Zdeněk Knotek

Diseases in pet degus: a retrospective study in 300 animals

INTRODUCTION Degus are commonly used as laboratory animals; however, over the past few years, they have become increasingly popular as pets. OBJECTIVES The aim of this article was to present disease prevalence in 300 pet degus divided in two age groups (under and above two years). METHODS Medical records of degus (Octodon degus), which were presented to the authors clinic in the period from January 2007 to December 2009, were reviewed. RESULTS The most common diseases in degus were (1) acquired dental disease (60·0%) with significantly higher prevalence in older animals (P<0.001), (2) skin alopecia due to fur chewing (13·33%) and (3) lens cataracts (13·33%). Other common disorders included traumatic injuries to soft tissues (bite wounds and tail slip), traumatic fractures and dietary diarrhoea. Reproductive disorders were most commonly associated with dystocia and pathological changes in the post-natal period. Only 38 degus in a total of 300 animals were healthy. CLINICAL SIGNIFICANCE This is the first study to describe the disease prevalence in two age groups of pet degus. The majority of diseases were caused by improper diet, self-mutilation and improper handling; as such client education is necessary to avoid such a high disease prevalence.

Impact of pelleted diets with different mineral compositions on the crown size of mandibular cheek teeth and mandibular relative density in degus (Octodon degus)

The impact of pelleted diets with different mineral compositions on the crown size of the mandibular cheek teeth, as well as the mandibular bone and cheek teeth density, in degus (Octodon degus) was investigated. A total of 28 animals were randomly divided into four groups and fed different calcium or phosphorous dietary content, in the presence or absence of UV light, for 14 months. Dental radiographs and CT images of the head were taken, and the crown size of premolar and molar teeth was recorded. Apical and coronal crown elongation of all cheek teeth and significantly smaller relative cheek teeth and mandibular densities were recorded in degus fed a high-phosphorus diet with an improper calcium:phosphorus ratio. A diet with a calcium:phosphorus ratio of 1:1 was also responsible for the rapid development of dental disease with subsequent severe health impairment.

Blood sampling from the cranial vena cava in the Norway rat (Rattus norvegicus).

This paper describes blood sampling from the cranial vena cava (CVC) in the Norway rat. In order to limit stress, the blood sampling should be done under short-term inhalation anaesthesia, for example, an oxygen/isoflurane mixture. The injection site is just cranial to the first rib, 0.3–0.8 cm lateral to the manubrium when the animal is in dorsal recumbency. The needle, attached to a syringe, is inserted at 30° in the direction of the opposite femoral head. After penetration of the skin, negative pressure is developed in the syringe and the insertion of the needle is continued for another 0.2–1 cm in the given direction until blood begins to flow. The amount of blood sampled ranges from 0.8 to 2.5 mL depending on the body weight of the patient. A trial on 50 rats aged 5–24 months included 25 rats sampled once, eight rats sampled twice with an interval of seven days, 11 rats sampled twice with an interval of three weeks and four rats sampled four times with intervals of four weeks – a total of 87 blood samplings. The serious complications quoted in association with blood sampling from the CVC in other experimental animals (vascular lacerations, heart puncture, serious haemorrhage, tracheal and throat trauma) were not observed in our study. There were only four blood samplings (4.5%) with mild haemorrhage from the injection site, due to erroneous sampling from the jugular vein.

Extrahepatic biliary tract obstruction in two ferrets (Mustela putorius furo)

This report describes extrahepatic bile duct obstruction in two ferrets, which were presented with anorexia, chronic weight loss and general weakness. Physical examination revealed lethargy, cachexia, dehydration, abdominal pain and icterus. Marked haematological, serum chemistry and urinalysis abnormalities included hyperbilirubinaemia (65·5 and 114·2 μmol/L), high concentrations of alanine transaminase (1327·53 and 2578·88 IU/L) and biluribinuria. Abdominal ultrasonography revealed thickening of the bile duct together with the gall bladder wall. The common bile duct was obviously distended. Choledochotomy revealed inspissated bile with fragile green gelatinous plugs that was removed to allow the bile to flow into the duodenum. Cytology and culture of the biliary tract contents were negative for bacteria. Laboratory analyses of biliary plugs showed presence of only protein substances, without detectable mineral composition. Histopathological examination of the liver showed diffuse steatosis and non-specific cholangiohepatitis in both cases.

