[Follow-up study in German Hunting Terrier dogs with exercise induced metabolic myopathy]. / Verlaufsuntersuchungen bei Deutschen Jagdterriern mit belastungsabhängiger metabolischer Myopathie.

OBJECTIVE: Exercise induced metabolic myopathy in German Hunting Terrier dogs is an autosomal-recessively inherited disorder, caused by a nonsense variant of the gene encoding for the very long-chain acyl-CoA-dehydrogenase (VLCAD) enzyme. Clinical signs include exercise- induced fatigue, muscle pain and weakness. In the present study, the long-term course of this disease was investigated over a period of 1 year in 9 affected German Hunting Terriers. The dogs were treated symptomatically with oral L-carnitine, coenzyme Q10 and a special diet characterized by a low content of long-chain fatty acids and a high proportion of carbohydrates. MATERIAL AND METHODS: In 9 affected dogs, the phenotype as well as clinical, laboratory parameters, and histopathological findings are described (time point 1) and compared to follow-up examinations 1 year later (time point 2). At both time points clinical and neurological examinations, complete blood cell count, clinical chemistry profile and the concentration of brain natriuretic peptide (NT-proBNP) were investigated. RESULTS: In the follow-up examinations, the same post-exercise clinical signs were present as in the initial presentation of the homozygous dogs. Dark-brownish discoloration of the urine, weakness, myalgia as well as stiff and tetraparetic gait were apparant. All hematological values and the concentration of NT-proBNP were within the relevant reference ranges. Plasma CK and ALT activities were compared between the first presentation and the follow- up examination and no significant differences were detected (pCK = 0.31, pALT = 0.64). Signs of myopathy remained unchanged throughout the examination period. CONCLUSION AND CLINICAL RELEVANCE: Oral supplementation with L-carnitine, coenzyme Q10 and the special dietary management did not result in any improvement of clinical signs or laboratory parameters. No progression of the disease was observed. The prognosis for affected dogs remains cautious as long-term observations of affected dogs over several years are lacking. Our findings provide further important information on inherited disorders of mitochondrial ß-oxidation in dogs, especially focused on the exercise induced metabolic myopathy in the German Hunting Terrier. This may provide new insights for novel treatment modalities in conjuntion with the development of improved breeding guidelines.

Nutrient digestibility, organ morphometry and performance in vaccinated or non-vaccinated Lawsonia intracellularis infected piglets.

BACKGROUND: Lawsonia intracellularis is one of the world's most important infectious diseases in pork production with regard to economic losses. So far, studies are missing that describe the effects of a natural infection of piglets on the digestibility of nutrients, possible effects on performance and the morphometrics of the intestine depending on whether piglets are vaccinated, clinically healthy or clinically affected with regard to Lawsonia intracellularis induced diarrhoea. RESULTS: Digestibility studies were performed on a total of 27 eight-week-old piglets with naturally occurring Lawsonia intracellularis infection in a trial with three repetitions. Nine out of 27 animals were vaccinated as suckling pigs with a commercial Lawsonia intracellularis vaccine (vac; Enterisol®Ileitis). Half of the remaining 18 animals were without clinical signs of infection (non-vac/cs-), half showed moderate clinical signs of Lawsonia intracellularis induced diarrhoea (non-vac/cs+). All three groups were fed one identical complete diet ad libitum. Faecal shedding of Lawsonia intracellularis was found in all groups (25 out of 27 animals). Numerically, the mean excretion in the group non-vac/cs + (7.69 ± 1.65 log10 copies/ g faeces) was higher in comparison to the group non-vac/cs- (5.83 ± 2.35 log10 copies/ g faeces) and vaccinated animals (vac: 6.00 ± 2.89log10 copies/ g faeces). The average daily weight gain (ADG; Ø 8.66 day period) differed significantly (vac: 894a ± 73.3, non-vac/cs-: 857ab ± 86.3, non-vac/cs+: 785b ± 137 g/day). The apparent total tract digestibility (ATTD) of nitrogen was significantly lower in clinically affected animals (vac: 83.0a ± 1.72, non-vac/cs-: 83.9a ± 2.03, non-vac/cs+: 80.7b ± 2.57).The total length of the small intestine in clinically affected animals increased significantly (vac: 15.9ab ± 1.57, non-vac/cs-: 14.6b ± 1.12, non-vac/cs+: 16.2a ± 1.37 m). The relative body weight depending on the length of the small intestine was lower for clinically affected animals (vac: 1.72a ± 0.21, non-vac/cs-: 1.83a ± 0.17, non-vac/cs+: 1.56b ± 0.12 kg/m). CONCLUSION: These studies show that clinically moderate L. intracellularis infections lead to significantly lower ADGs in comparison to vaccinated animals. The disease is also found in altered intestinal morphometry and reduced total N digestibility if clinical signs occur.

