Veterinary Services

High mortality in chicks aged three weeks on a small free-range unit was investigated.  Severe crop impaction, malnutrition and coccidiosis caused by Eimeria necatrix and E. acervulina was found at postmortem examination.  Coccidiosis, exacerbated by severe chilling and wetting, was diagnosed in chicks aged three weeks on another farm, where the owner had reported 24 deaths from a batch of 170 birds over a two-day period.

Infection with rotavirus was confirmed in turkey poults aged seven days.  The owner had reported 43 deaths out of the group of 200.

Game birds

Spironucleosis (hexamitosis) caused problems in red-legged partridges and pheasants aged five to seven weeks, before the birds were due to be transferred to release pens.  The same condition was seen in older pheasants up to eleven weeks of age that had already been released.  Affected birds were dull, some had watery faeces, and mortality rate was elevated.

Tenosynovitis associated with Staphylococcus aureus was diagnosed in four batches of pheasants aged eight to ten weeks.  Birds were described as lame or unwilling to move when approached.  This condition is not uncommon in pheasants in the period following transfer to release pens, and the SAC considers that S. aureus may gain entry through small abrasions to the feet or skin acquired when the birds are being caught or transported.  Concurrent coccidiosis was seen in two of the batches, and hexamitosis in a third batch.

Coccidiosis was considered to be the cause of death of red-legged partridges aged six weeks – mortality was approximately two per cent.  Coccidiosis was also the cause of apparent sudden deaths in partridges aged ten weeks.  Heavy burdens of gapeworms (Syngamus trachea) were found in pheasants aged nine weeks.  Over 160 birds from the group of 2000 had reportedly died since purchase two weeks earlier, and prior to death some birds had been seen gasping.

A single adult red grouse found moribund on a Strathspey moor was submitted as a suspect case of louping ill.  There was no evidence of exposure to louping ill virus but a total worm count of 16,000 Trichostrongylus tenuis was considered the likely cause of the problem.

Waterfowl

Histopathological examination of tissues from a Muscovy duck confirmed changes consistent with a diagnosis of “Muscovy duck pneumonitis”.   This condition was described by Randall and others in 1987 (Avian Pathology 16, 471-491) and is associated with numerous round-to-oval faintly basophilic organisms in the cytoplasm of pulmonary capillary endothelial cells. The organisms stain poorly using haematoxylin and eosin but are strongly positive with a periodic acid-Schiff stain, but their identity remains unknown. The owner had reported two deaths in a group of six birds purchased three weeks earlier.  The submitted bird had apparently exhibited nervous signs and inability to stand prior to death, and the main postmortem finding was congestion of the lungs.

Pigeons

Pigeon paramyxovirus 1 (PPMV-1) was isolated from young racing pigeons from two lofts.   Watery faeces were reported in both lofts, and in one loft mortality was high.   Birds had not yet been vaccinated against PPMV-1 in one loft, and in the other loft the birds had only been vaccinated two weeks prior to the onset of disease. Pigeon paramyxovirus is a notifiable disease and the appropriate Divisional Veterinary Managers of Animal Health were informed. Pigeon paramyxovirus infection was also suspected in feral pigeons showing incoordination.

Wild birds

Infection with E. coli with the profile of E. coli O86 was considered to be the cause of mortality of siskins (Carduelis spinus) from four different sites feeding garden birds.  Most deaths from E. coli O86 in siskins are recorded in the months March to May, and the reasons for the upsurge of deaths in July remain unclear.

Presumed or confirmed cases of trichomoniasis were diagnosed in greenfinches (Carduelis chloris) and a chaffinch (Fringilla coelebs) from three gardens in the second half of July.   A rise in the number of recorded cases of trichomoniasis in garden birds occurred in August 2006, and a similar rise is anticipated in August 2007.