Clinical,Ultrasonographic and Pathological Findings in a Bull with Segmental Aplasia of the Mesonephric Duct

On assessment for use in an AI stud, a 12‐month‐old bull was found to produce low volume ejaculates with 41% of the sperm having morphological abnormalities. No left epididymal tail was palpable and the head of the epididymis on the left was twice the size compared with the right. Ultrasound examination showed the left testis to contain a large central area of decreased echogenicity, which could be followed proximally to a 15‐mm echolucent lesion at the site of the epididymal head. Postmortem examination revealed a 15‐mm diameter cyst in the region of the left epididymal head, and absence of the body and tail of the epididymis. The mediastinum testis of the left testis was dilated, corresponding to the area of decreased echogenicity observed on ultrasonography. No left seminal vesicle was present and the ampulla was significantly smaller than the same structure on the right. Histological examination revealed incomplete or absent spermatogenesis involving the majority of seminiferous tubules in the left testis, and a small proportion of those of the right testis. The cystic structure at the site of the left epididymal head was lined by irregular, sometimes attenuated, epithelium and contained sparse spermatozoa. This case demonstrates the adverse impact, which segmental aplasia of the mesonephric duct had on the testicular and epididymal function of a bull, and highlights the importance of careful clinical assessment in its diagnosis.     

In this issue – March 2010

Topical anaesthesia for castration and tail docking in lambs · Disease surveillance activities for saleyard pigs · Reproductive effects of time on prepartum transition diets in dairy cows · Bovine herpesvirus type 5 in bull semen · Rib osteomyelitis in three foals · Mycobacterium ulcerans in two horses · Nasal vascular hamartoma in a cat     

In this issue – November 2010

Management and preventive health care in aged horses · Echocardiographs in healthy Thoroughbred foals · Surgical stapling technique for caecal impaction in horses · MRI of the second phalanx in horses · Radiotransmitters in snakes · Nasotracheal intubation of a kangaroo · Avian tracheal resection and anastomosis · Nasal bot fly in a cat · First report of Cryptosporidium andersoni in Australian cattle     

IN THIS ISSUE – July 2010

Presence of Mycobacterium avium subsp. paratuberculosis in raw milk · Profiling of Haemophilus parasuis in live pigs · Cysticercus bovis in Australian cattle · Thoracoscopy for lung lobectomy in the dog · Common bile duct cyst in a cat · Caecal intussusceptions in horses in New Zealand · Improving access to the oral cavity of the wombat · Mycobacterium in a Tasmanian devil · Surgical treatment of osteomyelitis in an alpaca cria     

Erythrocytic pyruvate kinase deficiency and AB blood types in Australian Abyssinian and Somali cats

Objective   To determine the frequency of the mutant pyruvate kinase (PK) allele, haematological parameters and AB blood types of Abyssinian and Somali cats in Australia.
Design   Complete blood cell and reticulocyte counts, DNA PK mutation testing and blood typing were performed in all cats.
Results   A total of 60 cats (36 Abyssinians, 24 Somalis) were included (37 females, 23 males). For the mutant PK allele, three female Somalis were homozygous (affected, 5%), 17 cats were heterozygous (carrier, 28%) and 40 cats tested negative (normal, 67%). Pedigree analysis revealed common ancestry of affected and many carrier cats. Of affected cats, two had regenerative anaemias and all had reticulocytosis (range 64–390 × 10⁹/L; P < 0.001 compared with normal or carrier cats). The only consistent historical sign was lethargy. One affected cat was euthanased 18 months after testing, because of anaemia, neutropenia, anorexia and weight loss. The mutant allele frequency was 0.19 overall (0.29 in Somalis, 0.13 in Abyssinians). All cats had blood type A. The commercial blood typing card method incorrectly identified 12 cats as having type AB blood.
Conclusions    The frequency of the mutant PK allele is high in Australia. Screening for PK deficiency is indicated before mating and in individual cats of these breeds, even in the absence of anaemia and especially when there is reticulocytosis. Although all cats in the present study had blood type A, blood type B is common in these breeds worldwide. Retyping of any AB typed cats by a laboratory technique is recommended.