Selected haematological and plasma chemistry parameters in juvenile and adult degus (Octodon degus)

Thirty-five juvenile (mean age 6.3 weeks) and 35 adult (mean age 2.0 years) healthy degus (Octodon degus) were studied to investigate selected haematological and plasma biochemistry parameters. Animals were anaesthetised with isoflurane, and blood was withdrawn from the cranial vena cava. Erythrocyte, haematocrit and neutrophil counts (including the percentage of neutrophils) were significantly higher in the adult degus than in the juveniles. In contrast, the reticulocyte count, mean corpuscular volume, mean corpuscular haemoglobin, number of platelets and percentage of lymphocytes were significantly lower in the adult animals. Total protein and globulin levels were significantly higher in the adult degus. The albumin:globulin ratio and plasma levels of urea nitrogen, cholesterol, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, potassium, total calcium and inorganic phosphorus were significantly lower in adults than in juveniles.

Evaluation of the Influence of Formulation and Process Variables on Mechanical Properties of Oral Mucoadhesive Films Using Multivariate Data Analysis

Oral mucosa is an attractive region for the local and systemic application of many drugs. Oral mucoadhesive films are preferred for their prolonged time of residence, the improved bioavailability of the drug they contain, their painless application, their protection against lesions, and their nonirritating properties. This work was focused on preparation of nonmedicated carmellose-based films using both solvent casting and impregnation methods, respectively. Moreover, a modern approach to evaluation of mucoadhesive films applying analysis of texture and subsequent multivariate data analysis was used. In this experiment, puncture strength strongly correlated with tensile strength and could be used to obtain necessary information about the mechanical film characteristics in films prepared using both methods. Puncture work and tensile work were not correlated in films prepared using the solvent casting method, as increasing the amount of glycerol led to an increase in the puncture work in thinner films. All measured texture parameters in films prepared by impregnation were significantly smaller compared to films prepared by solvent casting. Moreover, a relationship between the amount of glycerol and film thickness was observed, and a greater recalculated tensile/puncture strength was needed for an increased thickness in films prepared by impregnation.

The effect of deslorelin acetate on the oestrous cycle of female guinea pigs.

Deslorelin acetate, a GnRH agonist, is commonly used to prevent folliculogenesis in several species. However, little is known of the effect of deslorelin acetate implants on the oestrous cycle of female guinea pigs. Fifteen intact healthy female guinea pigs were investigated in this study. Signs of sexual behaviour, the presence of a vaginal membrane along with plasma concentrations of oestradiol (E 2 ) and progesterone (P 4 ), were monitored during two consecutive oestrous cycles. At the beginning of the third oestrous cycle each guinea pig was administered an implant of the GnRH analogue, deslorelin acetate, (4.7 mg). When compared to the untreated state, deslorelin implantation was associated with altered signs of oestrus. The average time to opening of the vaginal membrane was delayed. After opening, the vaginas were found to be variably opened and closed. A significant reduction in P 4 (to less than 1.0 ng/ml) and cessation of P 4 cyclical variation was observed. Plasma E 2 remained high during the whole experimental period. This study shows that cessation of the oestrous cycle by the deslorelin implant might be useful in preventing pregnancy in guinea pigs.

Age-related changes in the tooth-bone interface area of acrodont dentition in the chameleon.

