in inhibiting Escherichia coli, Pasteurella multocida, and beta‐haemolytic streptococci than was tylosin. Groups of chicken were offered tiamulin medicated drinking water at rates of 125 and 250 mg/litre for 48 hours. Average serum tiamulin concentrations were 0.38 and 0.78 μg/ml, respectively. When tylosin tartrate was added to the drinking water at 500 and 700 mg/litre, average serum drug levels were 0.12 and 0.17 μg/ml, respectively.

Tiamulin was 45% bound in chicken serum, as against 30% serum protein binding or tylosin. Correlations were made between free (non protein bound) serum drug levels and the MIC values of the two drugs. Such comparisons suggest that when tiamulin is given in the drinking water at rates of 125 to 250 mg/litre, better antimycoplasmal activity is to be expected in vivo than by giving tylosin tartrate in the drinking water at 500 to 700 mg/litre. Based on these data, no clinical efficacy of these dose rates can be expected in flocks infected by gram‐negative microorganisms such as E. coli or P. multocida. The tylosin tartrate rate of 500 to 700 mg/litre, may be clinical ineffective the treatment of Staphylococcus aureus infections.