Fecal Alpha1-Protease Inhibitor Activity
in Soft Coated Wheaten Terriers
Presented at 2002 ACVIM Forum
Published in the Journal of Veterinary Internal Medicine, 2002
The SCWT colony consists of 18 dogs (10 purebred SCWT, 8 SCWT-x-Beagles), 7 of which have overt PLE defined as increased Fecal Alpha1-PI ( >5.67μg/g) with panhypoproteinemia (decreased serum albumin and globulin concentrations). Fecal Alpha1-PI concentrations of 3 consecutive defecations were measured in these dogs every 3 months, while dogs ranged from 0.08 to 7 yr of age. All dogs had at least 1 sample in which either the maximum value of the 3 samples or the average value of the 3 samples was increased above the reference concentration (i.e., (>5.67 μg/g). However, those dogs that eventually developed overt PLE, as previously defined, had significantly greater number of Fecal Alpha1-PI submissions in which either the mean or maximum of the 3 samples was in excess of 15 μg/g. Both the mean and maximum Fecal Alpha1-PI concentrations of the 3 consecutive defecations were significantly greater at 1 yr of age when compared to values obtained at 3 yr of age.
A total of 193 Fecal Alpha1-PI submissions were available from 157 SCWT in the general population (49 males, 94 females, 14 gender unspecified; dogs ranged in age from 0.33 to 12 yr). Of the 49 dogs for which other clinical screening data was available (e.g., biochemical profile, complete blood count, urinalysis, urine protein:creatinine ratio), PLE, PLN or PLE/PLN was diagnosed in 2, 5 and 5 dogs, respectively. Fecal Alpha1-PI was increased in 82 of the 157 dogs (52%); 32 of these dogs had concentrations in excess of 15 μg/g. Of the 7 dogs with documented PLE, 6 had increased Fecal Alpha1-PI concentrations. One of these 6 dogs had concentrations in excess of 15 μg/g.
The findings of this study suggest that increased Fecal Alpha1-PI is common in SCWT. Fecal Alpha1-PI concentrations can be increased in any situation in which the intestinal tract becomes damaged (e.g., intestinal parasitism, viral enteritis, dietary indiscretion). However, persistently increased concentrations in a SCWT that does not have any other reason for intestinal disease may be suggestive of PLE of SCWT. Those dogs that have concentrations in excess of 15μg/g may be at increased risk for the development of overt PLE as defined in this study. Fecal Alpha1-PI concentrations may decrease with advancing age. However, this does not imply that these results are not also valuable in dogs that are older than 3 years of age. Instead, this data may support the idea that early screening is beneficial in early detection of PLE of SCWT.
We also found that increases in Fecal Alpha1-PI concentrations are common in the general population of SCWT. The difficulty in comparing data from the population with data from our colony dogs is that samples were collected under different circumstances. We collect samples from our dogs every 3 months throughout their lives, which is cost prohibitive for most breeders and pet owners. Furthermore, we have other clinical data analyzed in each dog at the same time that we are collecting feces. We received the results of other clinical screening tests from less than one-third of the general population dogs for which Fecal Alpha1-PI concentrations were available. We need more data from more dogs in the general population that are studied over time before we can say with certainty that the findings in our colony dogs are representative of findings in the population at large.