Chameleon teeth develop as individual structures at a distance from the developing jaw bone during the pre‐hatching period and also partially during the post‐hatching period. However, in the adult, all teeth are fused together and tightly attached to the jaw bone by mineralized attachment tissue to form one functional unit. Tooth to bone as well as tooth to tooth attachments are so firm that if injury to the oral cavity occurs, several neighbouring teeth and pieces of jaw can be broken off. We analysed age‐related changes in chameleon acrodont dentition, where ankylosis represents a physiological condition, whereas in mammals, ankylosis only occurs in a pathological context. The changes in hard‐tissue morphology and mineral composition leading to this fusion were analysed. For this purpose, the lower jaws of chameleons were investigated using X‐ray micro‐computed tomography, laser‐induced breakdown spectroscopy and microprobe analysis. For a long time, the dental pulp cavity remained connected with neighbouring teeth and also to the underlying bone marrow cavity. Then, a progressive filling of the dental pulp cavity by a mineralized matrix occurred, and a complex network of non‐mineralized channels remained. The size of these unmineralized channels progressively decreased until they completely disappeared, and the dental pulp cavity was filled by a mineralized matrix over time. Moreover, the distribution of calcium, phosphorus and magnesium showed distinct patterns in the different regions of the tooth–bone interface, with a significant progression of mineralization in dentin as well as in the supporting bone. In conclusion, tooth–bone fusion in chameleons results from an enhanced production of mineralized tissue during post‐hatching development. Uncovering the developmental processes underlying these outcomes and performing comparative studies is necessary to better understand physiological ankylosis; for that purpose, the chameleon can serve as a useful model species.

Variations of plasma protein electrophoresis in healthy captive Green Iguanas (Iguana iguana)

BACKGROUND Serum or plasma protein electrophoresis is used as a routine test for health assessment in veterinary medicine, but there are only a limited number of studies regarding clinical use of electrophoresis in reptile species. OBJECTIVE The goals of this study were to establish reference intervals for plasma protein electrophoresis in the Green Iguana (Iguana iguana), compare values between males and females, and to identify season-related changes. METHODS Plasma samples were obtained from 21 healthy captive male and female Green Iguanas. Agarose gel electrophoresis was performed using an automated Hydrasys system. RESULTS Four main protein fractions were observed: albumin, α globulins, β globulins, and γ globulins. Bisalbuminemia was observed in 4 of 21 healthy iguanas. Minimum and maximum values were reported for healthy Green Iguanas in March, June, September, and December. Seasonal changes in albumin were determined between March and December, and in γ globulins between June and September. Differences between males and females were seen in albumin concentration in September. CONCLUSIONS Reference intervals of the plasma protein fractions according to electrophoresis in the Green Iguana can be affected by seasonal changes and sex of animals. It should be taken into account when clinical evaluation is performed.

Pharmacokinetics of Ciclopirox Olamine after Buccal Administration in Rabbits

BACKGROUND Prevalence of oral mucosal fungal infections increases with the frequent administration of antibiotics, corticosteroids and immunosuppressive drugs. Therapeutically used antifungals are usually associated with a variety of drug interactions. Furthermore, there has been a noticeable increase in microorganisms resistant to these preparations. Mucoadhesive buccal films represent a modern therapeutic system for the treatment of oral mucosal fungal infection paired with a high degree of patient compliance. Ciclopirox olamine applied directly onto the oral mucosa offers an attractive alternative to treatment with systemic antifungals thanks to its low incidence of resistance and side effects. OBJECTIVE The aim of this work was to evaluate the pharmacokinetic parameters of ciclopirox olamine after the buccal application of mucoadhesive film prepared by the solvent casting method. METHOD A chromatographic method using an internal standard was developed and validated for evaluation of ciclopirox olamine plasma concentrations. Method accuracy was 88.5-104.6% and 89.5-99.7% for interday and intraday assays, respectively. RESULTS The pharmacokinetic properties of ciclopirox olamine were studied in New Zealand White rabbits. The mucoadhesive films containing ciclopirox olamine in a total dose of 34.4 (33.0; 35.9) mg kg-1 were applied to all the rabbits. Plasma ciclopirox olamine concentrations were determined during the 12 h following application. The time taken to reach maximum plasma concentration was 1.7 (1.1; 2.2) h after the drug administration with cmax 5.73 (4.18; 7.28) μg mL-1. Overall elimination half-life was 3.8 (1.9; 10.8) h. CONCLUSION The experiment suggests that oral mucoadhesive film may be a valuable alternative ciclopirox olamine administration.