Effect of a single injection of autologous conditioned serum (ACS) on tendon healing in equine naturally occurring tendinopathies.

INTRODUCTION: Autologous blood-derived biologicals, including autologous conditioned serum (ACS), are frequently used to treat tendinopathies in horses despite limited evidence for their efficacy. The purpose of this study was to describe the effect of a single intralesional injection of ACS in naturally occurring tendinopathies of the equine superficial digital flexor tendon (SDFT) on clinical, ultrasonographic, and histological parameters. METHODS: Fifteen horses with 17 naturally occurring tendinopathies of forelimb SDFTs were examined clinically and ultrasonographically (day 0). Injured tendons were randomly assigned to the ACS-treated group (n = 10) receiving a single intralesional ACS injection or included as controls (n = 7) which were either untreated or injected with saline on day 1. All horses participated in a gradually increasing exercise programme and were re-examined nine times at regular intervals until day 190. Needle biopsies were taken from the SDFTs on days 0, 36 and 190 and examined histologically and for the expression of collagen types I and III by immunohistochemistry. RESULTS: In ACS-treated limbs lameness decreased significantly until day 10 after treatment. Swelling (scores) of the SDFT region decreased within the ACS group between 50 and 78 days after treatment. Ultrasonographically, the percentage of the lesion in the tendon was significantly lower and the echogenicity of the lesion (total echo score) was significantly higher 78 and 106 days after intralesional ACS injection compared to controls. Histology revealed that, compared to controls, tenocyte nuclei were more spindle-shaped 36 days after ACS injection. Immunohistochemistry showed that collagen type I expression significantly increased between days 36 and 190 after ACS injection. CONCLUSIONS: Single intralesional ACS injection of equine SDFTs with clinical signs of acute tendinopathy contributes to an early significant reduction of lameness and leads to temporary improvement of ultrasonographic parameters of repair tissue. Intralesional ACS treatment might decrease proliferation of tenocytes 5 weeks after treatment and increase their differentiation as demonstrated by elevated collagen type I expression in the remodelling phase. Potential enhancement of these effects by repeated injections should be tested in future controlled clinical investigations.

Individual differences in the phosphorus metabolism of fattening bulls--testing effects of crude fibre and calcium chloride in the diet.

Urolithiasis due to struvite concrements occurs in fattening cattle, but only in 1-5% of a herd, in spite of identical nutrient supply. Developing dietetic measures for these cattle was the primary aim of this study. The feeding experiments were focused on the general effects of varying the crude fibre supply and adding CaCl2 as a urine acidifier, especially concerning individual reactions to the different diets. Five standard balance trials were performed with three fattening bulls. The crude fibre content in the ration varied between 14.8% and 24.0% DM. In two trials, coated CaCl2 was fed (per day 20 g/100 kg BW). Influences on the macro mineral metabolism and the acid-base-balance were investigated. Unexpectedly, the crude fibre content had no significant effect on the renal P excretion, but individual differences occurred concerning digestibility, renal excretion and serum concentration of P: one bull constantly showed significantly higher values. Adding CaCl2 resulted in reduced renal P excretion and pH values of the urine (< 6.5). Thus, using CaCl2 might be a beneficial dietetic measure for preventing struvite. The huge individual differences in the P metabolism could be linked to genetically-based variations, as known for sheep.